Unsupported Suddenly no calls between 2N IP Verso and Yealink T40G

[Tm99]

Hi all,

we have some 2N IP Verso intercoms at several doors and since the update to 3CX version 18, these intercoms cannot call any T40G phones. This is a really strange behavior, other phones can be called without any problems, only the T40G is not working. The call never reaches the T40G and under "Active calls" in the Management console, I just see the stauts "Initiating" for the call.

All devices are on the latest firmware. I performed tests with the latest 3CX version for the T40G (T40G-76.84.0.95) and also the latest from Yealink site (T40G-76.84.0.125). We normally use customized templates but for sure we applied the latest 3CX template without any change.

I created a log on the IP Verso and found these lines:

<135>Jan 5 14:13:44.521 SST: sipstack_handle_sip_event(): SIP1 SIP_CALL_REQUESTFAILURE (cid = 43)
<135>Jan 5 14:13:44.521 SIP: _sipstack_on_call_failure(): call failed (sipcall = 85516780, status code = 407)

Has anybody seen similar problems with 2N and Yealink devices?

Cheers,
Timo

 

[JohnS_3CX]

Hi Timo,

The specific intercoms are not supported by 3CX so we are not in a position to know why this is happening.

The 407 could imply they are simply failing to authenticate on 3CX, but I'm just speculating.

They could also be sending an invite that contains something the T40 does not like

Take a look at this older post here and see if this solution helps you:
https://www.3cx.com/community/threa...to-work-after-v-18-upgrade.84301/#post-395158

 

[Tm99]

Hi John,

that was the trick, thank you very much! The phone is working again.

Cheers
Timo

 

[JohnS_3CX]

Glad to hear Timo! If I remember right, V16 would slighlty modify the SDP (hence removing the incompatibility) but V18 will pass it through untouched.

This means that when the verso sent an SDP the Yealink doesn't like, you now notice the issue. With supported devices, this would have been caught during the interop testing, and the SDP setting would have been changed on the doorphone to ensure compatibility.