Trunk Interface
Field
On
Off
On
Specifies whether robbed-bit signaling is to be used on T1 trunks. Robbed-bit signaling causes a signal-to-distortion ratio approximately 1.8 dB lower than that for 8-bit coding. With extended superframe format (ESF) on ISDN trunks, robbed bit signaling is not used, so select Off if you are using a T1 pack for ISDN. “Clear channel” (that is, 64 Kbit per second) operation is possible only if bit robbing is not used. This parameter does not apply to E1 trunks.