Exploiting Packet Header Redundancy for Zero Cost Dissemination of Dynamic Resource Information
Peter A. Dinda · 2002
Packet headers exhibit considerable coding redundancy from both a theoretical and a practical standpoint. We propose to exploit this redundancy to create an additional communication channel between hosts as a by-product of normal packet transfers. This channel would be zero cost: the number and size of packets transfered would not change. Dissemination of dynamic resource information is a natural user of such a channel. In the paper, we begin by illustrating the significant theoretical coding redundancy of typical TCP/IP traffic using widely available packet trace data. Next, we discuss a number of ways to practically exploit this redundancy using only end-system changes and evaluate their prospects. Then we describe proof-of-concept experiments that we have conducted using a user-level network stack. Finally, we describe how common forms of resource information could be communicated using this mechanism.