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AIXLink/X.25 1.1 for AIX: Guide and Reference

Introduction to SNA Server/6000

SNA Server/6000 implements two SNA components that control the operation of the local node in the network. These components are as follows:

SNA Configuration Profiles

SNA Server/6000 keeps all network information in structured files called profiles. It stores the profiles as database files that are controlled by system data management routines.

The profiles needed to use the 3270 host connection program with X.25 are:

SNA Describes the default characteristics of the SNA program and its environment, that is the maximum number of sessions (recommended value 200+), maximum number of conversions, restart action, standard input and output devices, and so forth.
Links Profiles used to support physical connectivity between SNA nodes. The DLC types represented include token ring, Ethernet, X.25, FDDI, and SDLC. Also affords the ability to control LU0 Primary Line and APPN Connection Network profiles.
X.25 SNA DLC Defines datalink device name (for example, x25s0, same as the COMIO interface name), maximum I-field size, local X.25 network address (NUA), transmit and receive window counts, maximum number of active link_stations, and various polling frequencies, counts, and secondary inactivity time-out values.
X.25 Link Station Defines local XID node ID, SNA DLC profile name, response to link inactivity, LU address registration, link trace and depth, CCITT level, station type, link activation parameters, virtual circuit type, supported session types, restart parameters, transmission group characteristics, and logical channel number (LCN).
X.25 Optional Facilities Defines optional facilities including throughput classes, closed user group characteristics, network user identification, reverse charging, RPOA, and so forth.
Sessions Profiles used to support session connectivity between supported LU types: Generic LU, LU0, LU1, LU2, LU3, and LU6.2

Session profiles define and register LU addresses, primary and secondary LU0 logical units and corresponding link station profile names, system services control point (SSCP ID), network name and remote LU name for LU1, LU2, and LU3 profiles, and for LU6.2 profiles: local and partner LU profiles, side information profiles for CPIC applications, mode profiles, transaction program name profiles, session and conversation security profiles, session time-out profiles, class of service profiles, and partner LU 6.2 location profiles.

Control Point The control point profile defines the local node's function in the network as well as uniquely identifying itself on the network (through the CP name). The control point is the default INDEPENDENT LU 6.2 LU for the system. The XID node ID value identifies this node when a link station profile specifies to use the control point's XID instead of supplying one of its own.
Security Profiles Used to add, remove, or change a communications authority password (CAP) to secure the configuration database.

For additional information on SNA configuration and profiles, see AIX SNA Server/6000: User's Guide, Order Number SC31-7002, and AIX SNA Server/6000: Configuration Reference, Order Number SC31-7014.

SNA Configuration Commands

A set of configuration commands is provided with SNA Server/6000 to assist with and accomplish network configuration and setup. An extensive list of these commands can be found in : Command Reference, Order Number SC31-7100, and : Configuration Reference, Order Number SC31-7014. A few of the more commonly used commands are:

mksnaobj Creates profiles.
mksnaobj -t ProfileType [-w link_type|-u lu_type] \
[-T template_profname] [suboptions... ] ProfileName
chsnaobj Changes the values in previously defined profiles.
chsnaobj -t ProfileType [-w link_type|-u lu_type] \
[suboptions... ] ProfileName
rmsnaobj Removes a profile.
rmsnaobj -A | -t ProfileType [-w link_type|-u lu_type] \ 
ProfileName [ProfileName ...]
qrysnaobj Retrieves information of a defined profile.
qrysnaobj [-C] [-S | -L] -t ProfileType [-w link_type| \
-u lu_type] ProfileName
sna Starts or stops SNA, sessions, link stations, traces, logging options, and so forth.
sna {-start(-s) [sna | session(s) | link_station(1) | \ 
anynet] -stop | -display | -trace(-t) | -setlogs} \
sna -start(-s) session(s) [ [Flag Value] ...]
sna -start(-s) session(s) [ [Flag Value] ...](LU6.2 only)
[-local_lu_name(-ln) Name | -local_lu_alias(-la) Alias]
{-partner_lu_name(-pn) Name | -partner_lu_alias(-pa) \ 
Alias} -mode(-m) Name [-session_type(-st) conwinner(cw) \ 
| conloser(cl)]
sna -start(-s) link_station(l) -profile(-p) Value
verifysna Verifies profiles in the working directory and optionally updates committed verified directory entries.
verifysna {[-R] | [-U] } [-B backup_ascii_file]
                         [-S backup_security_file]
-R Verifies dynamic reconfiguration.
-U Update committed database if verification is successful.
-B backup_ascii_file Create a flat ASCII backup file.
-S backup_security_file Create backup binary security file.

SNA Server/6000 Profile Types and Profile Parameters

The following table lists some of the common profile types, their corresponding profile parameters, and a brief description.

AIX SNA Server/6000 Profile Types and Profile Parameters
Profile Type Profile Parameter Description
SNA System Defaults -t'sna' SNA Node Defaults
X.25 SNA DLC -t'sna_dlc_x.25' Data Link Control
X.25 Link Station -t'link_station_x.25 Link Station
X.25 Optional Facilities -t'x.25_opt_facs' X.25 Facilities
Control Point -t'control_pt' Local Node Identification
Session (LU0, LU1, LU2, LU3, and LU6.2 -t'session' Application Sessions
LU 6.2 Local LU -t'local_lu' LU6.2 Characteristics
LU 6.2 Side Information Requirement -t'side_info' Dependent LU6.2
LU 6.2 Partner LU -t'partner_lu6.2' Session Characteristics
LU 6.2 Mode Definitions -t'mode' Control and Pacing
LU 6.2 TPN Name -t'local_tp' Transaction Program
LU 6.2 Session Security -t'session_security' Password Specification
Partner LU 6.2 Location -t'partner_lu6.2_location' Remote LU Location

SNA Server/6000 Components

SNA Server/6000 is comprised of:

The System Resource Controller, in turn, provides all services to transfer data over the network. To provide these services, the SRC requests information from the profile and data management components to define the characteristics of connections and link stations on the network. Refer to AIX Version 4.3 General Programming Concepts for more information on the SRC.

SNA Device Drivers

The following AIX device drivers are part of SNA Server/6000:

SNA Data Device Driver Provides the AIX subroutine interface to SNA Server/6000.
SNA Manager Device Driver Provides an interface for the SNA Server/6000 background processes to AIX subroutines that implement control functions internal to SNA Server/6000. The SNA Manager Device Driver interface is for the exclusive use of the SNA Server/6000 background processes.
SNA Generic Device Driver Provides a PU level subroutine interface for generic LU application. The LU0 support provided with SNA Server/6000 is written to the generic device driver interface.

These device drivers must be present for SNA Server/6000 to function properly. They should appear in a listing of the /dev directory as /dev/sna, /dev/snam, and /dev/gsna, respectively.

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