HP FlexNetwork MSR Series Configuration Manual page 52

NOTE:
Before you configure the number of busy tone detection periods, test the new value repeatedly to
make sure that the new value does not cause failed or false on-hook.
Enabling the busy tone sending
If the PBX fails to play a busy tone to a digital telephone, enable the FXO interface to send a busy
tone to the PBX, which will transparently send the busy tone to the digital telephone.
To enable the busy tone sending:
Step
1. Enter system view.
2. Enter FXO voice subscriber
line view.
3. Enable the busy tone
sending.
Enabling silence detection-based automatic on-hook
Silence detection-based automatic on-hook prevents the situations where the resource of the FXO
interface cannot be released owing to busy tone detection failure when the busy tone parameters
provided by the connected PBX are special.
When the signal values of two successive sampling points are less than the silence threshold, the
system considers that the line goes into the silent state. If the line stays in the silent state longer than
the silence duration for automatic on-hook, the system will automatically disconnect the call.
Do not enable silence detection-based automatic on-hook unless you are sure it is necessary.
Improper configuration of this function can lead to false on-hook.
To enable silence detection-based automatic on-hook:
Step
1. Enter system view.
2. Enter FXO voice subscriber
line view.
3. Enable silence
detection-based automatic
on-hook.
NOTE:
It is a good practice to test multiple sets of parameters and choose the set of parameters that can
quickly release the FXO voice subscriber line after on-hook and does not cause false on-hook.
Configuring the duration before a forced on-hook
In some countries, PBXs do not play busy tones, or the busy tones played only last for a short period
of time. When noise is present on a transmission link, the silence-th-span command might fail to
release the FXO interface after on-hook. In this case, use the hookoff-time command to solve the
problem.
Command
system-view
subscriber-line line-number
send-busytone { enable | time
seconds }
Command
system-view
subscriber-line line-number
silence-th-span threshold
time-length
39
Remarks
N/A
N/A
Optional.
Disabled by default.
The time option appears only
after the send-busytone enable
command is executed.
Remarks
N/A
N/A
Optional.
By default, the silence threshold is
3 and the silence duration for
automatic on-hook is 7200
seconds (2 hours).