WO2017157144A1

WO2017157144A1 - Sip over tcp/tls-based communication method and associated device

Info

Publication number: WO2017157144A1
Application number: PCT/CN2017/074382
Authority: WO
Inventors: 徐永国
Original assignee: 华为技术有限公司
Priority date: 2016-03-14
Filing date: 2017-02-22
Publication date: 2017-09-21
Also published as: CN105813228B; CN105813228A

Abstract

The invention relates to the field of communications, and in particular, to a session initiation protocol (SIP) over transmission control protocol (TCP)/ transport layer security (TLS)-based communication method and an associated device. The communication method comprises: after a network disconnection, a mobile terminal and a session border controller (SBC) maintain a service alive, and the SBC does not release a session resource allocated to the mobile terminal; after a network connection recovers, the SBC checks, using association information provided by the mobile terminal, association validity, if the association validity passes, the SBC uses the session resource allocated to the mobile terminal prior to the network disconnection to initiate to a call session control function (CSCF) a periodic registration; and after the network connection recovers, the mobile terminal further transmits to the SBC medium stream data to enable the SBC to learn from a first packet once the association validity passes. Accordingly, the terminal can realize calling service continuation without re-initiating another call, reducing service downtime, and increasing service experience.

Description

Communication method based on SIP over TCP/TLS and related device

The present application claims priority to Chinese Patent Application No. 201610143258.6, entitled "SIP over TCP/TLS based communication method and related device", filed on March 14, 2016, the entire contents of which are hereby incorporated by reference. Combined in this application.

Technical field

The present invention relates to the field of communication technologies, and more particularly to a SIP over TCP/TLS based communication technology.

Background technique

With the rapid development of smart terminals and VoIP, more and more applications based on IMS (IP Multimedia System IP Multimedia Subsystem) SIP calls.

Smart terminal mobility, data security, and power consumption requirements require SIP Over TCP/TLS. The SIP Over TCP/TLS technology also involves a Session Border Controller (SBC) and Call Session Control Function (CSCF) network element.

In the process of terminal movement, flashing, switching (Wifi, 3G/4G mutual cutting), returning from Wifi edge to Wifi coverage area (collectively referred to as network interruption) will cause TCP interrupt, for SIP Over TCP After the video is interrupted, the terminal re-initiates registration and re-initiates the service to the SBC. The SBC will use the new contact address Contact header field to register with the CSCF. The CSCF finds that it is a new Contact ID and considers it to be an offsite login. The existing call service and its session resources are removed. If the call service connection is required, the terminal needs to re-initiate the call, which consumes traffic and increases service delay, which greatly reduces the user experience.

Summary of the invention

In view of this, the purpose of the embodiments of the present invention is to provide a SIP over TCP/TLS-based communication method and related device to implement call service connection and reduce service delay.

In one aspect, an embodiment of the present application provides a SIP over TCP/TLS based communication method, in which, after a network interruption, both the mobile terminal and the SBC keep the call service from hanging up, and the SBC does not release the allocated for the mobile terminal. Session resources. After the network is restored, the SBC uses the associated information provided by the mobile terminal to perform association validity detection. If the detection is successful, the SBC initiates periodic registration with the CSCF using the session resources allocated for the mobile terminal before the network interruption. After the network is restored, the mobile terminal also sends media stream data to the SBC, so that after the detection is successful, the SBC performs the first packet learning. Since the session resources used for periodic registration after recovery are the same as those before the interruption, the CSCF does not perceive the network change and does not release the existing call service. After the network is restored, the media stream can be immediately transmitted, and the new address after the network recovery is obtained through the first packet learning, and the destination address of the media stream sent by the subsequent SBC to the terminal side is also the new address. Since the call service is not released before the timeout, and the first packet learning is resumed, the call service connection can be realized without re-initiating the call, and the service interruption time is reduced, and the service experience is improved.

In a possible design, the SBC reassigns the session resources to the terminal after the association legitimacy detection fails. The reassigned session resources initiate periodic registration with the CSCF. The SBC will then initiate periodic registration with the CSCF using the reassigned session resources. This makes communication better.

In one possible design, regardless of whether the association validity check is successful, the SBC generates and returns the association ID used in the next association validity check. More specifically, the association ID for the next association legitimacy detection may be carried in the success response message returned by the SBC. Further, taking the success response message as an example, the nextAssociateId field may be added in the Contact header field of the success response message, and the value in the nextAssociateId field is the association ID. By adding a field to the existing SIP message to carry the association ID, the SBC process is simple and consumes no performance, and there is no additional signaling overhead. Alternatively, the association ID used for the next association validity check may also be carried in the newly added SIP message returned by the SBC. This design does not need to change the format of the original SIP message. In one example, the association ID can be a call ID or a service cookie. In another example, the association ID may be generated by the SBC according to the set generation rules.

In one possible design, the SBC obtains the associated information by receiving a registration message carrying the associated information or a new SIP message carrying the associated information. More specifically, the associationId field may be included in the registration message or the new SIP message, and the field value is associated information. This makes it better to implement call connection.

In a possible design, the foregoing association validity detection may include: searching for a corresponding session resource according to the association ID. If the association validity check is successful, the association validity detection fails. This makes it better to implement call connection.

In a possible design, the association information further includes an MD5 value obtained by performing, by the terminal, an MD5Hash operation on the random password, where the random password is allocated together with the association ID before the network interruption The terminal's. The SBC obtains the associated information by receiving an RTCP message carrying the associated information. In this embodiment, the RTCP message is used to activate the SBC to re-learn the first packet of the media stream, which can reduce the disconnection time of the call after the network flash recovery.

In a possible design, the foregoing association validity detection may include: searching for a corresponding session resource according to the association ID; performing MD5 verification on the MD5 value in the RTCP message; if the corresponding session resource is found and the MD5 verification succeeds, The association validity check is successful, otherwise the association legality detection fails. The introduction of MD5 verification can improve the security of call connection.

In one possible design, the SBC will also generate and return the associated ID and random password used in the next association validity check. As an example, the association ID and random password may be carried in a SIP message returned by the SBC, such as a success response message (200 OK message) or a new SIP message. More specifically, the nextAssociateId field may be added in the Contact header field of 200 OK, and the value in the nextAssociateId field is the associated ID. By adding a field to the existing SIP message to carry the association ID, the SBC process is simple and consumes no performance, and there is no additional signaling overhead.

On the other hand, an embodiment of the present invention provides an SBC having a function of realizing the SBC behavior in the above method. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In one possible design, the structure of the SBC includes a processor, a memory, the processor executing the above method by running a software program stored in the memory, invoking data stored in the memory.

In another aspect, an embodiment of the present invention provides a terminal, where the terminal has a function of implementing CSU behavior in the actual method. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a possible design, the structure of the terminal includes: a processor, a memory, the processor, by running a software program stored in the memory, calling data stored in the memory, performing at least: after a network interruption And maintaining the call service on the terminal side is not released; after the network is restored, sending the association information to the SBC; the association information is used by the SBC to perform association validity detection, where the association information includes at least an association ID, and the association The ID indicates the session resource allocated to the terminal by the SBC before the network is interrupted. After the association validity check succeeds, the session resource indicated by the association ID is used by the SBC to initiate periodic registration with the CSCF; After the network is restored, the media stream data corresponding to the call service is transmitted to the SBC, and the media stream data is sent by using a new address, and the first packet in the media stream data is used by the SBC to learn the new address.

In still another aspect, an embodiment of the present invention provides a computer storage medium for storing computer software instructions for use in the SBC, including a program designed to perform the above aspects.

In still another aspect, an embodiment of the present invention provides a computer storage medium for storing computer software instructions for use in the terminal, including a program designed to perform the above aspects.

In the embodiment of the present invention, after the network is interrupted, both the mobile terminal and the SBC keep the call service from hanging up, and the SBC does not release the session resources allocated for the mobile terminal. After the network is restored, the mobile terminal provides the associated information to the SBC, and the SBC uses the associated information to perform association validity detection. If the detection is successful, the SBC initiates periodic registration with the CSCF using the session resources allocated for the mobile terminal before the network interruption. Since the session resources used for periodic registration after recovery are the same as those before the interruption, the CSCF does not perceive the network change and does not release the existing call service. After the network is restored, the media stream can be immediately transmitted, and the new address after the network recovery is obtained through the first packet learning, and the destination address of the media stream sent by the subsequent SBC to the terminal side is also the new address. Since the call service is not released before the timeout, and the first packet learning is resumed, the call service connection can be realized without re-initiating the call, and the service interruption time is reduced, and the service experience is improved.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

FIG. 1 is a schematic diagram of an application scenario according to an embodiment of the present disclosure;

2a-2b, FIG. 3, FIG. 4a-4c, FIG. 5a-5b, and FIG. 6 are schematic diagrams of interaction of a SIP over TCP/TLS based communication method according to an embodiment of the present invention;

7a and 7b are schematic diagrams showing possible structures of an SBC according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a terminal according to an embodiment of the present disclosure;

FIG. 9 is a schematic diagram of another possible structure of an SBC or a terminal according to an embodiment of the present invention.

detailed description

The embodiment of the present invention provides a SIP over TCP/TLS-based communication method and related device, so as to implement call service connection after network recovery, and at the same time, does not reduce the processing performance of the SBC or other IMS network elements.

Related devices involved in the embodiments of the present invention include a mobile terminal, an SBC, and a CSCF.

Figure 1 shows an application scenario of the above mobile terminal (MB), SBC and CSCF: during the mobile process, the mobile terminal recovers after an interruption, such as network flashing and network switching, and its public network address is changed from IP1 to IP1. IP2.

It should be noted that FIG. 1 exemplarily shows a mobile terminal. In an actual application scenario, the number of mobile terminals is not limited to one, and may be more. In addition, the change of the IP network accessed by the mobile terminal can also be considered as a network handover.

The mobile terminal is mainly responsible for logging in to the server, initiating a call, and transmitting an audio and video RTP media stream.

The SBC is primarily responsible for signaling and media agents for terminal access.

The CSCF is mainly responsible for signaling control during user login and processing of a multimedia call session.

It should be noted that the SIP protocol is a Client/Sever protocol, so SIP messages can be divided into two types: request messages and response messages.

The SIP request message related to the present invention is as follows:

INVITE: indicates that the calling user initiates a session request and invites other users to join a session. It can also be used to update the session after the call is established (the INVITE is also called Re-invite at this time);

ACK: Confirm that the final response to the INVITE request has been received;

REGISTER: Indicates the address information registered in the To field.

The response message in the SIP protocol is used to respond to the request message, indicating the success or failure status of the call. The response message involved in the present invention is as follows:

200: Successful response (OK);

401: Unauthorized.

The embodiments of the present invention will be further described in detail below based on the common aspects of the invention described above.

An embodiment of the present invention provides a SIP over TCP/TLS based communication method, and a mobile terminal, a BSC, and a CSCF based on the method.

The solution provided by the embodiment of the present invention will be described below with reference to FIG. 2a and FIG. 3.

2a is a schematic diagram of interaction of a communication method according to an embodiment of the present invention, which may generally include several sub-processes: an initial registration process, a call process, a network interruption process, a re-registration process after network recovery, and a call connection process.

Figure 3 shows the signaling interaction.

Among them, the initial registration process can include the following parts:

Part 200: The terminal (UE) registers using Sip Over Tcp/TLS in accordance with standard procedures.

The SYN and ACK messages in Figure 3 represent the TCP networking process.

In the initial registration part, the SBC allocates session resources to the terminal. The session resource includes a contact ID (indicated by contact ID1 in FIG. 3), and initiates a periodic registration to the CSCF (initiating a REGISTER message including contact ID1).

It should be noted that the periodic registration is used to maintain the registration session, which is equivalent to the heartbeat.

During the initial registration, the signaling of the three interactions involves a REGISTER message, a 401 response message, and a 200 OK message.

Section 201: After successful registration, the SBC returns an association identifier (ID) to the terminal.

Specifically, the association ID may be carried in the SIP message returned by the SBC, for example, a success response message (200 OK message). Specifically, the nextAssociateId field may be added in the Contact header field of the 200 OK, and the value in the nextAssociateId field is the associated ID. By adding a field to the existing SIP message to carry the association ID, the SBC process is simple and consumes no performance, and there is no additional signaling overhead.

In addition, the association ID may also be carried in the newly added SIP message. Further, the nextAssociateId field may be set in the Contact header field of the newly added SIP message, and the value in the nextAssociateId field is the association ID. At this point, you need to redefine the detection interface and associated information. This does not change the original SIP message format.

The association ID may indicate the session resource allocated by the SBC to the terminal, or the association ID represents a correspondence between the terminal and the session resource allocated by the SBC.

The association ID can be used for the next association validity check. The related legality detection will be introduced later in this paper.

The SBC can generate an association ID according to the set generation rule and return it to the terminal. In fact, the terminal only transparently transmits the association ID, and the SBC can customize the content of the association ID.

The call process is reflected in section 202. Reference may be made to existing technologies such as call setup and media stream data transmission, and details are not described herein. It should be noted that the current address of the media stream data is IP1. After a subsequent network interruption and recovery, its address will be changed to IP2.

The address here refers specifically to the IP address of the public network NAT corresponding to the terminal. In fact, most of the terminals send messages in the wifi scenario. The IP address used is the private network IP address. After the media stream or data sent by the terminal reaches the public network, it will correspond to the IP address of the public network NAT. This address is initially SBC and The terminal does not know. The SBC needs to learn the IP header of the media stream or data (that is, the initial IP packets), obtain the IP address of the public network NAT corresponding to the terminal, and record it.

The call process signaling involves at least an INVITE message and a 200 OK message.

The network interrupt processing process can include the following parts:

Part 203: After the network is interrupted, the terminal does not immediately release the call on the terminal side (maintaining VoIP), the purpose of which is to make the call not hang up.

More specifically, the terminal can keep the existing call service on the terminal side from being released within 15-30 seconds (which can be longer or shorter).

Part 204: After detecting the TCP abnormality on the terminal side, the SBC does not release the corresponding session resources before waiting for the timeout, and keeps the call service corresponding to the terminal from being released (that is, the call is not hanged).

In section 204, the associated ID of the terminal is not released until the timeout is waited.

In other embodiments of the present invention, if waiting for a timeout, the SBC will release the associated ID, session resources, and release call service corresponding to the terminal.

Specifically, the terminal generally sends the media stream in the normal call process. Therefore, the SBC can release the association ID, the session resource, and the call service after the media stream is not timed out, and the associated ID is not released until the media stream expires. , session resources and call services.

Of course, if the SBC does not detect an abnormality, the associated ID remains unchanged.

The re-registration process after network recovery can include the following parts:

Section 205: After the network is restored, the terminal initiates registration.

In one example, referring to FIG. 3, the association ID assigned to the SBC can be carried in the registration message. More specifically, an associateId field may be added to the REGISTER message, and the field value is a value in the 201 part of the nextAssociateId field.

In another example, the new SIP request message can also be used to carry the association ID. More specifically, the associateId field may be set in the newly added SIP message, and the field value is a value in the 201 part of the nextAssociateId field.

Section 206: The SBC uses the association ID for association validity detection.

More specifically, the SBC can find the corresponding session resource according to the association ID. If the association is found, the association validity check is successful, otherwise the association legality detection fails.

Section 207: If the association validity check is successful, the SBC initiates periodic registration with the CSCF using the session resource indicated by the association ID.

More specifically, the SBC will initiate periodic registration with the CSCF using the previous ContactID1. Since the ContactID1 remains unchanged before and after the network interruption, the CSCF does not perceive the network change and does not release the existing call.

In other embodiments of the present invention, referring to FIG. 2b, if the association validity detection fails, the SBC will re-allocate the session resources (part 2071) for the terminal. As mentioned above, the session resource includes a contact ID, and the reassigned contact ID can be referred to as contact ID2.

The SBC will then initiate a periodic registration (part 2,072) to the CSCF using the reassigned session resource (contact ID2).

Section 208: The SBC generates and returns the association ID used in the next association validity check.

In one example, the SBC may carry the associated ID used in the next association legitimacy check in the next AssociatedId of the registered 200 OK. In addition, the 200 OK may also carry the association legality detection identifier assFlag, which is used to notify the terminal whether the validity check of the association is successful.

It should be noted that regardless of whether the association validity check is successful, the SBC generates and returns the association ID used in the next association validity check.

The call connection process can include the following parts:

Section 209: The terminal transmits media stream data corresponding to the call service.

In an example, the terminal may transmit media stream data corresponding to the call service after confirming that the association validity detection is successful.

As mentioned above, the association legality detection identifier assFlag may be carried in the 200 OK, and is used to notify the terminal whether the validity check of the association is successful. The terminal can confirm whether the association legality detection is successful according to the assFlag.

In another example, the terminal may also send the association information and the media stream data at the same time. After confirming that the association validity detection fails, the terminal stops transmitting the media stream data. Those skilled in the art can flexibly design according to actual needs.

It should be noted that before the network is interrupted, the current address of the media stream data is IP1, and in the 209 part, the address is changed to IP2, that is, the new address.

Part 210: The SBC learns the first packet of media stream data and obtains a new address.

More specifically, the SBC will find the relevant call service according to the current subscriber number of the mobile terminal, and support the new address. The media stream data of the call service is received, and the first packet of the media stream data is learned to obtain a new address.

After that, the SBC will receive the relevant data of the above call service with the new address. The destination address of the media stream sent by the SBC to the terminal side is also the new address.

The first package of learning is a relatively mature technology, and will not be described here.

Section 211: The terminal initiates re-Invite to maintain the original call.

The re-invite is initiated to maintain the session heartbeat of the call, and try to keep the information on the terminal and the server side consistent.

It should be noted that there are also re-Invite processes in the prior art, but driven by timers, it may take a long time. In this embodiment, re-Invite is initiated after the network is restored.

It should be noted that after the association validity test fails, the SBC will not perform the first packet learning and the call is interrupted. Therefore, referring to Figure 2b, after confirming that the association validity check fails, the terminal will not initiate re-Invite.

In the embodiment of the present invention, after the network is interrupted, both the mobile terminal and the SBC keep the call service from hanging up, and release the session resources allocated for the mobile terminal. After the network is restored, the mobile terminal provides the associated information to the SBC, and the SBC uses the associated information to perform association validity detection. If the detection is successful, the SBC initiates periodic registration with the CSCF using the session resources allocated for the mobile terminal before the network interruption. Since the session resources used for periodic registration after recovery are the same as those before the interruption, the CSCF does not perceive the network change and does not release the existing call service. After the network is restored, the media stream can be immediately transmitted, and the new address after the network recovery is obtained through the first packet learning, and the destination address of the media stream sent by the subsequent SBC to the terminal side is also the new address. Since the call service is not released before the timeout, and the first packet learning is resumed, the call service connection can be realized without re-initiating the call, and the service interruption time is reduced, and the service experience is improved.

In other embodiments of the present invention, the session information may also be used as an association ID, for example, a Call ID (Call ID is a random string generated according to a certain rule) or a service cookie (Service Side Session Mapping Information) as an association ID.

See another interaction process shown in Figure 4a and Figure 4b:

In section 400: The terminal (UE) registers using Sip Over Tcp/TLS in accordance with standard procedures.

Figure 4b shows the signaling interaction.

The 400 part is similar to the 200 part and will not be described here.

It should be noted that if the Call ID is used as the association ID, the SBC will not need to generate the association ID specifically, and there is no need to add the nextAssociateId to the returned SIP message as in the embodiment (part 201) shown in Figures 2a, 2b and 3. Field.

Part 401: The terminal initiates a call.

Reference may be made to existing technologies such as call setup and media stream data transmission, and details are not described herein.

Part 402: After the network is interrupted, the terminal does not immediately release the call on the terminal side (maintaining VoIP), the purpose of which is to make the call not hang up.

Section 402 is similar to Section 203 and will not be described here.

Section 403: After detecting the TCP abnormality on the terminal side, the SBC does not release the corresponding session resources before waiting for the timeout, and keeps the call service corresponding to the terminal from being released (that is, the call is not hanged).

Section 403 is similar to Section 204 and will not be described here.

Section 404: After the network is restored, the terminal initiates registration.

In the re-registration process, since the Call ID is originally required to be carried in the REGISTER message, there is no need to add the associateId field to the REGISTER message as in the embodiment (part 205) shown in Figures 2a, 2b and 3, This further simplifies the processing of the SBC.

Part 405: The SBC uses the association ID (ie, call ID) for association validity detection.

Part 406: If the association validity check is successful, the SBC initiates periodic registration with the CSCF using the session resource indicated by the association ID.

Section 406 is similar to Section 207 and will not be repeated here.

In other embodiments of the present invention, referring to FIG. 4c, if the association validity detection fails, the SBC will reallocate the session resources (part 2061) for the terminal. As mentioned above, the session resource includes a contact ID, and the reassigned contact ID can be referred to as contact ID2.

The SBC will then initiate periodic registration (part 2062) to the CSCF using the reassigned session resource (contact ID2).

Part 407: The SBC returns a SIP message.

The SIP message may carry the association legality detection identifier assFlag, and is used to notify the terminal whether the validity check of the association is successful.

Section 408: The terminal transmits media stream data corresponding to the call service.

In an example, after confirming that the association validity check is successful, the terminal may transmit the media stream data corresponding to the call service, and after confirming that the association validity check fails, the terminal does not start to transmit the media stream data corresponding to the call service. Operation (Figure 4c).

In another example, the terminal may also send the association information and the media stream data at the same time, and after confirming that the association validity detection fails, the terminal stops transmitting the media stream data. Those skilled in the art can flexibly design according to actual needs.

Part 409: If the association validity check is successful, the SBC learns the first packet of the media stream data to obtain a new address.

Section 409 is similar to section 210 and will not be repeated here.

Part 410: If the association validity check is successful, the terminal initiates re-Invite to maintain the original call.

Section 410 is similar to Section 211 and will not be described here.

5a and 6 illustrate yet another exemplary interaction process of the above communication method (FIG. 6 embodies the signaling interaction involved in the interaction process shown in FIG. 5a), which may generally include several sub-processes: initial registration process, call Process, network interruption processing, first packet re-learning process after network recovery, and call connection process. Figure 6 illustrates the signaling interaction. It should be noted that the interaction between the SBC and the CSCF is the same as that of all the foregoing embodiments. Therefore, the interaction between the SBC and the CSCF is omitted in FIGS. 5a and 6. For details, refer to all the foregoing embodiments.

Among them, the initial registration process can include the following parts:

Part 500: The terminal (UE) registers using Sip Over Tcp/TLS in accordance with standard procedures.

In the initial registration part, the SBC allocates session resources to the terminal and initiates periodic registration to the CSCF (initiating a REGISTER message, including the contact ID).

After the periodic registration is successful, the SBC will return a 200 OK message.

Different from the initial registration process shown in FIGS. 2a, 2b and FIG. 3, in the initial registration process of this embodiment, the association ID is not returned, but the association ID is returned during the call.

The call process includes at least the following parts:

Section 501: After the registration is successful, the terminal sends an INVITE message to the SBC to establish a call;

Section 502: The SBC generates and returns an association ID and a random password (pwd) to the terminal.

The association ID and random password can be carried in the SIP message returned by the SBC, for example, a success response message (200 OK for invite message). Specifically, the nextAssociateId field may be added in the Contact header field of the 200 OK, and the value in the nextAssociateId field is the association ID and the random password (pwd). By adding a field to the existing SIP message to carry the association ID and the random password (pwd), the SBC process is simple and consumes no performance, and there is no additional signaling overhead.

In addition, the association ID and the random password can also be carried in the newly added SIP message. Further, the nextAssociateId field can be set in the Contact header field of the newly added SIP message, and the value in the nextAssociateId field is the association ID and the random password. At this point, you need to redefine the detection interface and associated information. This does not change the original SIP message format.

The SBC can generate an association ID according to the set generation rule. The terminal only transparently transmits the association ID, and the SBC can customize the content of the association ID. In this embodiment, the association ID is server-cookie. For other related content of the association ID, please refer to the introduction in section 201 above, and no further details are provided here.

The network interrupt processing process can include the following parts:

Section 503: After the network is interrupted, the terminal does not immediately release the call on the terminal side (maintaining VoIP), the purpose of which is to make the call not hang up.

Section 504: After detecting the TCP abnormality on the terminal side, the SBC does not release the corresponding session resource and association ID before waiting for the timeout, and keeps the call service corresponding to the terminal from being released (that is, the call is not hanged).

Sections 503-504 are identical to sections 203-204 and will not be described here.

It should be noted that, for the sake of simplicity, FIG. 6 omits the network interrupt processing procedure.

The first packet re-learning process after network recovery includes at least the following parts:

Section 505: The terminal sends an RTCP (Real Time Transmission Control Protocol) message carrying the associated information to the SBC.

The first, second, and fourth in the first packet re-learning process shown in FIG. 6 are standard protocol flows, in which Nonce and next nonce are used for authentication in registration. The third process corresponds to "the terminal sends an RTCP message carrying the associated information to the SBC."

The association information includes the association ID and the MD5 value (that is, MD5-Auth). The MD5 value is obtained by the terminal performing MD5Hash operation on the random password obtained during the call.

More specifically, an associateId field may be added to the RTCP message, and the field value is the association ID and the MD5 value returned by the 502 part.

Section 506: At the same time, the terminal sends a media stream corresponding to the call service to the SBC.

It should be noted that before the network is interrupted, the current address of the media stream data is IP1. After the recovery, the address is changed to IP2.

The address here refers specifically to the IP address of the public network NAT corresponding to the terminal. In fact, most of the terminals are in the wifi scene. Send the message, the IP address used is the private network IP address. After the media stream or data sent by the terminal reaches the public network, it will correspond to the IP address of the public network NAT. This address is not known to the SBC and the terminal at first. The SBC needs to learn the IP header (that is, the first packet) of the media stream or data, and obtain the IP address of the public network NAT corresponding to the terminal.

Section 507: The SBC uses the associated ID and MD5 values for association validity detection.

Specifically, the SBC searches for the corresponding session resource according to the association ID, and performs MD5 check on the MD5 value in the RTCP message; if the corresponding session resource is found and the MD5 check succeeds, the association legality detection succeeds, otherwise the association legality The test failed.

Among them, the MD5 check can include:

The SBC performs the MD5 value obtained by the MD5Hash operation using the random password previously assigned to the terminal. To distinguish from the MD5 value sent by the terminal, the MD5 value generated by the terminal and sent to the SBC can be referred to as the first MD5 value, and the MD5 generated by the SBC is referred to as the second MD5 value.

The SBC compares the first MD5 value with the second MD5 value. If the two are equal, the MD5 check succeeds, otherwise the MD5 check fails.

Section 508: If the association validity check is successful, the SBC supports receiving media stream data from the new address, re-learning the first packet of the media stream data, and obtaining a new address.

In one example, after the association validity check is successful, the SBC also initiates periodic registration with the CSCF using the session resource indicated by the association ID.

In other embodiments of the present invention, referring to FIG. 5b, if the association validity detection fails, the SBC will re-allocate the session resources (part 5081) for the terminal. As mentioned above, the session resource includes a contact ID, and the reassigned contact ID can be referred to as contact ID2. The SBC will then initiate periodic registration (Part 5082) to the CSCF using the reassigned session resource (contact ID2).

It should be noted that if the association validity check fails, the SBC will not perform the first packet learning, and discard the received media stream corresponding to the call service of the terminal (part 5083).

Section 509: The terminal initiates re-Invite to maintain the original call.

Section 510: The SBC generates and returns to the terminal the association ID and random password (pwd) used in the next association validity check.

The association ID and random password can be carried in the SIP message returned by the SBC, for example, a success response message (200 OK for invite message). Specifically, the nextAssociateId field may be added in the Contact header field of the 200 OK, and the value in the nextAssociateId field is the association ID and the random password (pwd). By adding a field to the existing SIP message to carry the association ID and the random password (pwd), the SBC process is simple and does not consume performance, and can also increase the signaling overhead.

In this embodiment, using the RTCP message to activate the SBC to re-learn the first packet of the media stream, the call disconnection time of the call after the network flash recovery is reduced. In addition, this embodiment introduces MD5 check, which can improve the security of call connection.

It should be noted that the continuity of the network flash call is implemented. The STG tunneling scheme is generally adopted, and this scheme requires a tunnel between the mobile terminal and the STG server. Among them, the STG server is deployed separately or the SBC built-in STG server, and the mobile terminal side needs to be embedded in the STG client. After the program is started, one or more tunnels are established between the mobile terminal and the STG server, and SIP messages and media stream data are transmitted on the tunnel.

When the network is restored, the STG client embedded in the mobile terminal re-establishes the tunnel. The information such as the virtual IP address and port that the STG client provides to the service remains the same as before, and the network interruption is not reflected for the service. In this way, SIP messages and media stream data can continue to be transmitted without perceiving the process of network interruption, thereby achieving call continuity.

However, deploying STG servers separately is costly. The built-in STG server in the SBC will seriously affect the performance of the SBC, making the ability of the SBC support drastically reduced. Moreover, the scheme of adopting the STG tunnel needs to wait for the tunnel to be successfully established before it can be connected, thereby increasing the time of service interruption.

However, the technical solution provided by the present invention does not need to establish a tunnel, and does not need to deploy an STG server or deploy an STG server in the SBC. The IMS network element such as the CSCF does not need to perform additional processing, and the SBC does not add too much processing, so This will result in a decrease in the processing performance of the SBC.

It should be noted that the above technical solution is also applicable to TLS.

The foregoing provides an introduction to the solution provided by the embodiments of the present invention from the perspective of interaction between the various devices. It can be understood that various devices, such as SBCs, terminals, etc., in order to implement the above functions, include hardware structures and/or software modules corresponding to the respective functions. Those skilled in the art will readily appreciate that the present invention can be implemented in a combination of hardware or hardware and computer software in combination with the elements and algorithm steps of the various examples described in the embodiments disclosed herein. Whether a function is implemented in hardware or computer software to drive hardware depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

FIG. 7a is a schematic diagram showing a possible structure of an SBC involved in the above embodiment, including:

The holding unit 701 is configured to: after the network interruption is detected, before the timeout is waited, the session resources corresponding to the terminal are not released, and the call service corresponding to the terminal is not released;

The session resource is allocated to the terminal before the network is interrupted by the SBC; and after the network is interrupted, the terminal will also keep the call service on the terminal side from being released.

The first receiving unit 702 is configured to receive association information from the terminal, where the association information includes at least an association ID, where the association ID indicates a session resource allocated by the SBC to the terminal before the network is interrupted;

The association legality detecting unit 703 is configured to perform association legality detection by using the foregoing association information.

The registration unit 704 is configured to initiate a periodic registration to the CSCF by using the session resource indicated by the association ID when the association validity check is successful.

a second receiving unit 705, configured to receive media stream data corresponding to the foregoing call service; the media stream data is sent by using a new address;

The learning unit 706 is configured to learn the first packet of the media stream data to obtain the new address.

In other embodiments of the present invention, referring to FIG. 7b, the foregoing SBC may further include a generating unit 707, configured to generate and Returns the association ID used in the next association validity check.

Therein, the holding unit 701 can be used to perform the 204 portion shown in Figures 2a and 2b, the 403 portion shown in Figures 4a and 4c, and the 504 portion shown in Figures 5a and 5b.

The first receiving unit 702 can be configured to receive association information transmitted by the terminal in the portion 205 shown in Figures 2a and 2b, the portion 404 shown in Figures 4a and 4c, and the portion 505 shown in Figures 5a and 5b.

The second receiving unit 705 can be configured to receive media stream data transmitted by the terminal in the portion 209 shown in FIG. 2a, the portion 408 shown in FIG. 4a, and the portion 506 shown in FIGS. 5a and 5b, and in other embodiments, the receiving terminal transmits Media stream data.

The association legitimacy detecting unit 703 can be used to execute the 206 portion shown in Figs. 2a and 2b, the 405 portion shown in Figs. 4a and 4c, and the 507 portion shown in Figs. 5a and 5b.

The registration unit 704 can be used to perform the 200 and 207 portions shown in FIG. 2a, the 200 portion, the 2071 portion, and the 2072 portion shown in FIG. 2b, the 400 portion and the 406 portion shown in FIG. 4a, and the 400 portion shown in FIG. 4c. Section 4061 and Section 4062, Section 500 shown in Figure 5a, Section 500, Section 5081, and Section 5082 shown in Figure 5b.

The learning unit 706 can be used to perform the 210 portion shown in Figure 2a, the 409 portion shown in Figure 4a, the 508 portion shown in Figure 5a, and the 5084 portion shown in Figure 5b.

The generating unit 707 can be used to perform the 201 part and the 208 part shown in FIGS. 2a and 2b, the 502 part and the 510 part shown in FIG. 5a, the 502 part and the 5083 part shown in FIG. 5b, and further, the generating unit can also be used to execute the figure. Section 407 shown in 4a and 4c.

FIG. 8 is a schematic structural diagram of a terminal involved in the foregoing embodiment, including:

The holding unit 801 is configured to keep the call service on the terminal side from being released after the network is interrupted;

The first sending unit 802 is configured to send association information to the SBC after the network is restored;

The association information is used by the SBC to perform association validity detection, where the association information includes at least an association ID, and the association ID indicates a session resource allocated by the SBC to the terminal before the network interruption, and after the association validity detection is successful, The session resource indicated by the foregoing association ID is used by the SBC to initiate periodic registration with the CSCF;

The second sending unit 803 is configured to: after the network is restored, transmit media stream data corresponding to the call service to the SBC, where the media stream data is sent by using a new address, and the first packet in the media stream data is used by the SBC to learn the foregoing. new address.

Among them, the holding unit 801 can be used to execute the portion 203 shown in Figs. 2a and 2b, the portion 402 shown in Figs. 4a and 4c, and the portion 503 shown in Figs. 5a and 5b.

The first transmitting unit 802 can be used to perform the 209 portion shown in FIG. 2a, the 404 portion shown in FIGS. 4a and 4c, and the 505 portion shown in FIGS. 5a and 5b.

The second transmitting unit 803 can be used to perform the 205 portion shown in Figures 2a and 2b, the 408 portion shown in Figure 4a, the 506 portion shown in Figures 5a and 5b, and the 5085 portion shown in Figure 5b.

In other embodiments of the present invention, the terminal may further include a calling unit, configured to complete call setup, and media stream data transmission during the call. The call unit can be used to perform the 202 and 211 portions shown in Figure 2a, the 202 portion shown in Figure 2b, the 401 portion and the 410 portion shown in Figure 4a, the 401 portion shown in Figure 4c, and the 501 portion shown in Figure 5a. And part 509, part 501 shown in Figure 5b.

FIG. 9 is a schematic diagram showing another possible structure of the SBC/terminal involved in the foregoing embodiment, including:

Bus, controller/processor 1, memory 2, communication interface 3, input device 4, and output device 5. The processor 1, the memory 2, the communication interface 3, the input device 4, and the output device 5 are connected to each other through a bus. among them:

The bus can include a path for communicating information between various components of the computer system.

The controller/processor 1 may be a general-purpose processor, such as a general-purpose central processing unit (CPU), a network processor (NP Processor, NP for short, a microprocessor, etc., or an application-specific integrated circuit. , ASIC), or one or more integrated circuits for controlling the execution of the program of the present invention. It can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The controller/processor 1 can also be a combination of computing functions, such as one or more microprocessor combinations, a combination of a DSP and a microprocessor, and the like.

The program for executing the technical solution of the present invention is stored in the memory 2, and an operating system and other applications can also be saved. In particular, the program can include program code, the program code including computer operating instructions. More specifically, the memory 2 may be a read-only memory (ROM), other types of static storage devices that can store static information and instructions, random access memory (RAM), storable information, and Other types of dynamic storage devices, disk storage, and the like.

Input device 4 may include means for receiving data and information input by a user, such as a keyboard, mouse, camera, scanner, light pen, voice input device, touch screen, and the like.

Output device 5 may include devices that allow output of information to the user, such as a display screen, printer, speaker, and the like.

Communication interface 3 may include devices that use any type of transceiver to communicate with other devices or communication networks, such as Ethernet, Radio Access Network (RAN), Wireless Local Area Network (WLAN), and the like.

The controller/processor of the SBC can be used to perform the processes of the SBCs of Figures 2a-2b, 3, 4a-4c, 5a-5b, 6 and/or other processes for the techniques described herein. . The controller/processor can also be used to implement the functions of the holding unit 701, the first receiving unit 702, the associated legitimacy detecting unit 703, the registration unit 704, the second receiving unit 705, the learning unit 706, and the generating unit 707.

The SBC's communication interface is used to support the SBC to communicate with other devices. For example, the OBU is used to support communication with other devices shown in Figures 2a-2b, 3, 4a-4c, 5a-5b, and 6.

The controller/processor of the terminal can be used to perform the processes involved in the terminal of Figures 2a-2b, 3, 4a-4c, 5a-5b, 6 and/or other processes for the techniques described herein . The controller/processor of the RSU can also be used to implement the functions of the holding unit 801, the first transmitting unit 802, the second transmitting unit 803, and the calling unit.

The communication interface of the terminal is used to support the terminal to communicate with other devices. For example, the support terminal is in communication with other devices shown in Figures 2a-2b, 3, 4a-4c, 5a-5b, and 6.

It will be appreciated that Figure 9 only shows a simplified design of the SBC or terminal. In practical applications, the SBC or terminal may include any number of transmitters, receivers, processors, controllers, memories, communication interfaces, etc., and all SBCs or terminals that can implement the present invention are within the scope of the present invention. .

The steps of a method or algorithm described in connection with the present disclosure may be implemented in a hardware, or may be implemented by a processor executing software instructions. The software instructions may be composed of corresponding software modules, which may be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, Mobile hard disk, CD-ROM or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor to enable the processor to read information from, and write information to, the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. Additionally, the ASIC can be located in the user equipment. Of course, the processor and the storage medium may also reside as discrete components in the user equipment.

Those skilled in the art will appreciate that in one or more examples described above, the functions described herein can be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored in a computer readable medium or transmitted as one or more instructions or code on a computer readable medium. Computer readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another. A storage medium may be any available media that can be accessed by a general purpose or special purpose computer.

The specific embodiments of the present invention have been described in detail with reference to the preferred embodiments of the present invention. The scope of the protection, any modifications, equivalent substitutions, improvements, etc., which are made on the basis of the technical solutions of the present invention, are included in the scope of the present invention.

Claims

A SIP over TCP/TLS based call method, comprising:

After detecting the network interruption and waiting for the timeout, the SBC keeps the session resources corresponding to the terminal from being released, and keeps the call service corresponding to the terminal from being released; wherein the session resource is allocated to the SBC before the network is interrupted. Said terminal; after the network is interrupted, the terminal keeps the call service on the terminal side from being released;

The SBC receives association information from the terminal, the association information includes at least an association ID, and the association ID indicates a session resource allocated by the SBC to the terminal before a network interruption;

The SBC uses the associated information to perform association validity detection;

If the association validity check is successful, the SBC initiates periodic registration with the CSCF by using the session resource indicated by the association ID;

The SBC receives media stream data corresponding to the call service; the media stream data is sent at a new address;

The SBC learns the first packet of the media stream data to obtain the new address.
The method of claim 1 further comprising:

If the association validity check fails, the SBC re-allocates the session resources for the terminal, and initiates periodic registration with the CSCF by using the re-allocated session resources.
The method according to claim 1, wherein the association validity detection comprises: searching for a corresponding session resource according to the association ID, and if found, the association legality detection is successful, otherwise the association legality detection fails.
The method according to claim 3, wherein the receiving the association information from the terminal comprises: receiving a registration message carrying the association information or adding a SIP message.
The method of claim 1 further comprising: said SBC generating and returning an association ID for use in the next association validity check.
The method of claim 1, wherein the receiving the associated information from the terminal comprises:

Receiving an RTCP message carrying the association information, where the association information further includes an MD5 value; the MD5 value is obtained by performing, by the terminal, an MD5 Hash operation on the random password, where the random password is the SBC before the network is interrupted The association ID is assigned to the terminal together.
The method of claim 6 wherein said associating legality detection comprises:

Finding a corresponding session resource according to the association ID;

Performing MD5 check on the MD5 value in the RTCP message;

If the corresponding session resource is found and the MD5 check succeeds, the association legality detection succeeds, otherwise the association legality detection fails.
The method of claim 7 further comprising: said SBC generating and returning the next association The correlation ID and random password used in the legality test.
A method according to claim 5 or 8, wherein

The association ID for the next association validity check is carried in the success response message or the newly added SIP message returned by the SBC; or

The association ID and random password for the next association validity check are carried in a success response message or a new SIP message returned by the SBC.
The method of claim 1 wherein the association ID is a call ID or a service cookie.
A SIP over TCP/TLS based communication method, comprising:

After the network is interrupted, the terminal keeps the call service on the terminal side from being released;

After the network is restored, the terminal sends association information to the SBC; the association information is used by the SBC to perform association validity detection, where the association information includes at least an association ID, and the association ID indicates that the SBC is The session resource allocated to the terminal before the network is interrupted. After the association validity check is successful, the session resource indicated by the association ID is used by the SBC to initiate periodic registration with the CSCF.

After the network is restored, the terminal transmits media stream data corresponding to the call service to the SBC, where the media stream data is sent by using a new address, and the first packet in the media stream data is used by the SBC learning station. State the new address.
The method according to claim 11, wherein the sending the association information to the SBC comprises: sending a registration message carrying the association information or adding a SIP message to the SBC.
The method of claim 11, wherein the transmitting the associated information to the SBC comprises:

Transmitting, by the terminal, an RTCP message carrying the association information to the SBC;

The association information further includes an MD5 value obtained by performing, by the terminal, an MD5 hash operation on the random password, where the random password is allocated to the terminal together with the association ID before the network interruption. of.
A session border controller SBC, comprising:

a holding unit, configured to keep the session resource corresponding to the terminal from being released after the network interruption is detected, and wait for the timeout, and keep the call service corresponding to the terminal from being released; wherein the session resource is the SBC in the network interruption The terminal is allocated to the terminal; after the network is interrupted, the terminal keeps the call service on the terminal side from being released;

a first receiving unit, configured to receive association information from the terminal, where the association information includes at least an association ID, where the association ID indicates a session resource allocated by the SBC to the terminal before a network interruption;

An association legality detecting unit, configured to perform association legality detection by using the associated information;

a registration unit, configured to initiate a periodic registration to the CSCF by using the session resource indicated by the association ID when the association validity detection is successful;

a second receiving unit, configured to receive media stream data corresponding to the call service; the media stream data is a new address send;

And a learning unit, configured to learn the first packet of the media stream data, to obtain the new address.
The SBC of claim 14, wherein the registration unit is further configured to:

When the association legality detection fails, the terminal resources are re-allocated for the terminal, and the re-allocated session resources are used to initiate periodic registration with the CSCF.
The SBC according to claim 15, wherein in the aspect of association validity detection, the association legality detecting unit is configured to: search for a corresponding session resource according to the association ID, and if found, correlate legality detection Successful, otherwise the association legality test failed.
The SBC according to claim 16, wherein in the aspect of receiving the association information from the terminal, the first receiving unit is configured to: receive a registration message carrying the association information or add a SIP message. .
The SBC of claim 14 further comprising:

A generation unit for generating and returning the association ID used in the next association validity check.
The SBC according to claim 18, wherein in the receiving the association information from the terminal, the first receiving unit is configured to: receive an RTCP message carrying the association information, the association information The MD5 value is further obtained by the terminal performing an MD5 hash operation on the random password, where the random password is allocated to the terminal together with the association ID before the network interruption.
The SBC according to claim 19, wherein in the aspect of association legality detection, the association legality detecting unit is configured to:

Finding a corresponding session resource according to the association ID;

Performing MD5 check on the MD5 value in the RTCP message;

If the corresponding session resource is found and the MD5 check succeeds, the association legality detection succeeds, otherwise the association legality detection fails.
The SBC according to claim 18 or 19, characterized in that

The association ID used for the next association validity check is carried in the success response message or the newly added SIP message returned by the generating unit; or

The association ID and the random password for the next association validity check are carried in the success response message or the newly added SIP message returned by the generation unit.
A terminal, comprising:

a holding unit, configured to keep the call service on the terminal side from being released after the network is interrupted;

a first sending unit, configured to send association information to the SBC after the network is restored; the association information is used by the SBC to perform association validity detection, where the association information includes at least an association ID, and the association ID indicates The session resource allocated to the terminal by the SBC before the network is interrupted. After the association validity detection is successful, the association ID indicates the session. The voice resource will be used by the SBC to initiate periodic registration with the CSCF;

a second sending unit, configured to: after the network is restored, transmit media stream data corresponding to the call service to the SBC, where the media stream data is sent by using a new address, where the first packet in the media stream data is used for The SBC learns the new address.
The terminal according to claim 22, wherein, in the aspect of transmitting the association information to the SBC, the first sending unit is configured to: send a registration message carrying the association information or add a SIP to the SBC Message.
The terminal according to claim 22, wherein in the aspect of transmitting the association information to the SBC, the first sending unit is configured to:

Sending, to the SBC, an RTCP message carrying the associated information;

The association information further includes an MD5 value obtained by performing, by the terminal, an MD5 hash operation on the random password, where the random password is allocated to the terminal together with the association ID before the network interruption. of.
A session border controller SBC, comprising: a processor and a memory, wherein the processor performs at least the following steps by running a software program stored in the memory, calling data stored in the memory :

After detecting the network interruption and waiting for the timeout, the session resources corresponding to the terminal are not released, and the call service corresponding to the terminal is not released; wherein the session resource is allocated to the SBC before the network is interrupted. After the network is interrupted, the terminal keeps the call service on the terminal side from being released;

Receiving association information from the terminal, the association information including at least an association ID, the association ID indicating a session resource allocated by the SBC to the terminal before a network interruption;

Using the associated information to perform association legality detection;

When the association validity check is successful, the session resource indicated by the association ID is used to initiate periodic registration with the CSCF;

Receiving media stream data corresponding to the call service; the media stream data is sent at a new address;

Learning the first packet of the media stream data to obtain the new address.
A terminal, comprising: a processor and a memory, wherein the processor performs at least the following steps by running a software program stored in the memory, calling data stored in the memory:

After the network is interrupted, the call service on the terminal side is not released;

After the network is restored, the association information is sent to the SBC; the association information is used by the SBC to perform association validity detection, where the association information includes at least an association ID, and the association ID indicates that the SBC is before the network is interrupted. The session resource allocated to the terminal, after the association of the validity of the association is successful, the session resource indicated by the association ID is used by the SBC to initiate periodic registration with the CSCF;

After the network is restored, the media stream data corresponding to the call service is transmitted to the SBC, where the media stream data is sent by using a new address, and the first packet in the media stream data is used by the SBC to learn the new address. .