[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [RRG] LISP-NERD reachability and MTU detection



On 17 dec 2007, at 2:08, Dino Farinacci wrote:

How does it remain a corner case if we make a map-and-encap solution the cornerstone of all future Internet routing and we want to continue to support bulk transfers? It would

When the end-to-end path is 4470 bytes, than fairly large transfer can be done.

You can do fairly large transfers one bit at a time... That's not the issue.

If your ITR has a 4470 byte uplink and your ETR has a 4470 byte downlink and there's nothing smaller in the path between them, there aren't going to be any problems. In an ISP network it should be possible to meet these three conditions if we can get the slower brethren and internet exchanges to upgrade. But if we want to deploy xTRs in end-user controlled networks, the 1500+ byte MTU requirement won't be easy to meet.

I wasn't able to send quality video about 12 years ago and I can now. Technology upgrades allow this to happen. Same for MTU issues.

Last time I checked, the 10 gigabit ethernet standard had the exact same MTU as the original 10 megabit ethernet standard. Now of course all our favorite vendors sell non-compliant hardware that can send and receive packets larger than that, but unfortunately, hosts and routers don't communicate the maximum packet sizes that they can receive to other systems on the same subnet, so the only way to packets larger than 1500 bytes on ethernet hardware that supports it is by manually setting the desired MTU on all systems connected to that subnet. Or you can write a draft and try to whip up some IETF support for it:

http://www.ietf.org/internet-drafts/draft-van-beijnum-multi-mtu-01.txt

--
to unsubscribe send a message to rrg-request@psg.com with the
word 'unsubscribe' in a single line as the message text body.
archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg