Tandem Trunking
Note: Central Office Loop Supervision must be provided to prevent lines from remaining conferenced/busy when the parties hang up.
To establish an Note: When both outside parties finish the Unsupervised call, unsupervised conference must be man-
Conference: ually terminated by the telephone which set up the call.
1.Establish first outside call.
2.Press 
.
●The call is put on Hold.
3.Establish second outside call.
4.Press 
.
●
5.Press 
.
●Both outside parties are put on Hold.
6.
●Unsupervised Conference is established.
To later join an 1.
Unsupervised
Conference: 2. Press either 
of the Conference call.
To later join an 1. Establish a
Conference: 2.
●Both outside lines become idle.
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