Yealink T23g phones not provisioning over VLAN

[jk326598]

We are trying to segment the Yealink phones to a new subnet (192.168.11.0) from the primary subnet (192.168.1.0) due to space constraints.

We need to step into this a bit at a time because the phones and other primary devices like printers are all mixed together through several switches. Some managed some not.

For now I am testing one phone directly plugged into one port which is tagged as both 1 (PC network) and 10 (Phones).

DHCP from the Windows server worked and the phone received a 192.168.11.0 subnet address. But the phone never provisioned. Each time I checked the WAN port was not getting VLAN 10 as prescribed in the 3CX extension provisioning page and the admin password never updates .

I did create a 132 helper rule with a value of 10 in DHCP. I can ping the phone from the 192.168.1.0 subnet and the phone could ping the 3cx server on the 192.168.1.0 subnet. But still no provision.

So I decided to remove the DHCP server from the equation and plugged in the network, vlan and provisioning details directly in the phone web page. The good news is the phone showed up in 3cx under the phones as New in bold. But when I assign and extension it goes through the steps for the assignment but never "takes". The phone sits there as New.

In both scenarios I get a dial tone but no ability to call. The phone shows the error "Invite request no response".

On the firewall I do have traffic Any/All allowed between the LAN and the VLAN. Obviously this would get dialed back to specific ports once I get it working.

 

[JohnS_3CX]

Sounds like the issue comes down to networking and how you designed your network.

1. The phone boots up and sends a multicast PnP message
2. If your network allows that message to reach the PBX server's subnet, then you see the phone in bold
3. Once you assign the phone, the PBX sends a message to the phone informing it where to pick up config from
4. Phone picks up config, applies it and reboots.


Judging from what you said, the issue starts at either step 3 or step 4. In this case, you will have to look at

a) the phone UI - see if the SIP account has been populated to first confirm whether provisioning took place at all

b) if the account has been populated, you have to capture the LAN port where the phone connects to and see what the phone does: does it try to register? does it tag the packets?

c) Tagging the packets is one thing, but what your network does with those packets is another. If the phone sends registrations out, then you also need to run a capture on the PBX to see if they arrive. If they don't then you can be almost certain that your network environment is not delivering the traffic as you intended, and you need to address it

 

[jk326598]

Sounds like I need to run a packet capture. Are there any good examples of what I should be seeing back to the phone from the pbx?

 

[JohnS_3CX]

You don't need to worry about the content for now, but you do want to ensure that the packets reach their destination (the most basic of tests). So for example:

1. filter the PBX pcap and include the phone IP as source
2. filter the phone's pcap and include the PBX IP as destination

So then you put the captures side by side: If you see packets generated in the phone, with destination IP the PBX, but the PBX pcap does not include the same packets coming in, then you know for sure that whatever request the phone sent had never actually reached your PBX.



An important detail: If you are using the phone config tab in 3CX to add the VLAN information (so that tagging happens in the phone), then it means the phone cannot reach the PBX at all in its reset state. You might have to enter the VLAN info in the phone manually and then restart it before it can even see the network where the PBX lives on.

If on the other hand you avoided that, and performed the VLAN tagging straight on the switch ports, then the phone will not need any VLAN information, as the network will take care of it in a transparent manner. This might be a better alternative if your equipment allows it.