Hey everyone,
I inherited some strange setup with our Cisco VOIP. Last night I was replacing our firewall (Meraki MX100 > MX250) and found that one of my WAN links would not come back up after the switch. I called the ISP and discovered that it was set, on their end, to be 100mbps. I had him set it to auto and suddenly I had link lights. Hooray, I thought.
Then I found that, while the link was up, the phones would not work at all. I rebooted CUCM and looked through the voice gateway switch as best I could but could not figure it out. I spoke with my boss about it and he vaguely remembered this being an issue with the setup and them setting the speed to 100mbps in the past to get it to work. The phones registered fine and looked alright, but I just got no dial tone upon picking up a handset and couldn't ring outside or inside the company.
I called the ISP and had them set it back to 100, and put the old firewall back in place, and the phones started working again.
I'm more on the systems side than the networking or voip side of things.
Anyone have any idea at all where I can look to try to figure this out?