VOICE Complete.pdf

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Receiver off hook
No such number

Analog Signaling: Address Signal

Pulse – uses broken / connected to signal numbers
Dual tone multi-frequency – different sound frequencies to enter numbers

Video 6 – History Voice Continued:
Problems with analog connections
Distance limitation - signals degrade over distances, and require a repeater
Wiring requirements – High wiring requirements
Digitizing Voice –
Sample the signal.
Perform Quantization on the Sample
Convert the sample into binary
Compress the Samples
PCM – Pulse Code Modulation
Compress – Send just the changes, builds a codebook

Video 7 - Modern Voice:
Call Control Models: Distributed
Call manager express routers (CME)
Phone tells router that they dialed a #
CME looks at route table to find # in their database

Call Control Models: Centralized

Routers are used to direct IP phones to the call manager
Which is used as the brains of the VOIP system.
Drawback – Redundancy

Catching the Key Protocols
Signaling Protocols




Streaming Protocols

RTP (Real Time Transport Protocol)

RTCP (Real Time Transport Control Protocol) - Call statistics
Campus IPT Design
Single Site – Easiest
All call Managers in one location.