Modems on analogue extns dropping calls

[Bill Perry]

Hi

Just had our Shoretel 7.5 system installed last week in the UK. We seem to be having problems with modems and maybe faxes on analogue extensions dialling out over an ISDN E2 interface, dropping calls just as they have set them up. They dial 9 for the outside line then dial all the digits OK, the remote end answers and sends the answering tone. But as soon as the local end answers that tone and starts to send data, the Shoretel system drops the call and returns dial tone, which you can hear underneath the modem which is still trying to send data.

Has anyone come across this before and if so have they an answer?

Regards Bill

[Forum]

A few basic things to consider.
Fax/modems require close to zero packet loss. If the transmission goes over a WAN, be careful.

Maybe change the fax codec
Set the extension call stack to 1 (so incoming calls will get a busy)

Thats all I can think about so far...

Charles

[jmjstevens]

Fax/modems require close to zero packet loss. If the transmission goes over a WAN, be careful.

We're exploring putting our fax lines over our PRI as DID's and coming out of an analog port on our Shoretel switches. Any QOS or packet loss issues there?

[Forum]

In a properly configured switched network, there should be no problems. I have several sites with faxes over the PRI w/DID

[jmjstevens]

Thanks, Charles.

In a properly configured switched network

What's the key to a "properly configured switched network"?

[Jason Learmouth]

If you keep the fax on the local LAN you shouldn't run into any issues. Make sure the user assigned to the modem port is set as Fax Machine - No Redirect. If it is set as Fax Server then the call could be getting sent to the site fax extension.