How NAT-compatible are VoIP applications?

摘要: Today, the Internet is very diversified, further complicating classic NAT traversal problems. In order to solve these problems, there are many proposed methods classified into two categories. One enhances techniques of applications, and other tries modify behavior NATs. this article we focus on former because NATs have been installed, their cannot be altered through endpoint users. Accordingly, in test five VoIP applications (Skype, MSN, Google Talk, X-Lite, Linphone), three network topologies designed with endpoints behind same, different, or multilevel Through a series experiments from experiment results, observe that use some techniques, such as mappedaddress probe, peer discovery, path check, relay first, by STUN, TURN, ICE make direct connection when same different independent mapping rules. However, NATs, no can establish they above mentioned even if hairpin supported