Glossary d

In mathematics, a digit or numeral that is part of a number based on the decimal numbering systemnamely 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.

In mathematics, a convention for numbering things in which ten separate numerals are used.

DECnet was Digital Equipment Corporation's proprietary networking model.

The process of re-creating the original data that was transmitted over a network after being encrypted by the sender of the data.

A setting on a TCP/IP host that refers to the IP address of a router. The host sends packets to this default router, expecting the router to then be able to forward the packet to the destination.

The act of interpreting a received analog electrical signal to decode a binary 0 or 1.

An action that a cracker takes to cause a service or server to have problems, or possibly fail, which then denies legitimate users the opportunity to use the service.

The 6-byte long portion of an Ethernet header in which a NIC places the intended recipient's Ethernet address before sending a frame.

A field in the IP header that lists the IP address of the intended recipient of the packet.

In mathematics, a single symbol that can be used to represent part of a number; for instance, the digit "1" is part of the number "321." Another word for numeral.

A route that refers to a network or subnet that is connected to an interface on that router.

A subnet for which a router has a working physical interface connected to the physical network where the subnet resides.

A service from a phone company by which you call a well-known phone number and get help in finding someone's phone number.

A component of a computer that can permanently hold the contents of computer files.

A term referring to the original Ethernet standard, as developed by people at Digital Equipment Corporation, Intel, and Xerox.

A LAN where servers are installed in an enterprise network, with those servers available to users on the Internet. This allows separation of servers intended for internal use only (on the inside) from the servers that are available to the general public (on the DMZ).

An interface on a firewall that is connected to the DMZ LAN. It is considered to be more secure than the outside but less secure than the inside.

The protocols and conventions that define a worldwide, distributed TCP/IP host name database, which allows a client computer to use host names, request name resolution, and get a correct response that identifies the IP address that corresponds to the name.

A DNS protocol message, sent by an end user host to a DNS server, that supplies a TCP/IP host name and requests the corresponding IP address.

A TCP/IP host that makes a DNS resolution request, asking for resolution between a host name and the corresponding IP address.

A computer running DNS server software, providing name resolution services.

The set of computers whose names all end with the same domain name.

A term referring to a suffix of a host name that identifies the authority, organization, or company that controls all names that end in that suffix.

Jargon referring to the IEEE 802.1Q standard of VLAN trunking.

Jargon that refers to businesses that are primarily Internet based. The term refers to the top-level domain (.com) of their respective domain names.

A term referring to the format of TCP/IP addresses when written in decimal.

A file transfer in which the computer receives or gets a file that it did not previously have a copy of.

Public network technology that delivers high bandwidth over conventional copper wiring at limited distances. The most common types of DSL are ADSL, HDSL, SDSL, and VDSL. Because most DSL technologies do not use the complete bandwidth of the twisted pair, there is room remaining for a voice channel.

A device that generates and receives data over a local phone line.

A device, typically found at a telco CO, that splits the digital signals sent by DSL modems to a router and splits the voice signals out to a telephone switch.

A port number that is chosen at the TCP client computer. The computer simply chooses a currently unused port number.