Hi everyone! Hoping someone has an idea of what’s going on.
I’ve been using FreePBX for years with a few SIP flashed Cisco 7970 and 7960 phones. They have been working extremely well with the odd issue that ended up relating to the line cards and not FreePBX. However, recently (this week), in a span of two days, 3 separate phones began to develop a strange issue.
When lifting the handset, there is no audio to both parties, but switching back to speakerphone works. I initially thought it was a hardware problem with the phone, but a second phone exhibited the same symptom. I chalked it up to coincidence, and replaced both phones. A third phone has begun to exhibit the same symptom now, which tells me there is more going on.
I wasn’t able to find any information specific to this one, but does anyone have any idea, or has seen this before, why when lifting the handset all audio dies completely, and what would have caused this to happen like this?
FreePBX 2.11.0.43 with Asterisk 11.7.0.
Phone firmware:
Cisco 7970 SIP: SIP70.8-5-2S
Cisco 7960 SIP: P003-8-12-00
This is an isolated internal network, so there are no firewall or connectivity issues that should cause this as calls remain within the network using physical POTS lines fed from Digium line cards and other phones remain functional (for now and more I hope!)