RAI (Remote Alarm Indication) PRI alarm, also known as Yellow signal. This alarm indicates a carrier failure.

RBOC (Regional Bell Operating Company) Thisreferstotheoriginal seven regional telephone companies created by the AT& T divesti- ture: Nynex, Bell Atlantic, Bell South, Southwestern Bell, US West, Pacific Telesis and Ameritech.

RD (Received Data) RS-232 (V.24) data signal, sent from the data communications equipment to the data terminal equipment on pin 3. (See RS-232.)

REN (Ringer Equivalence Number) A standard requirement of the FCC. For devices such as a telephone or answering machine. The REN requirement can be found on a label on the bottom of the analog device.

Repeater Device that acts as an amplifier. Also known as a Line Extender. This device is needed when the distance between the phone company's Central Office and your premises exceeds distance or dB loss limits.

RFC (Request for Comment) IETF (Internet Engineering Task Force) documents that contain proposed standards and specifications. RFCs can be either approved, or simply archived as historical recom- mendations.

RI (Ring Indicator) RS-232(V.24)controlsignal,sentfromthedata communications equipment to the data terminal equipment on pin 22. Indicates an incoming call is present. (See RS-232.)

RIP (Routing Information Protocol) Within IP networks, RIP is an interior gateway protocol used by routers and host systems to exchange information about reachable networks. RIP uses a distance-vectoring algorithm to establish and maintain network routes.

RJ-45Standard 8-wire connector for IEEE 802.3 networks and some telephone applications.

Router Hardware device that connects two or more networks. A router determines where the destination computer is located, and then finds the best way to get there.

Routing Selecting the path to be taken by packets as they traverse the network.

Routing tables Stored in voice/data switches or routers to determine which of several possible paths will be taken through the net- work.

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