Introduction to Networking for NonStop S-Series Servers

TCP/IP Network Connections
Introduction to Networking for HP NonStop S-Series Servers—520670-005
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Simple Mail Transfer Protocol (SMTP) Gateway
One such component implements the TCP/IP network terminal protocol (TELNET).
The HP TELNET client allows you to log onto another computer on the TCP/IP network
as if your application were a terminal. The HP TELNET server lets users on other
systems or workstations log onto your NonStop S-series server to run line-at-a-time
applications, such as HP utilities or conversational Pathway applications. (The
TELNET server fully supports 6530 page-mode applications.) The remote system or
workstation must also support the TELNET protocol. The programmatic interface to
TELNET is a file-system interface.
The TCP/IP products also provide terminal-emulation software. The TN3270 server
product supports the standard TN3270 protocol used by IBM 3270 emulators over
TCP/IP.
Simple Mail Transfer Protocol (SMTP) Gateway
The TCP/IP products include a gateway that allows users of an HP TRANSFER mail
service to exchange electronic mail (e-mail) with UNIX workstations and hosts that use
the Internet-format mail. The gateway can also relay SMTP messages between hosts;
the NonStop S-series server is an intermediate system in such exchanges.
Domain Name Service (DNS)
Because a TCP/IP network is normally heterogeneous, a distributed name service is
defined to make resources on different nodes visible to, and addressable from, other
nodes. The resources for which name-to-address and address-to-name conversions
are supported include the nodes themselves, users, printers, and some others.
The TCP/IP name space consists of a hierarchy of domains. A domain is an arbitrary
division of a network; it usually has geographic or topological significance, with a node
serving as a gateway into the domains and a series of addresses assigned to the
domain. Within a domain there can be multiple administrative zones, whose main
significance is logical. (For instance, you might assign all devices in a building to one
domain and all devices on the same floor to one zone. Alternatively, you might define
domains and zones along organizational lines.) A domain typically has one or more
name servers capable of converting names to addresses or addresses to names and
of communicating with the name servers for zones in the domain. The domain name
server retains the name and address information for its own zone and communicates
with servers in the other zones for resolution of names defined there.
The HP Domain Name Service (DNS) allows the NonStop S-series server to act as a
name server in a TCP/IP network. Because the NonStop S-series server is
fault-tolerant, name information is protected against, and remains available through,
component failures, such as failure of the processor in which a disk process runs. The
DNS consists of an interactive utility and a server process, which in turn consists of a
domain name resolver (for name-to-address conversions) and a domain name server
(for address-to-name conversions).