On 10/24/2010 5:05 AM, George Bonser wrote:
And speaking of changing MTU, is there any reason why private exchanges
shouldn't support jumbo frames? Is there any reason nowadays that things
that are ethernet end to end can't be MTU 9000 instead of 1500? It
certainly would improve performance and reduce the packets/sec and
increase performance on latent links. Why are we still using 1500 MTU
when peering? Is there any gear at peering points that DOESN'T support
jumbo frames these days?
Probably no reason at all, though probably little perceived benefit.
1492 is common enough that google/youtube already runs lower MTU's just
to avoid common broken PPPoE setups (which often could run higher MTU,
but weren't configured that way).
Not uncommon for cell companies to request 1600 MTU or more for their
layer 2 transport, which one vendor had to custom patch 1648 into their
gear to even support that much. Of course, it will be lowered by a
variety of tags/tunnels/etc by the time it gets to the cell phone. It
cracks me up that SONET interfaces default 4470, and ethernet still
defaults to 1500. I've yet to see an MTU option in standard circuit
setup forms, which would indicate to me that asking for a higher MTU
might get me one extra link before dropping back to 1500ish.
Jack
