Cisco BPX-BXM-155-8DX Installation And Configuration Manual page 620

Glossary
T
The standard US. multiplexed 24-channel voice/data digital span line. Operates at a data rate of 1.544
T1
Mbps.
Transmission service at DS3 rate of 44.736 Mbps.
T3
The negotiated number of cells that the network would prefer to limit the source to send during the
TBE (Transient
Buffer Exposure) start-up period.
The process of combining several communication channels by dividing a channel into time increments
TDM (time division
multiplexing) and assigning each channel to a timeslot.
A field in certain FastPacket formats that indicates the amount of time the packet has spent waiting in
timestamp
queues during the transmission between its source and destination nodes. Used to control the delay
experienced by the packet.
An upper bound on the time between RM cells for an active source, i.e., RM cell must be sent at least
Trm
once every Trm msec.
A physical link between two nodes. The trunk may be one that supports 24-byte FastPackets (packet
trunk
trunk), or one that supports 53 byte ATM cells (cell trunk.)
A set of signalling and information bits that indicate a DS1 line failure.
trunk conditioning
The buffers in packet line cards (NTC, TXR) where the various FastPackets are queued up for
trunk queues
transmission over the packet line(s). The buffers attempt to prioritize each packet so it experiences
minimum delay.
U
An analog to digital encoding scheme used to convert voice samples to an 8-bit data word used in
-law
D3/D4 T1 multiplex equipment.
Unspecified Bit Rate.
UBR
The user to network interface, used for ATM connection to CPE. Compare with NNI.
UNI (User to
Network Interface)
A general procedure for controlling the rate of user data applied to an ATM network. There are a
UPC (Usage
number of different algorithms for performing UPC. See also GCRA.
Parameter Control)
A single-chip device used in certain applications that allows microprocessors to communicate with
USART (Universal
Synchronous/Async input/output (I/O) devices.
hronous Receiver
Transmitter)
The protocol at a frame relay port that passes information between the network and the user device
User to Network
Interface (UNI) attached to the port.
Cisco BPX 8600 Series Installation and Configuration
20
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001