R

random access memory (RAM)
RAM is the memory of a computer that can be read from or written to by computer hardware components such as a CPU.

random backoff
See backoff time.

reduced instruction set computer (RISC)
A RISC is a microprocessor that contains fewer instructions than traditional complex instruction set computer (CISC) processors, such as Intel or Motorola. As a result, they are significantly faster. RISC processors have been used in most technical workstations for some time, and a growing number of PC-class products are based on RISC processors.

refraction
Refraction is the tendency of a light ray, or electromagnetic signal, to be deflected from a straight path when it passes obliquely from one medium into another medium that has a different index of refraction. See index of refraction and total internal reflection.

remote access service (RAS)
The term RAS is normally used in the context of Windows NT, and the ability to access Windows NT and LAN services from a remote location.

remote procedure call (RPC)
RPC is a call made by an application program for services across a network connection, usually to a server.

repeater
A repeater is a Physical Layer device that connects one cable segment of a LAN to another, possibly connecting two different media types. For example, a repeater can connect a thin Ethernet cable to a thick Ethernet cable. It regenerates and boosts electrical signals, thus a repeater can be used to lengthen a network segment. Because a repeater reproduces exactly what it receives, bit by bit, it also reproduces errors. However, it is very fast and causes very little delay.

Request for Comment (RFC)
An RFC is one of the working documents of the Internet research and development community. A document in this series may be on essentially any topic related to computer communication, and may be anything from a meeting report to the specification of a standard.

requester
A requester is a set of software modules that processes requests from a client application program and directs the request to either the local OS or a remote NOS.

RJ-45 connector
RJ-45 is a snap-in connector for UTP cable, similar to the standard RJ-11 telephone cable connector. The RJ-45 connector can terminate up to 8 wires.

router
A router is a Layer 3 device with several ports that can each connect to a network or another router. The router examines the logical network address of each packet, then uses its internal routing table to forward the packet to the routing port associated with the best path to the packet's destination. If the packet is addressed to a network that is not connected to the router, the router forwards the packet to another router that is closer to the final destination. Each router, in turn, evaluates each packet and then either delivers the packet or forwards it to another router.

RSA
The acronym RSA stands for Rivest, Shamir, and Adelman, the inventors of a widely used public-key encryption algorithm. The RSA encryption algorithm has become the de facto standard for industrial-strength encryption across the Internet.