Cisco ATA 190 Administration Manual page 72

Glossary
Subscriber Line Interface Circuit. An integrated circuit (IC) providing central office-like phone
SLIC
interface functionality.
Small office, home office. Networking solutions and access technologies for offices that are not
SOHO
directly connected to large corporate networks.
T
T.38 is an ITU recommendation for allowing transmission of fax over IP networks in real time.
T.38
Transmission Control Protocol. Connection-oriented transport layer protocol that provides reliable
TCP
full-duplex data transmission. TCP is part of the TCP/IP protocol stack.
Trivial File Transfer Protocol. Simplified version of FTP that allows files to be transferred from one
TFTP
computer to another over a network, usually without the use of client authentication (for example,
username and password).
A TN power system is a power distribution system with one point connected directly to earth (ground).
TN power systems
The exposed conductive parts of the installation are connected to that point by protective earth
conductors.
Type of service. See CoS.
TOS
U
User agent client. A client application that initiates the SIP request.
UAC
User agent server (or user agent). A server application that contacts the user when a SIP request is
UAS
received, and then returns a response on behalf of the user. The response accepts, rejects, or redirects
the request.
User Datagram Protocol. Connectionless transport layer protocol in the TCP/IP protocol stack. UDP
UDP
is a simple protocol that exchanges datagrams without acknowledgments or guaranteed delivery,
requiring that error processing and retransmission be handled by other protocols. UDP is defined in
RFC 768.
See UAS.
user agent
V
Voice activity detection. When enabled on a voice port or a dial peer, silence is not transmitted over
VAD
the network, only audible speech. When VAD is enabled, the sound quality is slightly degraded but
the connection monopolizes much less bandwidth.
Cisco ATA 190 Analog Telephone Adapter Administration Guide for SIP (Version 1.1)
GL-6
OL-31821-02