Solved Attended transfer not working as expected

[SBV-IT]

We have a problem with forwarding calls since the update to v20.

If we transfer an external call via attended transfer, the call ends up in the parking position at the destination instead of the call being able to be continued directly.

In v18 the forwarded conversations could be continued directly after the transfer

 

[OlegR_3CX]

Hi there.
What SIP trunk are you using?

 

[SBV-IT]

Hi!
We're using Deutsche Telekom (CompanyFlex)

It happens sporadically.

After transfering the call, the recipient won't hear the caller. But the caller is able to hear the recipient.
Now the odd thing: When in this state: If the recipient puts the transfered caller on hold and gets him out of hold again - the recipient is able to hear the caller.

It seems that the 3CX puts the caller correctly on hold while our "agent" calls the recipient for transfer. Then the "agent" will transfer the call over to the recipient and the caller stays in a somewhat limbo-hold-state.

It's client indifferent, the problems shows with SNOM desk telephones, legacy 3CX Windows and also the new Webclient.

#Edit
Something new I found out:
When this happens the caller won't hear our configured OnHold-music but rather a different one.

Sorry if hard to understand, not native speaker here.

 

[OlegR_3CX]

Hi there.
Export your SIP trunk settings and then tell me if your options for below are different ?

<field name="IsSupportReinvite">0</field>
<field name="IsSupportReplaces">0</field>

 

[SBV-IT]

Hi!

Support is enabled:
<field name="IsSupportReinvite">1</field>
<field name="IsSupportReplaces">1</field>

 

[OlegR_3CX]

Hi there. This can be your issue. Can you please change and edit the file so you have it as 0.
So you will need to reimport your trunk and its settings after.

 

[SBV-IT]

Hi Oleg!
This fixed the problem for us!

 

[OlegR_3CX]

Perfect, and thank you for the feedback.
Glad its all working now.
Have a nice week ahead.