[asterisk-biz] PRI dropped calls, D channel traces, and more

[Harry McGregor]

Hi,

We are having some issues with dropped calls on our combined voice/data
T1 (ISDN PRI hand over of the voice channels).

Our users are reporting frequent (3-10/day for an 8 person office)
dropped calls, including calls with the other party being on a land line.

The telco keeps coming back that the line is clean.

Anyone here have solid experience in reading through D-Channel traces to
figure out what is going on exactly, enough that we can either fix our
Asterisk issue or push the telco for a fix.

Most of the issues started when we switched from doing our own analog
split out for fax (Sangoma T1 card, Sangoma Analog), to having our telco
split out the fax lines.

We had issues with fax reliability on the sangoma pair (even though it
had worked well for us in the past with other installs), and switched to
telco analog hand over for fax (which permitted the Windows SBS fax
server to work, though we are getting a lot of cut off faxes).

Environment is Asterisk 1.4.21 on Debian Lenny Kernel 2.6.26

01:06.0 Network controller: Sangoma Technologies Corp. A101 single-port
T1/E1 (rev 01)
01:07.0 Network controller: Sangoma Technologies Corp. A200/Remora
FXO/FXS Analog AFT card

-----

We really need to get to the bottom of this fax issue.  We can provide
logs, and we can provide supervised (screen),bastion host based SSH
access to the asterisk system.

I would like to keep the cost down of course, but can offer between $150
(looking at the logs, giving suggestions), up to $500 (if you can truly
solve the issue, and our users are happy).


                                        Harry