Glossary
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Cisco uBR10012 Universal Broadband Router Hardware Installation Guide
78-11450-03 Rev.B0
T3 Digital WAN carrier facility. T3 transmits DS3-formatted data at 44.736 Mbps through the telephone
switching network.
TAC A Cisco Technical Assistance Center. There are four TACs worldwide.
TACACS Terminal Access Controller Access Control System. Authentication protocol, developed by the DDN
community, that provides remote access authentication and related services, such as event logging.
User passwords are administered in a central database rather than in individual routers, providing an
easily scalable network security solution.
TACACS+ Terminal Access Controller Access Control System Plus. Proprietary Cisco enhancement to Terminal
Access Controller Access Control System (TACACS). Provides additional support for authentication,
authorization, and accounting.
TCC+ See Timing, Communication, and Control Plus (TCC+) card.
TDM Time-division multiplexing. A technique in which information from multiple channels can be allocated
bandwidth on a single wire based on preassigned time slots. Bandwidth is allocated to each channel
regardless of whether the station has data to transmit.
Telcordia Organization that performs research and development on behalf of the Regional Bell Operating
Companies (RBOCs). Formerly called Bellcore.
TELNET Standard terminal emulation protocol in the TCP/IP protocol stack. Telnet is used for remote terminal
connection, enabling users to log in to remote systems and use resources as if they were connected to
a local system. Telnet is defined in RFC 854.
Terminal Access
Controller Access
Control System Plus
See TACAC S+ .
TFTP Trivial File Transfer Protocol. Simplified version of FTP that allows files to be transferred from one
computer to another over a network.
Time-division
multiplexing
See TDM.
Timing,
Communication,
and Control Plus
The Timing, Communication, and Control Plus (TCC+) card in the Cisco uBR10012 chassis monitors
the cable interface line cards and power supply usage, controls the LCD display on the front panel, and
provides inputs for an external reference clock that is synced to a Stratum 1 source.
Traffic management A technique for avoiding congestion and shaping and policing traffic. It allows links to operate at high
levels of utilization by scaling back lower-priority, delay-tolerant traffic at the edge of the network
when congestion begins to occur.
Traffic shaping Use of queues to limit surges that can congest a network. Data is buffered and then sent into the network
in regulated amounts to ensure that the traffic will fit within the promised traffic envelope for the
particular connection. Traffic shaping is used in ATM, Frame Relay, and other types of networks. Also
known as metering, shaping, or smoothing.