| ABSTRACT
SYNTAX NOTATION |
(ASN.1)
An OSI language used to define datatypes for networks. It is used within
TCP/IP to provide conformance with the OSI model. |
| ACCESS
CONTROL |
A process
that defines each user's privileges on a system. |
| ACCOUNT |
A user
ID and disk area restricted for the use of a particular person. Usually
password protected. |
| ACKNOWLEDGMENT |
(ACK)
A positive response returned from a receiver to the sender indicating success.
TCP uses acknowledgments to indicate the successful reception of a packet. |
| ACTIVE
OPEN |
An operation
performed by a client to establish a TCP connection with a server. |
| ADDRESS |
A memory
location in a particular machine's RAM. A numeric identifier or symbolic
name that specifies the location of a particular machine or device on a
network, and a means of identifying a complete network, subnetwork, or a
node within a network. |
| ADDRESS
MASK |
(Subnet
mask) A set of rules for omitting parts of a complete IP address in order
to reach the target destination without using a broadcast message. The mask
can, for example, indicate a subnetwork portion of a larger network. In
TCP/IP, the address mask uses the 32 bit IP address. |
| ADDRESS
RESOLUTION |
Mapping
of an IP address to a machine's physical address. TCP/IP uses the Address
Resolution Protocol (ARP) for this function. |
| ADDRESS
RESOLUTION PROTOCOL |
(ARP)
See Address Resolution. ARP is a protocol used to correlate an IP address
to a machine's physical address. The reverse operation is performed by Reverse
Address Resolution protocol (RARP). |
| ADDRESS
SPACE |
A range
of memory addresses available to an application program. |
| ADVANCED
RESEARCH PROJECT AGENCY |
(ARPA)
DARPA's former name. ARPA was an agency funded by the U.S. federal government
originally for pure research. When it was changed to DARPA the funding became
part of the Defence budget. |
| AGENT |
In TCP/IP,
an agent is an SNMP process that responds to get and set requests. Agents
can also send trap messages. |
| ALIAS |
A short
name used to represent a more complicated one. Often used for mail addresses
or host domain names. |
| ALPHANUMERIC
CHARACTER |
A character
that is a single letter or a single digit. |
| AMERICAN
NATIONAL STANDARDS INSTITUTE |
(ANSI)
The U.S. body responsible for setting standards. |
| ANALOG |
A form
of electronic communication using a continuous electromagnetic wave |
| APPLICATION
LAYER |
The highest
layer in the OSF model. It establishes communications rights and can initiate
a connection between two applications. |
| APPLICATION
PROGRAMMING INTERFACE |
(API)
A set of routines available to developers and applications to provide specific
services used by the system, usually specific to the application's purpose.
They act as access methods into the application. |
| ARCHIVE |
A repository
of files available for access at an Internet site. Also, a collection of
files, often a backup of a disk or files saved to tape to allow them to
be transferred. |
| ARGUMENT |
A parameter
passed to a subroutine or function. |
| ARPA |
(Advanced
Research Projects Agency) a government agency that originally funded the
research on the ARPANET (became DARPA in the mid-1970s). |
| ARPANET |
An experimental
communications network funded by the government that eventually developed
into the Internet. |
| ARRAY
CONTEXT |
An array
value is required (either a normal array or an associative array, both of
which are lists). |
| ARTICLE |
Message
submitted to a UseNet newsgroup. Unlike an e-mail message that goes to a
specific person or group of persons, a newsgroup message goes to directories
(on many machines) that can be read by any number of people. |
| ASCII |
(American
National Standard Code for Information Interchange) An 8 character set defining
alphanumeric characters. Data that is limited to letters, numbers, and punctuation. |
| ASSIGNED
NUMBERS |
Used in
Request For Comment (RFC) documents to specify values used by TCP/IP. |
| ASSOCIATIVITY |
A term
to describe the way an operator takes its operands. |
| ASYNCHRONOUS |
Communications
without a regular time basis, enabling transmission at unequal rates. |
| ATTRIBUTE |
A form
of a command-line switch as applied to tags in the HTML language. HTML commands
or tags can be more specific when attributes are used. Not all HTML tags
utilize attributes. |
| AUTONOMOUS
SYSTEM |
A collection
of routers that are under the control of a single management body. The system
usually uses a common Interior Gateway Protocol. |
| AWK |
UNIX text
processing utility program. |