Playback on REFER

Setting the SPL options parameter to playback-on-refer or the ACLI ringback-trigger parameter to refer (or 183-and-refer) enables a REFER message to trigger playback toward the transferree. You configure this on the realm, session agent, or SIP interface for the transferrer, not for the transferee or the REFER target.

The REFER scenario requires that the Enterprise SBC performs local REFER termination, i.e., that it terminates the REFER locally. The SPL options you configure do not implement this behavior: You must configure local REFER termination separately. Proxying a REFER message is not a trigger.

Playback begins when the Enterprise SBC receives the REFER message, and stops when the REFER operation is deemed complete with a final response (200-299 or 400-699).

A call flow for the playback-on-refer scenario looks like this: