HP-UX SNAplus2 General Information (October 1998)

38 Chapter 2

Introducing SNAplus2

SNAplus2 Resources

Client/Server Support

Computers running SNAplus2 can be conﬁgured to communicate using

client/server protocols. When client/server protocols are used in a

network, all the computers using client/server protocols to communicate

in that network are referred to as a “domain.” Each computer in the

network speciﬁes the same domain name when SNAplus2 is installed.

The computers running SNAplus2 in a client/server conﬁguration can

take the following roles:

• A server contains an SNA node and its associated connectivity

components. The server provides SNA connectivity to applications on

the local system or on other machines in the same domain. Servers

must be HP-UX systems.

• A client does not contain SNA node components, but accesses them

through a server. A client can access one or more servers at the same

time, and can run concurrent applications as needed. Clients can be

HP-UX or Windows systems.

Servers and clients communicate across the SNAplus2 domain using

TCP/IP. The protocols used are different from those used by TN3270 and

support a wide range of applications, including 3270, 5250, RJE, APPC,

CPI-C, LUA, CSV, and NOF (HP-UX only).

You can have one or more separate SNAplus2 domains on the same

physical network, using a unique name for each different domain. A

single SNAplus2 domain can correspond to a TCP/IP subnet, can be part

of a TCP/IP subnet (so that there are two or more separate SNAplus2

domains in the same subnet), or can span multiple subnets.

If the SNAplus2 domain has multiple servers, one server holds the

master copy of the SNAplus2 conﬁguration. This server is known as the

master server. Other servers on the LAN can be identiﬁed as backup

servers. The conﬁguration is copied to backup servers—either when they

are started, or when the master copy is changed—so that all backup

servers hold a copy of the latest information.