[Serusers] call transfer INVITE / REFER

[Iqbal]

Hi

Should the call transfer use INVITE or REFER as a method, cause I seem, 
to be getting INVITE, but this then causes problems with authentication.

A <-->B  then B transfer to C (all IP phones)

This transfer seems fine, but it uses INVITE, no REFER . All phones on 
same sip domain/server

Now when this setup changes

pstn <---->B and then B tried to transfer to C, we get nothing, well we 
get 404 , it check the !location setting, and says ur not allowed.

Is the REFER the first message to be sent, or is there a INVITE 
transaction first,

Iqbal