[36936] in North American Network Operators' Group

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RE: jumbo frames

daemon@ATHENA.MIT.EDU (Tony Hain)
Thu Apr 26 14:53:05 2001

Reply-To: <alh-ietf@tndh.net>
From: "Tony Hain" <alh-ietf@tndh.net>
To: "John Fraizer" <nanog@Overkill.EnterZone.Net>,
	"Paul Lantinga" <prl@q9.com>
Cc: <nanog@merit.edu>
Date: Thu, 26 Apr 2001 11:47:16 -0700
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April 26, 2001 9:29 AM John Fraizer wrote:
> We only have jumbo frames enabled on router<->router links.  The GigE
> ports facing the aggregation switches runs standard 1500 MTU.

Hence my original question. Packets across the GE will be 1500 unless you
are packing them.

April 25, 2001 8:10 PM John Fraizer wrote:
> Partially because I can.  Partially because there seems to be a
> performance increase when you start stuffing the pipe.

Assuming you are just passing the packets as received from the aggregation
switch, this would only happen if your router hardware was better at
managing jumbo buffer allocations than 1500B ones. Clearly it will waste
large chunks of memory, so do you have measurements to show the actual
performance increase?

Tony




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