Technical data

heterogeneous network
A network consisting of different network protocols or different operating system
software, such as OpenVMS and UNIX.
hierarchical routing
Routing based on domains. Interdomain routers are responsible only for getting
data to the right domain and intradomain routers take responsibility for routing
within the domain.
hop count
The number of connections between two hosts, based on the number of different
routers needed to traverse the distance between the two hosts.
hop
A term used in routing. Number of hosts separating a source and final destination
(including the final destination) on a network.
host
A computer system that acts as a source or destination of network messages
sometimes called node.
The IP address of any system. Usually specified in dotted-decimal notation.
There are four values in the range from 0 to 255 inclusive, separated by dots (.).
For example, 132.236.199.63 or 10.0.0.51. It can also be specified as an 8-digit
hexadecimal string preceded by 0x. For example, 0x0a000043. In addition, if the
options
noresolv
statement is not specified, this can be a symbolic host name.
For example,
gated.cornell.edu
or
nic.ddn.mil
. The numeric forms are
preferred over the symbolic form.
host address
See host number.
hosts database
The Compaq TCP/IP Services for OpenVMS database that is created by default;
allows users to use host names; contains host names, IP addresses of the hosts, and
any alias names for the hosts.
host name
Thenamegiventoanetworkhost. See also fully qualified domain name and
alias.
host number
The part of an IP address that identifies which host on the network is being
addressed.
Host-to-Host Communication layer
Also called Transport layer. The second-highest level in the Internet architecture
model; provides end-to-end communication services, including mechanisms such as
end-to-end reliability and network control. Transmission Control Protocol (TCP)
and User Datagram Protocol (UDP) reside in this layer.
IAB
See Internet Architecture Board.
IBM TN3270
The TELNET options that allow TELNET users to connect to hosts that support
3270 terminals.
ICMP
See Internet Control Message Protocol.
Glossary–20