data link channel identifier (DLCI)
The Data Link Channel Identifier (DLCI) is a header field in the Frame Relay frame that specifies the permanent virtual connections( PVC) and the elected virtual connections( SVC) and contains the virtual channel numbers.
DLCI is a connection identifier used to identify the local endpoints of a virtual connection. The DLCI field is read and evaluated by the network nodes. By using different DLCIs on one and the same physical channel, different connections to different destinations can be realized simultaneously.
The DLCI field comprises 10 bits (16 bits or 23 bits), which could be used to address 1,024 addresses. Since some addresses are reserved for signaling tasks, usually about 875 logical channels can be addressed. In the DLCI field there is a bit, the DL-Core Control Indicator Bit( DC), which indicates the function of the rear DLCI subfield.