Yealink IP phones


Hi Support,

We are facing Caller ID problem in one of the Yealink IP Phones T20P models.

When the “Caller” calls the “Callee”, the Extension name is not displayed on the “Caller” side whereas on the “Callee” side, the Caller ID and Name is displayed. As per client, this was working in FreePBX but the same thing is not working in GS UCM6208.

Anyone facing this issue?

I have tried LDAP feature on GS IP Phones which works but some models like T20P doesnt support LDAP.
They have XML feature but there’s no configuration on IP Phone for such.



On a Grandstream phone this is adjusted in the Account SIP settings - Caller ID Display and Callee ID Display.


And how was it done in FPBX? I ask as the T20 is obsolete and no longer supported. The last firmware is from 2015. You may need to determine how done and then see if it is able to be replicated. I did find this in a release note-

Not sure if this is it, as I do not have a t20 by which to test.


GS IP Phone no issue. We recieved Caller ID on both the end.



As per the client, he said it was by default setting of the Caller name display. Checked and changed few settings on Yealink phones doesnt seem to do anything.

In UCM, does the SIP call send “Header” along with Caller ID and name and Extension as such? so that we could modify those settings on the SIP server level and see if this works.

have you setup any such do let me know…



I suggest you take a capture of calls from/to both GS and Yealink and compare.


yes i have both the capture packets from GS phone and Yealink.

how do we compare the calls?



Use wireshark, find the calls and open the SIP messages and see what is different.