[asterisk-users] Dropped calls when all DAHDI lines in use

[Andrew Martin]

Hello,

I am running Asterisk 11.17 with DAHDI 2.9.0 and an OpenVox A800P with 8x analog 
POTS lines coming into my Asterisk server from the phone company. Internally, I
have about 180 SIP clients defined in sip.conf. What appears to be happening is
that if existing calls are consuming all 8 external lines and a new SIP client
attempts to make a call, an existing call gets dropped. The asterisk log simply
shows this as a normal hangup, so I am not able to easily distinguish between a
normal hangup and this type of dropped call. In testing, I am able to get a new
SIP client to report "service unavailable" when all 8 lines are consumed, yet
still drops are reported.

I have been unable to find any configuration settings pertaining to prioritizing
existing calls over new calls. What else can I look for to attempt to debug and
fix this so that existing calls are not dropped?

Thanks,

Andrew