(network layer). A router responds to packets addressed to it by either a terminal or another router. Routers move packets over a specific path or paths based on the packet's destination, network congestion and the protocols implemented on the network. Routing Information Hop-count based interior gateway routing protocol. Protocol RIP is one of the oldest and, perhaps, still the most prevalent routing protocol. RS-170A A specification for adding color to the NTSC television signal. It uses the YIQ method to add hue and Glossary of Terms saturation to a luminance subcarrier. RS-232-C An EIA interchange specification specifying electrical characteristics and pin allocations in a 25-pin connection cable. The equivalent of the international V24 standard. RS-366 An EIA interface standard for autodialing. RS-449 A physical layer specification that defines a 37-pin data connector designed for high-speed transmissions. The signal pairs are balanced and each signal pin has its own return line instead of a common ground. Resource-Reservation Protocol. An IETF specification that allows users of conferencing over the Internet to reserve bandwidth at a given time. Real-Time Transport Control Protocol. A companion to RTP that will allow users to provide feedback on how an RTP session is working; how well packets are being delivered, etc. See Real-Time Transport Protocol. rubber bandwidth Coined by I-MUX manufacturer Ascend, the term refers to an ability to support applications that require varying speeds by dividing a signal up into 56- or 64- Kbps chunks and sending them over a switched digital network. run-length encoding Compression method that works at the bit level to reduce the number of repeating bits in a file. Sending only one example, followed by a shorthand description of the number of times it repeats, indicates a string of identical bits. S-Video Super Video (as opposed to composite). S-Video is a hardware standard that defines the physical cable jack used for video connections. The connector takes the form of a 4