[96057] in North American Network Operators' Group
Re: 1500 does not work: Thoughts on increasing MTUs on the internet
daemon@ATHENA.MIT.EDU (Petri Helenius)
Sun Apr 15 11:50:52 2007
Date: Sun, 15 Apr 2007 18:48:47 +0300
From: Petri Helenius <pete@he.iki.fi>
To: Marshall Eubanks <tme@multicasttech.com>
Cc: NANOG list <nanog@merit.edu>
In-Reply-To: <BBF8ACBD-F648-4B24-9D92-BBD6F9D6F0A2@multicasttech.com>
Errors-To: owner-nanog@merit.edu
Marshall Eubanks wrote:
>
> Dear Pete;
>
> The streaming servers that I have dealt with (such as Darwin Streaming
> Server) do the fragmentation at the application layer. They thus send
> out lots of packets at or near (in this case) 1450 bytes, but they are
> not UDP fragments.
> That's the whole point - many networks will not deliver fragments at
> all, much less the increased risk of loss when they do. (I use Cox
> Cable at home, and this network apparently does not forward fragments
> and also has an apparent MTU of 1480 bytes.)
>
> Just looked at a YouTube dump, btw, and almost all of the packets are
> 1448 bytes.
I'm referring to Windows Media and Real. They are the worst offenders,
though not too many use them without HTTP.
Pete
