The Modem Control (tsLineModem) field specifies the type of modem control the line is using. Possible values include
Unknown
None
Call-in
Indicates this dial-in modem uses the status of DTR to determine whether to answer an incoming call.
Call-out
Indicates this dial-out modem raises DTR to check if CTS becomes high to indicate that the host has noticed its signal.
Cts-required
Indicates the form of modem control that requires CTS to be high while the line is being used.
Ri-is-cd
Used for lines with high-speed modems. The modem answers the call if DTR is high, uses its CD signal to reflect the carrier presence, and has its CD signal wired to the ring input of the terminal service.
Inout
Used to configure a line for incoming and outgoing calls. The command enables a line to be used for incoming and outgoing calls on dial-in/dial-out modems.