Inbound busy signals

[alevene]

I have the latest patched 1.4.21.2 and have an odd problem.

I find that customers get busy signals on the first call, if the system hasn't received a call for 10 or more minutes.

I worked on this problem at the weekend, and although my SIP accounts are registered with two separate providers I can create a failure by doing the following -

I wait 10-20 minutes and then call the main DID, which gives a busy signal. I can then call again in about 15 seconds and the call connects to the IVR.

It appears that the inbound call isn't answered and just bounces the call, with a busy signal causing a Congestion email notice.

I've rebuilt the IVR without any change in outcome. Ideas?

 

[alevene]

The solution

After months of this problem I finally figured it out... the DNS lookup for the SIP provider was too slow for the PIAF box. As such when I changed the FQDN to the underlying IP address, the problem stopped instantly.