Van Jacobson TCP/IP Header Compression

Van Jacobson TCP/IP Header Compression is a data compression protocol described in RFC 1144, specifically designed by Van Jacobson to improve TCP/IP performance over slow serial links. Van Jacobson compression reduces the normal 40 byte TCP/IP packet headers down to 3–4 bytes for the average case; it does this by saving the state of TCP connections at both ends of a link, and only sending the differences in the header fields that change. This makes a very big difference for interactive performance on low speed links, although it will not do anything about the processing delay inherent to most dial-up modems.
Van Jacobson Header Compression is an option in most versions of PPP. Versions of Serial Line Internet Protocol with VJ compression are often called CSLIP.