Grandstream GXP 2135 not showing in Phone list. Cannot provision

[SimonLessard]

Dear everyone,

On a fresh 3CX linux install, I'm trying to provision my new GXP2135.
I upgraded the phone with the firmware provided by 3CX and resetted to factory defaults. The phone is still not showing in Phone list. If I manually configure the SIP credentials using the Phone's web page, I can register the SIP account and the Phone get in the list but obviously that is not the way I want to go... plus, I am not sure that the all config will be loaded in the device that way. I looked at all my routers to make sure they all have the Multicast enabled.
Do I need DHCP 66 enabled? I read so at some places, but I'm not sure this is required for PnP.
How can I troubleshoot?

Thanks for your help,
Simon

 

[YiannisH_3CX]

Hello @SimonLessard

Please check out the following guide that will help you troubleshoot PnP issues.
https://www.3cx.com/docs/plug-and-play-ip-phone/

 

[SimonLessard]

Hello @SimonLessard

Please check out the following guide that will help you troubleshoot PnP issues.
https://www.3cx.com/docs/plug-and-play-ip-phone/

Thanks for your help. I did checked that page. My 3CX server is running inside a VM in VirtualBox, I don't know if that changes something at all. However, when I use the "netstat -g" tool, I indeed see the sim.mcast.net entry. Not on ETH0 but on enp0s3, since it is virtualized.

 

[SimonLessard]

I tried this:
http://192.168.1.24:5000/provisioning/5f4cmfv95dgv/[MAC address of the phone].cfg
Shouldn’t I was supposed to receive the config file generated for this phone by the 3CX server?
I got a 404, website not found.

 

[SimonLessard]

I ran some capture with Wireshark and I do see some packet exchange between the phone and the 3CX server. At some point 3CX send these 4 packets about 10 times in a row, where the number in bold is incremented by 1 every time.
[protocol packet size ports packet content]

TCP 74 5000 → 41363 [SYN, ACK] Seq=0 Ack=1 Win=28960 Len=0 MSS=1460 SACK_PERM=1 TSval=3824181 TSecr=76760 WS=128

TCP 74 5000 → 41364 [SYN, ACK] Seq=0 Ack=1 Win=28960 Len=0 MSS=1460 SACK_PERM=1 TSval=3824187 TSecr=76762 WS=128

TCP 66 5000 → 41364 [ACK] Seq=1 Ack=518 Win=30080 Len=0 TSval=3824189 TSecr=76763

IPA 378 unknown 0x54

In that last packet sent by 3CX to the phone, I can see in the content is an HTML page with the only content “400 bad request”

Is that possible that my 3CX server doesn’t have the right template to generate the config file?

 

[cobaltit]

Not sure why you went from trying PnP to manually putting in SIP credentials but I'd try the manual provisioning method per below. And yes if you only put in SIP credentials then of course it won't have any other settings, 3CX hasn't implemented magic SIP yet

https://www.3cx.com/sip-phones/manually-provision-supported-grandstream-gxp/

I tried this:
http://192.168.1.24:5000/provisioning/5f4cmfv95dgv/[MAC address of the phone].cfg
Shouldn’t I was supposed to receive the config file generated for this phone by the 3CX server?
I got a 404, website not found.

I believe it's actually either cfgMAC or cfgMAC.xml not MAC.cfg

 

[SimonLessard]

Thanks for your comment Cobaltit. I really appeciate!
I tried to manually put the SIP credentials just to make sure that my phone can actually talk to the server. I removed those after I confirmed.
I tried to manually provision like described in the link you shared but still no luck. But before even talking about provisioning, should'nt I be seeing the new phone in the Phones menu in 3CX?
Whatever I tried, I never saw the phone being listed here. However, 3CX found another phone on the network, one from Fanvil. This phone is actually connected to my Toshiba PBX and I manually entered the SIP credential in this Fanvil to connect to my Toshiba... but 3CX found it and listed it as "new". I'm trying to get the PnP working so I can complete the migration to 3CX.

 

[cobaltit]

@SimonLessard

It should, but it's not a requirement for things to work as you've noticed. Before PnP most did DHCP Option 66 and I still do on many occasions. The fact that PnP isn't working simply means your 3CX isn't listening on the multicast address or your phone isn't announcing itself. The fact that the Fanvil shows up seems to imply that 3CX is listening. This is a simple announcement at boot-up so it really doesn't matter if the phone is provisioned to 3CX already or another PBX for that matter unless that announcement is turned off in the provisioning. Try pulling the config file in a browser like you were before but using the other formats I listed and see if that works.

 

[YiannisH_3CX]

I tried this:
http://192.168.1.24:5000/provisioning/5f4cmfv95dgv/[MAC address of the phone].cfg
Shouldn’t I was supposed to receive the config file generated for this phone by the 3CX server?

The format for Grandstream phones is http://192.168.1.24:5000/provisioning/5f4cmfv95dgv/cfg[MAC address of the phone].xml
Try this and see if you can get the configuration from a browser.
The fact that you can see the fanvil device means that your server is listening to PnP however either the phone is not sending a request or the request is not reaching the server. Is the phone in the same subnet as the PBX?

 

[SimonLessard]

Thanks again for your help. Yes, the phone is on the same subnet. We have everyone on 192.168.1.x.
So I have some developments...
By first specifiying the provisioning server in the phone’s web ui then manually addind the phone (+ add phone button in 3CX) I was able to provision the phone. Even more surprising, I have been able to play a little with that phone : assign to an extension, provision, remove from that extension and assign to another extension. When dissociated from it’s extension, the phone appeared as “new” in the list (although there was a ghost entry of that phone in the list after I dissociated it!? Anyway when I re-assigned it to a different extension the two listing merged and there was only one entry for that phone, assigned to the good extension so I guess it is ok).
So I was really happy about this progress! I decided to wipe the phone to factory default and try again, just to confirm it is reproductible. Unfortunately, after setting the provisioning server on the phone then manually add the phone to an extension in 3CX, the phone provisioned but there is no way I can recover that auto-provisiniong functionnality! The phone is no longer identified as “new” when I dissociate from it’s extension so I have to add the phone again using it’s MAC address.

 

[YiannisH_3CX]

Glad to see you were able to provision the phone and got the chance to test a few things.

When dissociated from it’s extension, the phone appeared as “new” in the list (although there was a ghost entry of that phone in the list after I dissociated it!?

The phone will remain visible under phones until its Registration times out. So even if you unplug the phone the system will wait for the entire duration of the registration for a re-registration from the phone. If that never arrives then the system will remove the phone.

The phone is no longer identified as “new” when I dissociate from it’s extension so I have to add the phone again using it’s MAC address.

At this point i would recommend using wireshark to help you troubleshoot the PnP issue. You will need to run a capture on the PBX and see if the multicast request is being received by the phone.