cvaIfFXSRingGround 1.3.6.1.4.1.9.9.62.1.4.2.1.3

This object contains the incoming ring ground indication. It is only valid when the cvaIfFXSCfgSignalType is fxsGroundStart. If the object is true, then the interface is presenting a ring ground to the connected equipment; otherwise, it doesn't.