[c-nsp] Latency on ATM IMA circuits

[John Neiberger]

I'm beginning to migrate our sites to an MPLS-based VPN product. All but
one of our sites has a full T-1, but one site has an ATM IMA circuit
composed of four T1s. When I ping from a T1 site to another T1 site I
see an average round-trip time of about 32 ms. However, when I ping from
or to the site with the IMA, the round-trip time ranges between 65 and
80 ms. That's a pretty big jump! And one I wouldn't have expected.

Is this type of added latency to be expected with IMA circuits? This is
the first one I've ever used before so I have no frame of reference. I'm
wondering if the multiplexing functions add some latency that isn't
present on our other circuits.

Any thoughts?

Thanks!
John
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