Steve,
I believe the 3 T1 are multiplexed using multilink PPP using an Adtran
router if I remember correctly.
Is there any way to tell if this PPP bundle is causing out of order
packets or other issues?
Thanks,
--Jim
> > One off the wall idea - the site had two T1's (3.0 Mbps) multiplexed
> > via PPP before. The problems seem to start close to around when
they
> > added a third T1 (again via PPP) for a total of approx 4.5Mbps. Is
> > there any chance that this could cause issues - seems to be a pretty
> > standard provider setup...
>
> How are the three T1s load-balanced? Multilink PPP or just using
three
> paths that the routers see between each other? When there are just
> three paths seen between the routers, the routers will often cache
which
> destination goes over which circuit so the packets are transmitted
> across the same circuit in proper order for each destination on the
> other end. Multilink PPP sends the packets in more of a round-robin
> fashion, where one of the packets could get caught behind a larger
> packet on say the first T1 while two other packets from the same
session
> make it across the other two T1s quickly. This would cause
out-of-order
> packets. Although that case is usually confined to slower speed links
> (< 768Kbps) and is called serialization delay.