Zaptel Randomly Dying

Hi All,
We’re having a problem with zaptel randomly dying on us. Everything works fine for a couple weeks or so, and then for no apparent reason nobody will be able to dial in or out - sip continues to work normally.

Each failure coincides with the following message showing up in the system log:

kernel: zaptel Disabled echo canceller because of tone (rx) on channel 1

From what I understand, these messages are normal; zaptel is detecting an incoming fax and has disabled echo cancellation. But it’s happened too often to be a coincidence, imho.

I’ve tried running ztcfg -vv after it stops working but it returns normal results; no error messages, and there is nothing else abnormal in the system log.

We are using a TDM800P with 4 analog lines. Asterisk version 1.4.15 , zaptel-1.4.7.

zapata.conf:

[channels] busydetect=yes busycount=6 usecallerid=yes hidecallerid=no transfer=yes callwaiting=no threewaycalling=yes echocancel=yes echotraining=yes signalling=fxs_ks group=1 context=incoming channel=> 1-4

Please let me know if I can provide any other info. Thanks.

Ryan