question

Wow, time flies.  I meant to report back earlier but once things began working I forgot about it and Ben's comment above reminded me.  The solution I posted previously was a complete success.  I no longer have any problems with my RC line.  Everything is working great!

I've had this problem for months as well. It's EXTREMELY annoying. I have also asked RC for help to no avail. Polycom phones are essentially Linux boxes. Linux boxes have sophisticated firewalls built in that could *easily* be set to restrict incoming traffic to only that from the RC servers. But alas, RC has the control over the Polycom phone firmware and settings... and fail to take the simple step(s) of enabling the firewall. Worse, they have the phones locked down so consumers with the knowledge to do so can't go in on their own to make the necessary changes. Very very frustrating.

I'll take a look at Will Hunter's advice. If I remember right, the Polycom installation actually told us to enable SIP ALG.

My question to Will is - it almost sounds like this could cause a problem with incoming calls?? Or is that handled through a continuous link between the phone and the RC endpoint that is/was initially established by the phone?

My router (which is combination cable modem & router provided by cable company) does not seem to have a SIP ALG feature. I did, however, have port triggering enabled for two ranges of ports. Everything worked OK except for the "ghost" calls - which came in frequently enough that I had to turn the ringer of my phone down. If I'm sitting at my desk, I can tell if it's a real call or not by looking at the screen. I got tired and frustrated running to the phone from elsewhere every time a ghost call came in.

Turning off the port triggering solved the ghost call problem. Now, legit inbound calls are hit-and-miss so they must rely at least partly on the port triggering and/or a recent solid socket connection with the RC servers. Sometimes the phone rings, sometimes I get the forward to my cell without the phone ringing at all. It's still not a good solution, and I'm still not happy. I've NEVER received an answer or suggestion from RC on this even though I've asked more than once.

As I said before, the phone itself is capable of blocking out these ghost triggers. RC has it locked down to the point I can't get in. I'd be happy if they just let me know how to ssh or telnet in to the phone and give me the needed server address ranges so I can set the phone's iptables appropriately.

I'm not happy. The IP phone they pushed me to upgrade to has limited value. I'm very busy with other things, but if/when I fin a better solution I don't have a problem giving RC the boot at this point.

I have not seen any installation guides so I'm uncertain what is considered best practice in this area.  That said, I plugged my phone into the router and it mis-behaved immediately.  As I recall, I could make calls, but the audio was hit or miss, usually only one-way (don't recall which way).  I was only able to fix that issue by configuring port forwarding in my firewall.  While that fixed the audio, that is when I started getting the ghost calls.  I tried manually configuring different ports over the next few months with mixed results.  When using anything other than the default port I found that incoming calls would not always ring my phone.  Finally after many months of varying results (and continuous ghost calls), I decided to start from the beginning, which is when I found the SIP ALG setting.  Knowing that RC was using the SIP protocol, I decided to disable all port forwarding and toggle the setting to off (on by default on my router).  To my surprise, the audio worked, ring in worked, and the ghost calls stopped.  I have not had a problem since.

My understanding is that when the phone boots up, it establishes a connection to the RC endpoint which in turn provides communication back to the phone from RC (and only RC) through that port, therefore no need for port forwarding.  Port forwarding is what opened my phone up to the ghost calls.  My best guess is that the SIP ALG was somehow preventing the initial "handshake" from occurring properly.  I also read that SIP ALG is poorly implemented in many consumer routers... so maybe there is something to that.  

All I know is my RC line has been on par with any landline I've used since the change.  Good luck!

Would someone mind posting the resolution for this problem as it relates to a soft phone?  I experienced this issue maybe 50 times on my tablet so I uninstalled the app.  Now I'm having the problem on my smartphone.  Based on this thread the soft phone issues seems to have been resolved but I can;t find the solution.  Thank you.

Same problem. Ringcentral changed my ports, VVX 500 is updating right now. Hopefully it fixes this. I get 100-200 calls a day. 3 at a time, simultaneously. 

Update just finished with a new DND (do not disturb) softkey. 

Will repost tomorrow with update.

Great suggestion, Will, thank you.

I know it is a shot in the dark, but mine is a combination cable modem / router too (Motorola SBG6580).  In case it helps someone with this same model, it is on the Advanced menu under Options as "SIP ALG Enable".