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From: POSTEL@USC-ISIB.ARPA
Newsgroups: mod.protocols.tcp-ip
Subject: re: IEEE and Ethernet
Message-ID: <8606270252.AA15496@ucbvax.Berkeley.EDU>
Date: Thu, 26-Jun-86 13:09:18 EDT
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Posted: Thu Jun 26 13:09:18 1986
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David:

Opening another can of worms ...

In IEEE 802 the thing most similar to the Ethernet type is called a
"service access point" or SAP, but it is only 8 bits and two of those
are wasted on some other general coding, so there are only 64 SAPs to
assign.  So after assigning one to identify ISO-IP and one to identify
DOD-IP, the IEEE 802 committee decided that there weren't enough and
refused to assign a SAP to identify ARP.  There is some committee work
in progress to come up with an extended SAP field.

--jon.
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