Voice Over Internet ProtocolVoice Over Internet Protocol“VoIP”“VoIP”

Muayyed Al KadhemMuayyed Al Kadhem

Abdulkhaleq Al MusaleemAbdulkhaleq Al Musaleem

ContentContent

IntroductionIntroduction VoIP Vs Traditional PhonesVoIP Vs Traditional Phones Types of VoIPTypes of VoIP AdvantagesAdvantages DisadvantagesDisadvantages How VoIP WorksHow VoIP Works ConclusionConclusion

IntroductionIntroduction

VoIP “Voice over Internet Protocol”VoIP “Voice over Internet Protocol”

Definition: The routing of conversation Definition: The routing of conversation over IP-based network (Internet)over IP-based network (Internet)

Packet switching instead Circuit switchingPacket switching instead Circuit switching

VoIP is any Protocol used to carry audio VoIP is any Protocol used to carry audio signals over an IP networksignals over an IP network

IntroductionIntroduction

The first VoIP protocol: 1973 for The first VoIP protocol: 1973 for APRANETAPRANET

VoIP can not only be used over the VoIP can not only be used over the Internet but also in a private networkInternet but also in a private network

Types of VoIPTypes of VoIP

There are three types of There are three types of VoIP service:VoIP service:

1.1. Analog Telephone Adaptor Analog Telephone Adaptor (ATA):(ATA):

- the simplest and most common the simplest and most common way.way.

- It is an analog-to-digital converter.It is an analog-to-digital converter.- It connects a phone to a computer It connects a phone to a computer

or directly to internet connection.or directly to internet connection.- Service providers for this type is Service providers for this type is

Vonage & AT&T. Vonage & AT&T.

VoIP Vs Traditional PhonesVoIP Vs Traditional Phones

VoIP has better efficiency than VoIP has better efficiency than traditional phones.traditional phones.

In VoIP, there is no different between In VoIP, there is no different between a local and international call. a local and international call. However, it depends on the service However, it depends on the service provider.provider.

Types of VoIPTypes of VoIP

2. IP Phones: 2. IP Phones:

- they look like normal phones but - they look like normal phones but instead of having the standard RJ-11 instead of having the standard RJ-11 (phone connectors), IP phones have (phone connectors), IP phones have an RJ-45 (Ethernet connector)an RJ-45 (Ethernet connector)

Types of VoIPTypes of VoIP

3. Computer-to-Computer:3. Computer-to-Computer:

- the easiest way to use VoIP.- the easiest way to use VoIP.

AdvantagesAdvantages

The big advantage is the costThe big advantage is the cost• VoIP to VoIPVoIP to VoIP• VoIP to PSTNVoIP to PSTN

Direct Inward Dialing “DID”: Connect the Direct Inward Dialing “DID”: Connect the caller directly to the VoIP user.caller directly to the VoIP user.

DID usually has a monthly fee.DID usually has a monthly fee. Access Numbers: Requires the caller to input Access Numbers: Requires the caller to input

the extension number of the VoIP user. This the extension number of the VoIP user. This costs usually as a local call.costs usually as a local call.

AdvantagesAdvantages

FunctionalityFunctionality• Incoming calls are routed anywhere you Incoming calls are routed anywhere you

are connected to the Internet.are connected to the Internet.• Include video conversation, messaging Include video conversation, messaging

or data file exchanging. or data file exchanging. • Only Voice in one location in traditional Only Voice in one location in traditional

Circuit switched telephony.Circuit switched telephony.

AdvantagesAdvantages

MobilityMobility• enables a user to access all of their enables a user to access all of their

telecommunication services, and to telecommunication services, and to make and receive calls, on any terminal.make and receive calls, on any terminal.

• Software like Skype & Yahoo Messenger Software like Skype & Yahoo Messenger provide mobility all over the world if we provide mobility all over the world if we have an Internet access.have an Internet access.

DisadvantesDisadvantes

ReliabilityReliability• IP does not provide a mechanism to IP does not provide a mechanism to

ensure that data packets are in ensure that data packets are in sequential ordersequential order

• There will be a momentary drop out of There will be a momentary drop out of voice because some of packets are voice because some of packets are delivered out of order or even delayed delivered out of order or even delayed and lost.and lost.

• The receiving node must restructure the The receiving node must restructure the packets that received out of order.packets that received out of order.

DisadvantagesDisadvantages

DSL: already uses a traditional phone DSL: already uses a traditional phone line which reduces the benefits of line which reduces the benefits of VoIPVoIP

Integration In a common global Integration In a common global standard:standard:• The traditional phone line & mobile The traditional phone line & mobile

phones share a common global standard phones share a common global standard (E.164), while VoIP doesn’t share. (E.164), while VoIP doesn’t share.

DisadvantagesDisadvantages

Demand on VoIPDemand on VoIP• because of mobile phones have already because of mobile phones have already

achieved complete market penetration, achieved complete market penetration, there is low demand on VoIP.there is low demand on VoIP.

SecuritySecurity• VoIP doesn’t support any type of VoIP doesn’t support any type of

encryption which makes it easy to listen encryption which makes it easy to listen in and change the content. Also, it is in and change the content. Also, it is susceptible worms and virus although it is susceptible worms and virus although it is rare.rare.

How VoIP WorksHow VoIP Works

Circuit switching:Circuit switching:• connection is open and constant bitrate, connection is open and constant bitrate,

packet switching:packet switching:• opens a brief connection, just long opens a brief connection, just long

enough to send a small chunk of data enough to send a small chunk of data “packets” from one system to another. “packets” from one system to another.

How VoIP WorksHow VoIP Works

Step 1:• The caller’s voice is digitized as the

existing phones. This can be done by the telephone company (which is how carriers use IP in their networks), by an Internet service provider (ISP), or by a PC on your desk.

How VoIP WorksHow VoIP Works

Step 2:• Next using complex algorithms the

digital voice is compressed and then separated into packets; and using the Internet protocol, the packets are addressed and sent across the network to be reassembled in the proper order at the destination. Again, this reassembly can be done by a carrier, and ISP, or by one’s PC.

How VoIP WorksHow VoIP Works Step 3:

• During transmission, packets could be lost or delayed, or errors may damage the packets.

• Conventional error correction techniques would request retransmission of unusable or lost packets, but if the transmission is a real-time voice communication that technique obviously would not work, so sophisticated error detection and correction systems are used to create sound to fill in the gaps.

• This process stores a portion of the incoming speaker’s voice, and uses a complex algorithm to “guess” the contents of the missing packets and create new sound information to enhance the communication.

How VoIP WorksHow VoIP Works

Step 4:• After the packets are transmitted and

arrive at the destination, the transmission is assembled and decompressed to restore the data to an approximation of the original form.

ConclusionConclusion

The benefits of VoIP over traditional The benefits of VoIP over traditional phone.phone.

VoIP still has challenges.VoIP still has challenges.

Questions??Questions??