I don't think it matters that everything can use jumbograms or that every single device on the Internet supports them. Heck, I still know networks with kit that does not support VLSM!
What would be good is if when a jumbogram capable path on the Internet exists, jumbograms can be used. This way it does not matter than some box somewhere does not support anything greater than a 1500 byte MTU, anything with such a box in the path will simply not support a jumbogram. How do you find out? Just send a jumbogram across the path and see what happens.. ;-) -- Leigh Porter UK Broadband -----Original Message----- From: [EMAIL PROTECTED] on behalf of [EMAIL PROTECTED] Sent: Fri 4/13/2007 3:36 PM To: Saku Ytti Cc: NANOG list Subject: Re: Thoughts on increasing MTUs on the internet On Fri, 13 Apr 2007 08:22:49 +0300, Saku Ytti said: > > On (2007-04-12 20:00 -0700), Stephen Satchell wrote: > > > From a practical side, the cost of developing, qualifying, and selling > > new chipsets to handle jumbo packets would jack up the cost of inside > > equipment. What is the payback? How much money do you save going to > > jumbo packets? > > It's rather hard to find ethernet gear operators could imagine using in > peering or core that do not support +9k MTU's. Note that the number of routers in the "core" is probably vastly outweighted by the number of border and edge routers. There's a *lot* of old eBay routers out there - and until you get a clean path all the way back to the source system, you won't *see* any 9K packets. What's the business case for upgrading an older edge router to support 9K MTU, when the only source of packets coming in is a network of Windows boxes (both servers and end systems in offices) run by somebody who wouldn't believe an Ethernet has anything other than a 1500 MTU if you stapled the spec sheet to their forehead? For that matter, what releases of Windows support setting a 9K MTU? That's probably the *real* uptake limiter.
