Call Transfer - Bad Request - with Fritz!Box 4790

Question

Hello, 

I don't know much about the configuration, so sorry if my question is stupid. 

I use zoiper on  a fritz!box 4790 and if I get an external call and use the transfer function to transfer the call to e.g. connected DECT phone or analogous phone I get the message bad request. 

Earlier I used another softphone and this function worked well. 

Thanks for your effords,

Answer 1

Hello,

As I am aware the almost all FritzBox! devices do not support call transfers, the ones that does, I believe require DTMF tone based transferring. The standard one which Zoiper is using ( with SIP "REFER" method) will not work.