138 APPENDIX : GLOSSARY
SS7 Signaling System 7—A global standard for telecommunications as defined by the
International Telecommunication Union (ITU). The SS7 standard defines the
procedure protocol by which network elements in the PSTN exchange information
over a digital signaling network.
SMS System Management Services—Allows provisioning and updating of information
on subscribers and services in near-real time for billing and administrative
purposes.
SNMP Simple Network Management Protocol—Standardized method of managing and
monitoring network devices on TCP/IP-based internets. A standard way for
computers to share networking information. In SNMP, two types of
communicating devices exist: agents and managers. An agent provides
networking information to a manager application running on another computer.
The agents and managers share a database of information, called the
Management Information Base (MIB). An agent can use a message called a
traps-PDU to send unsolicited information to the manager.
SQL Structured Query Language—A standard interactive and programming language
for requesting information from and updating databases.
SRAM Static Random Access Memory—Type of RAM that retains its contents for as long
as power is supplied. SRAM does not require constant refreshing, like DRAM.
SS Silence Suppression—A way to save on bandwidth by not transmitting the silences
or gaps in conversation. A voice compression process where the time when there
is no voice being transmitted over the line during a conversation, that space is
filled with data, and video transmission on the line.
SST Silence Suppression Threshold—The limit of silence allowed on the voice
transmission before data, and video packets are sent on the line. This can be
defined by the user.
STP Signal Transfer Point—SS7 Signal Routing Node. It is a very reliable packet switch
used to forward signaling messages in an SS7 network. The network switches and
the SCPs connect directly to the STPs for message routing.
SVGA Super Video Graphics Array—An enhancement of the VGA display standard.
SVGA can display at least 800 pixels horizontally and about 600 lines vertically.
TCM Total Control Manager—See IP Telephony Manager.
TCP Transmission Control Protocol—Connection-oriented protocol that provides a
reliable byte stream over IP. A reliable connection means that each end of the
session is guaranteed to receive all of the data transmitted by the other end of the
connection, in the same order that it was originally transmitted without receiving
duplicates.
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 w hether the station has
data to transmit.