Telephony and VoIP Fundamentals · President, Distributed Networking Associates, Inc....
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Telephony and VoIP Fundamentals Steven Taylor President, Distributed Networking Associates, Inc. Publisher/Editor, Webtorials [email protected] Larry Hettick Vice President, Wireline Solutions Current Analysis [email protected] Professional Opinions - All information presented and opinions expressed by Distributed Networking and/or Larry Hettick are the current opinions of Distributed Networking and/or Larry Hettick based on professional judgment and best available information at the time of presentation. Consequently, the information is subject to change, and no liability for advice presented is assumed. Ultimate responsibility for choice of appropriate solutions remains with the Customer. Copyright, 2004 - Distributed Networking Associates and/or Larry Hettick. All portions of this presentation are copyrighted by Distributed Networking Associates and/or Larry Hettick and/or the organization credited as the source of information. All forms of reproduction and/or recording, including photocopying, tape recording, and video taping are strictly prohibited without the express prior written permission of Distributed Networking Associates and/or Larry Hettick. Copyright & Notices
Transcript of Telephony and VoIP Fundamentals · President, Distributed Networking Associates, Inc....
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Telephony and VoIPFundamentals
Steven TaylorPresident, Distributed Networking Associates, Inc.
Publisher/Editor, [email protected]
Larry HettickVice President, Wireline Solutions
Current [email protected]
Professional Opinions - All information presented and opinions expressed by DistributedNetworking and/or Larry Hettick are the current opinions of Distributed Networking and/or Larry Hettick based on professional judgment and best available information at the time of presentation. Consequently, the information is subject to change, and no liability for advice presented is assumed. Ultimate responsibility for choice of appropriate solutions remains with the Customer.
Copyright, 2004 - Distributed Networking Associates and/or Larry Hettick. All portions of this presentation are copyrighted by Distributed Networking Associates and/or Larry Hettickand/or the organization credited as the source of information. All forms of reproduction and/or recording, including photocopying, tape recording, and video taping are strictly prohibited without the express prior written permission of Distributed Networking Associates and/or Larry Hettick.
Copyright & Notices
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Thanks to the sponsor…This presentation is made possible in part due to the generous support of Nortel Networks.
Agenda
The Public Switched Telephone Network (PSTN)
ArchitectureDigital Voice
What is Voice over IP (VoIP)?Implementing VoIPUnified Communications and Applications Convergence
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PSTN Architecture
Call infoControl info
SS7 Control Network
Tandem Office
CentralOffice
CentralOffice
Tandem Office
Digital Voice Example (PCM)
Source: Screen capture from “CoolEdit” - http://www.syntrillium.com/
8000 Samples per second255 code levels (8 bits per sample)64,000 bits per second
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Traditional Digital Hierarchy
64 kbps (DS0) is the fundamental building block
DS1 (T1) carries 24 DS0s in 1.544 MbpsDS3 (T3) carries 28 T1s in ~45 MbpsOC1 carries 3 T3s on ~150 Mbps
Data speeds have been adapted to fit into this hierarchy
Agenda
The Public Switched Telephone Network (PSTN)
ArchitectureDigital Voice
What is Voice over IP (VoIP)?Implementing VoIPUnified Communications and Applications Convergence
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Layer 1:Physical Layer
Layer 2: Ethernet, Frame Relay, etc.
Layer 3:IP
Layer 4:TCP, UDP
Layer 7:Application data
Traditional Data Nets
Layer 1:Physical Layer
Layer 2: Ethernet, Frame Relay, etc.
Layer 3:IP
Layer 4: UDPfor conversation content
Layer 7:Voice Packets
VoIP
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Voice VariablesThree distinct functions may or may not be used:
CompressionCould packetize 64 kbps PCMBut usually implies a more efficient coding scheme
PacketizingSame low-bit-rate algorithms can be used over a dedicated connectionVoIP is always packetized
Silence Suppression
Agenda
The Public Switched Telephone Network (PSTN)
ArchitectureDigital Voice
What is Voice over IP (VoIP)?Implementing VoIPUnified Communications and Applications Convergence
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Call infoControl info
Control Networks
IP NetworkTandem Office
CentralOffice
CentralOffice
Gateway GatewayTandem Office
Integrated Traditionaland VoIP Network
Typical VoIP Components
Hardware / Premise EquipmentGateway Function
Usually embedded into another deviceVoIP-enabled routersIP PBX and IP-enabled PBX
Services“IP Centrex”IP-based transport of POTS/PSTNcalls
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TraditionalPBX
TraditionalPhone
TraditionalPBX
TraditionalPhone
IP Phone IP Phone
VoIPRouter
VoIPRouter
IP PBX(with or WithoutRouter)
Internet
Private IP Network
IP PBX(with or WithoutRouter)
IP Centrex
IP Telephony Service Provider
(IPSP) PSTNPSTN
VoIP Network Architecture
ATM, Frame Relay, or Private Line
Network
Agenda
The Public Switched Telephone Network (PSTN)
ArchitectureDigital Voice
What is Voice over IP (VoIP)?Implementing VoIPUnified Communications and Applications Convergence
9
TraditionalPBX
TraditionalPhone
TraditionalPBX
TraditionalPhone
IP Phone IP Phone
VoIPRouter
VoIPRouter
IP PBX(with or WithoutRouter)
Internet
Private IP Network
IP PBX(with or WithoutRouter)
IP Centrex
IP Telephony Service Provider
(IPSP) PSTNPSTN
Converged IT Network Architecture
ATM, Frame Relay, or Private Line
Network
Information Processing and Storage
Thank you!Summary
The Public Switched Telephone Network (PSTN)ArchitectureDigital Voice
What is Voice over IP (VoIP)?Implementing VoIPUnified Communications and Applications Convergence
For more informationWebtorials
http://www.webtorials.comNortel Networks
Sponsor of this presentationhttp://www.nortelnetworks.com
