Appendix C: Glossary and Acronyms
RJ11
A sixpin jack typically used for connecting telephones, modems, and fax
machines in residential and business settings to PBX or the local
telephone CO.
SIP
Session Initiation Protocol
An IETF standard for setting up sessions between one or more clients. It
is currently the leading signaling protocol for Voice over IP, gradually
replacing H.323.
T1
A dedicated digital carrier facility which transmits up to 24 voice
channels (DS0s) and transmits data at 1.544 Mbps. Commonly used to
carry traffic to and from private business networks and ISPs.
T3
A dedicated digital carrier facility which consists of 28 T1 lines and
transmits data at 44.736 Mbps. Equivalent to 672 voice channels (DS0s).
TDM
Time Division Multiplexer
A device that supports simultaneous transmission of multiple data streams
into a single highspeed data stream. TDM combines signals by
interleaving bits one after the other.
TE
Terminal Equipment
A device that is established as a point of termination of a communications
circuit or channel. Terminal equipment comprises all customer premises
equipment (CPE). TE devices are connected to NT devices.
Digium, Inc.
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