On Wed, 2009-02-25 at 14:39 +0000, Gabor Paller wrote: > " It does the > signaling translation from REFER to re-INVITE." > > How does it do it? What is the exact call flow of this translation?
See RFC 5359, the famous "service examples" RFC, especially sections 2.4 through 2.6. For a simple, "blind" transfer: 1. The gateway sends an INVITE to target 1. 2. Target 1 responds OK. 3. Target 1 decides to transfer the call to target 2. 4. Target 1 sends a REFER to the gateway, specifying the URI of target 2 in the Refer-To header. 5. The gateway, upon receiving the REFER, sends a new INVITE to target 2. 6. Target 2 responds OK. 7. The gateway terminates the dialog with target 1 (if target 1 hasn't already done so), and redirects its media streams to the dialog with target 2. One curious feature of this is that while the gateway does most of the work, the transfer-to address (target 2) is determined entirely by target 1. If the call enters sipX via sipXbridge, sipXbridge "shortstops" the REFER, and acts on the REFER itself, leaving the dialog originally established from the gateway to sipXbridge intact. Dale _______________________________________________ sipx-users mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-users Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-users
