Aastra Telecom 57I C53I manual SIP Message Sequence for Blind Transfer

Advanced IP Phone Operational Features

Advanced Operational Features

SIP Message Sequence for Blind Transfer

The SIP message sequence for Blind Transfer avoids the transfer target having two simultaneous calls. Prior to release 1.4, a CANCEL message was sent to the transfer target (if it was in a ringing state) after sending a REFER to the transferee to complete the transfer. In the 1.4 and later releases, the CANCEL is now sent before the REFER message.

The following parameter allows the system administrator to force the phone to use the Blind Transfer method available in software versions prior to 1.4:

sip cancel after blind transfer

This parameter is configurable via the configuration files only.

Configuring SIP Message Sequence for Blind Transfer

Configuration Files

For the specific parameter you can set in the configuration files for enabling/disabling the blind transfer method, see Appendix A, the section, “Blind Transfer Setting.” on page A-135.

Advanced Operational Features

41-001160-00, Rev 01 Release 2.0 6-5