Hello,
I am an IT service provider and my clients use Polycom VOIP phones. They asked me to look into this and the VOIP provider is not of much help.
Intermittently, when the receptionist rings someone internally, the light will go on but the ringer is silent. We have checked the ringer volume on all phones and they are all at the max. This creates a problem because when the receptionist buzzes someone to notify them of a call, they will not become aware of this unless they are looking at their phone. The annoying part is that sometimes the ringer works on internal calls and sometimes it doesn;t.
The VOIP provider is telling me that the firewall/router is incorrectly setup. He has instructed me to disable SIP ALG, and I have done this, but it does not make a difference. I have tried a different brand modem and a different brand router and nothing seems to fix this and I am out of ideas. If anyone has any suggestions I am all ears.
Thanks!