Fax issues with CCM and ATA

[NastyNed2]

Hello all-

New here, but was on the Meridian forum for a long time. Got a lot of really great help over there.

We just converted our first building to CCM and are having persistent but intermittent problems faxing.

Call Manager 7
ATA 186
Toshiba e-studio 455 multi-function printer/copier/fax/scanners

Faxes are either missing a line or two, or a line of print will "smear" down the page. Hard to replicate, but some symptoms seem to be that shorter faxes (a few pages) have a better chance of success than long faxes (numerous pages), internal (4-digit) faxes have a better chance of success than external faxes, either through the PSTN between our own machines or to/from machines at other agencies.

This is a pretty critical issue for our business. Any hints? I searched first on the word "fax" but the titles of the resulting threads didn't look promising.

Thanks in advance,

Ned

 

[Iwontremember]

are theses line added in your config?

voice rtp send-recv
voice service voip
fax protocol pass-through g711ulaw
modem passthrough nse codec g711ulaw
no ccm-manager fax protocol cisco

mgcp fax rate 9600


Hope this helps.

 

[pndscm]

One of the most important things in the above post is the speed. The newer fax machines on ATA's have the problem you described. Our organization has almost stopped supporting faxes on ATA's. I was told it has to do with the way the ATA's cache the information. The cache fills up too fast on fast machines and long faxes. You'll probably need to slow your fax machine down to 9600 also.

 

[Silverblade]

As stated above set you're fax machines to a max. baud rate of 9600.
What sometimes also will help is to disable ecm (error correction mode) on the fax machine(if supported)