Path: utzoo!attcan!uunet!husc6!rutgers!mailrus!ames!sgi!vjs@rhyolite.SGI.COM
From: vjs@rhyolite.SGI.COM (Vernon Schryver)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: TCP/IP over FDDI (13-byte MAC hdr)
Summary: could RFC-1042 fix it?
Message-ID: <22275@sgi.SGI.COM>
Date: 20 Nov 88 01:21:23 GMT
References: <8811190332.AA13232@venera.isi.edu>
Sender: daemon@sgi.SGI.COM
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 25

In article <8811190332.AA13232@venera.isi.edu>, postel@VENERA.ISI.EDU (Jon Postel) writes:
> 
> Does anyone think a 13 byte MAC header is a good idea?  
> 
> Do the guys on the 802 committee ever thing about anything bigger than a
> single bit?  What favor can they possibly think they are doing to the
> users of FDDI networks by having a 13 byte header?

Some have helped calm my hysterical giggles by pointing out that AMD's 7982
DPC chip can shift by 0-3 bytes, so if you leave 3 bytes free at the start
of every buffer, ...

Others have said that 13 bytes of MAC + 3 bytes of LLC is just find.
Perhaps the 802 guys were thinking, but only about 802.2.

Could there be a new IP encapcapsulation in the style of RFC-1042 that
would be 7 or 11 bytes long?  Adding 3 bytes of 0 after the RFC-1042 802.2
header would waste no significant bandwidth, and would remove some
craziness in drivers--even if you do use the DPC.  One hears rumors
and more of other chip sets.


Vernon Schryver
Silicon Graphics
vjs@sgi.com