IEEE 802.3

IEEE 802.3 is the IEEE standard defining the hardware layer and transport layer of (a variant of) Ethernet. The maximum segment length is 500m and the maximum total length is 2.5km. The maximum number of hosts is 1024.

The maximum packet size is 1518 bytes. If the upper layer protocol submits a PDU (Protocol data unit) less than 64 bytes, 802.3 will pad the LLC Info field to achieve the minimum 64 bytes.

Although it is not technically correct, the terms "packet" and frame are used interchangeably. The ISO/IEC 8802-3 ANSI/IEEE 802.3 Standards refer to MAC sub-layer frames consisting of the Destination Address, Source Address, Length, LLC Info., and FCS fields. The Preamble and SFD are (usually) considered a header to the MAC Frame. This header plus the MAC Frame constitute a "Packet".

External Links:

http://www.ieee802.org/3/ -- The IEEE 802.3 Working Group

This article (or an earlier version of it) contains material from FOLDOC, used with permission.