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MPM/CCL/OPR

Overview

This section includes information and call flows related to MPM/CCL/OPR. MPM, CCL and OPR messages are implemented as defined by CHINA ISUP specifications.

Definitions

MPM

Meter Pulse Message: A message is sent in the backward direction after Answer at equal intervals (usually every one minute).

CCL

Calling Party Clear Message: This message is sent in the forward direction when the calling party, which has called the special service node, wants to release the call.

OPR

Operator Message: This message is sent in the backward direction from the special service node if the calling party needs to be provided with a ring after hanging up.

Call Flows

MPM - Normal

Calling Party Clear—Normal Release Sequence

The normal release sequence for Calling Party Clear (ITU). The call flow starts with the call in the answered state:

Host 1 = Calling Party

Host 2 = Called Party

Calling Party Clear—Operator Callback—Subscriber Re-answers

Shows the normal release sequence for Calling Party Clear (ITU) with an operator callback. The call flow starts with the call in the answered state:

Host 1 = Calling Party
Host 2 = Called Party

Calling Party Clear—Operator Callback—Re-Answer Timeout

This call flow shows the normal release sequence for Calling Party Clear (ITU) with an operator callback and a re-answer timeout. The call flow starts with the call in the answered state:

Host 1 = Calling Party
Host 2 = Called Party

See Integrated Services Digital Network User Part.
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