Download Voice Over IP - Christopher P. Furner

Voice Over IP
Section 1: VoIP Basics
Section 2: VoIP at ECU
Christopher P. Furner
April 2002
DSCI 4123, 002
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Section 1 ~ VoIP Basics
Analog
Digital Voice
Transfers through Routers,
LAN Switches etc, using their Protocols
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Definitions [1]
 Internet
Protocol (IP)
 Private Branch Exchange (PBX)
 Gateway
 Public Switched Telephone Network
 Public Switched Data Network
 Coder/Decoder (Codec)
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From Voice to Data
Analog
Voice
CODEC: Analog to Digital
Compress
Create Voice Datagram
Add Header
(RTP, UDP, IP, etc)
Digital
Network
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From Data to Voice
Digital
Network
Process Header
Re-sequence and
Buffer Delay
Decompress
CODEC: Digital to Analog
Analog
Voice
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Origin of Standards [4]
Internet Engineering Task Force [6]
International Telecommunication Union
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Protocols [2]
H.323 components
H323 : Standard for multimedia communication over IP
H.323 Functions:
 System and components
H.323
 Call model descriptions
H.323
 System control
Call Seup
H.225 (Q.931)
Channel negotiation
H.245
 Audio coding, compression G.711, G.7222, G.723
G.723.1, G.729
 Video coding, compression H.261, H.263
 Data
T.120
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How VoIP Works [2]
VoIP Typical Configuration
Public
Switch
(LEC)
Public
Switch
(LEC)
Com puter
Local loop
Com puter
Local loop
Telephone
Telphone
TI
Line
TI
Line
H.323
ISP
Gateways
Routers
H.323
Internet
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ISP
Gateways
Routers
Voice Over IP Phone [3]
Costs $361
Built In Browser
Has MAC Address
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Advantages of VoIP
 More
Efficient Use of Network [2]
 Integration Capabilities [3]
 Improved Voice Quality [3]
 Wireless Capabilities [3]
 Less Workload on Call Manager [3]
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Traffic Related
Network Characteristics
Voice
Data
No Loss
 No retransmission
 Direct Pass
Through

Packet Loss
 Retransmission
 Uses protocols

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Section 2
–VoIP At ECU
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Section 2: VoIP At ECU
 March
2001, ECU’s first successful
calls were placed across the Internet
Link to North Carolina State
University.
 Voice
quality was excellent and no
problems were experienced.
 Currently
all VoIP phones are routing
PSTN calls via the gateway.
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ECU as VoIP Leader
 Mr.
Jackson at Conference in
November
 Reported
Great Success
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Other NC Schools
Interested in VoIP
 UNC
Chapel Hill
 North Carolina State University
 UNC Wilmington
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ECU’s Distinction
 Only
University to use VoIP 100%
independent from regular Phone
System
– VoIP will work if our phone system goes
down
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VoIP Workshop &
TOS Priority Model [3]
6: Network Control
5: Voice (Highest Priority)
4: Video (Telecast, Videoconferencing)
3: Not Used
2, 1, 0: Normal Data Traffic
Differs from Standard QOS
architecture [5], Page. 116
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Dual Environment [3]
 ECU
Currently uses both the old
switch and VoIP for voice.
 $12,000,000.00
 35
Switch (DMS)
Phones Across Campus
– Running Very Well
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Funding Issues
 Funding
Cutting Edge Technology
Difficult in a Large Organization
 Recent
 No
Budget Cuts
Funding for Next Semester
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Context Diagram [3]
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Deployment Diagram [3]
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Intelligence
 With
Conventional Phones, more
then 95% resides within the Call
Manager
 With
VoIP, Call Manager only
connects call, then gets out of way.
 In
VoIP, 30% of Intelligence resides
within the Hosts (phones)
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Phones, A Closer Look [3]
 Cost
$361
– Own Mac Address
– Soft Keys
– 6 Lines
– Do Not require Line Card
– Built In Browser
A
Comparable standard Business
Phone costs around $500
– Requires a $200 Line Card
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Exciting Features [3]
 Integration
with Existing Databases
– Exchange Directory
– Calendars
 Integration
with E-mail
– .wav Messages
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Exciting Features [3]
 Speech
Recognition Potential
– Dictation
– Text E-mail Messages
 Compatible
with Wireless
– SpectraLink offers VoIP using Cellular
Technology
– Access Points Allow VoIP
– However a Carrier needs to pick up the
signal when user leaves AP’s Range
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VoIP’s Future at ECU [3]
Will Continue to Use a Dual Enviroment
until full switchover is cost effective
 Expect Cotanch building to be all VoIP by
end of May
 Expect to be 165 Phones Strong by August
 New Science and Technology Building will
be 100% VoIP, and be 100% Compatible
with Wireless and Gigabit t-100 Blades

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VoIP’s Future at ECU [3]
 Introduction
into Residence Halls
– 1 Phone per room with 2 lines and 2
distinct Rings
– Wireless
 Need
to find a Carrier
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Works Cited
 [1]
Shafer, Kevin. Novell’s Dictionary
of Networking. 2002. P242
 [2] How IP Telephony Works Online
 [3] Interview with Martin Jackson
– 04/11/02
 [4]
What is Internet Telephony
Online
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Works Cited
 [5]
Muller, Nathan J. Desktop
Encyclopedia of the Internet. 2002.
 6: Internet Engineering Task Force:
Overview. Online
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Thank YOU
Questions?
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