[c-nsp] PPPoE session load balancing

Tom Storey tom at snnap.net
Thu Jan 14 06:41:52 EST 2016

Both of them will make an offer, invariably one of them will be first
or the CPE will choose one at random, and invariably the two will end
up somewhat balanced. Sometimes more on box A, other times more on box

If you find one of them getting too far ahead of the other in terms of
sessions, and this is of particular concern, you could either:

1. clear some sessions on one box and a portion of them will probably
land on the other
2. set a session limit on each box that is approx, but slightly above,
50% of the CPE base that you need to serve

#1 may cause some perceived quality/reliability issues if peoples
sessions keep dropping off.

#2 will have some added maintenance to keep updating the session limit
as your CPE base increases, but will cause the first box that reaches
that session limit to stop offering for new sessions forcing them all
on to the second box. The only problem to deal with then is if one of
the boxes dies, you will need to manually (or perhaps automatically
via some kind of script) lift the session limit on the remaining box
so that the other half of your CPE base can get back on line - then
restore the ~50% limit after its all fixed again.

Otherwise, unless theres some pressing technical issue that you need
to resolve (in that case details might be handy so we can understand
why this is particularly important), just leave them to do what they
do. It will swing naturally over time.

On 14 January 2016 at 12:20, Mohammad Khalil <eng_mssk at hotmail.com> wrote:
> Hi Dears
> I have two VXRs functioning as PPPoE aggregation servers
> What am trying to do is to load balance the sessions to be distributed among the two boxes?
> Is that doable?
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/

More information about the cisco-nsp mailing list