[cisco-voip] TDM through an IAD2400

[Joseph Mays]

We have two IAD2400’s with 16 analog voice ports daisychained together with a PRI running between them. We pass some phone lines coming into IAD-1 over the PRI to ports on IAD-2.  This seems to work fine for voice, but to our surprise we realized the other day that faxes don’t work on IAD2. Nothing is different on the way the voice ports are configured, and with the exception of having one end of the PRI configured to act like a PRI source,  the PRI is configured just as we would any other plugged into a PRI.

Fax calls get answered, but then at some point the fax fails complaining about line quality. Calls on IAD-2 sounded fine, at first, but after this we made some and generated a continuous tone, and noticed that we hear a very faint and very regular click noise about once a second. That noise doesn’t exist on calls coming out of IAD-1. We don’t know for sure that the noise is the reason faxes are failing, but it’s suspicious.

My first question is, are the 2400’s converting, and then reconverting the voice, or just passing it through? Do they do TDM?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/cisco-voip/attachments/20140103/2a8efa6e/attachment.html>