Cisco Systems 8600 Series 921/Q.931, Queue, RIF Rate increase factor, RDF Rate decrease factor

Q

Q.921/Q.931

ITU-T specifications for the ISDN use network interface (UNI) data link layer.

QSIG

Acommon-channel message-oriented signalling protocol, defined by the European Telecommunications Standard Institute (ETSI), commonly used by private branch exchanges (PBXes). The INS Dynamic Network Switching application supports QSIG signalling to the Cisco WAN switching network.

queue

A buffer that is used to temporarily hold data while it waits to be transmitted to the network or to the user.

R

RIF (Rate increase factor)

Controls the amount by which the cell transmission rate may increase upon receipt of an RM cell.

RDF (Rate decrease factor)

Controls the amount by which the cell transmission rate may decrease upon receipt of an RM cell.

red alarm

Another name for local alarm as the local alarm lamp on most digital transmission equipment is red in color.

remote alarm

An IPX alarm indicating that the associated T1 line is down due to a receive line failure on another node. (See also yellow alarm.)

RPS (repetitive pattern suppression)

Also called data frame multiplexing (DFM). An option for data circuits where repeating strings of data are replaced on the packet line by a single occurrence of the data string and a code that indicates to the far end how may repetitions of the string was being transmitted. Used to conserve network bandwidth.

robbed bit signaling

A type of signaling used on T1 lines where the signaling bits for each channel are substituted for the least significant voice bit in each channel word during frames 6 and 12.

RS-232

A physical and electrical interface standard for a low-speed, unbalanced, serial, data interface adopted by the EIA committee on data communications. Generally used for data circuits operating at data rates below 56 Kbps.

RS-422/423

Another EIA standard electrical interface for serial data circuits operating at higher data rates than RS232. RS422 is a balanced interface; RS423 is unbalanced. Uses RS-449 for the physical interface (connector).

Glossary E-15