SIP “Reason” Header in CANCEL Message SupportThis new feature added to the 7.4.7 firmware release seems to be a really great improvement...but there's no supporting documentation.  I've tried using the RFC outlined CANCEL message with the "Reason" he...

After upgrading to firmware version 7.4.7, the SPA-504G phone disconnects the existing call when a speeddial button is pressed.  This problem occurs with 7.4.7, 7.4.6, 7.4.4, but does NOT occur in 7.4.3.  This problem occurs with both fnc=blf+sd and ...