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Re: Jumbo Frames (was Re: MAE-EAST Moving? from Tysons corner to reston VA. )

  • From: Vadim Antonov
  • Date: Mon Jun 19 03:49:13 2000 
Bora Akyol <[email protected]>  wrote:

> What is the big, clear advantage of supporting jumbo frames?

There are none, not without doing something about TCP congestion
control.

The bigger frames are, the more coarse the congestion control is,
and the flows are short enough on average to make it barely
effectual.  Increasing frame size to 10kb makes most flows
"mice" flows, which kills the slow-start algorithm.

Of course, flows may start by sending smaller frames first,
but, again, what's the point?

With 1500 byte frames, the framing overhead is about 2.8%,
however, given that the 40% of packets are only 40-41 bytes long,
this seems to be a very minor effect.

--vadim