WO2006111086A1

WO2006111086A1 - A method for intercommunication among the domains and the communication network

Info

Publication number: WO2006111086A1
Application number: PCT/CN2006/000721
Authority: WO
Inventors: Ying Wang; Jun Yan
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2005-04-20
Filing date: 2006-04-19
Publication date: 2006-10-26

Abstract

A method for intercommunication among the domains and the communication network are provided. The communication network includes the application function entity (AF), the resource admission and control subsystem (RACS), the intercommunication media control function (I-MCF) entity and the intercommunication media gateway (I-MGF). The method includes: A. AF of the calling domain obtains the calling media address and the called information after receiving the call initiation signaling from the calling party and routes the session signaling to the I-MCF entity in the current domain; B. I-MCF entity controls I-MGF in the current domain to translate the calling media address according to the called information; C.I-MCF entity determines whether the domain to which the translated calling media address belongs can intercommunicate with the called domain directly, if not, I-MCF routes the session to the I-MCF entity of the next domain, if so, I-MCF directly routes the session to the related communication entity of the called domain. The present invention can solve the problem that the media session can’t be established in the case that the bearer networks of the calling party and the called party can not intercommunicate with each other.

Description

Inter-domain interworking method and communication network

Technical field

The present invention relates to Next Generation Network (NGN) technology, and more particularly to a method and communication network for inter-domain interworking. Background of the invention

The NGN network is entering the stage of scale deployment to gradually replace the traditional public telephone switching network/integrated service digital network (PSTN/ISDN); the NGN network is based on packet bearer technology, session control and bearer separation. NGN has the following characteristics:

(1) The end-to-end nature of IP packet technology makes point-to-point setup of call control flows and media streams possible. This is a qualitative difference between media based on TDM technology and segment-by-segment forwarding.

(2) Separation of session control and bearer, so that these two levels can be constructed on different bearer networks.

(3) The session control layer and the bearer layer can be networked and operated by different operators.

The architecture of NGN is still under development. There are two architecture schemes based on softswitch and IP Multimedia Subsystem (IMS). These two schemes have different areas in networking and call setup and service deployment. This also makes the networking of NGN more complicated and more varied.

Figure 1 is a mode of inter-domain interworking in the NGN. The interworking mode is based on the end-to-end interworking of the signaling bearer planes, and the inter-domains of the media bearer planes managed by the management domain are also interworking.

In the service control layer, direct signaling from the originating application function entity (AF entity) to the AF entity where the called object is located, and obtain the domain and media address of the called media, and the signaling interaction is as follows. Figure 2 shows. The originating AF entity determines that the domain in which the master/called party is located and the media address of the terminal are also interoperable, so no additional gateway or conversion device is required to participate. The resource control of the IP bearer network is transmitted by the originating resource admission control subsystem (ACS) to the AF command, and then the transport layer control policy is sent to the bearer network. The originating RACS system is responsible for the end-to-end media resource guarantee. The entire transport control layer and the service control layer are single-point connections.

The above technical solution is only applicable to the case where the signaling bearer can communicate with each other end-to-end, and the media bearer can also communicate with the IP layer but can be managed by the management domain.

However, in the actual networking of the operator, the signaling control bearer plane and the media bearer plane may be managed by different operators. In this case, inter-operator interworking (including routing, billing, anti-attack, etc.) The limitation is that the interworking between the operators and the media bearer cannot be directly performed between the operators.

In another case, in the actual networking of the operator, the physical capacity of the session control layer is large, the function is large, and the number is relatively small. At the same time, the signaling network requires higher security and reliability than the media bearer network. The operator will set up a large inter-regional session control network. This network is fully inter-enabled. However, the media carrier operator may be different from the carrier at the session control level. At the same time, there are many media bearer devices. Very large, network traffic is also very large, it may be operated and managed by multiple operators. Inter-operators communicate with each other through border interworking gateways, and for inter-network settlement (flow accounting), security, etc. And the possibility of different inter-carrier codec capabilities, which requires the border interworking gateway to terminate and repackage the media stream, which is not done by the router device or the layer 3 switch at the media bearer level. In this case, the media bearer plane of the bearer network between operators cannot directly communicate with each other. .

However, the above existing session establishment technologies are based on the assumption that the media bearer network can be mutually end-to-end (both signaling interworking and media bearer interworking), but if there are two types of media bearer networks mentioned above. In the actual scenario, it cannot be completed using the existing technology. A session is established between the calling terminal and the called terminal. Summary of the invention

The present invention provides a method for inter-domain interworking and a communication network thereof, so as to solve the problem that a media session cannot be established in a scenario where the calling and called carrier networks cannot directly communicate with each other.

The technical solution for implementing the present invention is as follows:

A method for inter-domain interworking, the method comprising the following steps:

A. The AF of the calling domain receives the call origination signaling of the calling party, obtains the calling media address and the called information, and routes the session signaling to the interworking media control function I-MCF entity of the local domain;

B. The I-MCF entity controls the interworking media gateway in the domain. The I-MGF converts the calling media address according to the called information.

C. The I-MCF entity determines whether the translated domain of the calling media address and the domain of the called party can directly communicate with each other. If not, the session is routed to the I-MCF entity of the next domain and returns to step B; if yes, Route the session directly to the relevant communicating entity in the domain where the called party is located.

Preferably, when the interworking between the domain of the calling party and the called party can perform interworking, but the media bearer cannot be interworked, the specific process of obtaining the called information in step A is: the AF entity in the domain where the calling party is located will receive The call origination signaling of the calling party is directly signaled to the domain where the called party is located, and the called information is obtained by the AF entity of the domain in which the called party is located. In step A in this case, when the AF entity in the domain of the calling party directly routes the AF entity to the AF domain in the called domain, the called terminal is controlled not to ring.

Preferably, when the communication between the calling and called domains is incapable of performing interworking and media bearer interworking, the method for obtaining the called information is: the AF of the calling domain is from the received calling party. The called information is extracted from the call origination signaling. In this case, in step A, if the calling media address determined by the AF entity is a private network address, further control is performed. The A-MGF entity of the domain translates the private network address into a public network address.

Preferably, the method further includes: in the step A, the AF entity of the calling domain acquires the calling media resource information, and sends the resource requirement to the resource admission control subsystem RACS according to the calling media resource information, and obtains The return message available to the resource is then processed.

Preferably, the method further includes: acquiring, by the AF entity of the calling domain, the calling media resource information; and further transmitting, in step B, the obtained calling media resource information to the I-MCF entity, and the I-MCF entity according to the calling The media resource information is sent to the RACS, and the subsequent processing is performed after the return message available for the resource is obtained.

The specific manner of the AF entity of the calling domain acquiring the calling media resource information is: the AF entity obtains the calling media resource information from the calling media description information carried in the call origination signaling; or, the AF entity And extracting, by the calling media description information carried in the call origination signaling, part of the calling media resource information, and generating the remaining part of the calling media resource information according to the configuration policy; or, the AF entity generates all the calling media resources according to the configuration policy. Preferably, in step ,, the I-MCF entity carries the calling media address and the called information in the command sent to the I-MGF entity, where the information about the domain of the called party is included, and the I-MGF entity according to the called The interworking policy of the domain and its own configuration converts the calling media. In the step ,, the I-MCF entity directly controls the I-MGF entity to convert the media address of the calling terminal, or the I-MCF entity controls the I-MGF entity to convert the media address of the calling terminal through the RACS.

Preferably, after the session is established, if the codec supported by the master/called party is not unified, the I-MGF entity further performs a codec conversion operation on the media stream.

Preferably, the method for determining whether the domain of the calling media address and the domain of the called party can directly communicate with each other is as follows: According to whether the related device can perform direct inter-domain interaction Judging by the static configuration.

Preferably, the method for determining whether the domain of the calling media address and the domain of the called party can directly communicate with each other is: determining whether the called user number dialed by the calling user is the called user number in the domain. .

Preferably, the method of determining whether the domain of the calling media address and the domain of the called party can directly communicate with each other is as follows: According to whether the domain name in the called user identifier is a domain name in the domain.

Preferably, the I-MGF entity is based on per-flow er-flow control.

Preferably, the related communication entity of the domain in which the called party is located in step C is: an AF entity or an I-MCF entity.

A communication network, comprising: an AF entity and an admission control subsystem RACS; the communication network further comprising at least one interworking media control function I-MCF entity and at least one interworking media gateway function I-MGF entity; When the calling domain and the called domain cannot directly communicate with each other, the session signaling is routed to the I-MCF entity, and the I-MCF entity controls the I-MGF entity to convert the calling media address, and converts the same to the available The media address governed by the domain in which the called domain is directly interworking.

Preferably, the calling domain and the called domain cannot directly communicate with each other: the signaling interworking can be performed but the media bearer interworking cannot be performed; and the AF entity of the domain in which the calling party is located is used to receive the received calling party. The call origination signaling direct signaling is routed to the domain where the called party is located, and the called information is obtained by the AF entity of the domain in which the called party is located, and the called information is sent to the I-MCF entity, and the I-MCF entity is configured by the I-MCF entity. Controlling, by the called information, the I-MGF entity to convert the calling media address.

Preferably, the calling domain and the called domain cannot directly communicate with each other: the signaling interworking and the media bearer interworking cannot be performed; and the AF of the calling domain originates from the received calling call. Extracting the called information, sending the called information to the The I-MCF entity controls, by the I-MCF entity, the I-MGF entity to convert the calling media address according to the called information.

Preferably, the AF entity and the I-MCF entity are independent entities, or the AF entity and the I-MCF entity are integrated.

Preferably, the I-MGF entity is further configured to perform an edit code conversion on the media stream. Preferably, the I-MGF entity is a device based on per flow control.

In the case that the bearer networks of different domains cannot directly communicate with each other (including the case where the signaling interworking can be performed but the media bearer interworking cannot be performed, or the signaling interworking cannot be performed, and the media bearer interworking cannot be performed), The signaling and media sessions are established on a piecemeal basis to enable the primary and the called terminals to communicate with each other, so that the session establishment process can be completed under different bearer network conditions. The invention effectively solves the establishment of signaling and media path by introducing the inter-domain interworking gateway device and the interworking gateway control device, and seamlessly combines with the existing service quality (Qos) guarantee mechanism RACS to ensure the media path. The quality of the session is completed at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

1 is a networking diagram of the prior art signaling bearer end-to-end interworking and media bearer direct interworking;

2 is a flow chart of direct signaling addressing of an application function entity in the prior art;

3 is a schematic diagram of networking of the present invention;

FIG. 4 is a flowchart of establishing signaling and media bearer segment by segment according to Embodiment 1 of the present invention; FIG. 5 is a flowchart of establishing signaling and media bearer segment by segment according to Embodiment 2 of the present invention. Mode for carrying out the invention

The present invention is applicable to a scenario in which a communication bearer network cannot directly communicate with each other. Generally, the bearer network cannot directly communicate with each other, including signaling interworking but not media bearer interworking. And the two scenarios of signaling interworking and media bearer interworking cannot be performed.

In order to establish a session between the calling party and the called party in a scenario in which the communication bearer network cannot directly communicate with each other, the present invention adds an Interworking Media Control Function (I-MCF) entity and an Interworking Media Gateway Function (I-MGF) entity in the network system. To establish signaling and media bearers segment by segment, and complete media interworking between the calling terminal and the called terminal.

FIG. 3 is a schematic diagram of networking of a communication network according to the present invention. Referring to Figure 3, the communication network includes:

Application Function Entity (AF, Application Function), a functional entity belonging to the session control layer, mainly responsible for session establishment, transfer, and termination; with routing addressing, call control, service triggering, charging information collection, etc. Enter the first access point of the control network.

The Resource Admission and Control Subsystem (RACS), a functional entity belonging to the resource control layer, is mainly responsible for obtaining resource request information from the AF, transforming, distributing, and finally implementing these requests to the entity at the bearer level according to its own policy. Execution, such as: Router, Access Media Gateway Functional Entity (A-MGF), etc.

The access-transport resource control function (A-TRCF, Access-Transport Resource Control Function) belongs to the RACS system and is responsible for accessing the access network (IP-Access) accessed by the user to the edge of the core network (IP-Core). Resource control.

The core transport resource control function entity (C-TRCF, Core-Transport Resource Control Function) belongs to the RACS system and is responsible for resource control of the core network.

User Premise Equipment (CPE), terminal equipment deployed by non-operators, such as SIP/H.248/MGCP E-phone, IAD or soft terminal with small port capacity.

The policy decision function entity (PDF) is a function of the RACS system. It is responsible for the single-point connection with the upper-layer AF. It resolves the resource request information sent by the AF and converts it to A-TRCF according to the local policy. And C-TRCF access and core resource control strategies. And is responsible for receiving feedback from A-TRCF and C-TRCF, The status of new media resources.

The Access-Media Gateway Function (A-MGF) belongs to the functional entity of the media resource layer and is responsible for media address translation, packet filtering, tagging, and gating of the user.

Inter-media Gateway (I-MGF), a functional entity belonging to the media resource layer, responsible for media stream termination based on each session, media layer address translation between domains, re-labeling, gating, generating new Media streaming, possible media encoding and decoding conversion and other functions.

The inter-media control function (I-MCF, Interconnection Media Control Function) is mainly responsible for session control layer interworking between different operator domains, including routing of next hop session control devices, command I-MGF for address translation, gating, etc. Operation to cooperate with the interworking of the media bearer layer and the collection of inter-network billing information.

Since the domain of the calling terminal cannot directly communicate with the domain where the called terminal is located, at least one interworking media gateway device (I-MGF) is required to perform inter-network conversion in the entire media bearer route. The media gateway device is based on each stream. (per-flow) control (ie, control for each traffic flow, such as media address translation for each flow), and per flow control can only be based on sessions. For such a flow-based control-based device is controlled by the service control layer entity I-MCF, the functions of the I-MGF entity include media stream termination based on each session, address translation, re-typing, generating a new media stream, possible Media codec conversion, etc. In order to control the I-MGF entity of the media bearer, the original end-to-end route must be changed and passed through the I-MCF entity. At this time, the signaling route is no longer end-to-end, but is forwarded segment by segment.

Before the media bearer is established, the I-MGF entity mainly performs the terminal media address translation function, and reserves other resources required after the end-to-end media bearer is established. After the master/called media bearer is established, these resources actually start working. If the codec mode supported by the master/called party is not uniform, such as supporting voice G.711 encoding on one side and voice G.723 encoding on the other side, then I-MGF The entity also needs to complete the codec conversion of G.711 and G.723 so that the master/called parties can communicate. In the process of encoding and decoding the I-MGF entity, the media stream needs to be intercepted, and the RTP-based voice payload portion is completely decoded, that is, the media stream is terminated, and then the decoded voice is encoded and tagged by using a new coding method. Generate a new media stream. If the established session service is a fax service, the I-MGF entity performs a T.38-based IP fax packet (IFP, IP Fax Packet; based on TCP or UDP) and a G.711 packet (a voice transmission code) for the media stream. Decode the packet, based on RTP/UDP) conversion.

The core technical solution of the method of the present invention includes: A. The AF of the calling domain acquires the calling media address and the called information after receiving the call origination signaling of the calling party, and routes the session signaling to the local area. Interworking media control function I-MCF entity; B, I-MCF entity controls the interworking media gateway I-MGF in the domain to convert the calling media address according to the called information; C, I-MCF entity judges the converted main Whether the domain where the media address is located and the domain of the called party can directly communicate with each other. If not, the session is routed to the I-MCF entity of the next domain and returns to step B; if yes, the session is directly routed to the domain of the called party. AF entity or I-MCF entity.

In view of the fact that the communication bearer network cannot directly communicate with each other, there are mainly two scenarios, namely, the interworking of the signaling can be performed but the media bearer interworking cannot be performed, and neither the signaling interworking nor the media bearer interworking can be performed. The solution to the two scenarios of the present invention will be separately described below in two embodiments.

The first embodiment is a processing flow when the bearer network can perform signaling interworking but cannot perform media bearer interworking. Referring to FIG. 4, the signaling and media bearer need to be established segment by segment. The specific processing process includes:

Step 401: The calling CPE initiates a call origination signaling of the session.

Step 402: Since the signaling layer can be interconnected end-to-end, the AF entity in the domain where the calling party receives the call origination signaling (Invite message) initiated by the calling CPE, and directly routes the call origination signaling to The AF entity or I-MCF entity of the domain in which the called domain is located, by the called party The AF entity of the domain obtains the called information, that is, the media information of the called party, and the media information of the called party includes the domain name of the domain where the called terminal is located, the media address of the called terminal, and media related parameters, and the domain of the calling party. The AF entity also obtains the calling media description information from the call origination signaling, where the calling media description information includes the calling media address, and may also include the calling media resource information.

In this process, it is ensured that the called user does not ring, for example, by not carrying the calling SDP information in the Invite message, and the AF of the called domain returns a 183 message.

In this step, the specific manner in which the AF entity of the primary domain obtains the calling media resource information of the calling party may be: if the calling media description carried in the call originating signaling includes the calling media resource information, the AF entity The calling media resource information may be obtained directly from the call origination signaling; or the AF entity extracts part of the calling media resource information from the calling media description information carried in the call origination signaling, and generates the rest according to the configuration policy. Part of the calling media resource information. If the calling media information does not include the calling media resource information, the AF generates all the calling media resource information according to the configuration policy.

For a call with a service quality requirement, the AF entity in the domain of the calling party may also deliver the resource requirement to the resource admission control subsystem RACS according to the calling media resource information, and perform subsequent information after obtaining the return message obtainable by the resource. deal with.

Step 403: After the calling-side AF entity obtains the calling media address and the called media resource information, it determines whether the calling terminal and the media bearer of the domain where the called terminal is located cannot directly communicate with each other. If yes, the calling side AF The entity determines that the signaling route needs to be reselected, selects the next hop to the I-MCF entity of the local domain, and performs step 404.

The calling party AF entity determines that the domain of the calling media address cannot directly communicate with the domain of the called party. Therefore, the media bearer layer needs to determine the routing policy. This policy reflects the information sent by the calling party AF entity to the next hop of the signaling. And the resource requirements and policies sent by the AF entity to the PDF entity. The A entity determines whether the media bearer of the domain in which the calling party is located and the domain in which the called domain can communicate with each other can be: According to the static configuration that the operator can directly communicate with each other according to the network condition, the self determines The network situation includes the connection between the devices in the management domain of the enterprise and the devices in other management domains. If the communication entity of the domain and the communication entity of the other domain can directly communicate with each other, the information that can be interconnected is statically configured in the domain. On the device, the static configuration information is used as a basis for judging whether the domain of the calling and called parties can directly communicate with each other.

The determining whether the media carrier of the calling domain and the domain of the called domain can directly communicate with each other may be: whether the calling AF is called according to the called user number (for example, the E.164 number) dialed by the calling user. If the domain name in the domain is the domain name in the domain, .

Step 404: The I-MCF entity controls the I-MGF entity to convert the calling media address in the calling media information and obtain the converted media address from the I-MGF. Meanwhile, the I-MCF entity allocates the resource according to the calling media resource information. The requirements are distributed to the Resource Access Control Subsystem (RACS) to ensure inter-domain resources.

The command sent by the I-MCF entity to the I-MGF entity carries the calling media address and the media information of the called terminal (such as the domain of the called party, the media address of the called party, etc.), and the I-MGF entity according to the called The inter-domain interworking policy configured by the domain and its own is used to convert the calling media. The specific conversion is the same as the network address and port translation (NAPT, Network Address and Port Translator). For example, if the A operator wants to go to certain operators of the B operator, it selects the 10000-20000 port of the 1.1.1.1 address of the I-MGF of A, and the carrier A chooses the I-MGF of the A operator to some domains of the C operator. The 2.2.2.2 address of 10000-20000 ports, A carrier to D operator certain domains, select A's I-MGF 3.3.3.3 address 10000-20000 ports, etc. In this way, A can determine the range of the conversion of the calling media address according to the domain of the called party. Step 405: The I-MCF entity determines whether the converted calling media address can directly communicate with the called media domain. If not, proceed to step 406. If yes, proceed to step 407.

Similar to step 403, the I-MCF entity determines whether the media carrier of the calling domain and the called domain can directly communicate with each other according to the static configuration of the related device according to the network condition of the operator, or may be based on The called user number dialed by the calling user, or the domain name in the entered called user identifier, etc. is determined.

Step 406: The I-MCF routes the session to the I-MCF in the next domain, and proceeds to step 404.

The I-MCF in one domain may correspond to the I-MCF in multiple other domains. The I-MCF determines which I-MCF to route to according to the configuration of the called media domain.

Step 407: The I-MCF directly routes the session signaling to the AF entity or the I-MCF entity in the domain where the called domain is located, completes the entire process of session signaling control, and the media resource reservation is also completed.

The number of times the media address is converted is related to the different carrier networks. Generally, after several inter-operator interworking, several different I-MCFs are required, until the calling media address can directly communicate with the called media domain. Interoperability.

In the above step 404, the I-MCF can directly control the I-MGF to convert the calling terminal media address; the I-MCF can also control the I-MGF to convert the calling terminal media address through the RACS.

As can be seen from the above, in the first embodiment, in the case that the signaling layer can be interconnected end-to-end but the media layer cannot be end-to-end, the inter-domain communication is implemented by using the principle of establishing signaling and media segment by segment. In each media establishment process, the resource control mechanism provided by the RACS is first ensured by the session control device to ensure the availability of resources, and then the session control device selects the next hop signaling route, and starts the next segment of signaling and media establishment process. .

The second embodiment is a process in which the bearer network can not perform the signaling interworking or the media bearer interworking. Referring to FIG. 5, the signaling and the media bearer need to be established step by step. The process includes:

Step 501: The calling user terminal equipment CPE initiates call origination signaling of the session. Step 502: The AF entity in the domain where the calling party is located obtains the calling media description and the called information from the call origination signaling. The calling media description includes a calling media address, and may also include calling media resource information. The called information includes but is not limited to the called E.164 number and the domain name information in the called identifier.

If the calling media description includes the calling media resource information, the AF entity may directly obtain the calling resource information from the call origination signaling; or the calling media description information carried by the AF entity from the call originating signaling A part of the calling media resource information is extracted, and a part of the calling media resource information is generated according to the configuration policy. If the calling media description does not include the calling media resource information, the AF generates all the calling media resource information according to the configuration policy.

For the call with the service quality requirement, the AF of the calling domain also sends the resource requirement to the resource admission control subsystem (RACS) for resource control according to the calling media resource information, so as to ensure resource reservation between the domains. And after the information obtained by the resource is obtained, the subsequent processing is performed.

Step 503: The AF entity of the calling domain determines that the signaling and the media bearer cannot directly communicate with the domain of the called party, and the session signaling is routed to the I-MCF entity of the local domain as an interface to other domains.

The AF entity can determine whether the calling domain and the called domain can directly communicate with each other. The basis may be that the operator performs static configuration on the related device according to the network condition of the network, or the calling AF may dial the calling user. The called user number, or the domain name in the entered called user ID.

Step 504: The I-MCF entity sends a command carrying the calling media address and the called information to the I-MGF, and controls the I-MGF entity in the domain to switch to the calling media address according to the called information. Change and get the converted media address from the I-MGF entity. For the call with the service quality requirement, in this step, the I-MCF entity extracts the resource requirement according to the received media description information, and delivers the resource requirement to the resource admission control subsystem (RACS) to ensure the inter-domain resource. And after the information obtained by the resource is obtained, the subsequent processing is performed.

The I-MCF entity can directly control the I-MGF entity to convert the media address of the calling terminal; the I-MCF entity can also control the I-MGF entity to convert the media address of the calling terminal through the RACS.

The command sent by the I-MCF entity to the I-MGF entity carries the calling media address and the media information of the called terminal (such as the domain of the called party, the media address of the called party, etc.), and the I-MGF entity according to the called The interworking policy between the domain and its own configuration domain translates the calling media. The specific conversion is the same as the Network Address and Port Translator (NAPT). For example, if the A operator wants to go to certain operators of the B operator, it selects the 10000-20000 port of the 1.1.1.1 address of the I-MGF of A, and the carrier A chooses the I-MGF of the A operator to some domains of the C operator. The 2.2.2.2 address of 10000-20000 ports, A carrier to D operator certain domains, select A's I-MGF 3.3.3.3 address 10000-20000 ports, etc. In this way, A can determine the range of the conversion of the calling media address according to the domain of the called party.

Step 505: The I-MCF entity determines whether the converted calling media address can directly communicate with the called media domain. If not, proceed to step 506, and if yes, proceed to step 507.

The criteria for the judgment of the I-MCF entity are the same as those for the AF entity of the calling party.

Step 506: The 1-MCF entity routes the session signaling to the I-MCF entity in the next domain, and proceeds to step 504.

An I-MCF entity in a domain may correspond to an I-MCF entity in multiple other domains. The I-MCF entity determines which I-MCF entity to route to according to the configuration of the called media domain.

Step 507: The I-MCF entity directly routes the session signaling and the media to the domain of the called party. The AF entity or the I-MCF entity completes the session signaling and media establishment process.

The number of times the media address is converted is related to the different carrier networks. Generally, after several inter-operator interworking, I-MCF needs to go through several different domains until the calling media address and the called media domain. Direct interoperability.

In step 502, if the AF entity determines that the media address of the calling party is a private network media address, firstly, the access media gateway function (A-MGF) entity of the local domain controls the private network media address to be converted into a public network media address. .

It can be seen from the above that in the case that the signaling layer and the media layer cannot directly communicate with each other end-to-end, the inter-domain communication is implemented by using the principle of establishing signaling and media segment by segment. In each segment of signaling and media establishment, the resource control mechanism provided by the RACS can be used by the session control device to ensure the availability of resources. Then, the session control device selects the next hop signaling route, and starts the next segment of signaling and The media establishment process. It is within the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and the modifications of the invention

Claims

Claim

A method for inter-domain interworking, characterized in that the method comprises the following steps:

The method of inter-domain interworking according to claim 1, wherein the called information is obtained in step A when the inter-domain of the calling party and the called party can perform interworking with each other but cannot perform media bearer interworking. The specific process is as follows: the AF entity of the calling domain directly routes the received call origination signaling of the calling party to the domain where the called party is located, and obtains the called party by the AF entity of the domain in which the called party is located. information.

The inter-domain interworking method according to claim 2, wherein in step A, when the AF entity of the calling domain directly signals to the AF entity of the domain in which the called party is located, the called terminal is not vibrated. bell.

The inter-domain interworking method according to claim 1, wherein the method for obtaining the called information when the domain between the calling party and the called party cannot perform signaling interworking or media bearer interworking The AF of the calling domain is extracted from the received calling call origination signaling.

The inter-domain interworking method according to claim 4, wherein, in step A, if the calling media address determined by the AF entity is a private network address, further controlling the present The A-MGF entity of the domain translates the private network address into a public network address.

The method of inter-domain interworking according to claim 1, wherein the method further comprises: in step A, the AF entity in the calling domain acquires the calling media resource information, and the resource is obtained according to the calling media resource information. The requirement is sent to the resource admission control subsystem RACS, and subsequent processing is performed after the return message available for the resource is obtained.

The inter-domain interworking method according to claim 1, wherein the method further comprises: acquiring, by the AF entity of the calling domain, the calling media resource information; and further acquiring the obtained calling media resource in step B. The information is sent to the I-MCF entity, and the I-MCF entity delivers the resource requirement to the RACS according to the calling media resource information, and performs subsequent processing after obtaining the return message obtainable by the resource.

The inter-domain interworking method according to claim 6 or 7, wherein the specific manner in which the AF entity of the calling domain acquires the calling media resource information is: the AF entity initiates signaling from the call. The calling media information information is obtained by the calling media description information; or the AF entity extracts part of the calling media resource information from the calling media description information carried in the call origination signaling, and generates the rest according to the configuration policy. The calling media resource information; or, the AF entity generates all the calling media resource information according to the configuration policy.

The inter-domain interworking method according to claim 1, wherein in the step B, the I-MCF entity carries the calling media address and the called information in the command sent to the 1-MGF entity, including the The related information of the domain is called, and the I-MGF entity converts the calling media according to the interworking policy of the domain in which the called party is configured and itself.

The inter-domain interworking method according to claim 9, wherein in step B, the I-MCF entity directly controls the I-MGF entity to convert the media address of the calling terminal, or the I-MCF entity controls through the RACS. The I-MGF entity translates the calling terminal media address.

The inter-domain interworking method according to claim 1, wherein, after the session is established, if the codec supported by the master/called party is not unified, the I-MGF entity is also paired with the media stream. Perform codec conversion operations.

The inter-domain interworking method according to claim 1, wherein the method for determining whether the domain of the calling media address and the domain of the called party can directly communicate with each other is as follows: Whether it can be directly judged by the static configuration of inter-domain interworking.

The inter-domain interworking method according to claim 1, wherein the method of determining whether the domain where the calling media address is located and the domain of the called party can directly communicate with each other is: Whether the called subscriber number is the called subscriber number in the domain is judged.

The inter-domain interworking method according to claim 1, wherein the method for determining whether the domain where the calling media address is located and the domain of the called party can directly communicate with each other according to the method is as follows: Whether the domain name is a domain name within the domain is judged.

The inter-domain interworking method according to claim 1, wherein the I-MGF entity is based on per-flow per-flow control.

The inter-domain interworking method according to claim 1, wherein the related communication entity of the domain in which the called is located in step C is: an AF entity or an I-MCF entity.

A communication network, comprising: an AF entity and an admission control subsystem RACS; wherein the communication network further comprises at least one interworking media control function I-MCF entity and at least one interworking media gateway function I-MGF entity; The AF entity routes the session signaling to the I-MCF entity when the calling domain does not directly communicate with the called domain, and the I-MCF entity controls the I-MGF entity to convert the calling media address. Convert it to a media address governed by the domain that can communicate with the domain in which it is called.

The communication network according to claim 17, wherein the calling domain and the called domain cannot directly communicate with each other: the signaling interworking is possible but the media bearer interworking cannot be performed; and the calling domain is The AF entity is configured to directly route the received call origination signaling of the calling party to the domain where the called party is located, and obtain the AF entity in the domain where the called party is located. The called information is sent to the I-MCF entity, and the I-MCF entity controls the I-MGF entity to convert the calling media address according to the called information.

The communication network according to claim 17, wherein the calling domain and the called domain cannot directly communicate with each other: the signaling interworking and the media bearer interworking cannot be performed; and the calling domain is The AF extracts the called information from the received calling call origination signaling, and sends the called information to the I-MCF entity, and the I-MCF entity controls the I according to the called information. - The MGF entity translates the calling media address.

The communication network according to claim 17, wherein the AF entity and the I-MCF entity are independent entities, or the AF entity and the I-MCF entity are integrated.

The communication network according to claim 17, wherein the I-MGF entity is further configured to perform an edit code conversion on the media stream.

The communication network according to any one of claims 17 to 21, wherein the I-MGF entity is a device based on per-flow control.