ISDN Protocol Administrator's and Developer's Guide ... - Intervoice

E1 Transfer MethodsE1 Transfer MethodsExplicit Call TransferCall transfer methods that function in an E1 environment are discussedin the topics on the following pages.Euro-ISDN does not provide for a method of call transfer, so Intervoiceimplemented the supplemental service of Explicit Call Transfer (ECT)as defined in EN 300 367 and EN 300 369-1.Explicit Call Transfer (ECT) is a method of transferring a call using twolines:• Primary• OutboundAfter the outbound call reaches the ringing (Alerting) state, the OmviaMedia Server makes a request to transfer the call to the switch. The twolines are connected inside the switch, and the calls are released from theOmvia Media Server. The transfer request can be configured. It can alsowait until the outbound call is answered before transferring the call.The characteristics of ECT are shown in Table 3-4.Table 3-4. ECT Transfer CharacteristicsSpan Type Transfer Type connect UserDLL?E1 Two Line Transfer Yes60001262, First Edition Call Transfer 3-5