SPA2102 "180 Ringing" delay

[marc.cardinal]

Good afternoon,

We have several SPA2102 in productions and we are experiencing an odd problem that started a few days ago.

Most of them have the firmware Linksys/SPA2102-5.2.5 or Linksys/SPA2102-5.2.10 installed, this was confirmed by looking at the useragent they are sending.

When we send an invite to these devices, it replies with a "100 Trying" within a few milliseconds and then with a "180 Ringing" aproximately 10 seconds after the initial invite.

The ~10 seconds delay before receiving a "180 Ringing" is actually causing a PRI Timer Timeout on our carrier's side and they cancel the call.

Here is a trace I ran of the following call path: Carrier -> Switch -> Linksys SPA2102

The switch sends an INVITE to the linksys at 0.044 seconds, the linksys replies with a 100 Trying at 0.124 seconds and then sends a 180 Ringing at 9.625 seconds.

Is this considered normal?

What could be the cause of that late 180 Ringing?

How can I troubleshoot this?

Would setting up a syslog help pinpointing the problem at all?

Thanks for your help,

Marc

[Daniele Giordano]

Strange issue.
The 180 response of SPA must be very fast.

Can you capture the SPA syslog? It can be helpful:

Post also a SPA config in mht format.
Thanks.

[marc.cardinal]

Good evening,

Setting up the device with a syslog server information (setting "Syslog Server", "Debug Server", "Debug Level" to 3, "SIP Debug Option" to full) greatly helped figuring out what the problem was.

It seems that between the 100 Trying and the 180 Ringing the device made several attempts at contacting it's configured STUN Server without any success.

All of these attempts took time and eventually depleted the allowed 10 seconds.

By setting the STUN Server value correctly, the device is now accepting inbound calls very fast.

This problem has been resolved.

Cheers,

Marc