we are experiencing a strange issue with BLF with polycom Phone on our IP PBX system.
BLF on polycom phones does not work and the phone return SIP 482 loop detected error on received notify message.
Our system structure:
Opensips balancer (10.100.0.70 in the trace)
Freeswitch media server (10.100.0.77 in the trace)
the phone has ip address 10.200.24.50, ext 8752 is trying to monitoring 8666.
Subscribtion seems to be accepted by the freeswitch and the notify is sent to the phone.
This one anyway replys with a SIP 482 errors. Any ideas?
Please find attached a trace and our phone config.
Phone firmware version is UCS 4.0.7. We also tried to downgrade to 4.0.5, 4.0.6 and 4.0.4 without any changes.
just to update you about the state of the issue.
The problem was on the Cseq index (inside the notify dialog). It seems that freeswitch reach the maximum value (2^32 unsigned) but for Polycom endpoint the maximum is 2^31: this is why the phone detects the loop and reply as 482.
We are testing a patch on freeswitch (moved from 1.2.23 to 1.2.24).
Let you know about results. Till now everything seems to be fine.
Was this problem ever fixed?
We are getting floods of "482 loop detected" messages in call flows which, upon analysis of the PCAP and the PBX configs, do not show any evidence of actual looping. However, the report of looping from the phones is causing call failures.
We are using Polycom VVX 300s and 400s running 5.5.2 firmware.