SNA Fundamentals

Objectives
On successful completion of this course, attendees will be able to:

• develop an extensive SNA vocabulary
• identify the major SNA components and their role within the architecture
• identify and use the various address structures used in SNA
• describe the purpose and data flow characteristics of each session type
• explain how chaining, bracketing, and pacing operate
• identify the major SNA commands and command flows
• characterise SNA requests and responses
• interpret SNA message structures at each level
• describe the operation of path control and it's components
• list the characteristics of APPC communication
• interpret SNA data link message structures in SDLC, Token Ring, X.25, and Frame Relay networks
• describe the importance and use of APPC verbs
• identify the APPN node types and explain their function
• explain the principles of APPN routing and addressing.

Who Should Attend
This course is ideal for all personnel working in operations, systems programming, and networking departments. Programmers, analysts, network designers, and managers will also benefit.
Prerequisites
No previous SNA knowledge or experience is required, although some familiarity with basic networking principles would be an advantage.
Duration
3 days

Course Code
CSNF
Contents
Introduction
What is SNA?; hardware and software; nodes and datalinks; SNA layers; bibliography.


Network Accessible Units
SNA NAUs; SSCP functions; CMC and data hosts; PU types and function; LU functions; NAU data flow; address awareness; network addresses message format.


SNA sessions
Sessions and half-sessions; half session layers; session types; setup flows; initiation sequences; logon request processing; LU-LU session types.


SNA message structures
Message format and flow; RU categories; BIU structures; request header format; response header format; transmission header formats; additional TH fields; FID conversion.


Path control
Path control functions; boundary node path control; intermediate node path control; transmission groups; explicit routes; virtual routes; VR activation; route selection; virtual route pacing; FID4 TH header format; segmentation and PIU blocking.


Session data flow
The NAU layers; session profiles; session level pacing; adaptive session level pacing; request chaining; bracketing; Send/Receive modes; function management headers; BIND command.


SNA network interconnection
Addressing limitations; SNI; gateway NCP functions; address translation; gateway SSCP functions; alias name translation; cross network logon sequence.


Advanced Program to Program Communication
SAA: APPC and SAA; LU6.2 sessions; conversations and sessions; required information; mapped and basic conversations; APPC verbs; Generalised data stream; GDS variables.


Advanced Peer to Peer Networking
Subarea SNA limitations; APPN differences; distributed database; route calculation; APPN routing & message format; high performance routing: principles, path switching, format.


Data Link Control (optional topic, in-house only)
DLC functions; SDLC: structure, frame format, addressing, control field formats; SNA in SDLC frames; Token Ring structure; Logical Link Control; Token Ring frame format; Token Ring addressing; Token Ring control; SNA in Token Ring frames; X.25: structure, X.25 packet format, addressing, packet control (QLLC); SNA in X.25 packets; Frame Relay: structure, frame format, addressing, control (RFC1490); SNA in Frame Relay frames; ATM: structure, cell format, addressing, control (RFC1483), Adaption Layer: SNA in ATM cells.