I have a pair of Polycom Trio 8800 phones that have worked perfectly now for over a year. In the last month or so, they simply stopped working. Given that they are in use for a pair of mini Zoom conference rooms, I've worked with Zoom tech support to try and get them back to working but with zero success.
The problem: when the phone powers on, it makes a DHCP request to get the normal set of IP parameters: address, SNM, GW, DNS servers. It never gets a response from the DHCP server. And with no network parameters, it obviously doesn't work.
Things tried. We've tried a number of different things to try and find out why the phone and the DHCP server are at odds with one another:
- We have reset the phone to factory settings then did the minor configuration settings that Zoom requires for their SIP phones. Actually, we tried this several times but then remembers that "definition of insanity" maxim.
- We took the phone off of DHCP and hard-coded its IP address, SNM, GW, and used Google's 8.8.8.8 and 8.8.4.4 addresses for DNS. It could never reach the Zoom SIP servers.
- We unplugged the phone's network cable and plugged it into a Windows 10 Pro laptop. An IPCONFIG shortly thereafter showed proper IP parameters both for the laptop's WiFi and Ethernet connections. So I know the DHCP server saw the request from the laptop and it provided the right set of IP settings.
- We had our network provider make sure the firewall had all the outbound IP addresses and associated ports open as required by Zoom. No change. Of course, if the DHCP request fails to supply parameters, it doesn't much matter what the firewall settings are.
- Debugging is a tad difficult: the phones are in New York; I am in Dallas. And there are no IT folks in the New York office. So while I can get some help, it is definitely limited.
This is kind of a mystery. The phones worked perfectly for over a year then something changed. I'm just looking for suggestions on how best to resolve what should be a simple setup.