Fax and modem connection using IP trunk

[zagi]

Fax and modem connection using IP trunk

Who have some experience with sending fax and establishing modem connection using IP trunk?

We have following environment. Avaya Media Server S8300 with Media Gateway G700 (SW 1.3), and on other side IP Office 403 (SW 2.0.16). They are connected to different networks/sides which are connected by two Cisco routers with 2M link. On both sides we have IP phones (4620) controlled by S8300, and analog phones connected to G700 and to IPO. Each side is connected to MD110 by BRI and PRI (but it is not important). Between S&G and IPO we have IP trunk (linked by mentioned routers). We have next problems…
- We try to send fax between those two sites (using IP trunk, which is working for all other communications good; e.g. analog phone to analog phone from one site to another), but when one fax called another, another replay, but first does not realize that second answered, so connection failed). Sending fax between faxes on same site off course works.
- Another problem is establishing modem connection between mentioned two sites using IP trunk.

Which setting should be applied for setting IP trunk (on Communication Manager and IP Office) which will support fax and modem connection, and settings of stations/extensions used for attaching fax and modem. Is there some requirement for involved routers, faxes and modem settings?

If somebody have any advice regarding mentioned things, please let me know.

Thanks in forward.

Cheers!

 

[crashtest1000]

I think I can answer the modem question and that would be NO you cannot send a modem signal over an IP trunk on any system.

The reason for this is that the IP trunk uses a codec which makes its best effort to interpret the analogue sound voice or modem into IP send it and reproduce the signal at the other end the problem is it will fail to reproduce the modems analogue tone correctly and the modem needs the exact tone.

Faxing I believe this can work between IPO and 8700 however I cannot shed any more light on it. I have it working between IPO and IPO but not to an 8700.

In the case of Fax the signal is relayed by a modem on the VCM card in the IPO and sent in a standard digital format for reproduction at the remote end don’t think it uses a codec at all.