Public network information detection method, device and system for point-to-point transmission

Abstract

The invention belongs to the technical field of data network transmission, and specifically relates to a public network information detection method, apparatus and system for point-to-point transmission. The method comprises the steps that a client sends a first binding request to a port PORT _X of an STUN server through a local port PORT _A, and sends a second binding request to a port PORT _Y of the STUN server through the local port PORT _A; if the client does not receive a response message of the first binding request or the second binding request, the current detection fails; otherwise, the client analyzes the response message of the first binding request to obtain a public network IP address NAT_IP1 and a public network port NAT_PORT1, and analyzes the response message of the second binding request to obtain a public network IP address NAT_IP2 and a public network port NAT_PORT2; the client sends a loopback test message to the public network IP address NAT_IP1 and the public network port NAT_PORT1 through the local port PORT _A; the client sends a third binding request to the port PORT _X of the STUN server through a local port PORT _B, and sets a parameter request server to reply response information through a port PORT _Z; and the client judges the public network information.

Description

technical field [0001] The invention belongs to the technical field of data network transmission, and in particular relates to a public network information detection method, device and system for point-to-point transmission. Background technique [0002] In the IPV4 environment, there is a shortage of IP addresses in China. NAT (Network Address Translation, Network Address Translation) devices convert private networks into public networks, but NAT devices cannot directly obtain their own public network information (including public network IP, public network port, NAT type, whether it supports loopback), it needs to communicate with the device on the public network to obtain its own public network information. [0003] STUN (Simple Traversal of UDP over NATs, NAT's UDP simple traversal) is a network protocol that allows a client behind a NAT (or multiple NATs) to find out its own public network address. The STUN detection process requires a STUN server with a public network...

AI Technical Summary

Problems solved by technology

[0005] For point-to-point data transmission applications, since both sides of the transmission have only one fixed IP address, no matter whether it is an IP-restricted NAT type, it will not affect the point-to-point transmission data between clients. In this case, the traditional STUN detection method is used. There are the following problems: 1. The STUN server needs two different public network IP addresses, resulting in a waste of network equipment and IP address resources; 2. There are unnecessary protocol interaction processes, which waste interaction time and reduce detection efficiency

In addition, the current research believes that when the point-to-point side is a symmetric NAT, if the other side is not a complete cone NAT, point-to-point (P2P) data transmission cannot be performed, and data transmission needs to be transferred through the TURN server on the public network

This processing method does not further subdivide symmetric NAT according to the filtering properties of NAT, and ignores the possibility that some types of symmetric NAT can realize point-to-point data transmission with other NAT networks.

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