Although it is not mentioned in any of the RFCs, the universal way of using REFER for call transfer is to send the REFER within the dialog that you are transferring, the dialog that was created by the initial INVITE. "Out of dialog REFER" is rarely used for call transfer.
It is very uncommon to have a subscription and an "INVITE dialog usage" (that is, phone call) within the same dialog -- with the exception of the subscription that is created by a REFER within the INVITE dialog usage. Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
