Glossary
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XN120 Voice Over IP Card Guide
Glossary
CODEC
COder/DECoder. An integrated circuit that converts digital signals to and from analog
(Pulse Code Modulation) form.
DDI
Direct Dial In
The Network will send the last digits of the number to the telephone system. The
telephone system can then route the call based on its own routing tables.
DSP
Digital Signal Processor.
Converts analogue signals to a digital form (sampled).
IP Internet
Protocol
ISDN
Integrated Services Digital Network
IETF
Internet Engineering Task Force.
The IETF is an international community of network designers, operators, vendors and
researchers whose purpose is to coordinate the operation, management and evolution of
the Internet and to resolve short- and mid-range protocol and architectural issues.
PSTN.
Public Switched Telephone Network.
The collection of interconnected systems operated by the various telephone companies
and administrations (telcos and PTTs) around the world.
SIP
Session Initiation Protocol. An IETF standard that defines the delivery of Voice over IP
and Multimedia services.
VoIP
Voice over Internet Protocol
