Cannot Register ANY Phones

[healthy]

We have been running our local 3CX instance for a number of years. Recently we needed to add new phones, but have been unable to do so.... I have gone as far as setting up a new 3CX Server to rule out a configuration issue, but it appears that there's something that I'm missing as both refuse to register...

It's a simple network, originally separated subnets - 1 for PCs and Servers (50 or so) and 1 subnet with PoE switch just for phones connected to our router with a VM and the 3CX Windows Server running on it. (10 phones). Now, I have even simplified and moved everything onto the same network segment, yet I don't see a single phone listed. I have factory reset and am unable to see any phones at all.

I added a dns zone for our 3cx.us FQDN address that points to the internal LAN IP of the 3CX Server but that hasn't helped any either.

Any help would be most appreciated

 

[eddv123]

refuse to register

Phones wont refuse, they will always register if the following is configured correctly:

* Registration/authentication details.
* The network permits.

I think chances are that your subnet configuration is blocking this perhaps (are you using VLAN's?). If using Yealink phones there is a PING mechanism in the web interface of the phone - can you ping the PBX ?

What is the PBX hosted on ? Windows or Linux ?

 

[healthy]

Thanks eddv123, much appreciated!

No VLANs, removed even the physical segments I had (originally the 3CX Phone server (a Windows Server) was on separate PoE switch connected to a separate port on our router so that the IP Phone network was separate from our computers... I now have them all on the same network with the PoE switch connected to our regular network switch.

I'm unclear what Registration/Authentication details means....

I can ping both the phones from the 3CX server and ping from the phone I'm testing to the 3CX server...

Phones wont refuse, they will always register if the following is configured correctly:

* Registration/authentication details.
* The network permits.

I think chances are that your subnet configuration is blocking this perhaps (are you using VLAN's?). If using Yealink phones there is a PING mechanism in the web interface of the phone - can you ping the PBX ?

What is the PBX hosted on ? Windows or Linux ?

 

[JohnS_3CX]

If you reset the phone and it does not appear in the phones section as "new" then you probably have a network misconfiguration. At the very least we can say that multicast messages are blocked.

In this case it will become impossible to autoprovision the phones

 

[eddv123]

@JohnS_3CX I am surprised you did not post the guide:
https://www.3cx.com/docs/plug-and-play-ip-phone/

I have obviously assumed that the phone is auto-provisioned, you are right it may not be.

 

[JohnS_3CX]

@JohnS_3CX I am surprised you did not post the guide:
https://www.3cx.com/docs/plug-and-play-ip-phone/

I have obviously assumed that the phone is auto-provisioned, you are right it may not be.

@healthy said he wanted to add new phones but could not. Also "yet I don't see a single phone listed. I have factory reset and am unable to see any phones at all. "

I suppose the multicast message is not reaching the PBX should be the likely cause here.

 

[Alphabetic]

What have you got configured in your DHCP server options?

 

[healthy]

I know of nothing that has changed regarding blocking multicast, and as far as DHCP Server options, I am just specifying local DNS, IP address, Gateway, but nothing specific to 3CX.

What have you got configured in your DHCP server options?

 

[Alphabetic]

What's your physical network topology?

 

[healthy]

What's your physical network topology?

It's a single segment LAN, the 3CX Server is a VM on a hosted server which has 2 NICs one on the same segment and one on the old VoIP segment that was in use. 2 switches, 24-ports each 1 PoE, 1 just GB switch...

 

[Alphabetic]

Which one of your devices is doing the LAN segmenting?

Whats the make/model of your switches? Have you tried factory resetting them.

 

[ASC Admin]

I had a problem yesterday assigning a Fanvil X5S to an extension through an SBC. The new phone would show up in the management console, but it would not provision itself when added to an extension. The phone itself would flash an 'invalid file' window each time I tried. I ended up deleting the extension itself and recreating it. Then the phone provisioned just fine. Try adding the phone to a new dummy extension. You never know.

 

[JohnS_3CX]

I had a problem yesterday assigning a Fanvil X5S to an extension through an SBC. The new phone would show up in the management console, but it would not provision itself when added to an extension. The phone itself would flash an 'invalid file' window each time I tried. I ended up deleting the extension itself and recreating it. Then the phone provisioned just fine. Try adding the phone to a new dummy extension. You never know.

Unrelated in this case, as you were receiving the multicast SUBSCRIBE message.

 

[healthy]

Which one of your devices is doing the LAN segmenting?

Whats the make/model of your switches? Have you tried factory resetting them.

Both Netgears, a GS324TP S350 Series 24-Port Gigabit Ethernet PoE+ Smart Managed Pro Switch with 2 SFP Ports (190W)
and a GS348T S350 Series 48-Port Gigabit Ethernet Smart Managed Pro Switch and 4 SFP Ports

 

[JohnS_3CX]

I know of nothing that has changed regarding blocking multicast, and as far as DHCP Server options, I am just specifying local DNS, IP address, Gateway, but nothing specific to 3CX.

Unfortunately though, This still does not tell us why the multicast message is not received by the management console.

You need to see if the system is listening to multicast, and if the discovery messages from the phones are reaching the PBX.

For example, I started a capture on my PBX and reset my phone. I see a subscribe message in the capture like so

Notice the destination is the SIP multicast IP. In this case, the phone appears on my management console as new

 

[Alphabetic]

Im wondering if this is your cause

 

[healthy]

I will try factory resetting both switches when we break for lunch. Shouldn't be an issue as I didn't make any changes to them to start with...

 

[JohnS_3CX]

Also, since you have 2 NICs, you must make sure that the one listening to the multicast messages, is on the same network as the phones.

The NIC that is bound to the SIP server can be selected here:

 

[Alphabetic]

I'd do as John said first.

Run a Wireshark from the 3CX, reset the phone and filter in wireshark for ip.addr >= 224.0.0.0 && sip to see if 3CX can see it.

 

[JohnS_3CX]

I'd do as John said first.

Run a Wireshark from the 3CX, reset the phone and filter in wireshark for ip.addr >= 224.0.0.0 && sip to see if 3CX can see it.

May I add, make sure the capture is on the interface that the SIP server runs. If the messages arrive on the secondary interface, I would not expect them to appear in the management console