Design And Implementation Of Streaming Media Transmission System Based On NAT Traversal

With the rapid development of the Internet,streaming media technology is increasingly important.Today,streaming media technology is widely used in video surveillance,live video streaming,short video and many other fields.Network transmission is one of the important parts of streaming media technology.And P2 P is one of the most important network transmission methods.Compared with other methods,P2 P has great advantages because it is directly end-to-end and does not need to be relayed by the server,which reduces the pressure of server and reduces the delay.However,the rapid development of the Internet has also led to the shortage of IP addresses.In order to solve this problem,the IETF proposed NAT technology.NAT technology temporarily solves the problem of insufficient IP address by converting the internal network address to the public network address,but NAT hides the internal network host,thus limiting P2 P communication.Because the existing NAT traversal scheme has the disadvantages of low success rate in symmetric NAT,this paper proposes a new NAT traversal scheme.This scheme has the following advantages:1.The traversal success rate of symmetric NAT is improved,especially for Port Restricted Cone NAT-Incremental Symmetry NAT,Port Restricted Cone NAT-Random Symmetry NAT,Incremental Symmetry NAT-Incremental Symmetry NAT,Random Symmetry NATIncremental Symmetry NAT and Other NAT-Constant Symmetry NAT;2.Different strategies are adopted adaptively in different networks;3.Robust to interference,especially for heavy load NAT;4.Unlike STUN,only one IP address is required in NAT detection.In this paper,a new NAT traversal algorithm is implemented on the embedded ARM system and PC.The experimental results show that the new NAT traversal scheme has higher success rate and stronger anti-interference ability compared with the traditional algorithm.Finally,a streaming media transmission system based on the new NAT traversal algorithm is studied.The NAT traversal algorithm is ported into a P2 P streaming network camera application system,An embedded network camera based on the N32926 processor is developed.The system consists of a WAN P2 P server,a network camera based on an embedded Linux system,and a remote video browsing client.With the P2 P server,the remote video browsing client can traverse through NAT and access the Webcam behind the NAT device in P2 P mode.In this system,the remote video browsing client can directly access the webcam in most network topologies and stream the remote video in real time.