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Re: How many T1's can a 2621 handle?

Hello, snipped-for-privacy@hotmail.com!

> You wrote on 23 Feb 2005 03:24:45 -0800: > > a> MPPP is CPU intensive and the performance numbers with MPPP are > a> not in any way related to any general published performance > a> figured. For n links each packet is divided into n pieces and each > a> piece sent down a different link. > > It depends. What I seen on 2600 series, if you are not using interleaving or if > links in MPPP bundle are fast enough, there would be no fragmentation > whatsoever. > > With best regards, > Andrey.

Andrey, I have only just noticed your response.

I believe that _by-definition_ MPPP divides the packets such that in the case of N links there are N fragments.

However in general with respect to MPPP performance I have no recent experience of mppp and may be out of date. Clearly it would be perfectly possible to fragment the packets in hardware and incur no performance penalty whatsoever. It seems unlikely to me that a 2621 does this.

A key benefit of fragmenting the packets in this way is that the Transmission Delay is reduced. Additionally packet order is conserved which is not the case with some other load sharing techniques.

Reply to
AnyBody43
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Hello, AnyBody43! You wrote on 19 Mar 2005 05:32:20 -0800:

??>> It depends. What I seen on 2600 series, if you are not using ??>> interleaving or if links in MPPP bundle are fast enough, there ??>> would be no fragmentation whatsoever.

A> I believe that _by-definition_ MPPP divides the packets A> such that in the case of N links there are N fragments.

From RFC 1990 - ... Systems implementing the multilink procedure are not required to fragment small packets. There is also no requirement that the segments be of equal sizes, or that packets must be broken up at all. ...

A> However in general with respect to MPPP performance A> I have no recent experience of mppp and may be out A> of date. Clearly it would be perfectly possible to A> fragment the packets in hardware and incur A> no performance penalty whatsoever.

And that is normally found on IMA devices.

A> A key benefit of fragmenting the packets in this way A> is that the Transmission Delay is reduced. Additionally A> packet order is conserved which is not the case with A> some other load sharing techniques.

Serialization delay on T1 for 1500 bytes is less than 8ms. Packet order is preserved even though packets are not fragmented. There is a special MLPPP buffer dealing with packets re-assembly and re-ordering.

With best regards, Andrey.

Reply to
Andrey Tarasov

Thanks.

I did consider heading for the RFCs but was pretty convinced. Wrong, again!

Thanks a lot.

Reply to
anybody43

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