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From: kwe@buit13.bu.edu (Kent England)
Newsgroups: comp.dcom.lans
Subject: Re: Does the EtherSwitch eat preamble?
Summary: Is that a frame buffer or a MAC address table size?
Message-ID: <63454@bu.edu.bu.edu>
Date: 30 Aug 90 14:48:08 GMT
References: <1990Aug27.143144.62@arizona.edu>
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Reply-To: kwe@buitb.bu.edu (Kent England)
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Organization: Boston U. Information Technology
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In article <1990Aug27.143144.62@arizona.edu> leonard@arizona.edu writes:
>
>The question is, what exactly does this Kalpana EtherSwitch thingy do 
>when the segment it wants to transmit onto has a collision in effect?
>
>I think the answer is that it buffers.  I got some literature from 
>Kalpana and it says that there is a 256-packet buffer per Ethernet
>interface.

	I think you're right, but that sounds like a lot of buffer.
The Kalpana has to have very fast table lookup for forwarding.
Perhaps the 256 refers to the size of the MAC address table per
interface?  At any rate, I would be interested to know how big the MAC
address table is, per interface, since that would affect where these
things could be used.  I can't imagine that Kalpana could accept
arbitrary topologies with thousands of potential MAC addresses on some
interfaces and still maintain claimed forwarding rates.

	--Kent