WO2006114037A1 - A communication system with session border controller and a method for the transmission of the signaling - Google Patents

Abstract

A method of transmitting the signaling packet in the communication system with session border controller SBC comprises that: a user device sends a signaling packet with the register request to a signaling static translation function entity in the first network. After the signaling static translation function entity receives the signaling packet, it modifies the destination IP address/port number of this signaling packet to the IP address/port number of the signaling control function entity, and modifies the source IP address/port number to the IP address/port number distributed by the signaling static translation function entity itself, and then sends this signaling packet to the signaling control function entity. The signaling control function entity analyzes the signaling packet and sends it to the function entity in the second network. At the same time, there is a communication system with the SBC. The invention can effectively prevent from the malice attack on the signaling control function entity by the user, and makes the system to be more secure and enables the SBC to be more flexible without the restriction from the networking in the actual network.

Description

 Communication system with session border controller and method for transmitting signaling thereof

 The present invention relates to the field of communication technologies, and in particular to a session border controller

(SBC) communication network and its method of signaling transmission. Background of the invention

 The SBC is a concept proposed by the Internet Work Organization (IETF). It is called the Session Border Controller (SBC), which is used to solve the boundary control problem of border session services in the Next Generation Network (NGN), such as the access network. Boundary control of the core backbone network, border control of the core backbone network and the core backbone network, or border control between different management domain/address domains, used to resolve interworking and network security and services due to different management domains and address domains Problems such as quality (QoS) control, such as different address domains between different networks (access network, backbone network, etc.), cannot be directly interworked on the IP network, or because the management domain is different, it needs to be controlled at the boundary point. And for security reasons, 'end the packets coming from other networks, and hide the IP address, topology, server, etc. of the network to prevent attacks. In the networking structure shown in Figure 1, the access network and the backbone network are connected to the SBC for border control, and the two different backbone networks are interconnected by SBC for boundary control.

Figure 2 shows the networking diagram of interworking between two networks using SBC. Referring to FIG. 2, the communication system includes a network A, a network B, and an SBC. The network A and the network B are respectively connected to the SBC, and the SBC further includes a signaling control function entity and a media forwarding function entity. The signaling control function entity and the media forwarding function entity respectively have two interfaces, and each entity connects to the network A and the network B by using these two interfaces. The signaling control function entity completes the processing of the session signaling plane, such as the receiving and terminating of the signaling message, the processing of the media information in the signaling message, and the forwarding control of the media stream according to the session state in the signaling message. The function of (reject/allow, etc.), the media forwarding function entity completes the forwarding of the session media stream under the control of the signaling control function entity.

 Referring to FIG. 3, the signaling control function entity uses two IP addresses, namely, IP address 1 and IP address Γ, to communicate with the user equipment in network A and the functional entity in network B, respectively, and the media forwarding function entity utilizes two The IP addresses, namely IP address 2 and IP address 2, communicate with the user equipment in network A and the functional entities in network B, respectively. Moreover, the SBC signaling plane address and the media plane address seen by each user equipment in the network A are different, and the two addresses belong to the address domain of the network A and the address domain of the network B, respectively.

 As shown in Figure 4, the specific process of user interaction between the user equipment in network A and the functional entity in network B is as follows:

 Step 401: The user equipment in the network A sends a signaling message of the user registration request to the signaling control function entity of the SBC. .. ,

 Steps 402 to 403: After the signaling control function entity ^ goes to the registration request, analyzes and processes the signaling ^=艮文, implements some signaling control function, and then sends the registration of the user equipment to the functional entity in the network B. request.

 Step 404: The function entity in the network B authenticates the user equipment, and if the authentication succeeds, sends a response signaling packet with successful authentication to the signaling control function entity. If the authentication fails, the signaling is controlled. The functional entity sends a response signaling packet with the authentication failure.

 Step 405: After receiving the response signaling packet, the signaling control function entity sends the signaling packet to the user equipment in the network A.

 Step 406 ~ 410: After the user equipment in the network A receives the message, that is, after the registration is successful, the signaling control function entity sends a signaling message to the functional entity in the network B again; likewise, the network B The functional entity in the network also uses the signaling control function entity to send a signaling message to the user equipment in the network A.

At present, it can be seen from the above process that the networking solution shown in Figure 3 can be solved because Interworking between different networks such as the address domain or the management domain. However, in actual applications, the following problems exist in some networking scenarios:

 Since the signaling control function entity is used for the processing of the signaling plane, the media forwarding function entity is used for the processing of the media plane. The functional characteristics and processing models of the two entities are different, and the requirements of the two are also different. The processing of a single device can handle a large amount of capacity, and the processing of the media plane is limited by the forwarding capability, so that the number of concurrent ports supported is limited, so the functional entity capacity of the media plane is compared to the device capacity of the signaling plane. Smaller, so the signaling control function entity of one signaling plane may control multiple media forwarding function entities; on the other hand, the signaling plane is usually centralized, for example, the signaling plane device may be located in the central computer room of the operator network. The media device is distributed, close to the user, such as the residential property room where the user is located. Therefore, the above networking application mode has the following disadvantages:

 (1) The centralized large-capacity signaling control function entity is directly exposed to the access user. For example, one of the above-mentioned networks A or B is an access network, and the access is an uncontrollable end user with security threats. Therefore, there is a certain security risk. Once the centralized large-capacity signaling control function entity is attacked, all users accessing the functional entity using the signaling control function cannot perform session services.

(2) The centralized signaling control function entity and the distributed media forwarding function entity make the networking mode difficult to deploy in an actual network. For example, the signaling control function entity located in the operator center equipment room is not in the network B. The edge between the network A and the network A is usually located at the edge of the media forwarding function entity, so the signaling control function entity and the network A are difficult to directly interface (unless the private line is connected from the network A to the signaling control function entity directly. The mode is inconvenient and costly in practical applications, and the operator does not consider it. Therefore, the signaling control function entity cannot configure the IP address in network A, and the access user in network A cannot directly The signaling control function entity communicates directly, and as a result, the above model cannot be applied in the actual networking. At present, the signaling control function entity and the media forwarding function entity are implemented on one device, that is, the IP address 1 and the IP address 2 are combined, that is, the signaling control function entity and the media forwarding function entity are not separated. This scheme does not take into account the difference between the signaling plane and the media plane processing characteristics. Because the signaling plane technically requires more processing power of the general-purpose CPU, the media plane technically requires more professional CPU or directly through specific use. The hardware forwarding capability provided by the integrated circuit (ASIC) chip, so the separation of the two is more in line with the technical characteristics of signaling processing and media forwarding separation in the future network. Summary of the invention

 In view of this, an object of the present invention is to provide a communication network with SBC and a method for transmitting signaling thereof, so that a large-capacity centralized signaling control function entity shields an access user equipment and reduces a signaling control function entity. Security risks, and solve the problems that cannot be applied in the above actual networking.

 In order to achieve the above object, the present invention provides a method of transmitting signaling in a communication system having an SBC, the method being implemented as follows: the communication system includes at least a first network, a second network, and an SBC, and the SBC is at least The signaling static transformation function entity and the signaling control function entity include the following steps:

 A. The user equipment in the first network sends a signaling message of the registration request to the signaling static transformation function entity, where the destination IP address/port number of the signaling packet is a signaling static transformation function entity in the first network. IP address/port number, source IP address/port number is the IP address/port number of the user equipment in the first network;

 After receiving the signaling message of the user equipment, the signaling static conversion function entity modifies the destination IP address/port number of the signaling packet to the IP address/port number of the signaling control function entity, and the source IP address. /port number is modified to the IP address assigned by the signaling static conversion function entity

/port number, and the signaling message is sent to the signaling control function entity; After receiving the signaling message, the signaling control function entity analyzes and processes the signaling message, and sends the signaling message to the functional entity in the second network.

 Step B can further include:

 And setting a NAT entry of the signaling packet of the user equipment, where the entry is an IP address/port number of the user equipment in the first network and an IP address/port number assigned by the signaling static conversion function entity. Correspondence relationship.

 The step of setting the NAT entry of the signaling packet of the user equipment in the step B1 includes:

After receiving the signaling packet of the user equipment, the signaling static conversion function entity obtains the source IP address/port number in the signaling packet;

 B12. The signaling static conversion function entity allocates an IP address/port number of the signaling static conversion function entity to the user equipment, and saves the IP address/port number of the user equipment in the first network and the signaling static transformation function entity. The correspondence between the IP address/port number assigned by itself.

 The IP address/port number of the signaling control function entity in step B may use the destination IP address/port number in the signaling packet to statically change the IP address of the functional entity in the first network from the preset signaling. Obtained in the mapping relationship between the port number and the IP address of the signaling control function entity.

 The mapping relationship between the IP address/port number of the first network and the IP address of the signaling control function entity of the signaling static conversion function entity may be preset in the signaling static transformation function entity, or may be set in the static and signaling Transforming functional entities that functional entities can communicate with.

 The mapping relationship between the IP address/port number of the first network and the IP address of the signaling control function entity may be randomly configured, or configured according to a certain algorithm, or according to a predefined Mechanism configured.

 Step C can further include:

After receiving the signaling packet, the Cl and the signaling control function entity obtain the user identity in the signaling packet. And a source IP address/port number of the signaling packet, where the source IP address/port number is an IP address/port number assigned by the signaling static conversion function entity, and the signaling control function entity records the user identity Corresponding to the IP address/port number assigned by the signaling static conversion function entity itself.

 After step C, it may further include:

 If the signaling control function entity receives the response signaling packet of the second network function entity, the notification static signaling function entity successfully authenticates, and the signaling static conversion function entity permanently maintains the signaling message. NAT entry of the text;

 If the signaling control function entity receives the response signaling packet of the authentication failure of the second network function entity, the notification signaling static transformation function entity fails to authenticate, and the signaling static transformation function entity deletes the signaling message. NAT entry.

 When the signaling packet is sent to the signaling control function entity in step B, the method further includes:

 The timer is started, and if the signaling static conversion function entity receives the notification of successful authentication sent by the signaling control function entity before the timer expires, the timer is cancelled, and the subsequent processing steps are continued, if the timer expires before the timer expires. If the notification that the authentication succeeds is not received, the signaling static transformation function entity deletes the corresponding NAT entry.

 After the step C, the method may further include: after the signaling control function entity receives the command to cancel the user from the second network, sending a command to delete the signaling NAT entry of the user to the signaling static transformation function entity. After receiving the command, the signaling static conversion function entity deletes the NAT entry of the signaling packet of the user equipment.

 After step C, it may further include:

The signaling control function entity receives the signaling of the functional entity in the second network, and analyzes the signaling packet, and obtains the user identity from the signaling packet, according to step C1. The correspondence relationship is obtained, and the signaling static conversion function corresponding to the user identity is obtained. An IP address/port number of the entity, and forwarding the signaling packet to the signaling static conversion function entity according to the IP address/port number;

 D12. The signaling static conversion function entity uses the signaling message NAT entry to perform NAT address translation on the signaling packet from the signaling control function entity, and sends the signaling message after the translated address to the first network. The user device in .

 After step C, the method may further comprise:

 D21. The user equipment sends a signaling packet to the signaling static transformation function entity in the first network.

 D22. The signaling static conversion function entity performs static NAT address translation on the source and destination address/port number of the signaling packet according to the NAT entry of the signaling packet, and forwards the signaling packet to the signaling packet. Signaling control function entity;

 After receiving the signaling packet, the signaling control function entity parses and processes the signaling packet, and after determining that the user equipment has successfully registered, sends the signaling packet to the function in the second network. entity.

 Step B can further include:

 B2. The NAT entry of the signaling packet of the user equipment is set. The entry is an IP address/port number of the user equipment in the first network and an IP address/port number assigned by the signaling static conversion function entity. The correspondence relationship, and the mapping relationship between the IP address/port number of the first network and the IP address of the signaling control function entity.

 After receiving the signaling message of the user equipment or the signaling control function entity in the first network, the signaling static conversion function entity performs the NAT address conversion by using the NAT entry in step B21, and then sends the signaling entry to the NAT address. The signaling controls the functional entity or the user equipment in the first network.

The communication system is an SBC-enabled NGN network defined by the International Telecommunication Union (ITU-T), ETSI's NGN network standard telecommunications and Internet convergence service, and Advanced Network Protocol (TISPAN), or in the Internet Working Group (IETF). The communication network of the SBC model. When the communication system is an ITU-T defined SGN-enabled NGN network, the SBC is a Service Control Proxy Function (SCPF) and a Border Gateway Function (BGF); when the communication system is an SNB-defined NGN defined by TISPAN In the network, the SBC is an application function (AF) and an access border gateway (A-BGF); the access network is a plurality of digital subscriber lines (xDSL), a wireless local area network (Wlan), a cable (Cable), and a global microwave connection. Interoperability (WiMax) and a variety of wireless and wired access networks. The first network adopts an Internet Protocol version 4 (IPv4) address format or an Internet Protocol version 6 (IPv6) address format, and the second network adopts an IPv4 address format or an IPv6 address format.

 The signaling static transformation function entity may be set in the media forwarding function entity in the SBC or exist as an independent physical entity.

 In order to achieve the above object, the present invention provides a communication system having an SBC, the system comprising: the system comprising at least a first network, a second network, and an SBC, the SBC including at least a signaling static transformation function entity and signaling control a functional entity, the signaling static transformation function entity is connected to the first network and the signaling control function entity, and the signaling control function entity is connected to the second network and the signaling static transformation function entity, wherein

 The signaling static conversion function entity is configured to receive a signaling message of the user equipment in the first network, and modify the destination IP address/port number of the signaling packet to an IP address/port number of the signaling control function entity, The source IP address/port number is changed to the IP address/port number assigned by the signaling static conversion function entity, and the signaling packet is sent to the signaling control function entity;

 The signaling control function entity is configured to receive the signaling packet of the signaling static transformation function entity, analyze the processing of the signaling packet, and send the signaling packet to the functional entity in the second network.

The signaling static conversion function entity is further configured to: after receiving the signaling message of the first network user equipment for the first time, obtain the source IP address/port number of the signaling packet, and select signaling control for the user equipment. IP address/port number of the functional entity, the source IP address/port number is The IP address/port number of the user equipment in the first network, and the correspondence between the IP address/port number of the user equipment in the first network and the IP address/port number assigned by the signaling static conversion function entity.

 The signaling control function entity is further configured to: after receiving the signaling message of the signaling static conversion function entity for the first time, save the source IP address of the user identity identifier and the signaling packet carried in the signaling packet/ The source IP address/port number is the IP address/port number assigned by the signaling static conversion function entity itself.

 The signaling static conversion function entity is further configured to: when not receiving the signaling message of the first network user equipment for the first time, according to the IP address/port number and signaling static of the user equipment in the first network The corresponding relationship between the IP address and the port number assigned by the function entity is changed, the signaling packet is statically translated, and the converted signaling packet is sent to the signaling control function entity.

 The signaling control function entity is further configured to receive a signaling message from the second network, and determine a corresponding static signaling transformation according to a correspondence between the user identity and the source IP address/port number saved by the user. The IP address/port number assigned by the function entity itself, and the signaling packet is sent to the signaling static transformation function entity;

 The signaling static conversion function entity is further configured to receive a signaling message from the signaling control function entity, and convert the address of the signaling message according to the NAT entry of the signaling message saved by itself. Then sent to the user equipment of the second network.

 The communication system is an NGN network with SBC function defined by ITU-T, TISPAN, or a communication network satisfying the SBC model in the IETF,

 When the communication system is an ITU-T defined SGN-enabled NGN network, the SBC is SCPF and BGF;

When the communication system is an NGN network with SBC function defined by TISPAN, the SBC is AF and A-BGF; The access network is a network of xDSL, Wlan, Cable WiMax, and wireless access methods.

 The signaling static transformation function entity is a logical entity in a media forwarding function entity in the SBC, or an independent physical entity.

 It can be seen from the above technical solution of the present invention that the system and method of the present invention can provide only the media forwarding function entity for the users in the first network in the centrally arranged signaling control function entity and the distributed arrangement media forwarding function entity. The address resolves the actual networking configuration problem. In the present invention, since the signaling control function entity is connected to the second network and is not directly connected to the first network, the signaling message of the user must pass through the media forwarding function entity or the signaling static conversion function entity to reach the signaling. Control function entity. Therefore, users can only attack a media forwarding function entity or a signaling static transformation function entity, but the impact on the entire system is much smaller, which can effectively prevent malicious attacks by users and make the entire system more secure. At the same time, the present invention can flexibly adapt to complex address situations in various networking networks to meet the networking requirements of different operators. BRIEF DESCRIPTION OF THE DRAWINGS

 Figure 1 is a schematic diagram of the SBC networking model;

 2 is a schematic diagram of a network model with SBC in the prior art;

 3 is a schematic diagram of a typical network model with SBC in the prior art;

 4 is a schematic diagram of a signaling transmission flow based on the network model shown in FIG. 3;

 5A and 5B, wherein FIG. 5A is a schematic diagram of a networking model for implementing the system of the present invention, and FIG. 5B is a schematic diagram of a networking of a specific embodiment of the system of the present invention;

 Figure 6 is a schematic flow chart of the method of the present invention;

FIG. 7 is a schematic flow chart of a specific embodiment of implementing the method of the present invention based on the system shown in FIG. 5B. Mode for carrying out the invention

 In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings.

 Referring to Figure 5A, a communication system embodying the present invention includes: a first network, a second network, and an SBC. The SBC further includes a signaling control functional entity and a number of signaling static translation functional entities. The network A shown in Fig. 5A is a network, and the network B is a second network. The signaling control function entity is connected to the network B and the signaling static conversion function entity, and each signaling static transformation function entity is connected to the network 8, the network B, and the signaling control function entity. The signaling static transformation function entity may be a logical entity in a media forwarding function entity or an independent physical entity.

 The communication system of the present invention may be an NGN network with SBC function defined by ITU-T or TISPAN. When the communication system is an NGN network with SBC function defined by ITU-T, the SBC is SCPF and BGF; when the communication system is defined for TISPAN For an NGN network with SBC functionality, the SBC is AF and A-BGF. In general, network A is the access network and network B is the core network. Moreover, the access network can access the network for any of a variety of access modes, such as xDSL, Wlan, Cable, WiMax, and other wired and wireless modes. The IP address in the above network can be in the IPv4 address format or the IPv6 address format. The address translation includes address format conversion in various situations such as IPv4-IPv4, IPv4-IPv6, IPv6-IPv6, and IPv6-IPv4.

The signaling static transformation function entity is configured to forward signaling packets between the network A and the signaling control function entity. When the signaling static conversion function entity first forwards the signaling message of a user equipment in the network A, that is, the registration request of a user equipment in the network A, the network of the user setting message in the network A needs to be dynamically created. An address translation (NAT) entry, such as: a correspondence between an IP address/port number of the user equipment in the first network and an IP address/port number assigned by the signaling static conversion function entity, for receiving the subsequent From the first network or letter The signaling packets of the function control entity are translated by NAT, and the signaling packets are forwarded. That is, when the signaling static conversion function entity receives the signaling message that is not sent for the first time in the network A, the signaling packet is statically translated and then forwarded to the NAT entry according to the signaling packet. The signaling control function entity; when the signaling static conversion function entity receives the signaling message from the signaling control function entity, the signaling message is also subjected to static address translation, and then forwarded to the user equipment in the network A. At the same time, the mapping between the signaling address on the media forwarding packet and the address of the signaling control function entity is configured in the signaling static conversion function entity, and is used to convert the user equipment sent by the network device A. The destination address of the signaling packet, or the source address of the packet sent by the signaling control function entity.

 The signaling control function entity is configured to analyze and process the received signaling message, and perform signaling interaction with the functional entity in the network B. After receiving the signaling message of the registration request forwarded by the signaling static transformation function entity, the signaling control function entity obtains the user identity identifier in the information packet, and saves the user identity identifier and the source IP address in the signaling packet. The correspondence between the port number and the port number. Here, the source IP address/port number is the IP address/port number assigned by the signaling static conversion function entity itself. Thereafter, after receiving the signaling message sent by the functional entity in the network B to the user equipment in the first network, the signaling control function entity may obtain the user identity from the signaling message, and obtain the user identity and The mapping between the source address and the port number obtains the IP address/port number assigned by the signaling static conversion function entity corresponding to the user identity, and then forwards the signaling packet to the signaling static according to the IP address/port number. Transform functional entities.

Therefore, in the communication system based on the above-mentioned SBC, if the user equipment in the first network needs to perform signaling transmission with the functional entity in the second network, the signaling configuration allocated by the user equipment or the second network to the user is controlled. The address of the functional entity is the address of the signaling static transformation function entity. The user directly sends the signaling packet to the signaling static transformation function entity in the SBC, and the signaling static transformation function entity passes the signaling packet through the letter. The control function entity is forwarded to the functional entity in the second network. Similarly, functional entities in the second network need to be When the user equipment in the network performs signaling interaction, the signaling control function entity sends the signaling packet to the signaling static transformation function entity, and then the signaling static transformation function entity sends the signaling packet to the signaling entity. User equipment in the first network.

 Referring to Figure 6, the method of implementing the present invention includes the following steps:

 Step 601: The user equipment in the first network sends a signaling message of the registration request to the signaling static transformation function entity, where the destination IP address/port number of the signaling packet is a signaling static transformation function entity in the first network. The IP address/port number, the source address/port number is the address/port number of the user equipment in the first network.

 Step 602: After receiving the signaling packet of the user equipment, the signaling static transformation function entity modifies the destination IP address/port number of the signaling packet to the IP address of the signaling control function entity, and the source IP address/port. The number is modified to the IP address assigned by the signaling static transformation function entity.

/port number, and the signaling message is sent to the signaling control function entity.

 It should be noted that, in step 602, the IP address/port number assigned by the signaling static conversion function entity may be randomly selected by the media forwarding entity, or may be selected according to a certain priority, or may be selected according to an algorithm. , or other predefined mechanisms of choice.

 There are several ways to select the signaling control function entity IP address/port number.

 If the signalling IP address/port number of the signaling static conversion function entity and the IP address of the signaling control function entity are configured in the signaling static transformation function entity or the functional entity capable of communication with the signaling static transformation function entity Relationship, when the signaling static conversion function entity receives the signaling message from the first network, the IP address of the signaling control function entity may be obtained from the above mapping relationship by using the destination IP address/port number in the signaling message/ The port number. The mapping relationship between the IP address/port number of the signaling static conversion function entity and the IP address of the signaling control function entity can be configured according to the requirements of the operator.

If the mapping relationship between the signaling IP address/port number of the signaling static conversion function entity and the IP address of the signaling control function entity is not configured in advance, it may also be random, according to some kind Priority or choice according to some algorithm.

 Step 603: After receiving the signaling packet, the signaling control function entity analyzes and processes the signaling packet, and sends the signaling packet to the functional entity in the second network. Here, the process of analyzing and processing the signaling packet may be the same as or different from the prior art, and how it is handled does not affect the protection scope of the present invention.

 Further, after the user is successfully registered, the signaling static conversion function entity can correctly forward the subsequent signaling message sent by the user equipment, and the signaling sent by the second network to the user equipment, in the step A NAT entry is dynamically created in the 602 to perform static address translation on the received signaling packet, so as to achieve correct forwarding. The NAT entry of the signaling packet can include the following two conditions:

 Case 1: If the mapping between the signaling IP address/port number of the signaling static conversion function entity and the IP address of the signaling control function entity is configured in advance, the entry may include only the user equipment in the network. Correspondence between the IP address/port number and the IP address/port number assigned by the signaling static conversion function entity. In this way, the NAT entry of the signaling packet of the user equipment can be set as follows:

 After receiving the signaling packet sent by the user equipment for the first time, the signaling static conversion function entity obtains the source IP address/port number in the signaling packet after registering the request packet; the signaling static conversion function entity is the The user equipment allocates an IP address/port number of the signaling static conversion function entity, and saves the correspondence between the IP address/port number of the user equipment in the first network and the IP address/port number assigned by the signaling static conversion function entity. The relationship is the NAT entry of the signaling packet corresponding to the user equipment.

Case 2: If the mapping between the signaling IP address/port number of the signaling static conversion function entity and the IP address of the signaling control function entity is not configured, the NAT entry of the signaling packet of the user equipment may include: Correspondence between the IP address/port number of the user equipment in the first network and the IP address/port number assigned by the signaling static conversion function entity, and Correspondence between the IP address/port number of the first network and the IP address of the signaling control function entity. Therefore, you can obtain NAT entries in the following manner:

 After receiving the signaling message sent by the user equipment for the first time, the signaling static conversion function entity obtains the source IP address/port number and the destination IP address/port number in the signaling message after registering the request message, and The signaling static conversion function entity allocates a IP address/port number of the signaling static conversion function entity to the user equipment, and selects an IP address/port number of the signaling control function entity, and saves the user equipment in the first network. Correspondence between the IP address/port number and the IP address/port number assigned by the signaling static conversion function entity, and the correspondence between the IP address/port number of the first network and the IP address of the signaling control function entity. The corresponding relationship is the NAT entry of the signaling packet.

 The NAT entry of the above signaling packet can be deleted after the user logs out and the user fails to register.

 In addition, after the signaling entity sends a signaling message to the signaling static conversion function entity in the second network, the signaling control function entity can obtain the user identity in the signaling message after receiving the signaling message in the foregoing step 603. The identifier and the source IP address/port number of the signaling packet. The source IP address/port number is the IP address/port number assigned by the signaling static conversion function entity in step 602, and the signaling control function entity records the user identity. Corresponding to the IP address/port number assigned by the signaling static conversion function entity itself. Therefore, when receiving the signaling message sent by the function entity in the second network to the user equipment in the first network, the signaling control function entity obtains the signaling static transformation function entity from the corresponding relationship according to the called user number. The IP address/port number is forwarded to the signaling static transformation function entity according to the IP address/port number.

 The following describes the technical solution of the present invention by taking a signaling static transformation function entity as a logical entity in a media forwarding function entity as an example.

Referring to FIG. 5B, the communication system of this embodiment includes a first network and a second network. And SBC. The SBC further includes a signaling control function entity and a media forwarding function entity. The network A shown in FIG. 5B is the first network, and the network B is the second network. The signaling control function entity is connected to the network B and the media forwarding function entity, and the media forwarding function entity is connected to the network A, the network B, and the signaling control function entity.

 The communication system of the present invention may be an NGN network with SBC function defined by ITU-T, TISPAN. When the communication system is an NGN network with SBC function defined by ITU-T, the SBC is SCPF and BGF; when the communication system is defined for TISPAN For an NGN network with SBC functionality, the SBC is AF and A-BGF. In general, network A is the access network and network B is the core network. Moreover, the access network can access the network for any of a variety of access modes, such as xDSL, Wlan, Cable, WiMax, and other wired and wireless modes. The IP address in the above network can be in the IPv4 address format or the IPv6 address format. The address translation includes address format conversion in various situations such as IPv4-IPv4, IPv4-IPv6, IPv6-IPv6, and IPv6-IPv4.

The media forwarding function entity can be used to forward data packets between the network A and the network B, and can also be used to forward signaling messages between the network A and the signaling control function entity. When the media forwarding function entity first forwards the signaling packet of a user equipment in the network A, that is, the registration request of the user equipment in the network A, the NAT entry of the user equipment signaling packet in the network A needs to be dynamically created. That is, the correspondence between the IP address/port number of the user equipment in the first network and the IP address/port number assigned by the media forwarding function entity itself is used for the received network from the first network or the signaling function control entity. The signaling packet is translated by NAT, and the signaling packet is forwarded. That is, when the media forwarding function entity receives the signaling message that is not sent for the first time in the network A, the device performs the static address translation and then forwards the message to the message according to the NAT entry of the signaling message. The control function entity; when the media forwarding function entity receives the signaling message from the signaling control function entity, the signaling message is also subjected to static address translation, and then forwarded to the media forwarding function entity. At the same time, media forwarding The mapping between the signaling address on the media forwarding packet and the address of the signaling control function entity is configured in the entity to be used to convert the signaling sent by the user equipment in the network A. The destination address, or the source address of the packet sent by the signaling control function entity.

 The signaling control function entity is configured to analyze and process the received signaling message, and perform signaling interaction with the functional entity in the network B. After receiving the signaling message of the registration request forwarded by the media forwarding function entity, the signaling control function entity obtains the user identity identifier in the information packet, and saves the user identity identifier and the source IP address/port in the signaling packet. The correspondence between the numbers, where the source IP address/port number is the IP address/port number assigned by the media forwarding function entity itself. Thereafter, after receiving the signaling message sent by the functional entity in the network B to the user equipment in the first network, the signaling control function entity may obtain the user identity from the signaling message, and obtain the user identity and Corresponding relationship between the source address and the port number, obtaining the IP address/port number assigned by the media forwarding function entity corresponding to the user identity, and then according to the IP address

/port number forwards the signaling message to the media forwarding function entity.

 As shown in FIG. 7, the specific steps of the method of the present invention are as follows: Step 701: The user equipment in the network A sends a signaling message of the registration request to the media forwarding function entity, where the signaling packet includes the access. Request information and user information, and the destination IP address of the signaling message is the IP address of the media forwarding function entity, and the source IP address is the IP address of the user equipment in the network A.

Steps 702 to 703: After receiving the signaling packet, the media forwarding function entity obtains the source IP address/port number and the destination IP address/port number of the signaling packet, and allocates a media forwarding function entity's own IP address. /port number, and then dynamically create a NAT entry for the signaling packet of the user equipment, where the entry is the IP address/port number of the user equipment in network A and the IP address/port assigned by the media forwarding function entity itself. The source IP address/port number of the signaling packet is set to the media forwarding function according to the NAT entry of the signaling packet. The IP address/port number assigned by the user; and the mapping relationship between the IP address/port number of the first network and the IP address/port number of the signaling control function entity is obtained according to the pre-set mapping relationship of the IP address/port number of the signaling control function entity. The IP address/port number is converted into the IP address/port number of the signaling control function entity, and the signaling message is forwarded to the signaling control function entity.

 Steps 704 to 705: After receiving the signaling, the signaling control function entity parses and processes the signaling packet, and obtains the user identity and the source IP address/port number. The source IP address is the media forwarding function. The IP address/port number of the entity is used to store the correspondence between the user identity and the IP address assigned by the media forwarding function entity, and the signaling message is sent to the functional entity in the network B.

 Step 706: After receiving the signaling packet, the device in the network B authenticates the user equipment according to the user identity contained therein, and if the authentication succeeds, sends a response message to the signaling control function entity. If the authentication fails, the packet is sent to the signaling function control entity.

 Steps 707 - 708: After receiving the response signaling packet, the signaling control function entity obtains the user identity identifier, and obtains the media forwarding function entity corresponding to the user identity identifier according to the corresponding relationship in step 704. IP address/port number, and then set the destination IP address of the signaling packet to the IP address/port number of the media forwarding function entity, and the source IP address/port number is the IP address of the signaling control function entity itself. The signaling message is sent to the media forwarding function entity.

Step 709 710: After receiving the signaling packet, the media forwarding function entity obtains the source IP address of the signaling packet, that is, the IP address/port number of the signaling control function entity, and performs the signaling according to step 702. The NAT entry of the packet is obtained by obtaining the IP address/port number of the user equipment in the network A corresponding to the IP packet of the signaling control function entity, and then modifying the destination IP address of the signaling packet to the user equipment in the network A. IP address/port number, and then pre-set according to itself The media forwarding function entity has a mapping relationship between the IP address/port number of the first network and the IP address/port number of the signaling control function entity, and the source IP address/port number is changed to its own media forwarding function entity at the first The IP address/port number in the network, and the signaling message is sent to the user equipment in the first network end.

 In addition, in step 707, if the response signaling packet received by the signaling control function entity is a signaling message for successful authentication, the signaling control function entity needs to notify the media forwarding function entity to permanently save and maintain the user equipment. Corresponding NAT entry, that is, the correspondence between the IP address/port number of the media forwarding function entity and the IP address/port number of the signaling control function entity, until the user logs out, the signaling control function entity notifies the media forwarding function entity to delete This entry. If the response signaling packet is a signaling packet that fails to be authenticated, the signaling control function entity notifies the media forwarding function entity to delete the NAT entry of the signaling packet corresponding to the user equipment.

 Of course, in the actual operation, for example, in step 704, the media forwarding function entity may send a signaling message to the functional entity in the network B, and may start a timer, if the timer expires before the timer expires. If the notification packet of the authentication succeeded by the signaling control function entity is not received, the NAT entry corresponding to the user equipment is deleted after the timer expires. Of course, after the media forwarding function entity receives the command for the user to log off sent by the signaling control function entity, the NAT entry of the signaling packet needs to be deleted.

 After the registration is successful, the session request may be further accepted or initiated, such as performing step 711 to step 715 and/or step 716 to step 719. It should be noted that the processes of step 711 to step 715 and the processes of step 716 to step 719 are independent of each other, and only one of the processes may be executed, or two processes may be executed, and there is no prioritization between them. Describe these two processes.

Steps 711 to 715: The function entity in the network B sends signaling packets in the network through the signaling control function entity, the media forwarding function entity, and the user equipment in the network A. In this case, the signaling control function entity needs to obtain the media corresponding to the user identity carried in the signaling message. The IP address of the physical forwarding function entity. In the media forwarding function entity, the signaling packet is translated according to the NAT entry of the signaling packet and then sent out. This is the same as steps 706 ~ 710. .

 Steps 716 ~ 719: After the user equipment in the network A sends the signaling message for the first time, that is, accesses the request packet, and obtains the response signaling packet for successful authentication, it needs to interact with the network B again. The user equipment in the medium may perform signaling interaction with the functional entity in the network B through the media forwarding function entity and the signaling control function entity. At this time, the source IP address/port number of the media forwarding function entity conversion signaling needs to be implemented by using a NAT entry, and the destination IP address/port number needs to be searched for the media forwarding function entity configured in the media forwarding entity in the first network. The IP address/port number is mapped to the IP address/port number of the signaling control function entity. The IP address/port number of the corresponding signaling control function entity is obtained.

In addition, if the NAT entry of the signaling packet is set to include the correspondence between the IP address/port number of the user equipment in the first network and the IP address/port number assigned by the media forwarding function entity, and the first The mapping between the IP address/port number of the network and the IP address of the signaling control function entity. Then, after the user has successfully registered, the signaling message between the user equipment and the signaling control function entity in the first network reaches the media forwarding function entity, and the media forwarding function entity can use the NAT of the signaling packet. After the NAT entry is translated, the entry is sent to the signaling control function entity or the user equipment in the first network. The following is as follows: The user equipment sends a signaling message to the media forwarding function entity in the network A. The destination IP address/port number of the IP packet is the IP address/port number of the media forwarding function entity, and the source IP address/port number is The IP address/port number of the user equipment in the network A. The media forwarding function entity directly uses the NAT entry of the signaling packet to perform a static NAT address translation on the signaling packet, that is, the Transmitting the destination IP address of the packet to the IP address/port number of the signaling control function entity, converting the source IP address/port number to the IP address of the media forwarding function entity, and using the destination IP address/port number Signaling packets are forwarded to signaling control functions Can be an entity. After receiving the signaling packet, the signaling control function entity parses and processes the signaling packet, and determines the correspondence between the user identity identifier and the IP address/port number of the media forwarding function entity, that is, the user The device has been successfully registered, so the signaling message is sent directly to the functional entity in network B.

 As shown in the foregoing process, in this embodiment, the address of the SBC signaling control function entity configured by the access user is an address on the media forwarding function entity, and the access signaling flow passes through the media forwarding function entity, so the SBC letter The control function entity only needs to have a domain address, such as an administrative domain or an address domain address. And after the user equipment is successfully registered, the NAT entry of the signaling packet that has been established on the media forwarding function entity is used as a signaling channel to initiate or accept a call, and the network A is seen in the signaling control function entity. The user address/port number will also be the address/port information on the media forwarding function entity.

 In addition, when the signaling static transformation entity is an independent independent entity, the implementation process is the same as that in the foregoing embodiment, and details are not described herein again.

 In summary, the above description is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim  A method for transmitting a signaling message in a communication system having a session border controller SBC, the communication system comprising at least a first network, a second network, and an SBC, and the SBC includes at least signaling static Transforming functional entities and signaling control functional entities, the method comprising the steps of:  A. The user equipment in the first network sends a signaling message of the registration request to the signaling static transformation function entity, where the destination IP address/port number of the signaling packet is a signaling static transformation function entity in the first network. IP address/port number, source IP address/port number is the IP address/port number of the user equipment in the first network;  After receiving the signaling message of the user equipment, the signaling static conversion function entity modifies the destination IP address/port number of the signaling packet to the IP address/port number of the signaling control function entity, and the source IP address. /port number is modified to the IP address assigned by the signaling static conversion function entity /port number, and the signaling message is sent to the signaling control function entity;  After receiving the signaling packet, the signaling control function entity analyzes and processes the signaling packet, and sends the signaling packet to the functional entity in the second network.  The method according to claim 1, wherein the step B further comprises: b. setting a network address translation NAT entry of the signaling packet of the user equipment, where the entry is the user equipment in the first network The correspondence between the IP address/port number in the IP address/port number assigned by the signaling static conversion function entity itself.  The method according to claim 2, wherein the step of setting the NAT entry of the signaling packet of the user equipment in step B1 includes:  After receiving the signaling packet of the user equipment, the signaling static conversion function entity obtains the source IP address/port number in the signaling packet; B12. The signaling static transformation function entity allocates a signaling static transformation to the user equipment. IP address/port number of the functional entity, and save the IP address of the user equipment in the first network The correspondence between the port number and the _IP address/port number assigned by the signaling static conversion function entity.  The method of claim 2, wherein: the IP address/port number of the signaling control function entity in step B is determined by using a destination IP address/port number in the signaling packet. The signaling static transformation function entity is obtained in the mapping relationship between the IP address/port number of the first network and the IP address of the signaling control function entity.  The method according to claim 4, wherein: the mapping relationship between the IP address/port number of the first network and the IP address of the signaling control function entity of the signaling static conversion function entity is preset in signaling In the static transformation function entity, or in a functional entity that can communicate with the signaling static transformation function entity.  The method according to claim 5, wherein: the mapping relationship between the IP address/port number of the first network and the IP address of the signaling control function entity is randomly configured by the signaling static conversion function entity, Or configured according to a certain algorithm, or configured according to a predefined mechanism.  The method of claim 2, wherein the step C further comprises: the Cl, the signaling control function entity receiving the signaling message, obtaining the user identity identifier and the signaling message in the signaling message Source IP address/port number, the source IP address/port number is an IP address/port number assigned by the signaling static conversion function entity, and the signaling control function entity records the user identity and the signaling static Change the correspondence between the IP address/port number assigned by the function entity itself.  8. The method of claim 2, further comprising: after step C, further comprising: If the signaling control function entity receives the response signaling packet for successful authentication of the second network function entity, the notification signaling static transformation function entity is successfully authenticated, and the signaling static transformation function is implemented. Permanently maintaining the NAT entry of the signaling message;  If the signaling control function entity receives the response signaling packet of the authentication failure of the second network function entity, the notification signaling static transformation function entity fails to authenticate, and the signaling static transformation function entity deletes the signaling message. NAT entry.  The method according to claim 2, wherein: when the signaling message is sent to the signaling control function entity in step B, the method further includes:  The timer is started, and if the signaling static conversion function entity receives the notification of successful authentication sent by the signaling control function entity before the timer expires, the timer is cancelled, and the subsequent processing steps are continued, if the timer expires before the timer expires. If the notification that the authentication succeeds is not received, the signaling static transformation function entity deletes the corresponding NAT entry.  10. The method according to claim 9, wherein after the step C, the method further comprises: after the signaling control function entity receives the command to cancel the user from the second network, and performs static conversion to the signaling. The function entity sends a command to delete the signaling NAT entry of the user. After receiving the command, the signaling static transformation function entity deletes the NAT entry of the signaling packet of the user equipment.  11. The method according to claim 7, wherein after step C, further comprising:  The Dll, the signaling control function entity receives the signaling packet of the functional entity in the second network, analyzes and processes the signaling packet, and obtains the user identity identifier from the signaling packet, according to the corresponding description in step C1. Obtaining, obtaining an IP address/port number of the signaling static conversion function entity corresponding to the user identity, and forwarding the signaling packet to the signaling static transformation function entity according to the IP address/port number; D12. The signaling static conversion function entity uses the signaling message NAT entry to perform NAT address translation on the signaling packet from the signaling control function entity, and sends the signaling message after the translated address to the first network. The user device in . 12. The method according to claim 7, wherein after the step C, the method further comprises:  D21. The user equipment sends a signaling packet to the signaling static transformation function entity in the first network.  D22. The signaling static conversion function entity performs static NAT address translation on the source and destination address/port number of the signaling packet according to the NAT entry of the signaling packet, and forwards the signaling packet to the signaling packet. Signaling control function entity;  After receiving the signaling packet, the signaling control function entity parses and processes the signaling packet, and after determining that the user equipment has successfully registered, sends the signaling packet to the second network. Functional entity.  The method according to claim 2, wherein the step B further comprises: B2, setting a NAT entry of the signaling packet of the user equipment, where the entry is an IP of the user equipment in the first network. The mapping between the address/port number and the IP address/port number assigned by the signaling static conversion function entity, and the mapping relationship between the IP address/port number of the first network and the IP address of the signaling control function entity.  The method according to claim 13, wherein after the step C, the signaling static conversion function entity receives the signaling message of the user equipment or the signaling control function entity in the first network, and uses the steps. After the NAT entry is forwarded by the NAT entry, the signaling entry is sent to the signaling control function entity or the user equipment in the first network.  15. The method of claim 1 wherein: The communication system is a SBC communication defined in the Next Generation Network NGN standard defined by the International Telecommunication Union ITU-T, the telecommunication and Internet convergence service and the advanced network protocol TISPAN, or the SBC communication defined in the Internet Working Group IETF Network, when the communication system is an ITU-T defined SGN-enabled NGN network, the SBC is a service control proxy function SCPF and a border gateway function BGF; When the communication system is an SBC-enabled NGN network defined by TISPAN, the SBC is an application function AF and an access border gateway function A-BGF. When the AF is an IP multimedia subsystem IMS, the AF is a proxy call session control function P. -CSCF;  The first network is an access network, and the access network is a network of a plurality of digital subscriber lines xDSL, a wireless local area network Wlan, a cable cable, and a global microwave access interoperation WiMax access method;  The first network adopts an Internet Protocol version 4 IPv4 address format or an Internet Protocol version 6 IPv6 address format.  The second network adopts an IPv4 address format or an IPv6 address format.  The method according to any one of claims 1 to 15, wherein the signaling static transform function entity is set in a media forwarding function entity in the SBC or is an independent physical entity.  A communication system having an SBC, the system comprising at least a first network, a second network, and an SBC, wherein: the SBC includes at least a signaling static transformation function entity and a signaling control function entity, and a signaling static transformation The functional entity is connected to the first network and the signaling control function entity, and the signaling control function entity is connected to the second network and the signaling static transformation function entity, where  The signaling static conversion function entity is configured to receive a signaling message of the user equipment in the first network, and modify the destination IP address/port number of the signaling packet to an IP address/port number of the signaling control function entity, The source IP address/port number is modified to the IP address/port number assigned by the signaling static conversion function entity, and the signaling message is sent to the signaling control function entity;  The signaling control function entity is configured to receive the signaling packet of the signaling static transformation function entity, analyze the processing of the signaling packet, and send the signaling packet to the functional entity in the second network. 18. The system of claim 17 wherein: The signaling static conversion function entity is further configured to: after receiving the signaling message of the first network user equipment for the first time, obtain the source IP address/port number of the signaling packet, and select signaling control for the user equipment. The IP address/port number of the functional entity, the source IP address/port number is the IP address/port number of the user equipment in the first network, and the IP address/port number of the user equipment in the first network is set and The correspondence between the IP address/port number assigned by the signaling static conversion function entity itself,  The signaling control function entity is further configured to: after receiving the signaling message of the signaling static conversion function entity for the first time, save the source IP address of the user identity identifier and the signaling packet carried in the signaling packet/ The source IP address/port number is the IP address/port number assigned by the signaling static conversion function entity itself.  19. The system of claim 18, wherein:  The signaling static conversion function entity is further configured to: when not receiving the signaling message of the first network user equipment for the first time, according to the IP address/port number and signaling static of the user equipment in the first network The corresponding relationship between the IP address and the port number assigned by the function entity is changed, the signaling packet is statically translated, and the converted signaling packet is sent to the signaling control function entity.  20. The system of claim 18, wherein:  The signaling control function entity is further configured to receive a signaling message from the second network, and determine a corresponding static signaling transformation according to a correspondence between the user identity and the source IP address/port number saved by the user. The IP address/port number assigned by the function entity itself, and the signaling packet is sent to the signaling static transformation function entity;  The signaling static conversion function entity is further configured to receive a signaling message from the signaling control function entity, and convert the address of the signaling message according to the NAT entry of the signaling message saved by itself. Then sent to the user equipment of the second network. 21. The system of claim 17 wherein: The communication system is an NGN network with SBC function defined by ITU-T, TISPAN, or an SBC communication network defined in the IETF,  When the communication system is an ITU-T defined SGN-enabled NGN network, the SBC is SCPF and BGF;  When the communication system is an SGN-enabled NGN network defined by TISPAN, SBC is AF and A-BGF;  The access network is a network of xDSL, Wlan, Cable, WiMax and wireless access methods.  The system according to any one of claims 17 to 21, wherein: the signaling static transformation function entity is a logical entity in a media forwarding function entity in the SBC, or an independent physical entity.