Transcript Voice and Data Integration over IP An analytical overview of voice

Voice and Data Integration over IP
An analytical overview of voice-over-IP
Prabhu Sivarja
Wichita State University, Wichita, KS
Spring 2003
Goal
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To define voice-over-IP
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To give a brief overview of this technology
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To enlighten and not confuse the listeners
Contents
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Introduction
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Traditional Voice Networks
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Voice-over-IP Networks
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Strategies regarding implementation
Introduction
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What is voice-over-IP?
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The transmission of voice over IP networks in the form of
packets.
What are the benefits of voice-over-IP?
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Cost Reduction
Voice and Data Integration
Bandwidth Efficiency
New Applications
Traditional Voice Networks
Voice-over-IP Networks
Standards in Voice-over-IP
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H.323
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Session Initiation Protocol(SIP)
Components of H.323
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Media Gateways
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Media Gatekeepers
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Multipoint Control Units (MCU)
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Protcols used
Components of H.323
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Media Gateways
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Hardware that acts an entry point for the voice into
the IP cloud.
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Searches and maps phone numbers to IP addresses
Connects to remote gateways
Converts from Analog to digital
Compresses voice
Components of H.323
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Media Gate Keepers
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Authority that manages the gateways
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Address Translation
Admission Control
Bandwidth Management
Zone Management
Call Management
Multipoint Control Unit (MCU)
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Conference calling support
Components of H.323
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Protocols Used
Control and
Signaling
Data
T.120
H.225.0 Call
Signaling
TCP
Network Layer
Data Link Layer
Physical Layer
H.245
Conference
Control
Audio/
Video
Registrati
on
RTP/RTCP
H.225.0 RAS
UDP
Steps involved in the transmission
of voice packets over a H.323
network
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Discovering gate keeper by gateway
Registering gateway with gatekeeper
Gateway enters setup phase
The capability exchange between gatekeeper and
gateway
The call is established between two gateways
Transmission of voice packets between gateways
Termination of logical connection
Session Initiation Protocol
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Application level protocol which manages voice
communication
Based on the client server approach
Communicates by passing messages
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Invite, Bye, Redirect, Acknowledge
Shares similarities between SMTP
Offers personal mobility
Steps involved in the transmission
of voice packets over a SIP network
H.323 vs. SIP
H.323
SIP
Complex Protocol
Comparatively Simpler
Binary Representation of msgs
Text Representation of msgs
Requires full backward
compatibility
Does not require full backward
compatibility
Not very modular
Very modular
Not very scalable
Very scalable
Complex signaling
Simple signaling
Large share of market
Not too large a share but
backed by IETF
Hundreds of elements
Only 37 headers
Strategies regarding
implementation
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Simple Toll Bypass
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Total IP Telephony
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Used for small organizations
Minimal changes
No PSTN integration
Complete overhaul of the phone network
Traditional phones -> IP phones
LAN servers
IP Enabled PBX
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Intermediate solution. PBX is upgraded to talk to IP cloud
Conclusion
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Voice-over-IP has it advantages.
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Economical
Efficient
Voice/Data Integration
New Services
Best strategy is the IP enabled PBX
(Intermediate approach)
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Can be implemented on top of existing voice
networks.
QUESTIONS ?