SNAX/XF and SNAX/APN Configuration and Management Manual

SNAX Quickstart and Overview
SNAX/XF and SNAX/APN Configuration and Management Manual—425836-006
1-8
SNAX User Applications
SNAX lines can use the following interfaces:

RS-232, enabling medium-speed serial data transmission

RS-422, enabling high-speed serial data transmission

X.21, enabling synchronous data transmission across public data networks using
leased lines; switched line connections are not supported
SNAX/XF lines also can work with V.25 bis modems that automatically send or receive
calls across the general switched telephone network.
SNAX User Applications
SNAX user applications communicate with remote applications and devices through
SNA LU-LU sessions (an LU is an SNA logical unit). For example, SNAX user
applications may be TACL processes, Pathway applications, or user-written server
processes.
The SNAX line handler process provides several application programming interface
(API) protocols through which applications on a NonStop system can send or receive
data across SNAX lines. The protocols vary in the amount of the SNA handling that
they provide and the types of SNA sessions they support. Table 1-3
lists the protocols.
Table 1-2. SNAX Lines
WAN Protocol Line Type Nonswitched Switched
SDLC
(58, 5)
Dedicated physical
connection
Physically-switched
connection
X.25
(58, 3)
Connection supporting
permanent virtual
circuits (PVCs)
Connection supporting
switched virtual circuits
(SVCs)
Table 1-3. SNAX Line Handler API Protocols
API Protocol Description
SNALU Application must handle all SNA flows
CRT For block-mode communication with 3270 devices,
including 3270 and SNA character string printers
ITI For line-at-a-time communication with 3270 devices
PRT (SNAX/XF only) For communication with SNA printers
SNALU/XS (SNAX/APN only) Proprietary protocol used by SNAX/APC
NAM (SNAX/APN only) Protocol used for Expand over SNAX/APN