Factory Reset Yealink Phone - Not prompting to login

[loyer]

I am trying to completely start fresh with an existing Yealink T48S phone. I remove the phone from the extension. Then I tell the user to factory reset the phone (press and hold the "ok" button). The user says it asks to reset, they click ok, and it reboots. The phone is behind a SBC. When the phone reboots, it looks fairly normal with a "No Service" blank BLFs, etc. In the web admin, on the phones page, I assign the phone back to the user's extension.

Then then phone reboots.... and doesn't ask for a login (extension and voicemail pin). It just starts working.

How can this be? When you factory reset the phone, doesn't it wipe it completely? How would it know the user's extension and voicemail pin? What am I missing?

 

[loyer]

Oh, PS, not sure if it matters but it is a Yealink T48S with the latest firmware connecting to a 3CX 15.5 SP3 server. The SBC is running on Windows.

I just want to make sure the phone really did fully reset and wipe clean.

Thanks for any help.

 

[big.LITTLE]

Do you have auto-provisioning through DHCP option 66 setup?

 

[loyer]

Not via DHCP... it is behind a SBC so it auto provisions like local LAN (multicast) but I just assumed that the user would need to enter the user/pass info. Or do you NOT have to enter user and pass with local LAN / SBC??

 

[Aram]

Not via DHCP... it is behind a SBC so it auto provisions like local LAN (multicast) but I just assumed that the user would need to enter the user/pass info. Or do you NOT have to enter user and pass with local LAN / SBC??

Hi loyer,

1. You don't need to enter login (using the etx. number and VM pin) when provisioning types are Local LAN and SBC. Only the RPS (Direct SIP - STUN) requires the login.
Please read this guide for more information:
https://www.3cx.com/sip-phones/yealink-t4-series/

2. Now about the provisioning.
It's impossible that the phone (running 3CX supported version) will provision by itself without any influence. So, you have 2 things to check:
a) Does someone else have access to 3CX Management Console and assigning the PnP requests to the appropriate extensions?
b) Does this user has DHCP options configured on his DHCP server. Check the following options - 66, 43, 120 and 132.
Remove them and phone will not provision "by itself".

 

[loyer]

Hi Aram,

Thank you. I was just confused about the login process for local/SBC provisioning. Everything else is working. Most of my users are remote so I usually provision them with Direct SIP / STUN --- so I was used to having to enter a username and password. I didn't know that with local and SBC, it did not require a login.

RE #2 - I did assign the phone to the user's extension after it showed up on the Phones page due to PnP. So it was me. It didn't do it automatically.

Again, thank you for your help and clarification.