Designing a tunneling header compression (TuCP) for tunneling over IP

Abstract

The IP tunneling mechanisms have important applications in network solutions and are widely used in numerous contexts such as security (VPN), IPv4 to IPv6 transition, and mobility support (MobileIP and NEMO). However, these tunneling mechanisms induce a large overhead resulting from adding several protocol headers in each packet. Moreover, this header overhead could be found on wireless links which have scarce resources by nature. Header compression methods are often used on connection oriented communication (e.g., UMTS networks) to reduce overhead on the wireless part. In this paper we describe our work toward a novel tunneling header compression protocol, TuCP (tunneling compression protocol), that could be used over IP tunneling mechanisms. It can compress headers of various tunneling protocols such as UDP, PPP, L2TP, GRE etc. TuCP provides a solution for the reordering problem (in tunneling) and thus it extends the usage of header compression mechanisms such as ROHC from point to point links to the IP tunnels passing over the Internet. We present the design and a preliminary implementation of TuCP. Further, we give an evaluation of header overhead reduction and compression efficiency achieved by the protocol.