A version of SLIP with header compression is called Compressed SLIP (CSLIP). The compression algorithm used in CSLIP is known as Van Jacobson TCP/IP Header Compression. CSLIP has no effect on the data payload of a packet and is independent of any compression by the serial line modem used for transmission. It reduces the Transmission Control Protocol (TCP) header from 20 bytes to seven bytes. CSLIP has no effect on User Datagram Protocol (UDP) datagrams.
Read more about this topic: Serial Line Internet Protocol