ADTRAN Atlas 550 User Manual page 250

Appendix G. Glossary
TDM
Time Division Multiplexing. A method for sending two or more signals over a common transmission
path by assignment the path sequentially to each signal, each assignment being for a discrete time
interval.
Telco
Telephone company.
Telnet
A terminal emulation protocol, part of the TCP/IP suite of protocols, that provides remote terminal-
connection services. (See also VT-100.)
TFTP
Trivial File Transfer Protocol. A simplified version of the TCP/IP file transfer protocol that does not
include password protection or user-directory capability.
TIA 464A
Telecommunication Industry Association's standard for DTMF detection and generation.
Transparent BOP
See TBOP
trunk
A direct line between two telephone switching centers.
TSU
T1 Service Unit.
UDP
User Datagram Protocol. Connectionless protocol defined by RFC 768 for transmission of data without
acknowledgment or error control.
UNI
User to Network Interface. Defines the interface between the CPE and the frame relay providers
switch.
VCOM Module
One of the ATLAS 550 option modules. The Voice Compression (VCOM) Module can provide 8, 16, 24,
or 30 compressed voice channels to implement voice over frame relay in the ATLAS 550.
Voice Compression
A means of reducing the bandwidth required for transmission of voice traffic with minimal impact on
the quality of the voice.
VT-100
A non-intelligent terminal or terminal emulation mode used for asynchronous communications. Used
to configure the ATLAS 550.
WAN
Wide Area Network. A network that connects users across large distances.
XMODEM
An error-correcting file transfer, data transmission protocol used to transmit files between PCs. The
XMODEM protocol sends information in128 byte blocks of data. Some sums (check sums) are done on
G-10 ATLAS 550 User Manual 61200305L1-1