CN103414798B - The communication means of address transition Network Based, equipment and system - Google Patents

Abstract

The present invention provides a communication method, device and system based on network address translation, wherein the method includes: after receiving a registration message sent by a mobile terminal through a NAT traversal server, including address information, a port identifier and a session identifier, obtaining the first mobile terminal and the second mobile terminal with the same session ID and port ID, and store the mapping of the session ID, the port ID, the address information of the first mobile terminal and the address information of the second mobile terminal relationship, to replace the source address information of the communication packet sent by the first mobile terminal or the second mobile terminal, including the session identifier and the port identifier, with the port identifier and its own IP address according to the mapping relationship, and It is sent to the second mobile terminal or the first mobile terminal, thereby improving the utilization efficiency of the NAT traversal server and meeting the needs of existing communication.

Description

Communication method, device and system based on network address translation

technical field

The embodiments of the present invention relate to the technical field of communication, and in particular, to a communication method, device and system based on network address translation.

Background technique

With the popularity of the mobile Internet, most mobile terminals have the ability to access the Internet. Due to the depletion of public network IP addresses, the mobile terminal accesses the Internet through its own corresponding Network Address Translation (NAT) device according to the private network IP address assigned by the operator, thus causing the mobile terminal not to It has the ability to address the whole network. Therefore, when mobile terminals A and B are in different private networks, because they cannot obtain the public network IP address of the other party, communication and interaction between A and B cannot be performed through IP, such as: transmitting voice, audio, Multimedia data such as video has certain limitations.

Therefore, in order to solve the above problem, the NAT traversal server assigns the first port in the idle state to mobile terminals A and B for communication interaction between mobile terminals A and B, however, communication interaction between mobile terminals A and B During the process, the port will not be occupied throughout the process, and the utilization rate is very low, which cannot meet the existing communication needs. In the prior art, the NAT traversal server also restores the first port before the communication interaction between mobile terminals A and B ends. It is allocated to the remaining pairs of mobile terminals with communication interaction requirements.

However, in the prior art, the first port is assigned to many pairs of different mobile terminals for communication such as mobile terminals A and B, mobile terminals C and D, and for assigning the first port to the same mobile terminal to communicate with other mobile terminals respectively During communication, such as the communication interaction between mobile terminals A and B, mobile terminals A and D, how the NAT traversal server performs conversion processing, there is an urgent need for a corresponding processing method to further improve the utilization efficiency of the NAT traversal server.

Contents of the invention

In view of the above-mentioned defects in the prior art, embodiments of the present invention provide a communication method, device and system based on network address translation.

One aspect of the present invention provides a communication method based on network address translation, including:

The network address translation NAT traversal server receives the registration message sent by the mobile terminal, and the registration message includes address information, port identification and session identification;

The NAT traversal server obtains the first mobile terminal and the second mobile terminal having the same session ID and port ID, and stores the session ID, the port ID, the address information of the first mobile terminal, and the second mobile terminal The mapping relationship of the address information of the mobile terminal, according to the mapping relationship, the source address information of the communication message sent by the first mobile terminal or the second mobile terminal and including the session identifier and the port identifier Replace it with the port identifier and its own IP address, and send it to the second mobile terminal or the first mobile terminal.

Another aspect of the present invention provides a communication method based on network address translation, including:

The first mobile terminal obtains the IP address and port identifier of the network address translation NAT traversal server occupied by the communication interaction with the second mobile terminal, and the session identifier corresponding to the communication interaction;

The first mobile terminal sends a registration message to the NAT traversal server corresponding to the IP address, and the registration message includes its own address information, the port identifier and the session identifier, so that the NAT traversal server according to The registration message sent by the second mobile terminal, including the port identifier, the session identifier and the address information of the second mobile terminal, stores the session identifier, the port identifier, the first mobile The mapping relationship between the address information of the terminal and the address information of the second mobile terminal, and according to the mapping relationship, the information sent by the first mobile terminal or the second mobile terminal, including the session identifier and the port The source address information of the identified communication message is replaced with the port identifier and the IP address, and sent to the second mobile terminal or the first mobile terminal.

Another aspect of the present invention provides a network address translation traversal server, including:

A receiving module, configured to receive a registration message sent by a mobile terminal, where the registration message includes address information, a port identifier and a session identifier;

A processing module, configured to obtain a first mobile terminal and a second mobile terminal having the same session ID and port ID, and store the session ID, the port ID, the address information of the first mobile terminal, and the second mobile terminal The mapping relationship of the address information of the mobile terminal, according to the mapping relationship, the source address information of the communication message sent by the first mobile terminal or the second mobile terminal and including the session identifier and the port identifier Replace it with the port identifier and its own IP address, and send it to the second mobile terminal or the first mobile terminal.

Another aspect of the present invention provides a mobile terminal, including:

An acquisition module, configured to acquire the IP address and port identifier of the NAT traversal server occupied by the communication interaction with the second mobile terminal, and the session identifier corresponding to the communication interaction;

A registration module, configured to send a registration message to the NAT traversal server corresponding to the IP address, the registration message including its own address information, the port identifier and the session identifier, so that the NAT traversal server can A registration message sent by the second mobile terminal that includes the port identifier, the session identifier, and address information of the second mobile terminal, and stores the session identifier, the port identifier, and the first mobile terminal The mapping relationship between the address information of the second mobile terminal and the address information of the second mobile terminal, and according to the mapping relationship, send the first mobile terminal or the second mobile terminal, including the session identifier and the port identifier The source address information of the communication message is replaced by the port identifier and the IP address, and sent to the second mobile terminal or the first mobile terminal.

Another aspect of the present invention provides a communication system based on network address translation, including: the above-mentioned network address translation traversal server, a first mobile terminal and a second mobile terminal, wherein the first mobile terminal is the above-mentioned mobile terminal.

Another aspect of the present invention provides a communication system based on network address translation, including: the above-mentioned network address translation traversal server, a session initiation protocol SIP server, a first mobile terminal and a second mobile terminal belonging to the SIP server, Wherein, the first mobile terminal is the mobile terminal described in the claims.

According to the communication method, device and system based on network address translation provided by the embodiments of the present invention, after receiving the registration message sent by the mobile terminal through the NAT traversal server, including address information, port identification and session identification, the registration message with the same session identification and port identification is obtained. identify the first mobile terminal and the second mobile terminal, and store the mapping relationship between the session identifier, the port identifier, the address information of the first mobile terminal, and the address information of the second mobile terminal, so that according to the mapping The relationship is to replace the source address information of the communication packet sent by the first mobile terminal or the second mobile terminal, including the session identifier and the port identifier, with the port identifier and its own IP address, and send it to the second mobile terminal. The second mobile terminal or the first mobile terminal, thereby improving the utilization efficiency of the NAT traversal server and meeting the needs of existing communication.

Description of drawings

FIG. 1 is a flowchart of a communication method based on network address translation provided by an embodiment of the present invention;

FIG. 2 is a flowchart of another communication method based on network address translation provided by an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a network address translation traversal server provided by an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a mobile terminal provided by an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a communication system based on network address translation provided by an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of another communication system based on network address translation provided by an embodiment of the present invention.

detailed description

Fig. 1 is a flowchart of a communication method based on network address translation provided by an embodiment of the present invention. As shown in Fig. 1, the method includes:

Step 100, the network address translation NAT traversal server receives the registration message sent by the mobile terminal, and the registration message includes address information, port identification and session identification;

When two mobile terminals under different private networks perform IP communication, first negotiate the IP address of the NAT traversal server occupied by the two mobile terminals for communication interaction and the port identifier of the port on the NAT traversal server, and obtain the IP address of the port on the NAT traversal server. The corresponding session identification is communicated and exchanged, and then each mobile terminal sends a registration message to the NAT traversal server, and the registration message includes the address information, port identification and session identification of the mobile terminal. Wherein, the address information of the mobile terminal refers to the IP address of the mobile terminal. It should be noted that the IP address and port identifier of the NAT traversal server occupied by the two mobile terminals for communication interaction are negotiated, and the session identifier corresponding to the communication interaction is obtained. There are many ways, examples are as follows:

Method 1: After negotiating an idle port with the NAT traversal server through the NAT gateway where it is located, one mobile terminal notifies the other party that communicates and interacts with it through the mobile switching network of the IP address of the NAT traversal server and the port identifier corresponding to the idle port. The mobile terminal, after confirming that another mobile terminal has received the IP address and port identifier of the NAT traversal server, generates a session identifier corresponding to the communication interaction and sends it to another mobile terminal through the mobile switching network. Method 2: After the SIP server and the NAT traversal server have negotiated an idle port, the IP address of the NAT traversal server and the port identifier corresponding to the idle port are notified to the mobile terminal for communication and interaction through a SIP message. After NAT traversing the IP address and port identifier of the server, a session identifier corresponding to the communication interaction is generated and sent to the mobile terminal through a SIP message.

Step 101, the NAT traversal server obtains the first mobile terminal and the second mobile terminal having the same session ID and port ID, and stores the session ID, the port ID, the address information of the first mobile terminal and the The mapping relationship of the address information of the second mobile terminal, so that according to the mapping relationship, the communication message sent by the first mobile terminal or the second mobile terminal and including the session identifier and the port identifier The source address information is replaced with the port identifier and its own IP address, and sent to the second mobile terminal or the first mobile terminal.

The NAT traversal server analyzes the received registration message to obtain the address information, port ID and session ID of the mobile terminal, and then compares the port ID and session ID in each registration message to obtain the first mobile terminal with the same session ID and port ID. A mobile terminal and a second mobile terminal, and store the mapping relationship between the session identifier, the port identifier, the address information of the first mobile terminal and the second mobile terminal, and then according to the mapping relationship, the first mobile terminal or the second mobile terminal The sent communication message is forwarded, so as to complete the communication process. Specifically: when the NAT traversal server receives the communication message sent by the first mobile terminal or the second mobile terminal, including the session identifier and the port identifier, it receives the communication message through the port corresponding to the port identifier, and according to the mapping The relationship obtains the address information corresponding to the session identifier and the port identifier, and the address information of the two parties performing communication interaction, that is, the address information of the first mobile terminal and the second mobile terminal, and then the source of the first mobile terminal or the second mobile terminal The address information is replaced with the port identifier and the IP address of the NAT traversal server itself, and the processed communication message is sent to the second mobile terminal or the first mobile terminal according to the address information of the received communication message.

In the communication method based on network address translation provided in this embodiment, after receiving the registration message sent by the mobile terminal through the NAT traversal server, including address information, port identification and session identification, the first mobile terminal with the same session identification and port identification is obtained. terminal and a second mobile terminal, and store the mapping relationship between the session identifier, the port identifier, the address information of the first mobile terminal and the address information of the second mobile terminal, so as to move the first mobile terminal according to the mapping relationship The source address information of the communication packet sent by the terminal or the second mobile terminal, including the session identifier and the port identifier, is replaced with the port identifier and its own IP address, and sent to the second mobile terminal or the port identifier. The first mobile terminal described above improves the utilization efficiency of the NAT traversal server and meets the needs of existing communication.

Fig. 2 is a flowchart of another communication method based on network address translation provided by an embodiment of the present invention. As shown in Fig. 2, the method includes:

Step 200, the first mobile terminal acquires the IP address and port identifier of the Network Address Translation NAT traversal server occupied by the communication interaction with the second mobile terminal, and the session identifier corresponding to the communication interaction;

When a first mobile terminal needs to perform IP communication with a second mobile terminal that is in a different private network, the first mobile terminal first needs to obtain the IP address of the NAT traversal server used for communication and interaction with the second mobile terminal and a port identifier, and a session identifier corresponding to the communication interaction, where it should be noted that the first mobile terminal obtains the IP address and port identifier of the NAT traversal server, and obtains the session identifier corresponding to the communication interaction Many, as illustrated below:

Mode 1, after the second mobile terminal negotiates an idle port with the NAT traversal server through its own NAT gateway, the IP address of the NAT traversal server and the port identifier corresponding to the idle port are sent to the first mobile terminal through the mobile switching network, After receiving the confirmation response returned by the first mobile terminal receiving the IP address and port identifier of the NAT traversal server, generate a session identifier corresponding to the communication interaction and send it to the first mobile terminal through the mobile switching network. Mode 2: After the SIP server and the NAT traversal server have negotiated an idle port, the IP address of the NAT traversal server and the port identifier corresponding to the idle port are notified by a SIP message to the first mobile terminal and the second mobile terminal for communication interaction, Then the SIP server generates a session identifier corresponding to the communication interaction. When the SIP server receives the first mobile terminal or the second mobile terminal receives the confirmation response returned by the NAT traversal server's IP address and port identifier, the SIP server sends the session The identifier is sent to the mobile terminal sending the confirmation response through the SIP message.

Step 201, the first mobile terminal sends a registration message to the NAT traversal server corresponding to the IP address, the registration message includes its own address information, the port identifier and the session identifier, so that the NAT After receiving the registration message sent by the second mobile terminal and including the port identifier, the session identifier and the address information of the second mobile terminal, the traversal server, according to the first mobile terminal and the second mobile terminal, The registration message sent by the second mobile terminal stores the mapping relationship between the session identifier, the port identifier, the address information of the first mobile terminal, and the address information of the second mobile terminal, and stores the mapping relationship according to the mapping relationship The source address information of the communication packet sent by the first mobile terminal or the second mobile terminal and including the session identifier and the port identifier is replaced by the port identifier and the IP address, and sent to the The second mobile terminal or the first mobile terminal.

After the first mobile terminal obtains the IP address and port identifier of the NAT traversal server occupied by the communication interaction with the second mobile terminal, and the session identifier corresponding to the communication interaction, it sends a message to the NAT traversal server corresponding to the IP address. A registration message, the registration message includes its own address information, the port identifier and the session identifier, so that the NAT traversal server parses the received registration message to obtain the address information, the port identifier and the first mobile terminal Session ID, when the NAT traversal server receives the registration message sent by the second mobile terminal, it can learn that the session ID and port ID in the registration message sent by the second mobile terminal are the same as those in the registration message sent by the first mobile terminal. The session identifier and port identifier are the same, and store the mapping relationship between the session identifier, the port identifier, the address information of the first mobile terminal and the second mobile terminal, and then send the first mobile terminal or the second mobile terminal according to the mapping relationship The communication message is forwarded and processed to complete the communication process. Specifically: when the NAT traversal server receives the communication message sent by the first mobile terminal or the second mobile terminal, including the session identifier and the port identifier, it receives the communication message through the port corresponding to the port identifier, and according to the mapping The relationship obtains the address information corresponding to the session identifier and the port identifier, the address information of the two parties performing communication interaction, that is, the address information of the first mobile terminal and the second mobile terminal, and then the source of the first mobile terminal or the second mobile terminal The address information is replaced with the port identifier and the IP address of the NAT traversal server itself, and the processed communication message is sent to the second mobile terminal or the first mobile terminal according to the address information of the received communication message.

In the communication method based on network address translation provided in this embodiment, the first mobile terminal acquires the IP address and port identifier of the network address translation NAT traversal server occupied by the communication interaction with the second mobile terminal, and corresponds to the communication interaction After the session identification of the IP address, send a registration message including its own address information, port identification and session identification to the NAT traversal server corresponding to the IP address, so that the NAT traversal server will receive the second mobile terminal after receiving the registration message including the port identification. , the session identifier and the registration message of the address information of the second mobile terminal, store the session identifier and the port identifier according to the registration messages sent by the first mobile terminal and the second mobile terminal , the mapping relationship between the address information of the first mobile terminal and the address information of the second mobile terminal, and according to the mapping relationship, the information sent by the first mobile terminal or the second mobile terminal, including the The source address information of the communication packet of the session identifier and the port identifier is replaced with the port identifier and the IP address, and sent to the second mobile terminal or the first mobile terminal. Therefore, the utilization efficiency of the NAT traversal server is improved, and the needs of existing communication are met.

Those of ordinary skill in the art can understand that all or part of the steps for realizing the above-mentioned method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the It includes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes.

FIG. 3 is a schematic structural diagram of a NAT traversal server provided by an embodiment of the present invention. As shown in FIG. 3 , the NAT traversal server includes: a receiving module 11 and a processing module 12, wherein the receiving module 11 is used to receive The registration message sent by the terminal, the registration message includes address information, port identification and session identification; processing module 12 is used to acquire the first mobile terminal and the second mobile terminal with the same session identification and port identification, and store the A mapping relationship between the session identifier, the port identifier, the address information of the first mobile terminal, and the address information of the second mobile terminal, so that the first mobile terminal or the second mobile terminal can be connected according to the mapping relationship The source address information of the communication message sent by the terminal, including the session identifier and the port identifier, is replaced with the port identifier and its own IP address, and sent to the second mobile terminal or the first mobile terminal .

For the functions and processing flow of each module in the NAT traversal server provided by this embodiment, refer to the method embodiment shown in FIG. 1 above. The implementation principles and technical effects are similar and will not be repeated here.

FIG. 4 is a schematic structural diagram of a mobile terminal provided by an embodiment of the present invention. As shown in FIG. 4 , the mobile terminal includes: an acquisition module 21 and a registration module 22, wherein the acquisition module 21 is used to acquire and communicate with a second mobile terminal. The IP address and port identifier of the network address translation NAT traversal server occupied by the interaction, and the session identifier corresponding to the communication interaction; the registration module 22 is used to send a registration message to the NAT traversal server corresponding to the IP address, so The registration message includes its own address information, the port identifier and the session identifier, so that the NAT traversal server sends the second mobile terminal according to the port identifier, the session identifier and the second A registration message of the address information of the second mobile terminal, storing the mapping relationship between the session identifier, the port identifier, the address information of the first mobile terminal and the address information of the second mobile terminal, and according to the mapping The relationship is to replace the source address information of the communication packet sent by the first mobile terminal or the second mobile terminal and including the session identifier and the port identifier with the port identifier and the IP address, and send to the second mobile terminal or the first mobile terminal.

Wherein, the acquisition module 21 acquires the IP address and the port identifier of the network address translation NAT traversal server occupied by the communication interaction with the second mobile terminal, and there are many ways of the session identification corresponding to the communication interaction, examples are as follows:

Way 1, the acquiring module 21 is specifically used for:

receiving the IP address of the NAT traversal server and the port identifier sent by the second mobile terminal through the mobile switching network, and returning a confirmation response to the second mobile terminal;

receiving the session identifier sent by the second mobile terminal through the mobile switching network, wherein the session identifier is generated after the second mobile terminal receives the confirmation response.

Method 2, the acquisition module 21 is specifically used for:

receiving the IP address of the NAT traversal server and the port identifier sent by the SIP server through the SIP message, and returning an acknowledgment response to the SIP server;

receiving the session identifier sent by the SIP server through a SIP message, wherein the session identifier is generated by the SIP server after receiving the confirmation response.

For the functions and processing flow of each module in the mobile terminal provided in this embodiment, refer to the method embodiment shown in FIG. 2 above. The implementation principles and technical effects are similar, and will not be repeated here.

FIG. 5 is a schematic structural diagram of a network address translation-based communication system provided by an embodiment of the present invention. As shown in FIG. 5 , the system includes: a network address translation traversal server 1, a first mobile terminal 2 and a second mobile terminal 3, Among them, the NAT traversal server 1 is the NAT traversal server provided by the embodiment of the present invention, and the first mobile terminal 2 receives the network address occupied by the second mobile terminal 3 for communication and interaction with the second mobile terminal sent by the second mobile terminal 3 through the mobile switching network. The address translation NAT traverses the server's IP address and port identifier, and the session identifier corresponding to the communication interaction.

For the functions and processing flow of each module in the network address translation-based communication system provided by this embodiment, refer to the above-mentioned method embodiment. The implementation principles and technical effects are similar, and will not be repeated here.

Fig. 6 is a schematic structural diagram of another communication system based on network address translation provided by an embodiment of the present invention. As shown in Fig. 6, the system includes: a network address translation traversal server 4, a session initiation protocol SIP server 5, belonging to the The first mobile terminal 6 and the second mobile terminal 7 of the SIP server 5, wherein the NAT traversal server 4 is the NAT traversal server provided by the embodiment of the present invention, and the first mobile terminal 6 and the second mobile terminal 7 receive SIP The server 5 transmits the IP address and port identifier of the NAT traversal server occupied by the first mobile terminal 6 and the second mobile terminal 7 for the communication interaction between the first mobile terminal 6 and the second mobile terminal 7 through the SIP message, and the session identifier corresponding to the communication interaction.

For the functions and processing flow of each module in the network address translation-based communication system provided by this embodiment, refer to the above-mentioned method embodiment. The implementation principles and technical effects are similar, and will not be repeated here.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (10)

1. a communication means for address transition Network Based, is characterized in that, comprising:

Network address translation NAT passes through the logon message that server mobile terminal receive sends, and described logon message comprises address information, port-mark and session identification;

Described NAT passes through server and obtains first mobile terminal and the second mobile terminal with same session mark and port-mark, and store described session identification, described port-mark, the mapping relations of the address information of described first mobile terminal and the address information of described second mobile terminal, with what described first mobile terminal or described second mobile terminal are sent according to described mapping relations, the source address information comprising the communication message of described session identification and described port-mark replaces with described port-mark and the IP address of self, and send to described second mobile terminal or described first mobile terminal.

2. a communication means for address transition Network Based, is characterized in that, comprising:

First acquisition for mobile terminal and the second mobile terminal network address translation NAT carried out shared by communication interaction pass through IP address and the port-mark of server, and the session identification corresponding with described communication interaction;

Described first mobile terminal passes through server to the NAT corresponding with described IP address and sends logon message, described logon message comprises self address information, described port-mark and described session identification, so that described NAT pass through server according to described second mobile terminal send, comprise described port-mark, the logon message of the address information of described session identification and described second mobile terminal, store described session identification, described port-mark, the mapping relations of the address information of described first mobile terminal and the address information of described second mobile terminal, and according to described mapping relations, described first mobile terminal or described second mobile terminal are sent, the source address information comprising the communication message of described session identification and described port-mark replaces with described port-mark and described IP address, and send to described second mobile terminal or described first mobile terminal.

3. the communication means of address transition Network Based according to claim 2, it is characterized in that, described acquisition and the second mobile terminal network address translation NAT carried out shared by communication interaction pass through IP address and the port-mark of server, and the session identification corresponding with described communication interaction specifically comprises:

Described first mobile terminal receives described second mobile terminal and passes through the IP address of server and described port-mark by the described NAT that mobile switch net sends, and returns confirmation response to described second mobile terminal;

Described first mobile terminal receives the described session identification that described second mobile terminal is sent by mobile switch net, and wherein, described session identification generates after described second mobile terminal receives described confirmation response.

4. the communication means of address transition Network Based according to claim 2, it is characterized in that, described acquisition and the second mobile terminal network address translation NAT carried out shared by communication interaction pass through IP address and the port-mark of server, and the session identification corresponding with described communication interaction specifically comprises:

Described first mobile terminal receives session initiation protocol sip server and passes through the IP address of server and described port-mark by the described NAT that SIP message sends, and returns confirmation response to described sip server;

Described first mobile terminal receives the described session identification that described sip server is sent by SIP message, and wherein, described session identification generates after described sip server receives described confirmation response.

5. a NAT traversing server, is characterized in that, comprising:

Receiver module, for the logon message that mobile terminal receive sends, described logon message comprises address information, port-mark and session identification;

Processing module, for obtaining first mobile terminal and the second mobile terminal with same session mark and port-mark, and store described session identification, described port-mark, the mapping relations of the address information of described first mobile terminal and the address information of described second mobile terminal, with what described first mobile terminal or described second mobile terminal are sent according to described mapping relations, the source address information comprising the communication message of described session identification and described port-mark replaces with described port-mark and the IP address of self, and send to described second mobile terminal or described first mobile terminal.

6. a mobile terminal, is characterized in that, described mobile terminal is the first mobile terminal, comprising:

Acquisition module, for obtaining the IP address and the port-mark that pass through server with the second mobile terminal network address translation NAT carried out shared by communication interaction, and the session identification corresponding with described communication interaction;

Registering modules, logon message is sent for passing through server to the NAT corresponding with described IP address, described logon message comprises self address information, described port-mark and described session identification, so that described NAT pass through server according to described second mobile terminal send, comprise described port-mark, the logon message of the address information of described session identification and described second mobile terminal, store described session identification, described port-mark, the mapping relations of the address information of described first mobile terminal and the address information of described second mobile terminal, and according to described mapping relations, described first mobile terminal or described second mobile terminal are sent, the source address information comprising the communication message of described session identification and described port-mark replaces with described port-mark and described IP address, and send to described second mobile terminal or described first mobile terminal.

7. mobile terminal according to claim 6, is characterized in that, described acquisition module specifically for:

Receive described second mobile terminal and pass through the IP address of server and described port-mark by the described NAT that mobile switch net sends, and return confirmation response to described second mobile terminal;

Receive the described session identification that described second mobile terminal is sent by mobile switch net, wherein, described session identification generates after described second mobile terminal receives described confirmation response.

8. mobile terminal according to claim 6, is characterized in that, described acquisition module specifically for:

Receive session initiation protocol sip server and pass through the IP address of server and described port-mark by the described NAT that SIP message sends, and return confirmation response to described sip server;

Receive the described session identification that described sip server is sent by SIP message, wherein, described session identification generates after described sip server receives described confirmation response.

9. the communication system of an address transition Network Based, it is characterized in that, comprise: NAT traversing server, the first mobile terminal and the second mobile terminal as claimed in claim 5, wherein, described first mobile terminal is the mobile terminal described in claim 6 or 7.

10. the communication system of an address transition Network Based, it is characterized in that, comprise: NAT traversing server as claimed in claim 5, and session initiation protocol sip server, the first mobile terminal belonging to described sip server and the second mobile terminal, wherein, described first mobile terminal is the mobile terminal described in claim 6 or 8.