Calls Dropping

[mark.milton]

Hi, am having issues with calls dropping randomly. Sometimes after a few seconds, sometimes several minutes into a call it's always random.

When calling out the call doesn't often drop but calls coming in always do. The caller can still hear but the receiver can't hear anything when it calls drops. With the Receiver being the phone connected to the PBX and the caller being external.

If you stay on the line it sometimes comes back

Any ideas?

 

[ict2842]

Not sure if this is it, but what is the registration time for the phones? Is keep alive enabled?

 

[mark.milton]

Keep alive is enabled at set to 30 seconds as default

 

[mcs3ss2]

in device settings change the pprotocol from tcp/udp to TLS
One of the ISP here blocks the 5060 and 5061 for third party voip providers and above is how I counter the issue.

 

[Adrian Fretwell]

Get a packet capture, and diagnose the actual issue, then we can look at solutions or workarounds. You can use tcpdump or sngrep to help with the capture.
Problems like these are often caused by a NAT related issue.
Describe your system topology, is your PBX behind a NAT? are your phones behind a NAT, if so it it the same NAT as the PBX?