QR
QoS

Quality of Service. This term refers to any of a number of different traffic-prioritization schemes that allow the network to treat different streams of data differently.



 

Quality of Service

See QoS.



 

Repeater

A device that amplifies, restores, and propagates network signals. In Ethernet networks, a repeater effectively extends a segment including both broadcasts and collisions. This extention is different from a bridge, which relays broadcasts, but not collisions. See also Bridge.



 

RFC

Request For Comments. The IETF publishes its standards, proposed standards, and recommended practices in the form of RFC documents. Each document is given a sequential-order number that is used when referring to the document.



 

RIF

Routing Information Field. Primarily in bridged networks, but also to a lesser extent in routed networks, it is possible for a frame to specify a RIF that indicates the path that it would like to take.



 

Ring

As a basic network topology, an architecture in which devices are connected to each of an upstream and a downstream neighbor device. These devices are connected in this way to form a circle so that following these neighbor-to-neighbor connections eventually leads back to the original device.



 

RIP

Routing Information Protocol. There are actually two distinct protocols called RIP discussed in this book. Both protocols are distance vector routing protocols. One is used for distributing TCP/IP routing information, and the other for IPX routing information.



 

RJ45

Registered Jack Type 45. RJ45 is standard modular jack and socket used for connecting network cables. In LAN applications, these jacks are primarily used with Category 3 and higher twisted-pair cabling, although there are other applications.



 

RMON

Remote Monitoring. Originally described in RFC 1271, RMON is a set of SNMP MIB extensions that are useful for many remote network management functions.



 

Roaming

In wireless technology, describes the ability to change association from one BSS or ESS to another.



 

Root Bridge

In Spanning Tree, the device at the center of the network. Every bridging device in the network looks for the shortest path to the Root Bridge to eliminate loops.



 

Router

A Router is a device that connects segments with different Layer 3 network addressing. It is able to forward packets between these segments based on Layer 3 information.



 

RPC

Remote Procedure Call. An intermediate network layer that allows client-server applications to have a consistent framework. Two distinct popular implementations of this concept share the same name. One was developed by Sun Microsystems and the other by Microsoft.



 

RS-232

One of the main standards for low-speed serial interfaces.



 

RSVP

Resource Reservation Protocol. This protocol, described in RFC 2205, allows applications to request particular network resources such as bandwidth or latency characteristics.



 

RWHO

Remote Who. A broadcast-based protocol developed for the early BSD UNIX platform that allowed each server on a segment to keep track of which users were logged in on which server.