The IBM® 
iSeries™ system uses data link connection
identifiers (DLCIs) to identify the logical connections between nodes.
A single physical connection to the frame-relay network is used to support multiple logical, or virtual, connections. The frame-relay network assigns a DLCI number that identifies each virtual connection, called permanent virtual circuit (PVC). The iSeries system supports up to 256 virtual circuits for each physical connection.
The frame-relay network provider assigns the DLCI number, typically at subscription time, that is used to identify a virtual circuit. The DLCI number applies only to the connection between nodes (TE-to-FH or FH-to-FH).
Figure 1 shows an example of DLCI assignments for a frame-relay connection.
To configure DLCI values for frame-relay and bridged local area network (LAN) line descriptions, specify the NWIDLCI parameter on the line description command. You can also configure DLCI values by specifying the DLCI number and line description name on the DLCI parameter of the Create Network Interface (Frame Relay) (CRTNWIFR) command.
The iSeries system uses DLCI 0 for the local management interface (LMI). This corresponds to the ANSI Annex-D standard. The LMI manages the physical and virtual connections between the terminal equipment (TE) and the frame handler (FH). Use DLCIs 1 through 1018 to identify logical connections to remote TEs.