Solved 18.0 Update 5 (Build 418) - default "User-agent field" is empty for SIP trunk config - can something be put in pls?

[k.lee]

Hi,

In version 18.0 Update 5 (Build 418), we discovered that in the SIP trunk configuration, outbound parameters, the default "user-agent field" is not sent during the registration process. The following is the log from the SIP server.



As a result, the trunk failed to register successfully. The trunk provider requires that the "user-agent field" line must be sent during the registration process.

In the SIP trunk outbound parameter screen, when we manually put in "3CX" as a custom value for the "user-agent field", the line appears during the trunk registration process and the trunk is successfully registered.



i have a customer who's on a very old version of 3CX on a PC who didn't face this problem. Only the ones who used version 18. The SIP trunk provider implemented some back end policy changes in Dec 22 that mandates the "User-agent:" field be filled with something; it cannot be left blank.

In the next build, is it possible to pls put in a value like "3CX ..." as the default value for "user-agent field" instead of not sending anything?

thk u
kenneth
ps: the above log is from a non-production SIP test account which will be de-activated shortly as we have discovered why the trunk registration failed.

 

[YiannisH_3CX]

Hi @k.lee

I would recommend switching to a supported 3CX provider to avoid issues like this in the future.

The user agent change was implemented a while back and it was done for security purposes for inbound traffic so not likely to change any time soon.
The first registration from 3CX does not contain a user agent header. Once the authentication is established then 3CX will start including a user agent header.