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MAEDS 45th Annual Conference
October 14 -16, 2009
IP Telephony for Poets
Sam LutgringDirector of Informational Technology
ServicesCalhoun Intermediate School District
MAEDS Board of Directors
Introduction
Voice Over Internet ProtocolAllows voice to become simply another piece of
data (packet) riding the network.A telephony system that takes advantage of
existing data networks by combining components of data and voice networks
Transports voice packets using Internet Protocol (IP)
What is VOIP?
VOIP is both a technology and a serviceThe TECHNOLOGY is IP(Internet Protocol)
which allows the packets to be transferred across the data network
The SERVICE is the voice portion, allowing voice to be transferred across the network
What is VOIP?
Three Common TypesGeek-to-Geek Gateway/Switch-to-PSTN PSTN-to-PSTN
Two “Flavors”Application BasedNetwork Based
What is VOIP?
`
File Server
`
`
PSTN
Traditional Data and Voice Networks
File Server
VOIP Gateway
PSTN
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`
`
Converged Network
One physical layer one infrastructure (single wiring closet) Simpler and less expensive to install and maintain Leverage common data network and equipment
Single network management systemSimplifies moves, adds, and changes for phonesChoice of phone powerFlexible IP address assignmentIncreased system redundancy
Why Should I Care?
VoIP GatewayConverts the voice call traffic from traditional
telephony to IP (data network) and vice versa VoIP PBX (Private Branch Exchange)
A PBX that natively supports Voice over IPVOIP Service provider
Company delivering traditional voice service by utilizing VOIP
IP (Internet Protocol)The universal language of computers
PSTNPublic Switched Telephone Network
What do the BUZZ words mean?
Convergence (multiservice networking)Marketing terminology used to describe the
utilization of one network facility to deliver multiple services; usually data, voice, and video.
Unified Messaging Integration of messaging and communication (e-
mail, voicemail, SMS, fax) into a single interfaceDigital Circuit
Delivery of voice services through a digital line. Usually a T1 with ISDN signaling in the US.
Analog Circuit/POTSTraditional analog line delivered to home or business
What do the BUZZ words mean?
What standards should I be aware of?Make sure vendor supports OPEN
STANDARDS.G.711 ulaw is the standard Codec used in
the US by carriers.SIP (session initiation protocol) is a
commonly used and supported VoIP peer-to-peer protocol.
H.323 another format used to define call control and setup.
What are some common solutions?Add IP support to existing PBXVoIP gatewayVoIP PBX
FEATURE TRADITIONAL VOIP
Power Multiple (redundant) power supplies
Multiple power supplies with multiple sources
Call Processing Redundant Processors on the same system
Multiple servers acting in a cluster
Modularity One system with multiple components
Multiple systems with isolated failures
Backups Backup of internal system, weekly tape rotation
Mirrored system drives, utilize existing server backup architecture
Administration Specialized mapping Web interface or text files
System Software
Proprietary Standards based
Feature Comparison
Feature ComparisonFEATURE TRADITIONAL VOIP
System Expansion
Major cost and usually replace system
Additional license or hardware
User Customization
Limited if any Web interface
Additional Phone Functionality
Replace Phone Software upgrade
Adds Define port in system, hard wire phone into port
Add extension and phone
Moves Reconfigure port and change wiring infrastructure
Plug the phone in somewhere else
Must have a robust data networkAll your eggs in one basket/networkNetwork outages/issues impact voice network
What are the Down Sides?
Always Remember E911/911E911 requires that the calling phone can
be tracked back to an addressPotential Issues
Multiple buildings routed out the same LEC (local exchange carrier) infrastructure.Work with LEC to identify a specific outbound
channels for each building to route 911 calls.Place analog lines with switch in each building for
emergency call routing only.VPN users calling on soft phones from home.
Train staff not to do this.Contract with a VoIP provider rather then
traditional LEC.Make sure this is addressed in your contract.
Traditional Desk Phone Grandstream/Polycom/Sonoma/Cisco
Soft phoneComputer Client
Low Cost Analog PhoneSame as your house
What about Phones?
Powering the phonesPOE (Power Over Ethernet)
POE switches capable of delivering powerPowered patch panel inserted between existing
switch and end devicesAC power adapter to wall socket
Digital InterfaceMultiport PCI cardUsually T1 interface with ISDN signaling
Analog Interface4-8 port PCI cardsChannel Bank with 8/12/16/24/32/40 portsFXO (Foreign exchange Office)
FXO interface receives power and receives ring signalPlug the Central Office in here
FXS (Foreign exchange Station)FXS interface provides power and generates ring
signalsPlug a handset in here
How do I talk to Grandma?
Data NetworkRedundancy/FailoverEmergency ServicesConnecting to traditional phone servicesVoicemail/e-mail integration
What do I need to consider?
AsteriskCiscoLucentSiemens… the list goes on
Where do I get it?
www.voip-info.orgWiki that provides excellent information on
VOIPwww.digium.com
Makers of voice processing cardswww.thevoipconnection.com
Great source for hardware
Where can I find out more?
What is the Future?
Any device to any device on any network
WIFIGateway
IP PhoneIP PBX
FaxGateway
SmartPhone
Video
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DesktopLaptop
(Soft Phone)IP Network
PDAWIFI
CellPhone