IBM SC30-3865-04 What APPN Functions Are Implemented on the Router?

A LEN node is a T2.1 node withoutAPPN extensions. A LEN node can establish

peer connections with other LEN nodes, APPN end nodes, andAPPN network

nodes, as long as all of the required destination LUs are registered with the LEN

node. ALEN node can also serve as a gateway between an APPN network and a

SNA subarea network.

Because a LEN node cannot establish CP-CP sessions with an APPN network

node server, it cannot register its resources with the server or request that the

server search for a resource and dynamically calculate a route to that resource. A

LEN node may indirectly use the directory and routing services of a network node

by pre-deﬁning remote LUs (owned by nonadjacent nodes) as being located on an

APPN network node, although the actual location may be anywhere in the network.

When the LEN node needs to initiate a session with the remote LU, it sends a

session activation request (BIND) for the LU to the network node. In this case, the

network node acts as the LEN node’s network node server, locating the requested

resource, calculating a route, and forwarding the BIND to its correct destination.

When conﬁguring the router network node, you can specify the names of LUs that

are associated with an attached LEN end node. These LU names reside in the

router network node’s local directory.If the router network node receives a request

to search for one of these LEN end node resources, it will be able to ﬁnd the LU in

its local directory and return a positive response to the node originating the search.

Toreduce the number of LU names you need to specify for an attached LEN end

node, the router supports the use of generic LU names, which allow a wildcard

character to represent a portion of an LU name.

A PU 2.0 node is a type T2.0 node containing dependent LUs. PU 2.0 nodes are

supported by the Dependent LU Requestor (DLUR) function which is implemented

by an APPN end node or network node. PU 2.0 nodes require the services of a

system services control point, which is made available through the DLUR-enabled

APPN node. Note that APPN nodes can contain dependent LUs supported by the

DLUR function. However, the router does not contain dependent LUs.

What APPN Functions Are Implemented on the Router?

The router implements the APPN Release 2 base architecture functions as deﬁned

in the Systems Network ArchitectureAPPN Reference. The APPN network node

functions implemented by the router are summarized in Table1. Notes on speciﬁc

functions follow the table. For a description of the APPN management services

supported by the router, see “Managing a Network Node”on page 17.

APPN uses LU 6.2 protocols to provide peer connectivity between CP-CP session

partners. The router network node implements the LU 6.2 protocols required for

CP-CP sessions and those used in sessions between a network node CP and its

network management focal point. The router implementation of APPN does not

provide an application program interface to support user-written LU 6.2 programs.

Table1. Implementation of APPN Network Node Functions

APPN Function Yes No Notes

Session services and supporting functions

Multiple CP-CP sessions X

APPN

Chapter1. APPN 3