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802.2 Packets

In 802.2 packets, the protocol-dependent section consists of a 2-byte length word, a 1-byte destination service access point (DSAP), a 1-byte source service access point (SSAP), a control byte, and an optional 5-byte subnet access protocol (SNAP) field. Thus this section of the packet can be either 5 or 10 bytes long.

Note

The 802.3 specification guarantees that the value of the 2-byte length word will always be less than 1501; therefore it is always possible to differentiate between Ethernet and 802.2 packets by examining the value of this field.

© 1999 Apple Computer, Inc. – (Last Updated 26 March 99)