IPX/SPX Configuration and Management Manual

Introduction to NonStop™ IPX/SPX
IPX/SPX Configuration and Management Manual—425731-001
2-7
Service Advertising Protocol (SAP) Interface
Service Advertising Protocol (SAP) Interface
The SAP interface allows a NonStop™ server application to advertise its services to
workstations on the NetWare LAN. Service nodes—such as file, print, and database
servers—register their services and addresses in the SAP table. Each IPXPROTO
process maintains a copy of the SAP table on the operating system and broadcasts SAP
entries to other NetWare servers. (See Service Advertising Protocol (SAP) Table
on
page A-2 for more information.)
A typical SPX application, such as Telserv or Open Database Connectivity (ODBC),
uses the SAP interface.
Figure 2-4
on page 2-6 shows the relationship of the SAP interface to the other
NonStop™ IPX/SPX components. (SAP is also described as a protocol under Protocols
and Frame Types on page 2-8.)
NetWare Core Protocol (NCP) Interface
NetWare APIs allow applications to access NetWare services, such as printing and
filing, through NCP. NonStop™ IPX/SPX provides a subset of the NetWare APIs that is
used exclusively by the LAN Print Spooler for NetWare process.
Figure 2-4
on page 2-6 shows the relationship of the NCP interface to the other
NonStop™ IPX/SPX components. (NCP is also described as a protocol under Protocols
and Frame Types on page 2-8.)
Sockets Interface
The Sockets interface provides a programmatic interface to the NonStop™ IPX/SPX
subsystem. The Sockets interface uses NonStop™ Kernel file-system procedures for
interprocess communications and provides sockets-library routines. You can use the
Sockets interface to write your own application services, either to the SPX network
protocol layer or directly to IPX.
If you write applications directly to the IPX protocol layer, you must provide your own
means of transport reliability and flow control. The Version 2 Sockets library, which
NonStop™ IPX/SPX shares with TCP/IP, allows you to write application services either
to the SPX protocol layer or directly to IPX. A typical SPX application, such as Telserv
or Open Database Connectivity (ODBC), uses the Sockets and SAP interfaces.
The sockets-library routines are based on the sockets programmatic interface primitives
in the 4.3BSD release of the UNIX operating system. The routines include extensions
for NonStop™ Kernel features such as nowait I/O. IPX and SPX sockets are equivalent
to TCP/IP ports.
Note. An IPX socket is distinct from a Berkeley Software Distribution (BSD) socket. An IPX
socket identifies a higher-level protocol or an application within a node. A BSD socket
identifies a connection or a communication endpoint.