Cell Relay Archive

[craigp@world.std.com (Craig Partridge)]

fahad@cs.pitt.edu (Fahad A Hoymany) writes:

>     That's what you get when you try to simplify things :-) What's missing
>from the example I mentioned earlier is the fact that I was talking about
>cut-through forwarding, not complete packet reception.  Also, with buffers
>I am not talking about switch output buffers, but rather router buffers.

Hi Fahad:

I understood you were talking about cut-through.  What I'm pointing out
is that the IP specification doesn't allow cut-through to start until the full
packet has been received, because you are not allowed to route the packet
until after you do the length checks.

So there's no buffering savings.

I can still see cases where cut through buys you a small performance win,
but these usually reflect problems in the bus or outbound interface design.

Craig