Configuration objects for frame relay

There are several options for network interface description, line description, and controller description.

The IBM^® iSeries™ system uses the following configuration objects for frame-relay communications:

Network interface description

The network interface (NWI) description defines the characteristics of the physical connection, including:

• Physical interface used
• LMI mode
• LMI timer and retry values
• DLCI numbers assigned to the virtual connections

Use the Create Network Interface (Frame Relay) (CRTNWIFR) command to create one NWI description for each input-output adapter (IOA).

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 data link connection identifier (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 iSeries system 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:

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 iSeries systems 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.

The value specified for the LINKTYPE parameter on the controller description determines the type of line description to which the controller can be attached:

• 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.

You can configure both APPC and SNA host controllers as APPN(*YES). If you configure the controllers as APPN(*NO), then you must also create APPC or SNA host device descriptions for each session that the remote system supports.

Figure 1 shows an example of objects that are configured for frame-relay communications, including the NWI, line descriptions (LINDs), and controller descriptions (CTLDs).