I have a three clients on hosted VOIP solutions, one is ring central, another two are phone.com. The Ring Central person and 1 of the phone.com person has a delay in the ring or sometimes a disconnect when they answer. The delay is say 2-3 seconds, meaning about 5 rings, but the desk phone has only run once and sometime not at all. The disconnect, to me seems more like the phone is still ringing, but this time, the delay was so long even though the phone is ringing, when they pick up handle, the call is to voice mail already. To make it worse, this only happens to every 10-15 calls. The other times, it works exactly the way it is supposed to. Caller hears one ring, so does the desktop phone.
The second Phone.com client's phone always works as expected, who also has the same cheap SOHO router as the Ring central person, so I don't think it is quality of router.
The problem Phone.com client has a SonicWall TZ 210. This client also has multiple phones, and there are times the "hunt" meaning it rings one phone, no answer it goes to the other phone, shows this behavior also. Example, ext1 rings 3 times, falls to ext2, which doesn't ring until 1-2 seconds after Ext1 stopped. They also observed ext2 to start ringing, but the call came through main line, skipping ext1 entirely. Or maybe rings once, sometimes not at all then VM light comes on showing they missed a call. Or when they pick up, the person mentions it rang a few times, even though the desk phone only rang once.
If the call is connected or outbound, all features work as expected.
They all bought their phones from the vendors. Speed tests based on the perspective company troubleshooting pages show good latency times as well as low jitter. The sonicwall has the address objects, rules, as well as Consistent NAT, per Phone.com web site. All three are static IPs. All of them have basic Polycomm desk phones.
The two that are having problems are on FIOS, the problem free is on cable (charter if it matters) .
Anyone hear of anything like this, or been able to fix it? I have been chasing my tail on this for a while. Can't seem to find any others with similar problem, and of course the support shows "everythign is fine" or "Unplug the phone and reboot it, it connects so it is fine!". Because it is intermittent, it is hard to reproduce on demand.