Trunk Signaling And Supervision; General Signaling & Supervision Concepts - Mitel SX-200 EL Technician's Handbook

Technician's Handbook

Trunk Signaling and Supervision

General Signaling & Supervision Concepts
All trunks share similar basic handshaking functions. The actual
signaling mechanism will vary with the trunk type.
Seize: (request to make a call) The calling party initiates the call by
requesting service from the called party.
Seize Acknowledgment: (ready to receive) The called party indicates
that the call can commence.
This acknowledgment occurs when the calling party expects a
response (Dial Tone) or when the called party needs time to establish
appropriate resources (DTMF receivers).
Digits: (who to talk with) The calling party generates the rotary pulse or
DTMF.
Stop Dial: (slow down, can't handle the pace) The called party
generates a signal to indicate that digits are in risk of being lost.
Receipt of Digits: (status of call) The called party generates audible
tones to indicate the status of the call (for example, Ringback, Busy,
and Reorder).
Answer Supervision: (called party has answered) The called party
indicates that the call has been answered. This signal is for billing
purposes (Hotel/Motel), generation of SMDR reports, etc.
Disconnect Supervision: (release and go back to idle) Either party
generates this signal to indicate the termination of a call and to return
the trunk to the idle condition.
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