Thought I would throw my story in the ring to see if it helps as I too have been having problems since Last Friday May 11th. Starting first thing that morning neither my wife or I could hear audio/RTP streams for inbound or outbound calls on our ObiTalk 202 adapter, call setup was not a problem. I was 10+ year veteran Vonage user and know that sometimes the RTP streams can be blocked so I did all my usual reboots, configuration checks but problems persisted. I searched the web and saw others having problems so I kept looking until I found this thread and decided it was time to follow SteveInWA's steps to see if it would resolve the problem, which it did not.
Background config: Spectrum/Brighthouse/Timewarner ISP using their cable Modem in Bridged mode I get 60Mbps down 6Mbps up. I use a Cisco E4200 Wifi Router and have the MacAddress of the ObiTalk 202 adapter defined in the DMZ, effectively in front of/outside the Wifi Router. Not a gamer, not a BW hog, relatively quiet network for the BW I have available. Let me add I have my own Google Voice number and my wife has her own, so effectively the 202 is configured for two Google Voice accounts. I didn't see the Google Chat setting in Legacy Settings for either account prior to executing Steve's steps and don't see after. I did see a change to my wife's Voicemail setting post reconfig. She doesn't want Voicemail on her line and there is no way to turn VM off which there was prior to the upgrade.
1) Prior to Steve's steps no audio/RTP in or out. However dialing in/out call setup worked fine
2) After rebooting everything in my network we would get audio/RTP to flow for 5-15 minutes and then it would stop, suggesting it's my network or ISP
3) This morning followed Steve's step to the "T" and audio/RTP worked for 5-15 minutes and then stopped
4) Reboot entire network and now when trying to make outbound call I get message "The number U have dialed has not received a response from the service provider". Inbound calls don't ring the adapter and go to voicemail.
I'm ready to call my ISP and blame them for blocking something referencing this
https://www.obitalk.com/info/faq/Troubleshooting-sec/ports-to-keep-open-on-my-router FAQ but thought I'd share to see if it's something bigger with Google at this point?
SM in sunny Florida.....
Hour or two later update: So eventually I got back to the same problem of call setup working but no audio. I rebooted my Wifi Router and was able to call my ISP. They confirmed no recent config changes of my cable Modem. I'm configured in bridged mode and they have a special rule I asked for years ago to resolve a Vonage problem that ports 10K-12K UDP are allowed inbound as that is/was the range Vonage used. I see ObiTalk uses 10K so I should be good. I have V3.2.2(5859EX) on the ObiTalk and my Cisco E4200 is running the latest and greatest firmware from Cisco.
I was hoping Bluescat or SteveInWA might want a customer with repeatable problem to see if they can correlate what's the root cause. I don't have a network tap to capture packets any more but if I did I'd be sniffing packets at each hop looking for errors.....