1500 does not work: Thoughts on increasing MTUs on the internet

Petri Helenius pete at he.iki.fi
Sun Apr 15 15:48:47 UTC 2007


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




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