Installation guide

Glossary
GL-27
Cisco 6260 Hardware Installation Guide
OL-2365-02
TC-PAM
trellis coded pulse amplitude modulation. Trellis coding provides forward error correction, while
pulse amplitude modulation is a modulation scheme where a continuous analog signal is represented
with a series of discrete analog samples.
TCP
Transmission Control Protocol. The major transport protocol in the Internet suite of protocols
providing reliable, connection-oriented, full-duplex streams. See SLIP.
Telnet
The virtual terminal protocol in the Internet suite of protocols. It allows users of one host to log in to
a remote host and use resources as if they were connected to a local system.
TFTP
Trivial File Transfer Protocol. A simple file transfer protocol (a simplified version of FTP) that allows
files to be transferred from one computer to another over a network. TFTP does not offer
password security.
tip and ring
A pair of wires that provide the electrical connection between a telephone set and the local CO. The
more electrically positive side of a POTS telephone line (0 V) is the tip. Its counterpart is the ring,
which is the more negative side, 52 v).
topology
Physical arrangement of network nodes and media within a networking structure.
trailer
A block of information that is transmitted at the end of a message to trace error impacts and
missing blocks.
training
The handshake procedure that initiates and establishes an end-to-end xDSL connection
training mode
The mode, either standard or quick, that a DSLAM port employs when it is training to a CPE. The
training mode uses RADSL technology to adjust line speed according to noise conditions on the
transmission line.
Transmission
Control Protocol
See TCP.
trap
Message sent by SNMP agent to an NMS, a console, or a terminal to indicate the occurrence of a
significant event, such as a specifically defined condition or a threshold that was reached. See also
alarm and event.
tree topology
A method of connecting devices that is similar to a bus topology, except that tree networks can contain
branches with multiple nodes. Transmissions from a station propagate the length of the medium and
are received by all other stations. Compare with bus topology, daisy-chain topology, ring topology, and
star topology.
trellis coded pulse
amplitude
modulation
See TC-PAM.
trellis encoding
A channel coding technique which provides forward error correction capability.
Trivial File Transfer
Protocol
See TFTP.
twisted pair
Two insulated copper wires twisted together with the twists or lays varied in length to reduce potential
signal interference between the pairs.