PAM Programming Manual

Introduction
PAM Programming Manual—142482
1-7
The PAM Subsystem’s Role Within the System
similar to how an application interacts with files; the application can open PORTs,
perform reads and writes to exchange data with a remote LAN entity, then close them.
The PORT object provides the following types of LSAPs:
Figure 1-4
shows the relationship between application types and port interfaces.
Ethernet The Ethernet PORT allows direct access to the DIX-compatible Ethernet
interface (using a protocol type field instead of a length field as in IEEE
802.3). Multiple Ethernet-type PORT objects can be configured, one for
each Ethernet protocol type. Access to the Ethernet interface is made
through file-system procedure calls and a formatting library that is used to
format aggregate service data units (SDUs).
LLC1 The Logical Link Control, Type 1 interface (LLC1) PORT gives LLC1
applications access to the LLC type 1 connectionless (IEEE 802.2) level-2
interface. Multiple LLC1-type PORT objects can be configured, one for
each LLC LSAP. Access to the LLC1 interface is made through file-
system procedure calls and a formatting library that formats aggregate
service data units (SDUs).
The LLC1 interface also provides send-and-receive access to LLC2
frames in TRSA and E4SA. The implementation of the LLC2,
connection-oriented protocol is the responsibility of your application.
Figure 1-4
shows the relationship between the applications, the LLC1
interface, and the adapters. The LLC1 interface is further described in
Section 3, Link-Level Interfaces.
LLC2 The Logical Link Control, Type 2 interface (LLC2) PORT gives SNAX
over token ring access to the LLC type 2 connection-oriented (IEEE
802.2) level 2 interface. The PAM process adds the LLC2 PORT when
SNAX opens a SAP through the SNATR MSAP.