CO On Hook (ms)

Parameter group

Signaling Type

Access level


Possible values

Integer multiples of 20, in the range 0 through 5100




Specifies the minimum duration for an on-hook signal from the switch to determine whether the signal is valid. It is used for incoming and outgoing calls. Note that the parameter does not apply to the EL7/CAS (Ericsson MD110) signaling protocol.

When the T1 CAS Protocol parameter is set to SAS or FXS (and the FXS Start Type parameter is set to Loop Start), the value of CO On Hook also affects recognition of a disconnect clear (wink off) signal. A disconnect clear signal, if provided by a switch, is a momentary change of state of the a-bit. Blueworx Voice Response interprets the change of state as a far-end disconnect, if the change lasts for the period specified by the CO On Hook parameter.