cusotmer want U1980 transfer the call back to trunk where it receive the call ,ut transfer fail
get log ,pbx send SIP/2.0 603 Decline ,transfer fail.
1.open all the permission that allow every terminal can register and make call ,but transfer still fail .
2.find an parameter in softargu 334 ,when make transfer ,if the incoming trunk and outgoing trunk is same ,and number of caller and callee is same too ,if forbid the call , in default it is forbidden .turn off it .then transfer success .
maybe caused by sip agent or default police of transfer.
before open this parameter ,we should confirm with operater that if the incoming trunk and outgoing trunk is same ,and number of caller and callee is same too