[153375] in North American Network Operators' Group
Re: IPv6 day and tunnels
daemon@ATHENA.MIT.EDU (Masataka Ohta)
Tue Jun 5 14:38:39 2012
Date: Wed, 06 Jun 2012 03:36:29 +0900
From: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
To: "Templin, Fred L" <Fred.L.Templin@boeing.com>,
"nanog@nanog.org" <nanog@nanog.org>
In-Reply-To: <E1829B60731D1740BB7A0626B4FAF0A65D374A8880@XCH-NW-01V.nw.nos.boeing.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Templin, Fred L wrote:
>> You don't have to do it with core routers.
>
> Tunnel endpoints can be located either nearer the edges
> or nearer the middle. Tunnel endpoints that are located
> nearer the edges might be able to do reassembly at nominal
> data rates, but there is no assurance of a maximum MRU
> greater than 1500 (which is too small to reassemble a
> 1500+20 packet). Tunnel endpoints that are located nearer
> the middle can be swamped trying to keep up with reassembly
> at high data rates - again, with no MRU assurances.
As operators know outer fragmentation is used to carry
inner 1500B packets, the proper operation is to have
equipments with large enough MRU.
As core routers may be good at fragmentation but not
particularly good at reassembly, operators do not
have to insist on using core routers.
>> I'm afraid you don't understand tunnel operation at all.
>
> I don't? Are you sure?
See above.
Masataka Ohta
