Configuration objects for frame relay
The System i™ platform uses several configuration objects, such as Network interface description, line description, and controller description, for frame-relay communications.
- Network interface description
- The network interface (NWI) description defines the characteristics of the physical connection, including:
Use the Create Network Interface (Frame Relay) (CRTNWIFR) command to create one NWI description for each input-output adapter (IOA).
- Physical interface used.
- Local management interface (LMI) mode.
- LMI timer and retry values.
- Data link connection identifier (DLCI) numbers assigned to the virtual connections.
- Line description
- The line description defines the logical connection to the network. You can attach up to 256 line descriptions to each frame-relay network interface. You must create one line description for each DLCI that is used. Use the following CL commands to create line descriptions attached to frame-relay NWI descriptions:
- CRTLINFR
- Systems Network Architecture (SNA) or IP direct connections to remote systems that support the frame-relay communications protocol, such as an SNA direct connection to another System i model or 3745 Communications Controller.
- CRTLINTRN
- Bridged token-ring network connections.
- CRTLINDDI
- Bridged distributed data interface (DDI) network connections.
- CRTLINETH
- Bridged Ethernet network connections.
- Controller description
- Use the controller description to define the remote system or controller. You can attach up to 256 controller descriptions to each line description. However, the NWI description supports no more than 256 active controllers. Controller descriptions occur across a number of line descriptions. Use the following CL commands to create controller descriptions for frame-relay communications:
The value specified for the LINKTYPE parameter on the controller description determines the type of line description to which the controller can be attached:
- CRTCTLAPPC
- Advanced Program-to-Program Communication (APPC) controllers represent systems that support APPC or Advanced Peer-to-Peer Networking® (APPN) communications. APPC controllers typically represent System i products and personal computers.
- CRTCTLHOST
- SNA host controllers represent controllers such as the 3745 controller running NCP.
- CRTCTLNET
- Network controllers are used for direct IP connections. They are automatically created when you configure and start TCP/IP communications for frame relay.
You can configure both APPC and SNA host controllers as APPN(*YES). If you configure the controllers as APPN(*NO), then also create APPC or SNA host device descriptions for each session that the remote system supports.
- Controller descriptions that specify LINKTYPE(*FR) attach only to frame-relay line descriptions.
- Controller descriptions that specify LINKTYPE(*LAN) attach to token-ring, DDI, or Ethernet lines.
Figure 1 shows an example of objects that are configured for frame-relay communications, including the NWI, line descriptions (LINDs), and controller descriptions (CTLDs).