Busy Signal/Beeping while on a call

[ppickens]

(10-04-2013 09:53 PM)briankelly63 Wrote:  use a tool like Wireshark to look at RTP stream and see whats coming from where. You may be able to use Wireshark to look at the pcap file from the phone itself also.

Ah, I've actually seen this issue too and have not found a solution. It's with two different clients (who are both behind grandstream gateways). This is an isolated issue with some extensions, all of which use the T2x series of phones (T26 and T28). They are both running the supported firmware by 3cx, one is a remote PBX and one is on-site. If I run a packet capture, I can get all audio in wireshark except for the "busy signal", and there is nothing out of the ordinary on the SIP and/or RTP packets.

This only happens when the phone is the initial point of contact (in my experience) for an inbound call from an external line. We have tried different ethernet cables, ports, and ports on the switches just to eliminate any kind of layer one issues. Also it is not easily replicated due to the fact that I have called in twice from the same cell phone and gotten the issue one time and the next there was no unwanted audio signal at all.

Well if there are any questions about this that would help me troubleshoot, it would be much appreciated.

Thanks!