Fax over Voip

[Blotnik]

Has anyone successfully done this consistantly through a BCM? I have 1 BCM with an ATA connected via VOIP trunks to another BCM which tandems to the PSTN. Once every 5 times or so, when I use a fax on the ATA I get a T.38 connection which works great. The other 4 times, the connection remains at G.729 and the fax fails. Is there a trick to getting a T.38 conection every time from a fax machine?

 

[redcomet]

What release is it? 3.6? There are patches for T.38 available.

 

[Blotnik]

Yes, I am running 3.6 with cumulative patch 2 (I think I got all the patches)

 

[redcomet]

You're right. Cumulative patch 2.0 already contains the T.38 patch.

What are the settings for the ATA? Is there any other ATA connected to that machine that works?

 

[Blotnik]

I have the ATA's at default. No tones, type modem.

I only have the 1 ATA (which I have swapped) with no better succcess..

 

[redcomet]

Ever tried it with another fax machine?

 

[pipo25]

Hi
I encoutered the same problems, but i can't send fax, you can send one fax for every 5 trials that sounds better; can u send me please the BCM settings you did, and the ATA settings as well;
please put them as a reply to your thread.
Thanks

 

[Blotnik]

Pipo25,

What I have heard is that in order for the fax to work reliably, you need to have a T.38 connection. This should be autonegotiated when the BCM's hear the CNG fax tones. The problem, I am told, is that some of the newer fax machines, like the HP Office try and get to a speed greater than 14.4 and the T.38 software cant handle this.

Again, I have been told that the solution is to call HP and get some secret (undocumented) codes to slow their machines down to 14.4 max. I have not been successful at this, but am working on it now. If you find any of the secret codes, please let me know.

Thanks,
Harold

PS Trying to find the person at HP who can tell you the secret codes to do this is probably harder than finding the holy grail.