VoIP call quality

[adamandamy]

I have a BCM400 4.0 and BCM50 3.0 networked over PtP T1 with MCDN and QSig on each.
Direct extension to extension call quality is good. However outside calls are sometimes forwarded from one location to the other and the voice quality on these calls are not good(lots of echo). THe BCM 400 has a PRI and the 50 has POTS however it doesn't matter as all outside calls in this forwarded arrangement are of inferior quality.
What can I look to or tune in these systems that may help the situation?

 

[oldestgeek]

You can set the impedance on each of the analog lines on the 50 and also the loop length. Both these settings have a huge impact on echo and call quality in general.