A

RAS

(Remote Access Server). The device on a network made up of a bank of modems that allows users to connect to the network over dial-up telephone lines.

Also see Modem Server

RDF (Resource Description Framework)

An XML DTD that describes resources of all types for easy cataloging, searching, and referencing.

Also see DTD

Repeater

A repeater is a simple device that regenerates a signal passing through the network, so that the transmission distance of that signal can be extended. A multi-port repeater is known as a hub.

The further a data packet travels along a network, the weaker the signal carrying that data packet becomes. Repeaters repeat (regenerate) data packets they so that neither the number of packets that pass through them, nor the distance they travel, has any effect on signal quality.

Repeaters are also used to connect two LANs of the same network type (for example Ethernet to Ethernet) and work at layer 1 of the OSI reference model.

Also see Bridge Hub LAN Layer 1 Network OSI Reference Model

Resource

A particular object of information provided on the Internet. Can be anything from a picture through to a video or application.

rj-11

A standard connector used to connect analog devices to a telephone line. The "RJ" stands for "registered jack".

Also see Analog Signals RJ-45

RJ-45

A standard connector used to connect Ethernet networks. The "RJ" stands for "registered jack".

Also see Ethernet Network

RMD (Required Markup Declaration)

An attribute in an XML document that specifies whether the processor needs to read and process a DTD along with the document.

root rule

The construction rule that specifies what action should be applied to an XML document's document element.

Router

A special-purpose computer (or software package) that handles the connection between 2 or more networks. Routers concentrate on looking at the destination addresses of the packets passing through them and deciding which route to send them on.

Routers provide a link between geographically separate networks. An internetwork based on routing consists of many different logical subnetworks. Bridges and switches connect these subnetworks, improving network performance by keeping traffic within segments. Repeaters and hubs link segments together, and the workstations within the segments.

Also see Bridge Hub Network Network Segment Switch Traffic

Routing Information Protocol (RIP)

The process of moving a packet from one node to another by forwarding the pack to the next router.

Also see Packet Router