RE: jumbo frames

[Roeland Meyer <rmeyer () mhsc com>]

In both cases, it is a bandwidth issue. You either consume the bandwidth in
the CPU or consume it on the wire. CPU is cheaper and often under-utilized.
Of the two, CPU bandwidth is also cheaper/easier to upgrade.

> -----Original Message-----
> From: Rowland, Alan D [mailto:alan_r1 () corp earthlink net]
> Sent: Friday, April 27, 2001 8:45 AM
> To: 'Kurt Kayser'; Tony Hain
> Cc: Roeland Meyer; John Fraizer; Paul Lantinga; nanog () merit edu
> Subject: RE: jumbo frames
>
>
> I am not an EE but maybe if you rephrased the question as
>
> Which is greater, the cpu cycles to assemble/dissemble jumbo 
> frames or the
> additional cycles/bandwidth of more numerous ACK packets?
>
> Then again, I may be way out of my depth here.
>
> -Al
>
> -----Original Message-----
> From: Kurt Kayser [mailto:kurt () noris de]
> Sent: Friday, April 27, 2001 8:07 AM
> To: Tony Hain
> Cc: Roeland Meyer; John Fraizer; Paul Lantinga; nanog () merit edu
> Subject: Re: jumbo frames
>
>
>
> 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.
> >
> > Tony
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