I’m not on-site yet, but as it’s reported to me, all of the phones (GXP2170 and GXP1630) periodically have a one-way audio issue when using an analog trunk. They have no SIP trunk, only one analog trunk with 3 ports.
I’m very familiar with one-way audio through routers due to NAT issues, but there are no SIP trunks here and all phones are on the same LAN as the UCM.
The problem is inconsistent, but they claim that rebooting the UCM fixes it for several hours. This system had been up and running for 300 days without a problem. We upgraded the firmware anyway and the problems remains. I had a tech swap out the UCM for a new one, restored a backup, and the problem returned a few hours later.
I’ve asked them to try internal calls next time the problem happens to help rule out handsets and network issues. I’m not entirely convinced that it isn’t a Telco problem, but have not been able to reproduce the problem on a butt phone yet.
Any other thoughts? Thank you!