Frame-Relay

http://www.cisco.com/univercd/cc/td/doc/cisintwk/itg_v1/tr1918.htm

0x0 - Added and inactive. The DLCI is programmed in the switch, but is not usable. One potential reason is that the other end of the PVC is down.

0x2 - Added and active. The DLCI is programmed in the switch, and the PVC is operational.

0x3 - Combines active status (0x2) and the receiver not ready (RNR) (or r-bit) that is set (0x1). A value of 0x03 means that the switch or a particular queue on the switch for this PVC is backed up, so the Frame Relay interface stops transmitting to avoid lost frames.

0x4 - Deleted. The DLCI is not programmed in the switch, but was programmed previously. Alternately, a deleted status can be caused by the DLCIs being reversed on the router or by the PVC being deleted by the telco in the Frame Relay cloud. Configuring a DLCI on a Frame Relay endpoint without a matching value on the switch leads to a 0x4 status value for the VC.