HP-UX SNAplus2 R7 Administration Guide

Introduction to SNAplus2
SNAplus2 Resources
• DLCs (see Section 2.4.1, Connectivity Resources).
If you use the Motif administration program to configure a port, the corresponding DLC definition is created
automatically. For command-line administration, the DLC is configured separately.
• Ports (see Section 2.4.1, Connectivity Resources).
• Link stations (see Section 2.4.1, Connectivity Resources).
• Connection networks (see Section 2.4.1, Connectivity Resources)
If you use the Motif administration program, you can define a connection network as part of port configuration.
For command-line administration, a connection network is configured separately.
In addition, you can enable the High-Performance Routing (HPR) feature of APPN. This feature provides support
for Rapid Transport Protocol (RTP), which minimizes cycles and storage requirements for routing network layer
packets through intermediate nodes on a session route, and automatic network routing (ANR), which enables APPN
networks to automatically reroute sessions if a portion of the originally computed route fails. HPR also provides end-
to-end dynamic window sizes for communications, and reduces storage and processing requirements on intermediate
nodes in the route.
DLCs
A DLC is the component responsible for communication over a physical link (or multiple links) using a specific
data link protocol, such as SDLC or token ring. Each DLC can manage one or more ports, as described in Section
2.4.1, Connectivity Resources.
SNAplus2 provides support for the following data link protocols:
• Synchronous data link control (SDLC)
• X.25 QLLC (qualified logical link control), for which the X.25 communications software may be provided by
your SNAplus2 supplier or by another supplier
• Token ring
• Ethernet (standard or IEEE 802.3)
• FDDI (Fiber Distributed Data Interface)
• Enterprise Extender (HPR/IP), providing HPR functionality for SNA traffic transported over an IP network
Note
In the Motif administration program, DLCs are not shown directly. The information required
for configuring a DLC is displayed as part of the configuration of a port owned by the DLC.
Ports
A port represents the local end of a communications link as a unique access point in the network. In general, this
corresponds to a single physical access point such as an adapter card. However, some link protocols (such as token
ring) enable you to define multiple ports for a single adapter; in this case, the different ports are distinguished by
addresses (such as the SAP address).
Each port is associated with a specific DLC. One or more ports can use the same DLC.
Link Stations
A link station represents the logical path through the SNA network between the SNAplus2 local node and a remote
computer. The remote computer can be any of the following:
• A host computer, on which SNAplus2 accesses a host program using 3270, RJE or LUA communications (or
uses APPC or CPI-C for program-to-program communications)
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