VoIPVoIPPresented by:Presented by:

Adnan SheikhAdnan Sheikh

Chris HowardChris Howard

Moises UribeMoises Uribe

Cheri KishidaCheri Kishida

OverviewOverview

The History of this new technology.The History of this new technology.

What is Internet Telephony?What is Internet Telephony?

How does it work?How does it work?

What are the Pros/Cons?What are the Pros/Cons?

What are some of the companies that What are some of the companies that provide VoIP?provide VoIP?

ObjectivesObjectives

To provide the class with an To provide the class with an understanding of VoIP for personal/home understanding of VoIP for personal/home useuse

To inform the class of the VoIP service To inform the class of the VoIP service providers availableproviders available

To be able to leave this presentation To be able to leave this presentation knowing how to obtain and implement your knowing how to obtain and implement your own VoIP servicesown VoIP services

HistoryHistory

February 1995, first internet phone released by February 1995, first internet phone released by VocalTec, then other companies like Cisco & VocalTec, then other companies like Cisco & lucent entered the marketlucent entered the market

1996, Internet Telephone Consortium created 1996, Internet Telephone Consortium created (ITC) used as a means of discussing the (ITC) used as a means of discussing the technology, regulation policies, and market technology, regulation policies, and market structure for the industrystructure for the industry

Over time, Advancements in technology have Over time, Advancements in technology have made internet phone easy to use and an made internet phone easy to use and an affordable service to useaffordable service to use

What is Internet Telephony?What is Internet Telephony?

Technology using an Internet connection Technology using an Internet connection to pass voice data using IP instead of the to pass voice data using IP instead of the standard public switched telephone standard public switched telephone network network

Current: PSTN & POTSCurrent: PSTN & POTS

Very flexible: supports PC to PC, PC to Very flexible: supports PC to PC, PC to Phone, and Phone to PhonePhone, and Phone to Phone

How it WorksHow it Works

Voice over internet protocol (VOIP) turns Voice over internet protocol (VOIP) turns analog voice signals to digital data.analog voice signals to digital data.

Lower costs – Domestic & InternationalLower costs – Domestic & International

Three types of internet telephonyThree types of internet telephony ATAATA IP PhonesIP Phones PC to PCPC to PC

ATAATA

ATAATA

Most common methodMost common method

Analog Telephone Adaptor (ATA) is an Analog Telephone Adaptor (ATA) is an analog to digital converteranalog to digital converter

Enables you to connect a standard phone Enables you to connect a standard phone to a computer or Internet connectionto a computer or Internet connection

IP PhonesIP Phones

IP PhonesIP Phones

Similar to normal phones but have an RJ-Similar to normal phones but have an RJ-45 (Ethernet) connection instead of the 45 (Ethernet) connection instead of the standard RJ-11 connectionstandard RJ-11 connection

Contains all hardware and softwareContains all hardware and software Connect directly to routerConnect directly to router Offices configured with all IP phones are Offices configured with all IP phones are

said to have an IP Private Branch said to have an IP Private Branch Exchange (PBX) set upExchange (PBX) set up

Computer to ComputerComputer to Computer

Obtain free or very low-cost software from Obtain free or very low-cost software from companies.companies.

Sender & receiver need equipment.Sender & receiver need equipment.

Need the software, Internet connection Need the software, Internet connection (preferably high speed), microphone, (preferably high speed), microphone, speakers, and a sound card..speakers, and a sound card..

Lower cost once equipment is purchasedLower cost once equipment is purchased

Standard PhoneStandard Phone

Dial tone means you have connection to local Dial tone means you have connection to local office of telephone carrieroffice of telephone carrier

Dial the number and call is routed through the Dial the number and call is routed through the switchswitch

Connection is made using several Connection is made using several interconnected switches along the wayinterconnected switches along the way

Receiving party answers the call and the Receiving party answers the call and the connection opens the circuitconnection opens the circuit

Once you hang up, the circuit is closed and all Once you hang up, the circuit is closed and all lines that were in use are freelines that were in use are free

VoIP: How it WorksVoIP: How it Works VOIP involves packet switching, therefore a constant VOIP involves packet switching, therefore a constant

connection is not requiredconnection is not required The sending computer splits the data up into packets, each The sending computer splits the data up into packets, each

packet containing an address on it so that network devices packet containing an address on it so that network devices know where to send themknow where to send them

Within each packet is a payload. The payload is whatever is Within each packet is a payload. The payload is whatever is being transmitted.being transmitted.

The packets are then sent to a router which sends the packets The packets are then sent to a router which sends the packets to another router, and so on and so forth until they reach their to another router, and so on and so forth until they reach their destination.destination.

The receiving computer then puts all of the packets back The receiving computer then puts all of the packets back together again in the proper order using instructions contained together again in the proper order using instructions contained within the packets. These instructions are necessary because within the packets. These instructions are necessary because the packets may take different paths and arrive in the wrong the packets may take different paths and arrive in the wrong order. order.

VoIP: How it WorksVoIP: How it Works VOIP uses the internets packet switching network VOIP uses the internets packet switching network

When you pick up the receiver it sends a signal to the ATAWhen you pick up the receiver it sends a signal to the ATA The ATA receives the signal and sends back a dial toneThe ATA receives the signal and sends back a dial tone When you dial a number the tones are converted into a digital format and When you dial a number the tones are converted into a digital format and

then momentarily stored.then momentarily stored. The phone number you dialed is then sent in the form of a request to the The phone number you dialed is then sent in the form of a request to the

VOIP companies call processorVOIP companies call processor The call processor then checks to see if the request is in a valid format.The call processor then checks to see if the request is in a valid format. The call processor then determines how best to map the callThe call processor then determines how best to map the call The phone number is then translated into an IP address.The phone number is then translated into an IP address. A device called a soft switch then connects the two devices, whatever A device called a soft switch then connects the two devices, whatever

they may be.they may be. A signal is then sent to the now connected phone telling it to ring.A signal is then sent to the now connected phone telling it to ring. Once the phone is picked up a session is established.Once the phone is picked up a session is established. As your conversation is going on packets are sent back and forth As your conversation is going on packets are sent back and forth

whenever there is data to be sent.whenever there is data to be sent. When the phone is hung up the circuit is closed and the ATA sends a When the phone is hung up the circuit is closed and the ATA sends a

signal to the soft switch terminating the session.signal to the soft switch terminating the session.

VoIP – Behind the ScenesVoIP – Behind the Scenes

ProtocolsProtocolsEncodingEncodingAchieving the qualityAchieving the quality

The ProtocolsThe Protocols

Various protocols include H.323, SIP, Skinny Various protocols include H.323, SIP, Skinny Client Control Protocol, Megaco (MGCP), Client Control Protocol, Megaco (MGCP), MiNET, IAX, and othersMiNET, IAX, and others

Source and destination of telephone call must Source and destination of telephone call must be equipped with compatible versions of the be equipped with compatible versions of the same protocolsame protocol

Gatekeeper assists the VoIP phones in placing Gatekeeper assists the VoIP phones in placing the call through such functions as Address the call through such functions as Address Translation, Admission control and Bandwidth Translation, Admission control and Bandwidth controlcontrol

The higher the call quality, the greater the The higher the call quality, the greater the bandwidth requirementbandwidth requirement

The EncodingThe Encoding

Source and destination phones must agree on the Source and destination phones must agree on the encoder/decoder to useencoder/decoder to use

Some ITU standards include:Some ITU standards include: G.711 – bandwidth requirement around 64kbpsG.711 – bandwidth requirement around 64kbps G723.1 – bandwidth requirement around 5.3kbps G723.1 – bandwidth requirement around 5.3kbps

Source speaks into phone and voice is chopped into 30 Source speaks into phone and voice is chopped into 30 millisecond slices, each slice representing a packet of millisecond slices, each slice representing a packet of datadata

Packet is given a number and time stamp, placed in a Packet is given a number and time stamp, placed in a UDP packet, and sent to destination’s phone via InternetUDP packet, and sent to destination’s phone via Internet

When there is silence, packets are even smaller and are When there is silence, packets are even smaller and are sent only one out of every 180 milliseconds sent only one out of every 180 milliseconds

Achieving the QualityAchieving the Quality

Factors of consideration Factors of consideration Lost Packets Lost Packets Latency - amount of time it takes for a Latency - amount of time it takes for a

data packet to move across a network data packet to move across a network connectionconnection

Jitter – variation in timing or time of Jitter – variation in timing or time of arrival of data packetsarrival of data packets

Achieving the Quality: Lost Achieving the Quality: Lost PacketsPackets

Packet loss cannot totally be prevented Packet loss cannot totally be prevented due to internet congestiondue to internet congestion

Packet loss is acceptable if the lost Packet loss is acceptable if the lost packets are distributed evenly and whole packets are distributed evenly and whole words are not omittedwords are not omitted

Achieving the Quality: LatencyAchieving the Quality: Latency

Direct effect on speech quality Direct effect on speech quality Delays less than 150 milliseconds can go Delays less than 150 milliseconds can go

undetectedundetected Delays greater than 500 milliseconds are Delays greater than 500 milliseconds are

highly annoyinghighly annoying

Indirect effect on speech qualityIndirect effect on speech quality Echo – although this can be minimized Echo – although this can be minimized

through use of a headsetthrough use of a headset

Achieving the Quality: JitterAchieving the Quality: Jitter

Sound packets do not arrive at Sound packets do not arrive at destination’s phone at the exact timing destination’s phone at the exact timing they left the source’s phone.they left the source’s phone.

Jitter is minimized when source and Jitter is minimized when source and destination are on the same LANdestination are on the same LAN

Digital buffer is used to ensure packets are Digital buffer is used to ensure packets are received in the intended orderreceived in the intended order

ATA ImplementationATA Implementation

ATA ImplementationATA Implementation

ATA ImplementationATA Implementation

ATA ImplementationATA Implementation

ATA ImplementationATA Implementation

ATA ImplementationATA Implementation

VoIP Phone ExampleVoIP Phone Example

VoIP Phone ExampleVoIP Phone Example

VoIP Phone ExampleVoIP Phone Example

VoIP Phone ExampleVoIP Phone Example

VoIP Phone ExampleVoIP Phone Example

PC to PCPC to PC

Very easy to startVery easy to start A number of companies offer this service A number of companies offer this service

at little or no costat little or no cost PC to PC communication is usually offered PC to PC communication is usually offered

free of cost to attract customersfree of cost to attract customers Local, long distance, and international Local, long distance, and international

rates offered are much lower than rates offered are much lower than traditional telecommunication company traditional telecommunication company ratesrates

Minimum RequirementsMinimum Requirements

A Pentium processor based PCA Pentium processor based PC Microsoft Windows 95 or newer operating Microsoft Windows 95 or newer operating

system system A properly configured sound cardA properly configured sound card A pair of speakers and a microphoneA pair of speakers and a microphone A stable internet connection (at least 28.8 A stable internet connection (at least 28.8

kbps)kbps)

Net2Phone.comNet2Phone.com

One of the first One of the first companies to start companies to start internet telephonyinternet telephony

Very easy to use:Very easy to use: Download softwareDownload software Create user accountCreate user account Select amount of money to Select amount of money to

add to your accountadd to your account Login to the softwareLogin to the software You are ready to make PC You are ready to make PC

to PC, PC to Phone, PC to to PC, PC to Phone, PC to FAX callsFAX calls

Net2Phone.comNet2Phone.com

Offers free PC to PC Offers free PC to PC communication communication serviceservice

Competitive rates for Competitive rates for international PC to international PC to Phone dialingPhone dialing

Hotfoon.comHotfoon.com A good service if calls are A good service if calls are

mainly made through Asia / mainly made through Asia / Far EastFar East

Offers PC to Phone service Offers PC to Phone service onlyonly

Rates:Rates: Whole USA and Canada: Whole USA and Canada:

10c/min10c/min India (All mobiles), some India (All mobiles), some

cities: 10c/mincities: 10c/min Pakistan - some cities at Pakistan - some cities at

10c/min10c/min Bangladesh - Dhaka: 10c/minBangladesh - Dhaka: 10c/min Saudi - Damman, Riyadh, Saudi - Damman, Riyadh,

Jeddah: 12c/minJeddah: 12c/min U.A.E.: 12c/minU.A.E.: 12c/min

Advantages of VoIPAdvantages of VoIP

A fairly new technology, useful for long A fairly new technology, useful for long distance voice communicationdistance voice communication

A much cheaper, often free, method of A much cheaper, often free, method of communicationcommunication

Relatively easy to use and installRelatively easy to use and install Far superior to that of a regular phone, Far superior to that of a regular phone,

especially for international calls especially for international calls You can choose your area code & can take You can choose your area code & can take

your phone number wherever you goyour phone number wherever you go

Advantages of VoIPAdvantages of VoIP

Low infrastructure costs – once IP is installed, Low infrastructure costs – once IP is installed, minimal telephony infrastructure maintenance minimal telephony infrastructure maintenance is requiredis required

Extra features that ordinary phone companies Extra features that ordinary phone companies don’t offer like having your voicemail being sent don’t offer like having your voicemail being sent to your email, and dialing numbers from outlookto your email, and dialing numbers from outlook

Disadvantages of VoIPDisadvantages of VoIP

The quality of VoIP is variable and degrades The quality of VoIP is variable and degrades when there is internet congestionwhen there is internet congestion

Possible latency and data integrity problemsPossible latency and data integrity problems Need constant High-speed internet (DSL, Cable)Need constant High-speed internet (DSL, Cable) Dependent on Power and InternetDependent on Power and Internet Inconsistent handling of outgoing calls from fax Inconsistent handling of outgoing calls from fax

machines, satellite television receivers, machines, satellite television receivers, conventional modems, or other devices conventional modems, or other devices dependent on voice-grade telephone linesdependent on voice-grade telephone lines

Disadvantages of VoIPDisadvantages of VoIP

911 less effective. Need to register phone or 911 less effective. Need to register phone or may not be routed to nearest emergency may not be routed to nearest emergency dispatch centerdispatch center

SummarySummary

Cheaper alternative to the conventional Cheaper alternative to the conventional phone servicesphone services

Easy to implement and maintainEasy to implement and maintain VoIP will likely grow in terms of popularity VoIP will likely grow in terms of popularity

but may not replace the standard phone but may not replace the standard phone servicesservices

Companies will come out with new Companies will come out with new communication services with extensive communication services with extensive features at competitive prices features at competitive prices

A look into the futureA look into the future

Companies will continue to come out Companies will continue to come out offering new communications servicesoffering new communications services

Services such as Teleconferencing, Services such as Teleconferencing, videoconferencing, and collaboration videoconferencing, and collaboration applications may soon be available as part applications may soon be available as part of your integrated IP-based voice of your integrated IP-based voice communications packagecommunications package

GlossaryGlossary Address translation: Address translation: The process of converting external The process of converting external

addresses into standardized network addresses and vice addresses into standardized network addresses and vice versa versa

Admission control: Admission control: A QoS policy used to control the A QoS policy used to control the admission of network traffic from outside a given admission of network traffic from outside a given administrative domain administrative domain

Bandwidth control: Bandwidth control: Setting the maximum capacity of data Setting the maximum capacity of data transfer capacity of a digital communications system that transfer capacity of a digital communications system that a service is allowed to use a service is allowed to use

Gatekeeper: Gatekeeper: a service which provides zone management a service which provides zone management in the VoIP environment in the VoIP environment

Internet TelephonyInternet Telephony: Technology using an Internet : Technology using an Internet connection to pass voice data using IP instead of the connection to pass voice data using IP instead of the standard public switched telephone network standard public switched telephone network

GlossaryGlossary

JitterJitter: - Variation in timing, or time of arrival, of : - Variation in timing, or time of arrival, of received signals; an unwanted lack of perfection received signals; an unwanted lack of perfection which can lead to bit areas which can lead to bit areas

LatencyLatency: Latency is the amount of time it takes for : Latency is the amount of time it takes for a data packet (i.e., a unit of data) to move across a data packet (i.e., a unit of data) to move across a network connection a network connection

PayloadPayload: In a set of data, such as a data field, : In a set of data, such as a data field, block, or stream, being processed or transported, block, or stream, being processed or transported, the part that represents user information and user the part that represents user information and user overhead information, and may include user-overhead information, and may include user-requested additional information, such as network requested additional information, such as network management and accounting information management and accounting information

GlossaryGlossary

PBXPBX: Private Branch Exchange. A privately-: Private Branch Exchange. A privately-owned telephone switch, often used in large owned telephone switch, often used in large corporations to provide inside telephone corporations to provide inside telephone connectivity and access to the PSTNconnectivity and access to the PSTN

ProtocolsProtocols: An agreed-upon format for : An agreed-upon format for transmitting data between two devices transmitting data between two devices

UDPUDP: A connection-less, unreliable, transport : A connection-less, unreliable, transport protocol which provides multiplexing and error protocol which provides multiplexing and error detection for applications which require a low-detection for applications which require a low-cost protocol for one-shot transactionscost protocol for one-shot transactions

Web ReferencesWeb References

http://http://en.wikipedia.org/wiki/Voice_over_IPen.wikipedia.org/wiki/Voice_over_IP

http://www.cse.ohio-state.edu/~jain/cis788-http://www.cse.ohio-state.edu/~jain/cis788-99/ftp/voip_protocols/index.html 99/ftp/voip_protocols/index.html

http://en.wikipedia.org/wiki/Voice_over_IP http://en.wikipedia.org/wiki/Voice_over_IP

http://www.tldp.org/HOWTO/VoIP-http://www.tldp.org/HOWTO/VoIP-HOWTO.html HOWTO.html

http://www.wilco-telephony.co.uk/voip.html http://www.wilco-telephony.co.uk/voip.html

http://www.jiwire.com/voip-guide-intro.htm http://www.jiwire.com/voip-guide-intro.htm

Web ReferencesWeb References

http://networking.ittoolbox.com/browse.asp?http://networking.ittoolbox.com/browse.asp?c=NetworkingPeerPublishing&r=http%3Ac=NetworkingPeerPublishing&r=http%3A%2F%2Fwww%2Eerlang%2Ecom%2F%2Fwww%2Eerlang%2Ecom%2Fprotocols%2Ehtml %2Fprotocols%2Ehtml

http://www.protocols.com/papers/pdf/http://www.protocols.com/papers/pdf/voip_practical_guide.pdf voip_practical_guide.pdf

http://www.net2phone.com/ http://www.net2phone.com/

Web ReferencesWeb References

http://www.dti.gov.uk/bestpractice/http://www.dti.gov.uk/bestpractice/assets/voip.pdf assets/voip.pdf

http://vonage.com/ http://vonage.com/

http://hotfoon.com/http://hotfoon.com/