Specifications

Glossary
17
Cisco BPX 8600 Series Installation and Configuration
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Q
QQ.921/Q.931
ITU-T specifications for the ISDN use network interface (UNI) data link layer.
QSIG
A common-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
RRIF (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 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
thefarendhowmayrepetitionsofthestringwasbeingtransmitted.Usedtoconservenetwork
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.
Routing Node
In tiered networks terminology, a routing node is a larger switch to which one or more feeders is
attached. Collectively, the feeder(s) and routing node form a type of supernode.
RS-232
A physicaland 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).
RS-449
The physical interface for the RS422 and R423 electrical interfaces. Contains the Processor Controller
Card and the PCC utility bus, and provides system timing and control via the system bus.