Technical data

Electronic Mail Services
Communication functions such a electronic mail are vital both within an
organizational internet and across the Internet worldwide. The electronic mail
components of TCP/IP Services are:
Simple Mail Transfer Protocol (SMTP) is the TCP/IP standard protocol for
transferring electronic mail messages from one system to another.
IMAP is the Internet Message Access Protocol. IMAP enables clients to access
email messages and folders from an IMAP server and synchronize them locally.
This enables a client to organize email messages and folders without continuous
access to the server.
Post Office Protocol (POP) is a mail repository used primarily by PCs.
1.2 Application Support
Beyond the industry-standard TCP/IP application services, TCP/IP Services
provides support for the following Compaq products:
• PATHWORKS or Advanced Server
•DECnet-Plus
1.2.1 PATHWORKS and DECnet-over-TCP/IP Support
The Compaq TCP/IP Services for OpenVMS software includes the PWIP driver and
the PWIPACP network ancillary control process (ACP). The PWIP driver enables
communication between OpenVMS systems running both PATHWORKS server
and TCP/IP Services software, and personal computers running PATHWORKS
client software. It also enables the DECnet-over-TCP/IP feature, which is included
with the DECnet-Plus for OpenVMS Version 6.0 and later software. For more
information, see Chapter 7.
1.3 APIs
Network applications specific to the Compaq TCP/IP Services can use the following
application programming interfaces (APIs):
•BerkeleySocketsInterface
• OpenVMS QIO System Services interface
• ONC RPC programming interface
• SNMP programming interface
1.3.1 Berkeley Sockets Interface
Sockets have become a popular programming interface. The Berkeley Sockets
Interface is a programming interface that provides applications with access to
network communication protocols. A socket is a generalized UNIX communication
endpoint on which the TCP/IP protocols have been implemented. Using the socket
programming interface makes it easy to implement network applications.
OpenVMS provides support for the socket interface through the C programming
language and the Compaq C Run-Time Library. The benefits of using the socket
interface on the OpenVMS platform include:
• Ease of porting network applications from other platforms to the OpenVMS
platform. A sockets interface can be generic.
Introducing Compaq TCP/IP Services for OpenVMS 1–5