VIP: A P2P Communication Platform for NAT Traversal

Abstract

Nowadays, the Internet architecture is complicated and IP addresses are limited in IPV4 context. Many users located behind different kinds of NATs or Firewalls can hardly get a public unique IP. So the hosts behind the NAT can not be accessed by the hosts behind the other NATs. Some P2P systems can partially solve such kind of problems, but unfortunately, these systems just focus the specific self-contained applications such as Skype and BitTorrent whose P2P architectures and NAT traversal mechanisms can not be re-used by other applications directly. In this paper we present a solution by setting up a Virtual Intranet Platform (VIP) which use the public DHT service -OpenDHT as the distributed address/port information rendezvous. Without changing the configuration of the NAT, all the network and distributed application service behind the NAT can make use of the VIP to communicate with the corresponding peer services outside the NAT. The performance of the bandwidth, data lost and delay problems are much better than the existing traditional C-S framework platforms, more general than specific P2P applications. The P2P Communication Platform for NAT Traversal-VIP, is robust and scalable because there are no single failure points in the platform, the structure is in distributed, and majority of the traffic data between two hosts behind the NAT can be transfer directly without relaying.

This paper is supported by National Natural Science Foundation of China(60403034) and Shanghai Technology and Science Committee Municipality (03dz15026, 03dz15027).