Yealink remote phones

[netswork]

Ive been a 3cx partner for years and installed thousands of phones....never until now have I needed to have remote phones that were not over VPN or SBC. I have a long time client who wants to be able to pickup a phone from his office and take the phone home. Currently we host their 3cx and have a VPN to their office.

Playing with this at my office I setup my phone for stun, forwarded all the required ports in my firewall to our 3cx server. My phone provisions and registers but I can not do anything. Cant make internal/external calls. Cant reach voicemail. Inbound calls don't work either.

Inside my t58 the stun server is pointing to my 3cx server fqdn and port 5060. If I change that to the 3cx stun server of stun-us.3cx.com my phone can make calls but none of my BLF's work. Is that normal?

My customer is wanting to move to something like 8x8 because they say they can make the yealink handsets work from anywhere.

 

[Evolute IT]

Is the 3CX exposed to the internet?

If so, why are you using a VPN for their office?

And, do you have an split DNS setup? If the PBX is local to you, STUN won't work correctly. It needs to be remote for real. Set it up using the default template, bring the phone home, do the port fowards and test it.

I have 6 phones in STUN here without issues.

 

[netswork]

I have a VPN to their office so I can provision the 40ish phones without an SBC or stun. We also host other servers for them. Yes their PBX and mine has a public IP out of our datacenter.

We are using a 3cx provided FQDN so split dns should be a non-issue. When testing with my phone I see my phone registered via its public internet IP. When I provisioned my phone as stun it registers but can't make or receive calls. Looking at the phones configuration its stun was setup pointing to the FQDN (3cx provided) on port 5060. I dont know if that is correct or not. I changed that to stun-us.3cx.com on port 3478, my phone re-registers and I can make calls just fine now but all of the BLF's are grayed out.

On my firewall I am forwarding 5060, 5090, 5000, 5001 and 9000-10999 to our 3cx server.

 

[Evolute IT]

BLF is simply because of the port forward that you probably didn't do for your testing (understandable.)

STUN issue is weird. 3CX does have a STUN server on port 5060but Yealinks templates usually use the stun.3cx.com.

 

[netswork]

So even using stun, if a person takes a phone to their house you have to port forward on their home router to their phone to get blf's to work?

 

[netswork]

Not sure what I am missing here. I factory reset the phone to give that a go. Set the provisioning url to the public fqdn url. Phone registered but it cant make any calls. I look in the phones configuration and it again received my 3cx public FQDN and port 5060 for the stun. I manually change that to one of 3cx's stun servers and I can make calls again but again the BLF's are all grayed out.

 

[leejor]

At the time the phone cannot place calls, does the Activity Log show the call attempt? ..or, is it not even reaching the PBX? No restrictions on the extension itself?

 

[netswork]

Looks like it may have been a firewall issue that the remote phone was behind. Doing some more testing.

 

[Evolute IT]

So even using stun, if a person takes a phone to their house you have to port forward on their home router to their phone to get blf's to work?

Yes. Some routers you can get away without it, but for most, you need it. Also, disable SIP ALG if not already done.

I look in the phones configuration and it again received my 3cx public FQDN and port 5060 for the stun. I manually change that to one of 3cx's stun servers and I can make calls again but again the BLF's are all grayed out.

It might depend on the Yealink phone model. Mine is a T46S and I am also running the PBX built-in STUN server, port 5060.