Introduction to Packet Voice Technologies Cisco Networking Academy Program

Traditional Telephony Thanks for joining us today to attend the Cisco Brand and Corporate Identity Workshop. In the first half of the workshop I am going to cover Brand Matters and talk in detail about the Cisco brand, and in the second half my colleague Gary McCavvit is going to take you through our updated visual identity system. At the end of the workshop we’re going to leave some time for a fun quiz as well as some Q&A.

Basic Components of a Telephony Network

Central Office Switches

What Is a PBX?

Basic Call Setup

Supervisory Signaling

Address Signaling Rotary telephone Pulse dialing Tone telephone DTMF dialing Rotary telephone Pulse dialing

Informational Signaling

Digital vs. Analog Connections

Time-Division Multiplexing

Frequency-Division Multiplexing

Packetized Telephony Networks Thanks for joining us today to attend the Cisco Brand and Corporate Identity Workshop. In the first half of the workshop I am going to cover Brand Matters and talk in detail about the Cisco brand, and in the second half my colleague Gary McCavvit is going to take you through our updated visual identity system. At the end of the workshop we’re going to leave some time for a fun quiz as well as some Q&A.

Packet Telephony vs. Circuit-Switched Telephony More efficient use of bandwidth and equipment Lower transmission costs Consolidated network expenses Increased revenue from new services Service innovation Access to new communications devices Flexible new pricing structures

Call Control

Distributed Call Control

Centralized Call Control

Packet Telephony Components

Real-Time vs. Best-Effort Traffic Real-time traffic needs guaranteed delay and timing. IP networks are best-effort with no guarantees of delivery, delay, or timing. Solution is quality of service end-to-end. If there is more text than will fit on a page, try use any of the following options: Size the text to 11 points. (Do not go smaller than 11 points.) Reduce or eliminate the space following paragraphs. Create a blank slide following the slide with a large amount of text and do the following: On the slide, make the slide title read, “Instructor Notes Attached.” On the notes page: Delete the slide image Resize the height of the body placeholder to use the entire page if necessary Enter the additional text In the Slide Sorter View, hide the slide so it won’t appear during a presentation.

Foreign Exchange Station Interface

Foreign Exchange Office Interface

E&M Interface

T1 Interface

E1 Interface

BRI

Physical Connectivity Options

Cisco IP Phone

Analog Voice Basics Thanks for joining us today to attend the Cisco Brand and Corporate Identity Workshop. In the first half of the workshop I am going to cover Brand Matters and talk in detail about the Cisco brand, and in the second half my colleague Gary McCavvit is going to take you through our updated visual identity system. At the end of the workshop we’re going to leave some time for a fun quiz as well as some Q&A.

Local Loops

Types of Local-Loop Signaling Supervisory signaling Address signaling Informational Signaling

On Hook

Off Hook

Ringing

Ringing (Cont.)

Pulse Dialing

Dual Tone Multifrequency

Informational Signaling with Call-Progress Indicators

Trunks

Foreign Exchange Trunks Foreign Exchange Office Connects directly to office equipment Used to extend connections to another location Foreign Exchange Station Connects directly to station equipment Used to provision local service

Types of Trunk Signaling Loop start Ground start E&M Wink Start E&M immediate start E&M delay start

Loop-Start Signaling

Ground-Start Signaling

E&M Signaling Separate signaling leads for each direction E-lead (inbound direction) M-lead (outbound direction) Allows independent signaling

E&M Type I

E&M Type V

E&M Type II

E&M Type III

E&M Type IV

Trunk Supervisory Signaling— Wink Start

Trunk Supervisory Signaling— Immediate Start

Trunk Supervisory Signaling— Delay Start

2-Wire to 4-Wire Conversion and Echo Echo is due to a reflection. Impedance mismatch at the 2-wire to 4-wire hybrid is the most common reason for echo.

Echo Is Always Present Echo as a problem is a function of the echo delay and the loudness of the echo.

Echo Suppression

Echo Cancellation

Analog-to-Digital Voice Encoding Thanks for joining us today to attend the Cisco Brand and Corporate Identity Workshop. In the first half of the workshop I am going to cover Brand Matters and talk in detail about the Cisco brand, and in the second half my colleague Gary McCavvit is going to take you through our updated visual identity system. At the end of the workshop we’re going to leave some time for a fun quiz as well as some Q&A.

Digitizing Analog Signals Sample the analog signal regularly. Quantize the sample. Encode the value into a binary expression. Compress the samples to reduce bandwidth, optional step.

Basic Voice Encoding: Converting Digital to Analog Decompress the samples, if compressed. Decode the samples into voltage amplitudes, rebuilding the PAM signal. Filter the signal to remove any noise.

Nyquist Theorem

Voice Compression Techniques Waveform algorithms PCM ADPCM Source algorithms LDCELP CS-ACELP

Example: Waveform Compression PCM Waveform coding scheme ADPCM Adaptive: automatic companding Differential: encode changes between samples only ITU standards: G.711 rate: 64 kbps = (2 * 4 kHz) * 8 bits/sample G.726 rate: 32 kbps = (2 * 4 kHz) * 4 bits/sample G.726 rate: 24 kbps = (2 * 4 kHz) * 3 bits/sample G.726 rate: 16 kbps = (2 * 4 kHz) * 2 bits/sample

Compression Bandwidth Requirements

Mean Opinion Score

Perceptual Speech Quality Measurement

Signaling Systems Thanks for joining us today to attend the Cisco Brand and Corporate Identity Workshop. In the first half of the workshop I am going to cover Brand Matters and talk in detail about the Cisco brand, and in the second half my colleague Gary McCavvit is going to take you through our updated visual identity system. At the end of the workshop we’re going to leave some time for a fun quiz as well as some Q&A.

T1 Digital Signal Format

Robbed-Bit Signaling

Channel Associated Signaling—T1

E1 Framing and Signaling

Channel Associated Signaling—E1

Common Channel Signaling

ISDN ISDN Standards-based Part of network architecture Definition for access to the network Allows access to multiple services through a single access Used for data, voice, or video Standards-based ITU recommendations Proprietary implementations

ISDN Network Architecture

Layer 3 (Q.930/931) Messages