CN117176893A

CN117176893A - Video call method, device, electronic equipment and storage medium

Info

Publication number: CN117176893A
Application number: CN202311188539.XA
Authority: CN
Inventors: 庄一嵘; 傅铭江; 陆立; 梁洁; 潘庆
Original assignee: China Telecom Technology Innovation Center; China Telecom Corp Ltd
Current assignee: China Telecom Technology Innovation Center; China Telecom Corp Ltd
Priority date: 2023-09-14
Filing date: 2023-09-14
Publication date: 2023-12-05

Abstract

The disclosure provides a video call method, a video call device, electronic equipment and a storage medium, and relates to the technical field of wireless communication networks. The method applied to the exchanger of the video call terminal comprises the following steps: receiving a call invitation (SIP) message initiated by video call terminal equipment; the call invitation SIP message carries address information of the video call called terminal equipment; forwarding the call invitation SIP information to the SDN controller so that the SDN controller can inquire the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment and forward the call invitation SIP information to the exchanger of the video call called terminal so as to establish a video SIP session between the video call calling terminal equipment and the video call called terminal equipment. According to the method and the device, under the condition that the SIP is still used for video call, the service capability of the SDN is called, the efficient cooperation of the service layer and the network layer is realized, and the QoS stability of the video call is ensured.

Description

Video call method, device, electronic equipment and storage medium

Technical Field

The disclosure relates to the technical field of wireless communication networks, and in particular relates to a video call method, a video call device, electronic equipment and a storage medium.

Background

In the process of making a call, in particular, a SIP (Session Initiation Protocol) protocol is generally selected for video call, and video call connection is established with the opposite terminal by adopting an overlay (user plane) mode, but the mechanism cannot cooperate with an operator underley (infrastructure plane) bearer network, and finally, the data flow between two ends through which the video passes cannot guarantee the stability of QoS (quality of service).

It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the present disclosure and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The disclosure provides a video call method, a video call device, an electronic device and a storage medium, which at least overcome the problem that QoS stability cannot be guaranteed in the related art to a certain extent.

Other features and advantages of the present disclosure will be apparent from the following detailed description, or may be learned in part by the practice of the disclosure.

According to a first aspect of the present disclosure, there is provided a video call method, applied to a switch of a video call terminal, including:

receiving a Session Initiation Protocol (SIP) message of a call invitation initiated by video call terminal equipment; the call invitation SIP information is used for requesting to establish a video call between the video call terminal device and the video call called terminal device, and the call invitation SIP information carries address information of the video call called terminal device;

Forwarding the call invitation SIP information to a Software Defined Network (SDN) controller, so that the SDN controller queries switch information of the video call called terminal according to address information of the video call called terminal equipment carried in the call invitation SIP information, and forwards the call invitation SIP information to a switch of the video call called terminal to establish a video SIP session between the video call calling terminal equipment and the video call called terminal equipment;

the SDN controller stores corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal.

In some embodiments of the present disclosure, the video call method provided, before receiving a session invite session initiation protocol SIP message initiated by a video call end device, further includes:

receiving calling end registration SIP information sent by the video call calling end equipment; the calling end registration SIP information carries the video call calling end equipment information and the corresponding relation information of the video call calling end equipment and the switch of the video call calling end;

and registering the SIP information of the calling terminal, forwarding the SIP information to the SDN controller, enabling the SDN controller to register the video call calling terminal equipment according to the video call calling terminal equipment information, and storing the corresponding relation information of the video call calling terminal equipment and a switch of the video call calling terminal.

In some embodiments of the present disclosure, forwarding the session invitation SIP information to an SDN controller includes:

and encapsulating the call invitation SIP information in an extended Packet-in message by using an OpenFlow protocol, and sending the message to the SDN controller.

Specifically, the extended Packet-in Packet at least includes: a SIP message body;

the SIP message body includes at least one of: a type field of the SIP protocol, a source destination address field of the calling end device, a source destination address field of the called end device, and a real-time transport protocol RTP source destination port information field.

In some embodiments of the present disclosure, a video call method is provided, further including:

receiving first extended flow table information issued by the SDN controller; the first extended flow table information carries switch information of the called terminal of the video call;

the first extended flow table information is used for indicating the switch of the video call terminal to process the SIP message.

receiving a call ending request (SIP) message initiated by the video call terminal equipment; the session ending request SIP message is used for requesting ending of the video session between the video session calling terminal device and the video session called terminal device;

And forwarding the session ending request SIP message to the switch of the video call called terminal according to the first extended flow table information, so that the switch of the video call called terminal forwards the session ending request SIP message to the video call called terminal equipment to disconnect the video SIP session between the video call calling terminal equipment and the video call called terminal equipment.

According to a second aspect of the present disclosure, there is provided a video call method applied to an SDN controller, including:

receiving call invitation SIP information forwarded by a switch of a video call terminal; the call invitation SIP information is used for requesting to establish a video call between the video call terminal device and the video call called terminal device, and the call invitation SIP information carries address information of the video call called terminal device;

inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to an exchanger of the video call calling terminal;

Forwarding the session invitation SIP message to a switch of the video call called terminal according to the switch information of the video call called terminal, so that the switch of the video call called terminal forwards the session invitation SIP message to the video call called terminal to establish a video SIP session between the video call calling terminal equipment and the video call called terminal equipment;

In some embodiments of the present disclosure, the video call method provided, before receiving the call invitation SIP information forwarded by the switch of the video call end, further includes:

receiving calling end registration information forwarded by an exchanger of the video call end; the calling end registration information carries the video call calling end equipment information and the corresponding relation information of the video call calling end equipment and the switch of the video call calling end;

registering the video call terminal equipment according to the video call terminal equipment information, and storing the corresponding relation information of the video call terminal equipment and the switch of the video call terminal.

receiving the registration information of the called terminal forwarded by the exchanger of the called terminal of the video call; the called terminal registration information carries the information of the video call called terminal equipment and the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal;

registering the video call called terminal equipment according to the video call called terminal equipment information, and storing the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal.

Specifically, the method for returning the switch information of the called terminal of the video call to the switch of the calling terminal of the video call comprises the following steps:

the first extended flow table information is issued to the exchanger of the video call terminal; the first extended flow table information carries switch information of the called terminal of the video call;

The application program APP layer of the first extended flow table information comprises SIP metadata information;

The SIP metadata information includes at least one of: SIP message type and SIP service data.

In some embodiments of the present disclosure, forwarding the session invite SIP message to the switch of the video call called terminal according to the switch information of the video call called terminal includes:

and encapsulating the call invitation SIP message in an extended Packet-out message by using an OpenFlow protocol, and sending the message to a switch of the called terminal of the video call.

Specifically, the extended Packet-out Packet at least includes: action group data;

the action group data is used to represent forwarding of the SIP message body, discarding of the SIP message body data, or forwarding of the encapsulated SIP message body to the SDN controller.

According to a third aspect of the present disclosure, there is provided a video call method applied to a switch of a called terminal of a video call, including:

receiving a call invitation (SIP) message forwarded by an SDN controller; the call invitation SIP message is used for requesting to establish a video call between a video call terminal device and a video call called terminal device, and the call invitation SIP message carries address information of the video call called terminal device; the SDN controller is used for inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to the exchanger of the video call calling terminal; forwarding the session invitation SIP message to the switch of the video call called terminal according to the switch information of the video call called terminal;

And forwarding the session invitation SIP message to the video call called terminal equipment so as to establish a video SIP session between the video call calling terminal equipment and the video call called terminal equipment.

In some embodiments of the present disclosure, the video call method provided, before receiving a call invite SIP message forwarded by an SDN controller, further includes:

receiving calling end registration SIP information sent by the video call called end equipment; the called terminal registration SIP information carries the video call called terminal equipment information and the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal;

and forwarding the called terminal registration SIP information to the SDN controller so that the SDN controller registers the video call called terminal equipment according to the video call called terminal equipment information, and storing the corresponding relation information of the video call called terminal equipment and a switch of the video call called terminal.

receiving second extended flow table information issued by the SDN control; the second extended flow table information carries switch information of the video call terminal;

The second extended flow table information is used for indicating the switch of the called terminal of the video call to process the SIP message.

receiving a call invitation response (SIP) message sent by the video call called terminal equipment; the session invitation response (SIP) message is used for informing the video call end equipment that the session invitation is received by the video call end equipment;

and forwarding the session invitation response (SIP) message to the switch of the video call terminal according to the second extended flow table information, so that the switch of the video call terminal forwards the session invitation response (SIP) message to the video call terminal to inform that the video call terminal has received the video SIP session invitation.

According to a fourth aspect of the present disclosure, there is provided a video call method applied to a video call end device, including:

initiating a Session Initiation Protocol (SIP) message of a call invitation to an exchanger of a video call terminal so that the exchanger of the video call terminal forwards the SIP message of the call invitation to an SDN controller, and the SDN controller inquires the exchanger information of the video call terminal according to the address information of the video call terminal equipment carried in the SIP message of the call invitation and forwards the SIP message of the call invitation to the exchanger of the video call terminal so as to establish a video SIP session between the video call terminal equipment and the video call terminal equipment;

The call invitation SIP information is used for requesting to establish a video call between the video call terminal device and the video call called terminal device, and the call invitation SIP information carries address information of the video call called terminal device;

and the SDN controller stores the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal.

According to a fifth aspect of the present disclosure, there is provided a video call method applied to a video call called terminal device, including:

receiving a call invitation (SIP) message forwarded by a switch of a video call called terminal to establish a video SIP session between video call called terminal equipment and video call calling terminal equipment;

the switch of the called terminal of the video call is used for receiving a call invitation SIP message forwarded by the SDN controller; the call invitation SIP message is used for requesting to establish a video call between a video call terminal device and a video call called terminal device, and the call invitation SIP message carries address information of the video call called terminal device;

the SDN controller is used for inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to the exchanger of the video call calling terminal; and forwarding the session invitation SIP message to the switch of the video call called terminal according to the switch information of the video call called terminal.

According to a sixth aspect of the present disclosure, there is also provided a video call apparatus, applied to a switch of a video call terminal, including:

the first invite SIP message receiving module is used for receiving a Session Initiation Protocol (SIP) message of a session invitation initiated by the video call terminal equipment; the call invitation SIP information is used for requesting to establish a video call between the video call terminal device and the video call called terminal device, and the call invitation SIP information carries address information of the video call called terminal device;

a first invite SIP message forwarding module, configured to forward the session invite SIP information to a software defined network SDN controller, so that the SDN controller queries switch information of the video session called terminal according to address information of the video session called terminal device carried in the session invite SIP message, and forwards the session invite SIP information to a switch of the video session called terminal, so as to establish a video SIP session between the video session calling terminal device and the video session called terminal device;

According to a seventh aspect of the present disclosure, there is also provided a video telephony apparatus, applied to an SDN controller, including:

the second invite SIP message receiving module is used for receiving the call invite SIP information forwarded by the exchanger of the video call terminal; the call invitation SIP information is used for requesting to establish a video call between the video call terminal device and the video call called terminal device, and the call invitation SIP information carries address information of the video call called terminal device;

the called terminal exchanger information inquiry module is used for inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to the exchanger of the video call calling terminal;

the second invite SIP message forwarding module is configured to forward the session invite SIP message to the switch of the video call called terminal according to the switch information of the video call called terminal, so that the switch of the video call called terminal forwards the session invite SIP message to the video call called terminal, so as to establish a video SIP session between the video call calling terminal device and the video call called terminal device;

According to an eighth aspect of the present disclosure, there is also provided a video call apparatus, applied to a switch of a called terminal of a video call, including:

a third invite SIP message receiving module, configured to receive a call invite SIP message forwarded by the SDN controller; the call invitation SIP message is used for requesting to establish a video call between a video call terminal device and a video call called terminal device, and the call invitation SIP message carries address information of the video call called terminal device; the SDN controller is used for inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to the exchanger of the video call calling terminal; forwarding the session invitation SIP message to the switch of the video call called terminal according to the switch information of the video call called terminal;

and the third invite SIP message forwarding module is used for forwarding the call invite SIP message to the video call called terminal equipment so as to establish a video SIP session between the video call calling terminal equipment and the video call called terminal equipment.

According to a ninth aspect of the present disclosure, there is also provided a video call apparatus applied to a video call end device, including:

an invite SIP message initiating module, configured to initiate a session initiation protocol SIP message to an exchange of a video call end, so that the exchange of the video call end forwards the session initiation SIP message to an SDN controller, and the SDN controller queries exchange information of the video call end according to address information of the video call end device carried in the session initiation SIP message, and forwards the session initiation SIP message to the exchange of the video call end device, so as to establish a video SIP session between the video call end device and the video call end device;

According to a tenth aspect of the present disclosure, there is also provided a video call apparatus applied to a video call called terminal device, including:

a fourth invite SIP message receiving module, configured to receive a session invite SIP message forwarded by an exchange of a video session called terminal, so as to establish a video SIP session between the video session called terminal device and a video session calling terminal device;

According to an eleventh aspect of the present disclosure, there is also provided an electronic device including: a processor; and a memory for storing executable instructions of the processor; wherein the processor is configured to perform the video call method of any one of the first, second, third, fourth and fifth aspects above via execution of the executable instructions.

According to a twelfth aspect of the present disclosure, there is also provided a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the video call method of any one of the above first, second, third, fourth and fifth aspects.

According to a thirteenth aspect of the present disclosure, there is also provided a computer program product comprising a computer program which, when executed by a processor, implements the video telephony method of any of the first, second, third, fourth and fifth aspects described above.

According to the video call method provided by the embodiment of the disclosure, through setting the SDN controller, call invitation SIP information forwarded by the switch of the video call terminal is received, switch information of the video call terminal is queried based on address information of video call terminal equipment carried in the call invitation SIP information, the switch information of the video call terminal is returned to the switch of the video call terminal, and the call invitation SIP information is forwarded to the switch of the video call terminal according to the switch information of the video call terminal, so that the switch of the video call terminal forwards the call invitation SIP information to the video call terminal, a video SIP session between video call terminal equipment and video call terminal equipment is established, service capability of SDN is invoked under the condition that the video call terminal equipment and the video call terminal equipment still use SIP for video call, and efficient cooperation of a service layer and a network layer is realized, thereby providing a stable transmission link capable of meeting audio and video data stream transmission QoS and guaranteeing QoS stability of the video call.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure. It will be apparent to those of ordinary skill in the art that the drawings in the following description are merely examples of the disclosure and that other drawings may be derived from them without undue effort.

FIG. 1 is a schematic diagram of a telephony system architecture in accordance with an embodiment of the present disclosure;

fig. 2 is a schematic flow chart of a video call method applied to a switch of a video call end in an embodiment of the disclosure;

fig. 3 is a schematic flow chart of a video call method applied to a switch of a video call end in some embodiments of the disclosure;

FIG. 4 is a flow chart of another method of video call applied to a switch of a video call end in some embodiments of the present disclosure;

fig. 5 is a schematic flow diagram of a video call method applied to a switch of a video call end according to another embodiment of the disclosure;

Fig. 6 illustrates a flow chart of a video call method applied to an SDN controller in an embodiment of the disclosure;

fig. 7 is a schematic flow chart of a video call method applied to a switch of a called terminal of a video call in an embodiment of the disclosure;

fig. 8 is a flowchart illustrating a video call method applied to a video call end device according to an embodiment of the disclosure;

fig. 9 is a flowchart of a video call method applied to a called terminal device for video call in an embodiment of the disclosure;

fig. 10 is a schematic diagram illustrating a structure and an interaction process of a video call system based on co-control of an SDN controller and SIP in an embodiment of the disclosure;

FIG. 11 shows a schematic diagram of an extended structure of an OpenFlow flow table in a specific example of the present disclosure;

FIG. 12 is a schematic diagram showing an extended structure of a Packet-in message in a specific example of the present disclosure;

fig. 13 shows a schematic diagram of an extended structure of a Packet-out Packet in a specific example of the disclosure;

fig. 14 is a schematic diagram of a call device of a switch applied to a video call end in an embodiment of the disclosure;

fig. 15 illustrates a schematic diagram of a call device applied to an SDN controller in an embodiment of the disclosure;

Fig. 16 is a schematic diagram of a call device applied to a switch of a called terminal of a video call in an embodiment of the disclosure;

fig. 17 is a schematic diagram of a call device applied to a video call end device in an embodiment of the disclosure;

fig. 18 is a schematic diagram of a call device applied to a called end device for video call in an embodiment of the disclosure; and

fig. 19 shows a block diagram of an electronic device in an embodiment of the disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus a repetitive description thereof will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in software or in one or more hardware modules or integrated circuits or in different networks and/or processor devices and/or microcontroller devices.

The following detailed description of embodiments of the present disclosure refers to the accompanying drawings.

Fig. 1 shows a schematic diagram of a telephony system architecture to which embodiments of the present disclosure may be applied. As shown in fig. 1, the system architecture may include: video call initiator device 10, video call initiator switch 20, SDN (software defined network ) controller 30, video call initiator switch 40, and video call initiator device 50. Any two devices in the system are connected through a network, and can be wireless networks.

Optionally, the wireless network described above uses standard communication techniques and/or protocols. The network is typically the Internet, but may be any network including, but not limited to, a local area network (Local Area Network, LAN), metropolitan area network (Metropolitan Area Network, MAN), wide area network (Wide Area Network, WAN), mobile or wireless network, private network, or any combination of virtual private networks. In some embodiments, data exchanged over the network is represented using techniques and/or formats including HyperText Mark-up Language (HTML), extensible markup Language (Extensible Markup Language, XML), and the like. All or some of the links may also be encrypted using conventional encryption techniques such as secure sockets layer (Secure Socket Layer, SSL), transport layer security (Transport Layer Security, TLS), virtual private network (Virtual Private Network, VPN), internet protocol security (Internet Protocol Security, IPSec), and the like. In other embodiments, custom and/or dedicated data communication techniques may also be used in place of or in addition to the data communication techniques described above.

In some embodiments of the present disclosure, the video call initiator device 10, the switch 20 of the video call initiator, the switch 40 of the video call target and the video call target device 50 need to be registered in advance in the SDN controller 30, so that the SDN controller 30 collects identity information, location information, anchor information and the like of the devices of both video call targets in advance.

Specifically, the video call end device 10 sends the call end registration SIP (SessionInitiation Protocol ) information to the switch 20 of the video call end, and after the video call end device 10 is authenticated by the switch 20 of the video call end, the call end registration SIP information is forwarded to the SDN controller 30 after the authentication is passed. It should be noted that the SIP information of the call end registration carries information of the video call end device and information of correspondence between the video call end device and the switch of the video call end, that is, information related to the video call end device, such as source destination address information, and information related to the switch of the video call end anchored by the video call end device, such as address information of the switch of the video call end. In particular, the switch 20 of the video call end may be connected to a plurality of video call end devices 10 in a network, and the corresponding relationship, that is, the anchoring relationship between the switch 20 of the video call end and the video call end device 10, needs to be sent to the SDN controller 30. The SDN controller 30 registers the video call-end device 10 according to the video call-end device information, and stores correspondence information between the video call-end device 10 and the switch 20 of the video call-end. After the registration is completed, the SDN controller 30 also feeds back SIP information of successful registration to the switch 20 of the video call end, and forwards the SIP information to the video call end device 10 through the switch 20 of the video call end, so as to inform the video call end device 10 that the registration is successful.

Similarly, the video call callee device 50 sends the callee registration SIP information to the switch 40 of the video call callee, and the switch 40 of the video call callee first authenticates the video call callee device 50, and after the authentication is passed, forwards the caller registration SIP information to the SDN controller 30. It should be noted that, the called-end registration SIP information carries information of a video call called-end device and corresponding relation information of a video call called-end device and a switch of the video call called-end. The SDN controller 30 registers the video call-called-end device 50 according to the video call-called-end device information, and stores correspondence information between the video call-called-end device 50 and the switch 40 of the video call-called-end. After the registration is completed, the SDN controller 30 also feeds back SIP information of successful registration to the switch 40 of the video call called terminal, and forwards the SIP information to the video call called terminal device 50 through the switch 40 of the video call called terminal, so as to inform that the video call called terminal device 50 is successfully registered.

It should be noted that, when the switch 20 of the video call end sends the call end registration SIP information to the SDN controller 30 and the switch 40 of the video call end sends the called end registration SIP information to the SDN controller 30, the call end registration SIP information is encapsulated in an extended Packet-in message. When the SDN controller 30 feeds back the SIP information of successful registration to the switch 20 of the video call end and the SDN controller 30 feeds back the SIP information of successful registration to the switch 40 of the video call end, the SIP information is encapsulated in an extended Packet-out message.

It will be understood by those skilled in the art that the switch 20 of the video call end device 10 and the video call end may also be used as the switch 40 of the video call end device 50 and the video call end in another video call, and the switch 40 of the video call end device 50 and the video call end may also be used as the switch 20 of the video call end device 10 and the video call end in another video call, which will be referred to as the switch 10 of the video call end, the switch 20 of the video call end, and the switch 40 of the video call end device 50 and the video call end for more clear description of the interaction process in only one video call.

After registration is completed, the video call-end device 10 initiates a call invite SIP message to the switch 20 of the video call-end. It should be noted that, the session invitation SIP information is used for requesting to establish a video session between the video call end device 10 and the video call end device 50, and the session invitation SIP information carries address information of the video call end device 50 and related information of the video call end device 10. The SIP video telephony apparatus supporting the Open SIP protocol for the video call-end device 10 may be a terminal, which is used to initiate a video call according to a user requirement, and may be various electronic devices, including but not limited to a smart phone, a tablet computer, a laptop, a desktop computer, a smart speaker, a smart watch, a wearable device, an augmented reality device, a virtual reality device, and the like.

After receiving the session invitation SIP information, the switch 20 of the video call end forwards the session invitation SIP information to the SDN controller 30. Note that, the switch 20 of the video call end is applicable to SIP, and can support the Open SIP protocol, which may be an Open vSwitch (Open Virtual Switch) switch. In implementation, because the SDN does not provide a call and negotiation interface mechanism for the video call service, flexible random tear-down service call for the video call service cannot be provided, and thus the call invitation SIP information cannot be directly sent to the SDN controller 30. The switch 20 of the video call end encapsulates the call invitation SIP information in an extended Packet-in message by using the OpenFlow protocol, and sends the Packet-in message to the SDN controller 30. By separating the control plane from the data plane of the network device by using the OpenFlow protocol, flexible control of network traffic is realized, and the network becomes more intelligent. It should be noted that, the extended Packet-in message further includes a SIP message body based on the original Packet-in message, specifically, the SIP message body includes at least one of the following: a type field of the SIP protocol, a source destination address field of the calling end device, a source destination address field of the called end device, and a Real-time transport protocol RTP (Real-time Transport Protocol) source destination port information field.

After receiving the session invitation SIP information, the SDN controller 30 queries the switch 40 information of the video session called terminal according to the address information of the video session called terminal device 50 carried in the session invitation SIP information, and returns the switch information of the video session called terminal to the switch 20 of the video session calling terminal. Since the video call-destination device 50 and the correspondence between the video call-destination device 50 and the switch 40 of the video call-destination are registered in advance in the SDN controller 30, the switch 40 information of the video call-destination connected to the network can be obtained based on the address information of the video call-destination device 50. Specifically, the SDN controller 30 issues the first extended flow table information to the switch of the video call end; the first extended flow table information carries switch information of a called terminal of the video call; and the first extended flow table information is used for indicating the switch of the video call terminal to process the SIP message. It should be noted that, the first extended flow table information is extended OpenFlow flow table information, which is used for guiding the openvswitch how to forward data, SIP metadata is extended on the basis of the original OpenFlow flow table information, and service guarantee transmission is implemented on the data plane. That is, the application APP layer of the first extended flow table information contains SIP metadata information including at least one of: SIP message type and SIP service data. Specifically, the SDN controller 30 uses the Flow-Mod message to issue the first extended Flow table information to the switch 20 of the video call end.

Further, the SDN controller 30 may also return a receive response SIP message to the switch 20 of the video call end, for example, a 100Trying response signaling, indicating that the call is already in process. Specifically, the SIP message of receiving the call invite SIP information needs to be encapsulated in an extended Packet-out Packet by using the OpenFlow protocol, so as to instruct the switch 20 of the video call end to forward the 100Trying SIP message to the video call end device 10.

The SDN controller 30 also forwards the session invite SIP message to the switch 40 of the video call called party according to the switch information of the video call called party. And forwarding the session invite SIP message and simultaneously, forwarding the second extended flow table information to the switch 40 of the video session called party to instruct the switch 40 of the video session called party to process the SIP message. It should be noted that the second extended flow table information carries the switch information of the calling end of the video call, so as to inform the switch 40 of the called end of the video call of the address of the counterpart in communication connection. The second extended flow table information is extended OpenFlow flow table information, and is used for guiding the Open vSwitch how to perform data forwarding, SIP metadata is extended on the basis of the original OpenFlow table information, and service guarantee transmission is realized on a data plane. That is, the application APP layer of the second extended flow table information contains SIP metadata information including at least one of: SIP message type and SIP service data. Specifically, the SDN controller 30 uses the Flow-Mod message to issue the second extended Flow table information to the switch 40 of the called end of the video call.

In implementation, the SDN controller 30 encapsulates the session invite SIP message in an extended Packet-out Packet by using the OpenFlow protocol, and sends the Packet invite SIP message to the switch 40 of the called end of the video session. The extended Packet-out message further comprises action group data based on the original Packet-out message, wherein the action group data is used for representing forwarding of the SIP message body, discarding of the SIP message body data or forwarding of the encapsulated SIP message body to the SDN controller. For example, the action group data in the Packet-out Packet extended this time indicates forwarding the SIP message body, that is, the switch 40 instructing the video call called terminal to forward the received SIP message, and forwards it to the video call called terminal device 50.

After receiving the session invite SIP message, the switch 40 of the video session called terminal forwards the session invite SIP message to the video session called terminal device 50 based on the content indicated by the action group data in the extended Packet-out message, so as to establish a video SIP session between the video session calling terminal device 10 and the video session called terminal device 50. The switch 40 at the called end of the video call is suitable for SIP, and can support the Open SIP protocol, which may be an Open vSwitch switch.

In particular, the video call callee device 50 needs to inform that the video call caller device 10 has received the call invitation and feedback the response to the call invitation, so after the video call callee device 50 receives the call invitation, a call invitation response SIP message is sent to the switch 40 of the video call callee, and it needs to be noted that the call invitation response SIP message is used to inform that the video call caller device 10 has received the call invitation by the video call callee device 50.

When forwarding the session invite response SIP message, the switch 40 of the called video call end forwards the session invite response SIP message to the switch 20 of the called video call end based on the second extended flow table information, and then forwards the session invite response SIP message to the video call end device 10 via the switch 20 of the called video call end, so as to inform the video call end device 10 that the video SIP session invite has been received.

Further, after the video call is received by the video call called terminal device 50, a call answer SIP message, that is, a signaling of 200OK is sent to the video call calling terminal device 10 via the switch 40 of the video call called terminal and the switch 20 of the video call calling terminal, so as to inform the video call calling terminal device 10 that the video call has been received. And the video call end device 10 sends an acknowledge SIP message, that is, ACK signaling, to the switch 20 of the video call end, and then the video call end device 50 is reached through forwarding between the switch 20 of the video call end and the switch 40 of the video call end device, so that a SIP session between the video call end device 10 and the video call end device 50 is established. After the SIP session is established, RTP audio and video stream data is transmitted between the video call-end device 10 and the video call-end device 50, so as to perform a video call service.

When the video call caller device 10 and the video call callee device 50 want to end the video call, one of them will issue a call end request SIP message, and the procedure of disconnecting the video call will be described taking the case where the video call caller device 10 issues a call end request SIP message.

The video call initiator device 10 initiates a call end request SIP message to the switch 20 of the video call initiator, where the call end request SIP message is used to request end of the video call between the video call initiator device 10 and the video call target device 50. The switch 20 of the video call caller forwards the call end request SIP message to the switch 40 of the video call callee based on the first extended flow table information. The switch 40 of the video call callee forwards the call end request SIP message to the video call callee 50 to disconnect the video SIP session between the video call caller device 10 and the video call callee device 50. In particular, after receiving the session end request SIP message, the video call called 50 informs that the video call calling device 10 itself has received the request for end of the video call, so that the video call called 50 will feed back a session end response SIP message, that is, a signaling of 200OK, to the switch 40 of the video call called, the switch 40 of the video call called forwards the 200OK to the switch 20 of the video call calling device according to the second extended flow table information, and the switch 20 of the video call calling device forwards the 200OK to the video call calling device 10 to disconnect the SIP session. Those skilled in the art will appreciate that the called terminal 50 of the video call may also be the sender of the call end request, and detailed descriptions thereof are omitted herein.

As shown in fig. 1, the interaction process is part of a call system, and includes:

s102, the video call calling terminal device 10 sends the calling terminal registration SIP information to the switch 20 of the video call calling terminal;

s104, after the switch 20 of the video call terminal passes the authentication of the video call terminal equipment 10, the call terminal registration SIP information is encapsulated in an extended Packet-in message and forwarded to the SDN controller 30;

s106, the SDN controller 30 registers the video call terminal equipment 10 according to the video call terminal equipment information carried by the call terminal registration SIP information, and stores the corresponding relation information between the video call terminal equipment 10 carried by the call terminal registration SIP information and the switch 20 of the video call terminal;

s108, the SDN controller 30 feeds back SIP information successfully registered to the switch 20 of the video call terminal by using the expanded Packet-out message;

s110, the exchanger 20 of the video call terminal forwards the SIP information successfully registered to the video call terminal device 10;

s112, the video call called terminal device 50 sends the called terminal registration SIP information to the switch 40 of the video call called terminal;

s114, after the switch 40 of the video call called terminal passes the authentication of the video call called terminal equipment 50, the called terminal registration SIP information is encapsulated in an expanded Packet-in message and forwarded to the SDN controller 30;

S116, the SDN controller 30 registers the video call called terminal equipment 50 according to the video call called terminal equipment information carried by the called terminal registration SIP information, and stores the corresponding relation information between the video call called terminal equipment 50 carried by the called terminal registration SIP information and the switch 40 of the video call called terminal;

s118, SDN controller 30 feeds back SIP information successfully registered to exchanger 40 of called terminal of video call by using extended Packet-out message;

s120, the exchanger 40 of the called terminal forwards the SIP information successfully registered to the called terminal equipment 50 of the video call;

s122, the video call terminal device 10 initiates a call invitation SIP message to the switch 20 of the video call terminal;

s124, the exchanger 20 of the video call end packages the call invitation SIP message in the extended Packet-in message and forwards the message to the SDN controller 30;

s126, the SDN controller 30 queries the exchanger 40 information of the video call called terminal according to the address information of the video call called terminal equipment 50 carried by the call invitation SIP message to form first extended flow table information, and forms second extended flow table information based on the exchanger information of the video call calling terminal carried by the call invitation SIP message;

S128, the SDN controller 30 utilizes the Flow-Mod message to send the first extended Flow table information to the switch 20 of the video call terminal;

s130, the SDN controller 30 utilizes the Flow-Mod message to send the second extended Flow table information to the switch 40 of the called terminal of the video call;

s132, the SDN controller 30 packages the SIP message of the call invitation in the expanded Packet-out message based on the information of the exchanger 40 of the called terminal of the video call, and sends the message to the exchanger 40 of the called terminal of the video call;

s134, the switch 40 of the video call called terminal forwards the call invite SIP message to the video call called terminal device 50 to establish a SIP session.

It will be appreciated by those skilled in the art that, in the specific implementation, the steps are not limited before and after the implementation, and fig. 1 is only an example, for example, S102 to S110 and S112 to S120 are processes that may be performed in parallel, and may be performed simultaneously.

Those skilled in the art will appreciate that the number of video call initiator devices 10, video call initiator switches 20, SDN controllers 30, video call initiator switches 40, and video call initiator devices 50 in fig. 1 are merely illustrative, and any number may be provided as desired. The embodiments of the present disclosure are not limited in this regard.

Under the system architecture described above, a video call method is provided in the embodiments of the present disclosure, and in some embodiments, the video call method provided in the embodiments of the present disclosure may be implemented by interactions among the video call caller device 10, the switch 20 of the video call caller, the SDN controller 30, the switch 40 of the video call callee, and the video call callee device 50.

As shown in fig. 2, a video call method of a switch of a video call end provided in an embodiment of the present disclosure includes the following steps:

s202, receiving a Session Initiation Protocol (SIP) message of a call invitation initiated by video call terminal equipment;

it should be noted that, the session invitation SIP information is used for requesting to establish a video session between the video session calling end device and the video session called end device, and the session invitation SIP message carries address information of the video session called end device, and when implementing, the session invitation SIP message also carries related information of the video session calling end device and related information of the switch of the video session calling end.

S204, forwarding the session invitation SIP information to the SDN controller so that the SDN controller queries the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the session invitation SIP information and forwards the session invitation SIP information to the exchanger of the video call called terminal so as to establish a video SIP session between the video call calling terminal equipment and the video call called terminal equipment.

It should be noted that, the SDN controller stores correspondence information between the video call called terminal device and the switch of the video call called terminal.

As can be seen from the above steps, in the video call method provided in the embodiments of the present disclosure, by forwarding the call invite SIP information to the SDN controller by using the switch of the video call end, the SDN controller is enabled to query the switch information of the video call end according to the address information of the video call end device carried in the call invite SIP message, return the switch information of the video call end to the switch of the video call end, and forward the call invite SIP message to the switch of the video call end according to the switch information of the video call end, so that the switch of the video call end forwards the call invite SIP message to the video call end, so as to establish a video SIP session between the video call end device and the video call end device, and under the condition that the video call end device still uses SIP to perform video call, call service capability of the SDN is invoked, thereby implementing efficient collaboration between the service layer and the network layer, and further providing a transmission link capable of satisfying the QoS of audio and video data stream transmission stability.

In some embodiments of the present disclosure, before the video call is performed, the video call-end device needs to register in the SDN controller in advance, so the video call method as shown in fig. 3 further includes, on the basis of fig. 2:

s302, receiving calling end registration SIP information sent by video call end equipment;

it should be noted that, the call end registration SIP information carries the information of the video call end device and the corresponding relation information of the video call end device and the switch of the video call end, that is, the anchoring relation between the video call end device and the switch of the video call end, so as to inform the SDN controller of which video call end device is connected with the switch network of which video call end.

S304, the call end registration SIP information is forwarded to the SDN controller, so that the SDN controller registers the video call end equipment according to the video call end equipment information, and the corresponding relation information of the video call end equipment and the switch of the video call end is stored.

It should be noted that the existing SDN does not provide a transmission mechanism for SIP messages, and in some embodiments of the present disclosure, forwarding session invitation SIP information to an SDN controller includes: and encapsulating the call invitation SIP information in an extended Packet-in message by using an OpenFlow protocol, and sending the message to the SDN controller. Registering the SIP information of the calling end and forwarding the SIP information to the SDN controller, wherein the method comprises the following steps: and encapsulating the call end registration SIP information in an extended Packet-in message by using an OpenFlow protocol, and sending the message to the SDN controller. That is, when the switch of the video call end sends the SIP message to the SDN controller, the corresponding SIP message needs to be encapsulated in an extended Packet-in Packet for sending.

Specifically, the extended Packet-in message at least includes: a SIP message body comprising at least one of: a type field of the SIP protocol, a source destination address field of the calling end device, a source destination address field of the called end device, and a real-time transport protocol RTP source destination port information field. That is, a SIP message body is extended on the basis of the original Packet-in Packet, where the SIP message body includes a type field of the SIP protocol (indicating the type of the SIP protocol, which may be invite=1, trying=100, ring=180, ok=200, ack=2, bye=300), a source destination address field of the calling device, a source destination address field of the called device, and a source destination port information field of the RTP (indicating information about an IP address, a port number, a media type, e.g., video, voice, text, etc., to be used by the RTP).

In some embodiments of the present disclosure, after the SDN controller queries the switch information of the called terminal of the video call, the switch information of the called terminal of the video call is notified to the switch information of the calling terminal of the video call, so as to perform information interaction between the two. Therefore, as shown in fig. 4, the video call method provided further includes, based on fig. 2:

S402, receiving first extended flow table information issued by the SDN controller.

It should be noted that, the first extended flow table information carries switch information of the called end of the video call, and the first extended flow table information is used for indicating the switch of the called end of the video call to process the SIP message. In specific implementation, the SDN controller utilizes the Flow-Mod message to send the first extended Flow table information to the switch of the video call terminal. Specifically, the APP layer of the first extended flow table information contains SIP metadata information, and the SIP metadata information includes at least one of: SIP message type and SIP service data, the SIP message type field may contain an invite=1, trying=100, ring=180, ok=200, ack=2 or bye=300 equivalent, typically 1 byte, and the SIP service data field may contain an encapsulation=rtp, audio=g.723 or video=h264 equivalent.

After the SIP session is established, there may be a case that the video call is ended, and accordingly, the video call method provided in some embodiments of the present disclosure, as shown in fig. 5, further includes the following steps on the basis of fig. 4:

s502, receiving a call ending request SIP message initiated by video call terminal equipment;

It should be noted that, the session end request SIP message is used to request to end the video session between the video session calling end device and the video session called end device.

S504, according to the first extended flow table information, the session ending request SIP message is forwarded to the exchanger of the video call called terminal, so that the exchanger of the video call called terminal forwards the session ending request SIP message to the video call called terminal equipment, and the video SIP session between the video call calling terminal equipment and the video call called terminal equipment is disconnected.

It should be noted that, because the address information of the switch of the called end of the video call is already recorded in the first extended flow table information, the switch of the called end of the video call can learn the destination address of message forwarding through table lookup, so as to forward the call end request SIP message to the switch of the called end of the video call.

In implementation, the switch of the video call end also needs to receive the call end response SIP message fed back by the switch of the called end of the video call, and forward the call end response SIP message to the video call end device to inform the video call end device of: the called terminal equipment of the video call has received the request for ending the video call, and disconnects the SIP session between the two.

Under the system architecture shown in fig. 1, the embodiment of the present disclosure further provides a video call method applied to an SDN controller, as shown in fig. 6, including the following steps:

s602, receiving call invitation SIP information forwarded by a switch of a video call terminal;

it should be noted that, the session invitation SIP information is used for requesting to establish a video session between the video session calling end device and the video session called end device, and the session invitation SIP information carries address information of the video session called end device.

S604, inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to the exchanger of the video call calling terminal;

s606, according to the exchanger information of the video call called terminal, the call invitation SIP message is forwarded to the exchanger of the video call called terminal, so that the exchanger of the video call called terminal forwards the call invitation SIP message to the video call called terminal, and a video SIP session between the video call calling terminal equipment and the video call called terminal equipment is established.

It should be noted that, the SDN controller stores the correspondence information between the video call end device and the switch of the video call end, which is known based on the fact that the video call end device registers in advance on the SDN controller. The SDN controller has SIP Proxy capability, can complete service addressing and Proxy forwarding of the corresponding SIP message next hop SIP Proxy.

receiving calling end registration information forwarded by an exchanger of a video call end; the calling end registration information carries video call end equipment information and corresponding relation information of the video call end equipment and a switch of the video call end;

Likewise, in some embodiments of the present disclosure, the video call method provided, before receiving the call invitation SIP information forwarded by the switch of the video call end, further includes:

Receiving called terminal registration information forwarded by a switch of a video call called terminal; the called terminal registration information carries the information of the video call called terminal equipment and the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal;

It should be noted that, after the SDN controller successfully registers the video call end device, the SDN controller feeds back SIP information, for example, 200OK, that is successfully registered to the switch of the video call end, encapsulates the SIP information in an extended Packet-out Packet, so as to instruct the switch of the video call end to forward the SIP message of 200OK to the video call end device, so as to inform the video call end device that the registration is successful. After the video call called terminal equipment is successfully registered, the SDN controller feeds back SIP information which is successfully registered to the switch of the video call called terminal, for example, 200OK, encapsulates the SIP information in an extended Packet-out message to instruct the switch of the video call called terminal to forward the SIP information of the 200OK to the video call called terminal equipment so as to inform the video call called terminal equipment that the registration is successful.

In some embodiments of the present disclosure, returning switch information of a called terminal of a video call to a switch of a calling terminal of the video call includes: the first extended flow table information is issued to a switch of the video call terminal; the first extended flow table information carries switch information of a called terminal of the video call; the first extended flow table information is used for indicating the exchanger of the video call terminal to process the SIP message. The application program APP layer of the first extended flow table information contains SIP metadata information; the SIP metadata information includes at least one of: SIP message type and SIP service data.

In some embodiments of the present disclosure, the SDN controller may determine switch information of the video call end according to the call invite SIP information, form second extended Flow table information, and send the second extended Flow table information to the switch of the video call called end through a Flow-Mod message. The SDN controller may calculate an optimal path when forwarding the SIP message according to addresses of the switch of the video call calling end and the switch of the video call called end, or addresses of the video call calling end device and the video call called end device, in combination with a service level required for the video call given by the session invitation SIP information, and include the optimal path in the first extended flow table information and send the optimal path to the switch of the video call calling end, and also include the optimal path in the second extended flow table information and send the optimal path to the switch of the video call called end. And the service quality of the video call is ensured by calling the route optimization capability of the SDN.

In some embodiments of the present disclosure, S606, when implemented, includes: and encapsulating the call invitation SIP message in an extended Packet-out message by using an OpenFlow protocol, and sending the message to a switch of a called terminal of the video call. It should be noted that, the extended Packet-out Packet at least includes: action group data, and the action group data is used to represent forwarding of the SIP message body, discarding of the SIP message body data, or forwarding of the encapsulated SIP message body to the SDN controller. That is, the action group data is extended on the basis of the original Packet-out message, so as to instruct the receiver of the message how to process the received SIP message, which may be one of forwarding, discarding or encapsulating and forwarding to the SDN controller.

Under the system architecture shown in fig. 1, the embodiment of the present disclosure further provides a video call method applied to a switch of a called terminal of a video call, as shown in fig. 7, including the following steps:

s702, receiving a call invitation SIP message forwarded by an SDN controller;

it should be noted that, the session invite SIP message is used for requesting to establish a video session between the video session calling end device and the video session called end device, and the session invite SIP message carries address information of the video session called end device. The SDN controller is used for inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to the exchanger of the video call calling terminal; according to the exchanger information of the video call called end, forwarding the call invitation SIP information to the exchanger of the video call called end;

S704, forwarding the session invite SIP message to the video call called end device to establish a video SIP session between the video call calling end device and the video call called end device.

receiving called end registration SIP information sent by video call called end equipment; the called end registration SIP information carries the information of the video call called end equipment and the corresponding relation information of the video call called end equipment and the exchanger of the video call called end;

and registering the SIP information of the called terminal, forwarding the SIP information to the SDN controller, enabling the SDN controller to register the video call called terminal equipment according to the video call called terminal equipment information, and storing the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal.

receiving second extended flow table information issued by SDN control; the second extended flow table information carries switch information of the video call end, and the second extended flow table information is used for indicating the switch of the called end of the video call to process the SIP message.

Further, in some embodiments of the present disclosure, the video call method provided further includes, after forwarding the call invite SIP message to the video call called end device:

receiving a session invite response (SIP) message, such as a 180Ring SIP message, sent by a called terminal device of a video session;

it should be noted that, the session invite response SIP message is used to inform the video call end device that the session invite has been received by the video call end device;

and forwarding the call invitation response (SIP) message to the switch of the video call terminal according to the second extended flow table information, so that the switch of the video call terminal forwards the call invitation response (SIP) message to the video call terminal equipment to inform the video call terminal equipment that the video call terminal equipment has received the video SIP session invitation.

Under the system architecture shown in fig. 1, the embodiment of the present disclosure further provides a video call method applied to a video call end device, as shown in fig. 8, including the following steps:

s802, a call invitation SIP message is initiated to a switch of a video call terminal, so that the switch of the video call terminal forwards the call invitation SIP information to an SDN controller, and the SDN controller inquires switch information of a video call called terminal according to address information of video call called terminal equipment carried in the call invitation SIP message and forwards the call invitation SIP information to the switch of the video call called terminal so as to establish a video SIP session between the video call terminal equipment and the video call called terminal equipment.

It should be noted that, the session invitation SIP information is used for requesting to establish a video session between the video session calling end device and the video session called end device, where the session invitation SIP information carries address information of the video session called end device; the SDN controller stores the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal.

Under the system architecture shown in fig. 1, the embodiment of the present disclosure further provides a video call method applied to a called terminal device for video call, as shown in fig. 9, including the following steps:

s902, receiving a call invitation SIP message forwarded by a switch of the video call called terminal so as to establish a video SIP session between the video call called terminal equipment and the video call calling terminal equipment.

It should be noted that, the switch of the called end of the video call is configured to receive the call invite SIP message forwarded by the SDN controller; the call invitation SIP message is used for establishing video call between the video call terminal equipment and the video call called terminal equipment, and the call invitation SIP message carries address information of the video call called terminal equipment; the SDN controller is used for inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to the exchanger of the video call calling terminal; and forwarding the session invitation SIP message to the switch of the video call called terminal according to the switch information of the video call called terminal.

In order to better explain the video call method provided by the embodiment of the present disclosure, a specific example is provided to further explain the video call system based on the cooperative control of the SDN controller and the SIP, which is constructed for the video call method provided by the embodiment of the present disclosure. The system, as shown in fig. 10, includes: SDN controller, SIP video telephony device (video telephony device a and video telephony device B), open vSwitch switch, hereinafter abbreviated as vSwitch (vSwitch-1 and vSwitch-2).

The system provides SDN calling capability for video call service based on the SIP protocol extension mode. When the video call device A used by the user A is accessed to the network, the terminal registration and anchoring are completed through the local vSwitch-1 switch by carrying authentication information. When the video call device A initiates a video call SIP request, the vSwitch-1 recognizes the SIP information, sends a Packet-in message encapsulated with the extended support SIP information to the SDN controller, the SDN controller performs addressing and routing calculation, and issues a Packet-out message aiming at the current SIP request to the vSwitch-2, and ensures transmission of RTP audio and video streams related to the SIP session at a data layer.

The SDN controller has the following functions: receiving Packet-in message which is sent by vSwtich and extends and supports SIP information, and identifying SIP business key information in the Packet-in, wherein the message comprises information such as Call-ID, caller, callee, RTP metadata (such as audio/video coding, code rate, transmission protocol and port) and the like; the SIP Proxy capability is integrated, so that service addressing can be completed, and the Proxy forwards the SIP message next hop SIP Proxy; according to the IP address information of the two ends of the SIP call and the service grade required by the video call, calculating an optimal path; corresponding flow table information is issued to the vSwtich, and service guarantee transmission is realized at a data layer; and sending a Packet-out message which extends the support of the SIP information to the vSwtich to indicate how the vSwtich acts on the SIP message body.

The vSwitch has the following functions: receiving authentication information sent by the SIP video telephone device, and sending related information of user registration and anchoring to the SDN controller after authentication; the SIP information (including, but not limited to Invite, bye, trying, ACK, etc.) sent by the user is identified and encapsulated in an extended Packet-in message, and is sent to the SDN controller; and receiving a Packet-out message of the SDN controller, forwarding, discarding or packaging a data plane of a corresponding SIP message body based on an instruction in the flow table information, and then sending the data plane to the SDN controller.

The SIP video telephone apparatus has the following functions: the system can support the OpenSIP protocol, is responsible for completing the registration of the SIP user, initiating the service request, establishing the SIP/RTP session connection, removing the SIP/RTP service session and other functions.

As shown in fig. 10, a specific video call and disconnect flow chart is shown,

the video telephone device and the vSwtch use the traditional SIP protocol to establish a call, the vSwtch and the SDN controller complete registration and addressing of the video telephone device to the SDN controller through extended Packet-in and Packet-out messages of the extended OpenFlow protocol, and the negotiation interaction of SIP metadata at two ends is completed through the extended flow table information carrying SIP metadata.

As shown in fig. 11, SIP Metadata (hereinafter, SIP Metadata) information is added to the APP layer in order to extend the OpenFlow flow table. SIP Metadata includes the following fields:

SIP type:1 byte, the value may be: invite=1, try=100, ring=180, ok=200, ack=2, bye=300;

SIP service data: for example, it may be: encapsulation=rtp, audio=g.723, video=h 264.

As shown in fig. 12, to expand a Packet-in message, a SIP message body is newly added to the Packet-in message in the related art, which includes: the type field of the SIP protocol, the source destination address of the calling party, the RTP source destination port, and other information fields.

As shown in fig. 13, to expand the Packet-out Packet, the Action (Action) function of the Packet-out Packet in the related art is defined as: forwarding the SIP message body, discarding the SIP message body data or encapsulating and forwarding to the controller.

Before a call, the video telephone device A and the video telephone device B need to register to the SDN controller, the registration information is carried by the Packet-in message encapsulated by the vSwitch through the extended OpenFlow protocol by sending the registration information to the corresponding vSwitch, and the registration is completed interactively with the SDN controller. At this time, the SDN controller will collect information such as identity information and location information of the two video telephony devices, and reply to the video telephony devices a and B with a 200OK SIP message successfully registered, and package the extended Packet-out Packet with the 200OK SIP message to the vSwitch-1 and vSwitch-2 through the extended OpenFlow protocol.

When video telephony device a initiates a video call to video telephony device B, video telephony device a initiates a SIP-Invite message containing the address of video telephony device B, and after video telephony device a sends the Invite message to vSwitch-1, vSwitch-1 queries the SDN controller via Packet-in message and forwards the Invite request to the SDN controller because vSwitch-1 has no address information for video telephony device B. The SDN controller finds the address information of the video telephony device B by addressing in the stored content, encapsulates 100 the Trying information by a Packet-out Packet and instructs vSwitch-1 to forward the SIP message body to the video telephony device a. The vSwitch-1 forwards the transfer information to the videophone apparatus a 100.

After addressing is completed, the SDN controller distributes the extended Flow table to the two vSwitch and respectively distributes the Flow table information of the two vSwitch extensions by using Flow-Mod messages. After completion, the SDN controller forwards Invite messages from video telephony device A to video telephony device B via vSwitch-2. Video phone device B immediately replies 180Ringing to video phone device a upon receipt of the Invite message. At this point, the vSwitch-2 has the routing address of videophone device B and forwards the lookup table directly to vSwitch-1. After the video phone apparatus B receives the video phone, the video phone apparatus B initiates a 200OK to the video phone apparatus a, and the video phone apparatus a replies an ACK after receiving it. So far, the session has been established, and video telephony device a and video telephony device B start RTP audio and video streaming.

When video telephone device A or video telephone device B hangs up the video telephone, the hang-up direction is followed by the hang-up party sending BYE's SIP message, the hang-up party replying to 200OK, the session is interrupted.

Therefore, the embodiment expands SIP information in Packet-in message and flow table information by expanding OpenFlow protocol message, expands action group data in Packet-out message to support the processing of SIP message body, thereby realizing the coordination among SDN controller, vSwitch switch and SIP video telephone device, providing QoS guaranteed capability of link-along-with-establishment for video call service, and improving video call service quality. Meanwhile, the problem that the SIP and audio/video service application layer and the network layer cannot cooperatively transmit is solved, and the callable capacity is provided by setting the SDN controller and the vSwitch, so that the system can call the route optimization capacity of the SDN at the service layer, and the service quality of the upper-layer video call is ensured. In addition, the existing OpenFlow protocol is fully utilized, the system architecture is pertinently expanded, and when the universal SIP protocol is used for video call, namely actions made by two parties of the video call are unchanged and new actions are not added, the service capability of SDN can be invoked without perception, and a link meeting the QoS service of audio and video transmission can be conveniently and rapidly constructed.

It should be noted that, in the technical scheme of the present disclosure, the acquisition, storage, use, processing, etc. of the data all conform to relevant regulations of national laws and regulations.

Based on the same inventive concept, a communication device is also provided in the embodiments of the present disclosure, as described in the following embodiments. Since the principle of solving the problem of the embodiment of the device is similar to that of the embodiment of the method, the implementation of the embodiment of the device can be referred to the implementation of the embodiment of the method, and the repetition is omitted.

Fig. 14 is a schematic diagram of a call device applied to a switch of a video call end in an embodiment of the disclosure, where, as shown in fig. 14, the device includes:

a first invite SIP message receiving module 1401, configured to receive a session invite session initiation protocol SIP message initiated by a video call end device; the call invitation SIP information is used for requesting to establish video call between the video call terminal equipment and the video call called terminal equipment, and the call invitation SIP information carries address information of the video call called terminal equipment;

a first invite SIP message forwarding module 1402, configured to forward session invite SIP information to the SDN controller, so that the SDN controller queries switch information of a video call called terminal according to address information of the video call called terminal device carried in the session invite SIP message, and forwards the session invite SIP information to a switch of the video call called terminal, so as to establish a video SIP session between the video call calling terminal device and the video call called terminal device;

It should be noted that, the first invite SIP message receiving module 1401 and the first invite SIP message forwarding module 1402 correspond to S202 to S204 in the method embodiment, and the foregoing modules are the same as examples and application scenarios implemented by the corresponding steps, but are not limited to those disclosed in the method embodiment. It should be noted that the modules described above may be implemented as part of an apparatus in a computer system, such as a set of computer-executable instructions.

It should be noted that, in some embodiments of the present disclosure, the call device applied to the switch of the video call end further includes:

the first registration module is used for receiving the calling end registration SIP information sent by the video call calling end equipment; the call end registration SIP information carries the video call end equipment information and the corresponding relation information of the video call end equipment and the switch of the video call end;

and registering the SIP information of the calling terminal, forwarding the SIP information to the SDN controller, enabling the SDN controller to register the video call calling terminal equipment according to the video call calling terminal equipment information, and storing the corresponding relation information of the video call calling terminal equipment and the switch of the video call calling terminal.

In some embodiments of the present disclosure, the first invite SIP message forwarding module 1402 is specifically configured to: and encapsulating the call invitation SIP information in an extended Packet-in message by using an OpenFlow protocol, and sending the message to the SDN controller. The extended Packet-in message at least comprises: a SIP message body; the SIP message body includes at least one of: a type field of the SIP protocol, a source destination address field of the calling end device, a source destination address field of the called end device, and a real-time transport protocol RTP source destination port information field.

In some embodiments of the present disclosure, a call device applied to a switch of a video call terminal further includes:

the call ending message forwarding module is used for receiving a call ending request SIP message initiated by the video call terminal equipment; the session ending request SIP message is used for requesting ending of the video session between the video session calling terminal device and the video session called terminal device;

Fig. 15 shows a schematic diagram of a call device applied to an SDN controller in an embodiment of the disclosure, where, as shown in fig. 15, the device includes:

a second invite SIP message receiving module 1501, configured to receive session invite SIP information forwarded by the switch of the video call end; the call invitation SIP information is used for requesting to establish video call between the video call terminal equipment and the video call called terminal equipment, and the call invitation SIP information carries address information of the video call called terminal equipment;

the called-side switch information query module 1502 is configured to query switch information of a video call called-side according to address information of video call called-side equipment carried in the call invitation SIP message, and return the switch information of the video call called-side to a switch of the video call calling-side;

a second invite SIP message forwarding module 1503, configured to forward the session invite SIP message to the switch of the video call called party according to the switch information of the video call called party, so that the switch of the video call called party forwards the session invite SIP message to the video call called party, so as to establish a video SIP session between the video call calling party device and the video call called party device;

It should be noted that, the second invite SIP message receiving module 1501, the called-side switch information query module 1502 and the second invite SIP message forwarding module 1503 correspond to S602 to S606 in the method embodiment, and the foregoing modules are the same as examples and application scenarios implemented by the corresponding steps, but are not limited to those disclosed in the foregoing method embodiment. It should be noted that the modules described above may be implemented as part of an apparatus in a computer system, such as a set of computer-executable instructions.

It should be noted that, in some embodiments of the present disclosure, a call device applied to an SDN controller further includes: the second registration module is used for receiving calling end registration information forwarded by the exchanger of the video call end; the calling end registration information carries video call end equipment information and corresponding relation information of the video call end equipment and a switch of the video call end; registering the video call terminal equipment according to the video call terminal equipment information, and storing the corresponding relation information of the video call terminal equipment and the switch of the video call terminal.

In some embodiments of the present disclosure, a call device applied to an SDN controller further includes: the third registration module is used for receiving the registration information of the called terminal forwarded by the exchanger of the called terminal of the video call; the called terminal registration information carries the information of the video call called terminal equipment and the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal; registering the video call called terminal equipment according to the video call called terminal equipment information, and storing the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal.

In some embodiments of the present disclosure, the called-side switch information query module 1502 is specifically configured to: the first extended flow table information is issued to a switch of the video call terminal; the first extended flow table information carries switch information of a called terminal of the video call; the first extended flow table information is used for indicating the exchanger of the video call terminal to process the SIP message.

It should be noted that, the application program APP layer of the first extended flow table information includes SIP metadata information; the SIP metadata information includes at least one of: SIP message type and SIP service data.

In some embodiments of the present disclosure, the second invite SIP message forwarding module 1503 is specifically configured to: and packaging the call invitation SIP message in an extended Packet-out message by using an OpenFlow protocol, and sending the message to a switch of a called terminal of the video call.

It should be noted that, the extended Packet-out Packet at least includes: action group data; the action group data is used to represent forwarding of the SIP message body, discarding of the SIP message body data or forwarding of the encapsulated SIP message body to the SDN controller.

Fig. 16 is a schematic diagram of a call device applied to a switch of a called terminal for video call in an embodiment of the disclosure, where, as shown in fig. 16, the device includes:

a third invite SIP message receiving module 1601, configured to receive a call invite SIP message forwarded by the SDN controller; the call invitation SIP message is used for requesting to establish the video call between the video call terminal device and the video call called terminal device, and the call invitation SIP message carries the address information of the video call called terminal device; the SDN controller is used for inquiring the exchanger information of the video call called terminal according to the address information of the video call called terminal equipment carried in the call invitation SIP message, and returning the exchanger information of the video call called terminal to the exchanger of the video call calling terminal; according to the exchanger information of the video call called end, forwarding the call invitation SIP information to the exchanger of the video call called end;

A third invite SIP message forwarding module 1602, configured to forward a session invite SIP message to the video call called end device, so as to establish a video SIP session between the video call calling end device and the video call called end device.

Here, the third invite SIP message receiving module 1601 and the third invite SIP message forwarding module 1602 correspond to S702 to S704 in the method embodiment, and the above modules are the same as examples and application scenarios implemented by the corresponding steps, but are not limited to those disclosed in the method embodiment. It should be noted that the modules described above may be implemented as part of an apparatus in a computer system, such as a set of computer-executable instructions.

It should be noted that, in some embodiments of the present disclosure, the call device applied to the switch of the called end of the video call further includes:

a fourth registration module, configured to receive called-side registration SIP information sent by a video call called-side device; the called end registration SIP information carries the information of the video call called end equipment and the corresponding relation information of the video call called end equipment and the exchanger of the video call called end; and registering the SIP information of the called terminal, forwarding the SIP information to the SDN controller, enabling the SDN controller to register the video call called terminal equipment according to the video call called terminal equipment information, and storing the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal.

It should be noted that, in some embodiments of the present disclosure, the call device applied to the switch of the called end of the video call further includes: the flow table information receiving module is used for receiving flow table information of a second extension issued by SDN control; the second extended flow table information carries the exchanger information of the video call terminal; the second extended flow table information is used for indicating the switch of the called terminal of the video call to process the SIP message.

It should be noted that, in some embodiments of the present disclosure, the call device applied to the switch of the called end of the video call further includes: a call invitation response information forwarding module, configured to:

receiving a call invitation response (SIP) message sent by a video call called terminal device; the call invitation response (SIP) message is used for informing the video call calling terminal device that the call invitation is received by the video call called terminal device; and forwarding the call invitation response (SIP) message to the switch of the video call terminal according to the second extended flow table information, so that the switch of the video call terminal forwards the call invitation response (SIP) message to the video call terminal equipment to inform the video call terminal equipment that the video call terminal equipment has received the video SIP session invitation.

Fig. 17 is a schematic diagram of a call device applied to a video call end device in an embodiment of the disclosure, where, as shown in fig. 17, the device includes:

an invite SIP message initiating module 1701, configured to initiate a session initiation protocol SIP message for a switch of a video call end, so that the switch of the video call end forwards session initiation SIP information to an SDN controller, and the SDN controller queries switch information of the video call end according to address information of video call end equipment carried in the session initiation SIP message, and forwards the session initiation SIP information to the switch of the video call end, so as to establish a video SIP session between the video call end equipment and the video call end equipment;

the call invitation SIP information is used for requesting to establish video call between the video call terminal equipment and the video call called terminal equipment, and the call invitation SIP information carries address information of the video call called terminal equipment; the SDN controller stores the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal.

It should be noted that, the above-mentioned invite SIP message initiation module 1701 corresponds to S802 in the method embodiment, and the above-mentioned module is the same as the example and application scenario implemented by the corresponding steps, but is not limited to what is disclosed in the method embodiment. It should be noted that the modules described above may be implemented as part of an apparatus in a computer system, such as a set of computer-executable instructions.

Fig. 18 is a schematic diagram of a call device applied to a called end device for video call in an embodiment of the disclosure, where, as shown in fig. 18, the device includes:

a fourth invite SIP message receiving module 1801, configured to receive a session invite SIP message forwarded by the switch of the video call called terminal, so as to establish a video SIP session between the video call called terminal device and the video call calling terminal device;

the switch of the called terminal of the video call is used for receiving a call invitation SIP message forwarded by the SDN controller; the call invitation SIP message is used for requesting to establish the video call between the video call terminal device and the video call called terminal device, and the call invitation SIP message carries the address information of the video call called terminal device;

It should be noted that, the fourth invite SIP message receiving module 1801 corresponds to S902 in the method embodiment, and the modules are the same as the examples and application scenarios implemented by the corresponding steps, but are not limited to what is disclosed in the method embodiment. It should be noted that the modules described above may be implemented as part of an apparatus in a computer system, such as a set of computer-executable instructions.

Those skilled in the art will appreciate that the various aspects of the present disclosure may be implemented as a system, method, or program product. Accordingly, various aspects of the disclosure may be embodied in the following forms, namely: an entirely hardware embodiment, an entirely software embodiment (including firmware, micro-code, etc.) or an embodiment combining hardware and software aspects may be referred to herein as a "circuit," module "or" system.

An electronic device 1900 according to such an embodiment of the present disclosure is described below with reference to fig. 19. The electronic device 1900 shown in fig. 19 is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present disclosure.

As shown in FIG. 19, the electronic device 1900 may be in the form of a general purpose computing device. Components of electronic device 1900 may include, but are not limited to: the at least one processing unit 1910, the at least one memory unit 1920, and a bus 1930 connecting the various system components, including the memory unit 1920 and the processing unit 1910.

Wherein the storage unit stores program code that is executable by the processing unit 1910 such that the processing unit 1910 performs steps according to various exemplary embodiments of the present disclosure described in the above section of the present description of exemplary methods. For example, the processing unit 1910 may perform the steps shown in fig. 2, fig. 6, fig. 7, fig. 8, or fig. 9 in the above-described method embodiments.

The storage unit 1920 may include readable media in the form of volatile storage units, such as Random Access Memory (RAM) 19201 and/or cache memory 19202, and may further include Read Only Memory (ROM) 19203.

The storage unit 1920 may also include a program/utility 19204 having a set (at least one) of program modules 19205, such program modules 19205 including, but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of which may include an implementation of a network environment.

Bus 1930 may be one or more of several types of bus structures including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

Electronic device 1900 may also communicate with one or more external devices 1940 (e.g., keyboard, pointing device, bluetooth device, etc.), one or more devices that enable a user to interact with electronic device 1900, and/or any devices (e.g., routers, modems, etc.) that enable electronic device 1900 to communicate with one or more other computing devices. Such communication may occur through an input/output (I/O) interface 1950. Also, electronic device 1900 can communicate with one or more networks such as a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network, such as the Internet, through network adapter 1960. As shown, network adapter 1960 communicates with other modules of electronic device 1900 via bus 1930. It should be appreciated that although not shown, other hardware and/or software modules may be used in connection with electronic device 1900, including, but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, data backup storage systems, and the like.

From the above description of embodiments, those skilled in the art will readily appreciate that the example embodiments described herein may be implemented in software, or may be implemented in software in combination with the necessary hardware. Thus, the technical solution according to the embodiments of the present disclosure may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (may be a CD-ROM, a U-disk, a mobile hard disk, etc.) or on a network, including several instructions to cause a computing device (may be a personal computer, a server, a terminal device, or a network device, etc.) to perform the method according to the embodiments of the present disclosure.

In particular, according to embodiments of the present disclosure, the process described above with reference to the flowcharts may be implemented as a computer program product comprising: and a computer program which, when executed by the processor, implements the video call method described above.

In an exemplary embodiment of the present disclosure, a computer-readable storage medium, which may be a readable signal medium or a readable storage medium, is also provided. In some possible implementations, various aspects of the disclosure may also be implemented in the form of a program product comprising program code for causing a terminal device to carry out the steps according to the various exemplary embodiments of the disclosure as described in the "exemplary methods" section of this specification, when the program product is run on the terminal device.

More specific examples of the computer readable storage medium in the present disclosure may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

In this disclosure, a computer readable storage medium may include a data signal propagated in baseband or as part of a carrier wave, with readable program code embodied therein. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A readable signal medium may also be any readable medium that is not a readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Alternatively, the program code embodied on a computer readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

In particular implementations, the program code for carrying out operations of the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device, partly on a remote computing device, or entirely on the remote computing device or server. In the case of remote computing devices, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., connected via the Internet using an Internet service provider).

It should be noted that although in the above detailed description several modules or units of a device for action execution are mentioned, such a division is not mandatory. Indeed, the features and functionality of two or more modules or units described above may be embodied in one module or unit in accordance with embodiments of the present disclosure. Conversely, the features and functions of one module or unit described above may be further divided into a plurality of modules or units to be embodied.

Furthermore, although the steps of the methods in the present disclosure are depicted in a particular order in the drawings, this does not require or imply that the steps must be performed in that particular order or that all illustrated steps be performed in order to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step to perform, and/or one step decomposed into multiple steps to perform, etc.

From the description of the above embodiments, those skilled in the art will readily appreciate that the example embodiments described herein may be implemented in software, or may be implemented in software in combination with the necessary hardware. Thus, the technical solution according to the embodiments of the present disclosure may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (may be a CD-ROM, a U-disk, a mobile hard disk, etc.) or on a network, including several instructions to cause a computing device (may be a personal computer, a server, a mobile terminal, or a network device, etc.) to perform the method according to the embodiments of the present disclosure.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This disclosure is intended to cover any adaptations, uses, or adaptations of the disclosure following the general principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A video call method, characterized in that the switch applied to the video call terminal comprises:

2. The video telephony method of claim 1, further comprising, prior to receiving a session invite session initiation protocol, SIP, message initiated by a video telephony calling end device:

3. The video telephony method of claim 1, wherein forwarding the call invite SIP information to an SDN controller comprises:

4. The video call method according to claim 3, wherein the extended Packet-in message at least includes: a SIP message body;

5. The video call method of claim 1, further comprising:

6. The video call method of claim 5, further comprising:

7. The video call method is characterized by being applied to an SDN controller and comprising the following steps:

8. The video call method as claimed in claim 7, further comprising, before receiving the call invitation SIP information forwarded by the switch of the video call end:

9. The video call method according to any one of claims 7 or 8, further comprising:

10. The video call method as claimed in claim 7, wherein returning the switch information of the called terminal of the video call to the switch of the calling terminal of the video call comprises:

11. The video call method of claim 10, wherein the application APP layer of the first extended flow table information includes SIP metadata information;

12. The video call method according to claim 10, wherein forwarding the call invite SIP message to the switch of the video call called terminal according to the switch information of the video call called terminal, comprises:

13. The video call method of claim 12, wherein the extended Packet-out message at least comprises: action group data;

14. A video call method, applied to a switch of a called terminal of a video call, comprising:

15. The video telephony method of claim 14, further comprising, prior to receiving a call invite SIP message forwarded by an SDN controller:

receiving the called-end registration SIP information sent by the video call called-end equipment; the called terminal registration SIP information carries the video call called terminal equipment information and the corresponding relation information of the video call called terminal equipment and the switch of the video call called terminal;

16. The video telephony method of claim 14, further comprising:

17. The video telephony method of claim 16, further comprising:

and forwarding the session invitation response (SIP) message to the switch of the video call terminal according to the second extended flow table information, so that the switch of the video call terminal forwards the session invitation response (SIP) message to the video call terminal equipment to inform the video call terminal equipment that the video call terminal equipment has received the video SIP session invitation.

18. A video call method, applied to a video call end device, comprising:

initiating a call invitation SIP message to a switch of a video call terminal so that the switch of the video call terminal forwards the call invitation SIP message to an SDN controller, and the SDN controller inquires switch information of the video call terminal according to address information of video call terminal equipment carried in the call invitation SIP message and forwards the call invitation SIP message to the switch of the video call terminal equipment so as to establish a video SIP session between the video call terminal equipment and the video call terminal equipment;

19. A video call method, applied to a called terminal device for video call, comprising:

20. A video telephony device, adapted for use with a video telephony call-end switch, comprising:

a first invite SIP message forwarding module, configured to forward the session invite SIP information to an SDN controller, so that the SDN controller queries switch information of the video call called terminal according to address information of the video call called terminal device carried in the session invite SIP message, and forwards the session invite SIP information to a switch of the video call called terminal, so as to establish a video SIP session between the video call calling terminal device and the video call called terminal device;

21. A video telephony device, for use in an SDN controller, comprising:

22. A video telephony device, adapted for use with a switch for a called party for video telephony, comprising:

23. A video telephony apparatus for use with a video telephony call-end device, comprising:

24. A video telephony apparatus for use with a video telephony called-side device, comprising:

25. An electronic device, comprising:

a processor; and

a memory for storing executable instructions of the processor;

wherein the processor is configured to perform the video telephony method of any of claims 1 to 19 via execution of the executable instructions.

26. A computer readable storage medium having stored thereon a computer program, wherein the computer program when executed by a processor implements the video telephony method of any of claims 1 to 19.