IBM AS/400e User Handbook Manual page 488

Operating System/400, 5769-SS1
This virtual address exists on the AS/400 system and can be reached from the
network through all installed physical interfaces. VIPA can dramatically increase
capacity for high-volume AS/400 e-business servers.
– Sockets and SSL support
• Sockets
Sockets programming uses the socket application program interface (API) to
establish communication links between remote and local processes.
The sockets API is located in the communications model between the application
and the transport layers. The sockets API that allows applications to interface with
the transport or networking layers on the typical communications model. It is
shipped as part of OS/400.
The sockets API is part of the open environment on the AS/400 system. The
sockets API, along with the integrated file system, eases the effort that is required
to move UNIX applications to AS/400 systems. Sockets on the AS/400 system are
based on and are compatible with Berkeley Software Distributions (BSD) 4.3
sockets. Application programs written in the Integrated Language Environment
(ILE) C/400 language can use the sockets API.
• SSL
Secure Sockets Layer (SSL) is a security protocol that provides privacy over an
open communications network (for example, the Internet). SSL protocol allows
client/server applications to communicate in a way that is designed to prevent
eavesdropping, tampering, and message forgery.
Many applications on the AS/400 system are SSL enabled in V4R4, including
TELNET, HTTP server, CA/400 host servers, systems management, and LDAP.
Also, OS/400 SSL support includes a set of APIs, which, when used in addition to
the existing OS/400 sockets APIs, provide the functions required for applications
to establish secure communications.
Transport Layer Security Support on AS/400
V4R5 includes support for Transport Layer Security (TLS), the latest protocol
update to the industry accepted Secure Sockets layer (SSL) support. TLS is the
industry-standard definition of Secure Sockets Layer (SSL). The TLS protocol is
defined as part of Request for Comments (RFC) 2246, The TLS Protocol , by the
Internet Engineering Task Force (IETF). The AS/400 Secure Sockets layer
support fully supports this approved standard specification.
The TLS protocol, as defined in RFC 2246, is an evolutionary upgrade of the SSL
Version 3.0 protocol. OS/400 V4R1 and later supports SSL Version 3.0 and
previous SSL protocol versions.
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AS/400e System Handbook