When working with AudioCodes Mediant 1000 FXS modules and single button emergency devices, the device was not able to detect the on hook provided by the Mediant 1000 during a far end disconnect situation. However, Audiocodes FXS Media Packs could.
The single button emergency device was plugged into a port in an FXS module in the Audiocodes Mediant 1000. We were using a standard six foot two-wire cable. The device was programmed to send four digits once the button was pressed. The Mediant 1000 was configured to route the call to a registered endpoint on another SBC. The call was answered by the registered SIP endpoint, stayed on the line for ten seconds, two-audio established, then hung up.
At this point, a SIP BYE was trigged back to the Mediant 1000, but the emergency device remained off hook and “fast busy” was heard until the device was unplugged. To resolve this, we had to enable “Current Disconnect”. A “Tel Profile” was built enabling the current disconnect feature and this profile was applied to all FXS ports. Once this was applied, when the far end hung up, a SIP BYE was trigged back to the Mediant 1000 and now provides an “on hook” current disconnect pulse to the single button emergency device.
However, the emergency device now starts automatically dialing treating the current disconnect pulse as a hook flash. This would continue as far as you would let it continue to make calls. To resolve this issue, we had to decrease the “Current Disconnect Duration” in the Audiocodes Mediant 1000. To do this, you must access the Mediant 1000’s “AdminPage” and select the “ini parameters” option, enter “currentdisconnectduration” in the “Parameter Name” field, and enter “500” in the “Enter Value” field.
TIP: Before you enter the value, you can click on “Apply New Value” just see what it is currently set at. The default value is “900”.
Once you apply the change, you can click on “Back to Main”, save your changes and reboot the device (required). I tested this in increments, first trying “700” then “500”; “500” being the silver bullet in this case. Now when the far end disconnects, the single button emergency device treats the current disconnect pulse as on hook versus a hook flash. Issue resolved!