anup kawtia- a presentation on voip

10 September 2008 A PRESENTATION ON VOIP 1

A PRESENTATION ON VOIPA PRESENTATION ON VOIP

BY: ANUP KAWTIA

0501206124 COMP SC. & ENGG.


CONTENTS• Introduction• How it works?• Types• Clients• Protocols• VOIP Service- Features• VOIP vs. PSTN• Advantages• Disadvantages• VoIP Subscribers worldwide• VOIP Service- Providers


Introduction

What is Voice Over Internet Protocol (VOIP) ?

• The ability to make phone calls over IP-based data network.

• The method of digitizing voice, encapsulating the digitized voice into packets and transmitting those packets over a packet switched IP network.

• The multi-billion revenue opportunity for the 21st century.


How VOIP works?

• Conversion of the analog voice signal to digital format

• Compress signal Internet protocol (IP) packets for transmission over the internet

• Transmit • Conversion of the digital signal back to analog

IP Network

IP Network


VOIP Types

• PC- to- PC VOIP

• PC- to- Phone VOIP

• Phone- to- Phone VOIP


PC- to- PC VOIP• Voice Communication between PCs connected

to the Internet.• Needs PC users online simultaneously.• Needs a PC with sound card, microphone and

same software such as MS NetMeeting at both ends.

• Only costs of Internet access is involved. • No need of Gateway on either side.

CentralOffice

CentralOffice

Modem

Internet

Modem


PC- to- Phone VOIP• Voice communication from PC on one end to

phone on PSTN via gateway on the other.• Needs gateway on the phone side to convert IP

packets back to telephone signals.• Gateway located as near to the callee to

minimize the price for the gateway-to-callee connection.

• The cost to caller is charged by gateway operator and is determined by the call placed from the gateway to the callee.

VoIPGateway

Modem CentralOffice

Internet

Central

Office

Gatekeeper


Phone- to- Phone VOIP• Needs two gateways, one to convert circuit

switched signals to packet switched signals and the other to perform reverse action.

• Allows consumers to place phone calls using just their ordinary home phones; No additional hardware, software, or Internet connectivity required.

• Cost Involved• Local Call cost• Cost Charged by Gateway Operators

VoIPGateway

Gatekeeper

VoIPGateway

VoIP Service Provider

CentralOffice

CentralOffice

IP


VOIP Clients

• Analog Telephone Adaptor

• VOIP Phones

• Wireless VOIP Phones

• VOIP Soft Phones


VOIP Protocols• H.323

• Handles voice, video, and data conferencing • Most VoIP traffic utilises this today

• Session Initiation Protocol (SIP)• Signaling protocol• Currently most favoured protocol for new

systems• Realtime Transport Protocol (RTP)

• Transport protocol• Fast, scaleable and efficient

• Media Gateway Control Protocol (MGCP)• Signaling and control protocol• Reduces traffic between gateways


VOIP Service- Features

• Call forwarding • Call hold• Call waiting• Calling Line Identification (CLIP) .• Directories—missed, placed, received calls list• Message waiting indication• Hands-free, full-duplex speakerphone • Speed dial—multiple speed dials per phone • Station volume controls (audio, ringer)• Recent dial list—calls to phone, calls from

phone, auto-dial, and edit dial • Multi-party conferencing


VOIP vs. PSTN

Network Features

PSTN VOIP

Switch Circuit Switched Packet Switched

Connection Connection Oriented

Connectionless

Bit Rate Fixed and low <=64kb/s

Wide variation to Gb/s

Info resending Cannot Can be done very fast

Delay Must be low and stable

Can be high and varying


Advantages of VOIP

• Cost Reduction• More Bandwidth• Integration of Voice and Data network• Network Efficiency• Easily Portable


Disadvantages of VOIP

• The Quality of Service:• Delays• Jitter • Packet Loss

• High Speed Internet • Power Outage• 911 Services• Directory Assistance


VoIP VoIP Subscribers worldwide worldwide


VOIP Service- Providers• iBase

• Teleglobe

• Vonage

• Skype

• Lingo

• EarthLink

• Pulver

• Google

http://www.vonage.com/index.php?lid=login_logo

http://www.lingo.com/

http://www.earthlink.net/


Conclusion

• Must be clear that VoIP is indeed cost-effective. • Protect its investment in circuit switched

telecom operations since VoIP would be complementary to its existing technology

• There must be significantly lower total cost of operation compared to today’s PSTN

• Technology is not fully developed to the point where it can replace the services and quality provided by PSTN

• Service Providers are awaiting the development of the remaining pieces of technology that will ensue quality transport in the last mile


References

• www.google.co.in• www.wikipedia.org


Thanks for your kind attention!

Questions are welcome!

Thank you

anup kawtia- a presentation on voip

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