I have been running IP over ISDN for a couple of years using a single B
channel at 64 Kbps. There is a Cisco router at each end, and my ping
response is about 30 ms.
Yesterday I switched to a pair of Motorola/UDS TA220k TAs and enabled
bonding (mode 1) using 2 B channels. The throughput improved as
expected, but my ping response time degraded to 100 ms.
I'm a bit surprised by the increased delay. I suppose the delay is
being introduced by buffering in the TA, but an increase of 70 ms seems
excessive for lines that should have essentially the same end-to-end
delay. Both ISDN lines are served by the same CO, so it seems unlikely
the additionaly delay is being introduced by the phone company. The
switch is a 5E9, with one line configured as NI-1 and the other as 5E
Is this reasonable? Is there a significant difference between vendors
with respect to bonding performance? Has anyone done any bonding
performance comparisons on various TAs?