Bizarre fax problem 2

[OldAndKnackered]

This one has turned me into a total bewilderbeest.

IPO500 v2 8.1(63) VCM 32 v2 ISDN 30. The customer has a fibre link to another building, but wants a fax, so we got an audiocodes mp-112 ATA and a 3rd party IP endpoint licence. After a bit of futtering about with it, I managed to get it to register, and reserved the licence to the extension. I can call the ATA both internally and externally, and faxes come through OK. If I plug my butt phone into the ATA and call to my mobile, it works. However if I connect my butt in parallel, I can hear an outgoing fax call ring to the far end, but when the far end answers and starts sending handshake tones, the fax at my end just beeps on and off (approx 1s on 1s off). I tried setting the extension and the ATA to use both G711 and T38, but no joy. Any ideas so that I can get the customer and all his toys re-perambulated?


Ta

 

[bmast]

Have you tried adjusting the settings on the fax machine itself. This has worked for us in the past. See this link:

http://www.voipmechanic.com/voip-fax-settings.htm

 

[stownsend]

My Experience with Faxing and IPO and SIP has not been the best. Several factors come into play.

We ended up having to knock down the Fax Baud Rate to 9600, Use the G.711 Codec and the Fax Machine has to be New.

We had 6 Fax Machines in our Building, When we switched to SIP Connections, All but 2 no longer worked with any reliability. The Ones that did work were new HP MFP Fax Printers and were purchased in the last year or so. Anything that was more than a few years old no longer can receive or send faxes with any reliability.

Scott<-

 

[intrigrant]

I have done a lot with faxes using Patton M-ATA's as SIP extension on IP Office with all kind of faxes and only once we had a issue with it. And the problem turned out to be the Cisco switches with VPN programming. And there were all kinds of faxes and fax modems, even 9600 baud modems work fine with it.
So if you have a problem I am certain it is NOT the IP Office to blaim.
We started with the audiocodes MP112 which did not perform very well, the Patton is simple to setup, five minutes work and then it is a set and forget device which will always work. The Audiocodes has way too many parameters and a poor manual, it only describes the features and not how to set it up.
By the way, the Patton is the only low priced SIP ATA I have found capable to send DTMF both ways, so ideal for analog doorphones as well.
And Grandstream has also a good SIP ATA but can't do two way DTMF.

A simple mind delivers great solutions

 

[OldAndKnackered]

Thanks for the suggestions, I'll give them a go when I'm next on site.

 

[dan1765]

+1 on the baud rates. I've had phone systems from avaya, nortel, cisco etc not work at default baud rates but when you knock down the max rate they start working.