A method of sip traversing symmetric NAT devices based on ice

Abstract

The invention discloses a method for traversing a Symmetric NAT (Network Address Translator) device by an SIP (Session Initiation Protocol) based on ICE (Interactive Connectivity Establishment). The method comprises following steps of step S1, collecting candidate addresses by two communication parties; interchanging address information; arranging to form address detection lists according to priorities; step S2, successively carrying out connectivity detection by the two parties; judging whether there is a Symmetric NAT in a located network topology according to whether server mapping candidate addresses are generated in the connectivity detection processes of the address couples from a host address to relay addresses; step S3, determining the source port selection strategy of the Symmetric NAT party; predicting port values distributed by the Symmetric NAT party; and S4, carrying out connectivity detection on the Symmetric NAT party by using the predicted port values. According to the method, the advantages of the ICE are reserved; various NAT environments can be adapted; the characteristics of the NAT itself are utilized; a STUN server does not need to detect the type of the NAT; the defects of the ICE under the Symmetric NAT are overcome skillfully; the service quality is ensured; the topological structure of the existing network is unnecessarily changed; and the NAT traversal flexibility and effectiveness problems can be solved well.

Description

technical field [0001] The invention belongs to the technical field of media data network transmission, and in particular relates to a method for ICE-based SIP traversing Symmetric NAT equipment. Background technique [0002] In recent years, due to the rapid development of Internet technology and smart mobile devices, real-time network audio and video communication VoIP (Voice over IP) has become an indispensable requirement for the development of mobile social networking. However, the use of NAT (Network Address Translator) equipment and technology makes it impossible for SIP to directly traverse NAT to communicate with peers in different LANs, which seriously affects the P2P implementation of audio and video. Therefore, how to effectively traverse Symmetric NAT is an important problem that VoIP P2P faces in the next generation network. Aiming at the problem of SIP-based NAT traversal, many traversal technologies have appeared in the industry, such as STUN or TURN, ICE, U...

AI Technical Summary

Problems solved by technology

In RFC (5389), the capability of NAT type detection has been removed. The main reason is that the current network types are complex. More and more practices have found that under multi-layer NAT, type detection is not always effective. This is bound to will introduce instability

At the same time, the RFC 3489 detection NAT type scheme points out that a STUN server with dual network cards and dual public IPs must be used. Building a STUN server that meets this requirement will undoubtedly increase the cost.

At the same time, when using ICE, there is no need to detect the NAT type in advance, and the clients ignore their respective network topology

In the above solution, for the non-Symmetric NAT network topology that ICE can traverse, it is also necessary to increase the complex NAT type detection process, which will undoubtedly increase unnecessary delay overhead.

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