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Compressed Packet Format

Figure 16 shows the format of a compressed TCP/IP packet. There is a change mask that identifies which of the fields expected to change per-packet changed, a connection number, so the receiver can locate the saved copy of the last packet for this TCP connection, the unmodified TCP checksum so the end-to-end data integrity check will still be valid, then for each bit set in the change mask, the amount the associated field changed. Optional fields, controlled by the mask, are enclosed in dashed lines in the figure.

Figure : The header of a compressed TCP/IP datagram
Fri Feb 10 12:57:56 EST 1995