jumbo frames

Fri Apr 27 15:45:04 UTC 2001

On Fri, 27 Apr 2001, Kurt Kayser wrote:

> Hi,
> 
> Isn't it a lot more cpu-intensive to 'collect' some 1500-byte frames
> into some larger bucket, reassemble it into a jumbo-frame when the next
> box has to chop it in order to send it out on a Sonet/PPP/etc interface which 
> might have a smaller MTU again?
> 
> Doesn't make too much sense to me. I guess that was Tony's aim as well..
> 
> Kurt
>  
> > Roeland you are talking about jumbo frames from the end system lan, while
> > John is talking about only using the jumbo frames between the routers. My
> > point was that in John's environment the packets will all be 1500 since the
> > packets are restricted to that size just to get to the router with the GE
> > interface. I understand that there are perf gains as long as the entire path
> > supports the larger packets, but I don't understand the claim that having a
> > bigger pipe in the middle helps.

I dont think that anyone discussed doing that... What was being said was
that it makes sence to use jumbo frames between routers when they are
encapsulating packets from links with a 1500b mtu, so you don't have to
reduce your MTU to 1450 or fragment, i.e.
endnode-ether-router>tunnel-jumbo_ether-router-jumbo-ether-tunnel>router-eth-end