[nsp] Multiple T1s: MLPPP vs. equal path CEF

jlewis at lewis.org jlewis at lewis.org
Wed Aug 20 16:14:06 EDT 2003

On Wed, 20 Aug 2003, Bruce Robertson wrote:

> We're using MLPPP to bond multiple T1s, rather than using CEF to load
> balance. Aside from the fact that MLPPP is a more elegant solution in my
> opinion, I've been using this configuration because of an assumption
> I've been making.  Since one of my routers is about to undergo CPU
> meltdown due to the MLPPP overhead, I though it was time that I verified
> this assumption.

More elegant how?  In your experience, does the multilink interface pause 
(stop passing traffic momentarily) every time a member link is 
added/removed or flaps?  Where's the elegance in tearing down the 
connection just because you wanted to en/disable CDP?

> Is it not true that when using equal path CEF, the maximum speed a single
> TCP stream can attain is 1.5 Mb/s, no matter how many T1s are in the group?

With the default "per-destination" load sharing, yes.  If you want single 
transfers to be able to use the "whole pipe", set all the interfaces 
involved with "ip load-sharing per-packet".

 Jon Lewis *jlewis at lewis.org*|  I route
 System Administrator        |  therefore you are
 Atlantic Net                |  
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