I have a strange problem with incoming calls with a UC540. 4 POTS lines in a trunk group by carrier (Verizon) is feeding the system.
This problem does not happen all the time but randomly here and there so it's very hard to troubleshoot - I would say maybe once every 8-10 calls or so.
When a caller from outside calls our main number and a user picks up the call, the call never connects, disappears for awhile and starts ringing again on the phones.
To give you more detail, this is what's happening in steps -
1. caller calls the main number
2. office phone rings with caller id and user tries to pick up the call
3. when the user picks up the handset or presses the speaker button, call is not connected and phone does not display any connected calls
4. caller keeps hearing the phone ring
5. after 2 rings or so, phone rings again this time with NO caller id
6. when the user picks up the handset or presses the speaker button, the call is connected
Has anyone had a problem like this in the past? When I just tried to replicate the issue, the call actually disappeared on me 3 times before I was able to pick up the call.
I've attached a debug voip ccapi inout just incase someone can analyze it.