Calls dropping

1

I have three systems version 2.11 Freepbx Distro. We inherited Escene ES410 phones. The trunks are SIP, and T1/PRI. We are experiencing random call dropping. I have captured the calls in TCPDump. and I see the packets just end. There are no messages to end the call, the packets just stop. I have contacted Escene but no reply as yet. We have installed Aastra and Yealink in these systems and they have no issues, reported. I know the Escene models passed in Aastra testing. The phones were not defaulted. The phones were OEM from another provider. I have looked into Reinvite sip and it is turned off in the system and in the phones.

Anyone have thoughts?

Thanks

2

I have found that the system is sending Bye messages to the phones. Why would it do that ? I have the
RTP timers:
RTPtimeout = 300
RTPHoldtimeout = 300
Keepalive=30

3

Still looking for a solution here. The call dropping has continued, the calls are even between phones on the same network behind the firewall.

4

You need to share at least the complete sip debug for a failed call or better a tcpdump trace for a falied call and do not masquerade the IPs.

5

We were unable to get this resolved with the existing phones. We installed Yealink T26 phones and now 5 days without a dropped call. So definately a phone issue.