Cisco
Configuration Tasks
Configuring Disconnect Supervision Commands
PBX and PSTN switches use several different methods to indicate that a call should be disconnected because one or both parties have hung up. The commands in this section are used to configure the router to recognize the type of signaling in use by the PBX or PSTN switch connected to the voice port. These methods include the following:
•Battery reversal disconnect
•Battery denial disconnect
•Supervisory tone disconnect (STD)
Battery reversal occurs when the connected switch changes the polarity of the line to indicate changes in call state (such as
Battery denial (sometimes called power denial) occurs when the connected switch provides a short (approximately 600 ms) interruption of line power to indicate a change in call state. This is the signaling looked for when the supervisory disconnect command is enabled on the voice port, which is the default configuration.
Supervisory tone disconnect occurs when the connected switch provides a special tone to indicate a change in call state. Some PBXs and PSTN CO switches provide a
Note In some circumstances, you can use the FXO Disconnect Supervision feature to enable analog FXO ports to monitor call progress tones for disconnect supervision that are returned from a PBX or from the PSTN. For more information, see the “Configuring FXO Supervisory Disconnect Tone Commands” section on page 16.
Cisco IOS Release 12.2(2)XT and 12.2(8)T
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