VOIP BASIC

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Voice Over IP Presented By Page 1 Dhara Patel Jay Patel 21-Feb-2013 21-Feb-2013

description

It gives you brief idea of VOIP technology.

Transcript of VOIP BASIC

Page 1: VOIP BASIC

Voice Over IP

Presented By

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Dhara PatelJay Patel

21-Feb-201321-Feb-2013

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OverviewVOIPVOIP uses the Internet Protocol (IP) to transmit voice uses the Internet Protocol (IP) to transmit voice

as packets over an IP network.as packets over an IP network.VOIP can be achieved on any data network that uses VOIP can be achieved on any data network that uses

IP, like the Internet, Intranets and Local Area Networks IP, like the Internet, Intranets and Local Area Networks (LAN). (LAN).

The voice signal is digitized, compressed and The voice signal is digitized, compressed and converted to IP packets and then transmitted over the IP converted to IP packets and then transmitted over the IP network.network.

VOIP services need only a regular phone connection, VOIP services need only a regular phone connection, while others allow you to make telephone calls using an while others allow you to make telephone calls using an Internet connection instead.Internet connection instead.

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Definition of VOIPDefinition of VOIP

VOIP is a technology that allows VOIP is a technology that allows telephone calls to be made over telephone calls to be made over

computer networks like the Internet.computer networks like the Internet.

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VoIP converts analog voice signals into VoIP converts analog voice signals into digital data packets and supports real-digital data packets and supports real-

time, two-way transmission of time, two-way transmission of conversations using Internet Protocol conversations using Internet Protocol

(IP).(IP).

Continue…Continue…

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What is VOIP?What is VOIP?

VoIP is actually a very simple technology. VoIP is actually a very simple technology.

But it is also powerful and as you will see it But it is also powerful and as you will see it can save you substantial money over can save you substantial money over conventional phone calls via your usual conventional phone calls via your usual telephone operator (Telkom) that basically telephone operator (Telkom) that basically does the same thing, but using their own does the same thing, but using their own network to route your calls.network to route your calls.

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Why VoIP? Can make and receive calls with / without a Can make and receive calls with / without a

computercomputer Can surf the net while making callsCan surf the net while making calls Can make local / long distance callsCan make local / long distance calls Supports both the Voice and DataSupports both the Voice and Data Integrates other media like Video, Electronic Integrates other media like Video, Electronic

White BoardWhite Board FlexibilityFlexibility Reliable ServicesReliable Services

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How does VOIP work ?How does VOIP work ?

You place your call by dialing a telephone number to You place your call by dialing a telephone number to any normal telephone number anywhere in the world. any normal telephone number anywhere in the world.

A connection between you and the dialed number is A connection between you and the dialed number is then established.then established.

As you talk into your telephone handset your voice is As you talk into your telephone handset your voice is converted into digital data.converted into digital data.

This data is then transmitted across the connection that This data is then transmitted across the connection that you have already established by dialing the other parties you have already established by dialing the other parties telephone number.telephone number.

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Continue…Continue… The data is routed across the Internet using the same The data is routed across the Internet using the same standard computer language that the Internet uses - which standard computer language that the Internet uses - which is called Internet Protocol (all computers connected to the is called Internet Protocol (all computers connected to the Internet understand and use this language to Internet understand and use this language to communicate).communicate).

The data that was your voice is reconstituted on the other The data that was your voice is reconstituted on the other side into normal analogue sound that human beings side into normal analogue sound that human beings understand.understand.

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VoIP calls can be made on the Internet using a VoIP VoIP calls can be made on the Internet using a VoIP service provider and standard computer audio systems. service provider and standard computer audio systems. Alternatively, some service providers support VoIP Alternatively, some service providers support VoIP through ordinary telephones that use special adapters to through ordinary telephones that use special adapters to connect to a home computer network. connect to a home computer network.

Many VoIP implementations are based on the H.323 Many VoIP implementations are based on the H.323 Protocol.Protocol.

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Protocols :Protocols :

Voice over IP has been implemented in various ways Voice over IP has been implemented in various ways using both proprietary and open protocols and using both proprietary and open protocols and standards. Examples of the network protocols used to standards. Examples of the network protocols used to implement VoIP include:implement VoIP include:

H.323H.323Media Gateway Control Protocol (MGCP)Media Gateway Control Protocol (MGCP)Session Initiation Protocol (SIP)Session Initiation Protocol (SIP)Real-time Transport Protocol (RTP)Real-time Transport Protocol (RTP)Session Description Protocol (SDP)Session Description Protocol (SDP)Inter-Asterisk eXchange (IAX)Inter-Asterisk eXchange (IAX)Jingle XMPP VoIP extensionsJingle XMPP VoIP extensions

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Voice Over IP – RFC 3714

The H.323 protocol was one of the first VoIP The H.323 protocol was one of the first VoIP protocols that found widespread implementationprotocols that found widespread implementation for long-distance traffic, as well as local area for long-distance traffic, as well as local area network services. However, since the development network services. However, since the development of newer, less complex protocols such as MGCP of newer, less complex protocols such as MGCP and SIP, H.323 deployments are increasingly and SIP, H.323 deployments are increasingly limited to carrying existing long-haul network limited to carrying existing long-haul network traffic. In particular, the Session Initiation Protocol traffic. In particular, the Session Initiation Protocol (SIP) has gained widespread VoIP market (SIP) has gained widespread VoIP market penetration.penetration.

What is H.323 protocol?What is H.323 protocol?

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H.323 ProtocolH.323 Protocol An International Telecommunications Union (ITU) An International Telecommunications Union (ITU)

standard that provides specification for computers, standard that provides specification for computers, equipment, and services for multimedia communication equipment, and services for multimedia communication over packet based networks that defines how real-time over packet based networks that defines how real-time audio, video and data information is transmitted. audio, video and data information is transmitted.

H.323 is commonly used in VoIP, Internet Telephony, H.323 is commonly used in VoIP, Internet Telephony, and IP-based videoconferencing. Users can connect with and IP-based videoconferencing. Users can connect with other users over the Internet and use arying products other users over the Internet and use arying products that support H.323. This standard is based on the that support H.323. This standard is based on the Internet Engineering Task Force (IETF) Real-Time Internet Engineering Task Force (IETF) Real-Time Protocol (RTP) and Real-Time Control Protocol (RTCP), Protocol (RTP) and Real-Time Control Protocol (RTCP), with additional protocols for call signaling , and data and with additional protocols for call signaling , and data and

audiovisual communicationsaudiovisual communications..

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Process of VOIPProcess of VOIP

The users voice (or fax) is converted into a digital The users voice (or fax) is converted into a digital signal, compressed, and broken down into a series of signal, compressed, and broken down into a series of packets.packets.The packets are then transported over private or The packets are then transported over private or public IP networks and reassembled and decoded on public IP networks and reassembled and decoded on the receiving side. the receiving side. At the receiving end, the re-assembled packets arrive At the receiving end, the re-assembled packets arrive as a normal sounding voice call. as a normal sounding voice call. Packet switching is very efficient. It lets the network Packet switching is very efficient. It lets the network route the packets along the least congested and route the packets along the least congested and cheapest lines. It also frees up the two computers cheapest lines. It also frees up the two computers communicating with each other so that they can accept communicating with each other so that they can accept information from other computers, as well. information from other computers, as well.

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Once the sound is recorded by the computer and Once the sound is recorded by the computer and compressed into very small samples, the samples are compressed into very small samples, the samples are collected together into larger chunks and placed into collected together into larger chunks and placed into data packets for transmission over the IP network. data packets for transmission over the IP network.

This process is referred to packetization. Generally, a This process is referred to packetization. Generally, a single IP packet will contain 10 or more milliseconds of single IP packet will contain 10 or more milliseconds of audio, with 20 or 30 milliseconds being most common.audio, with 20 or 30 milliseconds being most common.

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Ways Of Using VoIPWays Of Using VoIP

PC to PCPC to PCPC to PhonePC to PhonePhone to PCPhone to PCPhone to PhonePhone to Phone

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DiagramsDiagrams

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Conceptual ModelConceptual ModelVoice Over IP

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The phone works – why bother with VoIPThe phone works – why bother with VoIP

user perspective carrier perspective

variable compression: tin can to broadcast quality no need for dedicated lines

better codecs + silence suppression – packet header overhead = maybe reduced bandwidth

security through encryption shared facilities simplify management, redundancy

caller & talker identification advanced services

better user interface (more than 12 keys, visual feedback, semantic rather than stimulus)

cheaper bit switching

no local access fees (but dropping to 1c/min for PSTN)

fax as data rather than voiceband data (14.4 kb/s)

adding video, application sharing is easy

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Advantages of VOIPAdvantages of VOIP

Main advantage of VOIP is that the customer can make calls from Main advantage of VOIP is that the customer can make calls from anywhere in the world where broadband internet connection is anywhere in the world where broadband internet connection is available.available.Greater Efficiency.Greater Efficiency.Another main advantage is the amount of money you end up saving Another main advantage is the amount of money you end up saving on your phone bills as compared to a traditional phone line.on your phone bills as compared to a traditional phone line.Inexpensive and easy to use. Since it is simple, upgrading is Inexpensive and easy to use. Since it is simple, upgrading is relatively simpler too.relatively simpler too.You can integrate it with an existing phone connection.You can integrate it with an existing phone connection.With VOIP PC-to-PC, calls are free no matter the distance and PC-With VOIP PC-to-PC, calls are free no matter the distance and PC-to-Phone charges are nominal.to-Phone charges are nominal.For a monthly fee you may make unlimited free calls within a For a monthly fee you may make unlimited free calls within a geographic area.geographic area.

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Continue…Continue… You may purchase a number in a geography area of your choice, You may purchase a number in a geography area of your choice,

which works out very cheap. If your relatives and friends live in which works out very cheap. If your relatives and friends live in Virginia and you moved to California, you may purchase a Virginia Virginia and you moved to California, you may purchase a Virginia number and make local calls to your loved ones.number and make local calls to your loved ones.

You may access your VOIP account just like your email Id from any You may access your VOIP account just like your email Id from any where in the world as long as you have an internet phone. This where in the world as long as you have an internet phone. This makes it easy for those who travel frequently to make calls makes it easy for those who travel frequently to make calls frequently to those back at home at local call rates, no matter where frequently to those back at home at local call rates, no matter where they are.they are.

You may call or message or do both at the same time with VOIP You may call or message or do both at the same time with VOIP services.services.

VOIP cost about half the cost of traditional phone services and it VOIP cost about half the cost of traditional phone services and it seems that the taxes and surcharges are much lower. Also your bill seems that the taxes and surcharges are much lower. Also your bill is easier to understand and it can be viewed via the Internet.is easier to understand and it can be viewed via the Internet.

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DisadvantagesDisadvantages

You must have high-speed internet access in order to You must have high-speed internet access in order to obtain VoIP phone service.obtain VoIP phone service.

Loss of service during outages.Loss of service during outages.

Without power VOIP phones are useless, so in case Without power VOIP phones are useless, so in case of emergencies during power cuts it can be a major of emergencies during power cuts it can be a major disadvantage.disadvantage.

With VOIP emergency calls, it is hard to locate you With VOIP emergency calls, it is hard to locate you and send help in time.(Show video)and send help in time.(Show video)

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Some times during calls, there may be Some times during calls, there may be periods of silence when data is lost while it periods of silence when data is lost while it is being unscrambled.is being unscrambled.

Latency and traffic.Latency and traffic.

No standard protocol is applicable. No standard protocol is applicable.

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VoIPVoIP packet loss occurs when a large packet loss occurs when a large amount of traffic on the network causes amount of traffic on the network causes dropped packets. This results in dropped dropped packets. This results in dropped conversations, a delay in receiving the conversations, a delay in receiving the voice communication, or extraneous noise voice communication, or extraneous noise on the call.on the call.

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Threats / Risks Threats / Risks Many of the threats associated with VoIP are similar to the Many of the threats associated with VoIP are similar to the

threats inherent to any internet application. Internet users are threats inherent to any internet application. Internet users are already familiar with the nuisance of email abuse in the form of already familiar with the nuisance of email abuse in the form of spam and phishing attempts. VoIP opens yet another pathway for spam and phishing attempts. VoIP opens yet another pathway for these annoyances, which can lead to spam over internet telephony these annoyances, which can lead to spam over internet telephony (SPIT), spoofing, and identity theft. Additionally, the confidentiality of (SPIT), spoofing, and identity theft. Additionally, the confidentiality of VoIP conversations themselves has come into question, depending VoIP conversations themselves has come into question, depending on service type or VoIP configuration. on service type or VoIP configuration.

Spam over internet telephony (SPIT) Spam over internet telephony (SPIT)

Spoofing Spoofing

Confidentiality concerns Confidentiality concerns

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How to Protect Against RisksHow to Protect Against Risks Use and maintain anti-virus and anti-spyware programs. Use and maintain anti-virus and anti-spyware programs. Be cautious about opening files attached to email messages or Be cautious about opening files attached to email messages or

instant messages. instant messages. Verify the authenticity and security of downloaded files and new Verify the authenticity and security of downloaded files and new

software. software. Configure your web browser(s) securely. Configure your web browser(s) securely. Use a firewall. Use a firewall. Identify, back-up, and secure your personal or financial data. Identify, back-up, and secure your personal or financial data. Create and use strong passwords. Create and use strong passwords. Patch and update your application software. Patch and update your application software. If you are using a software VoIP application, consider using If you are using a software VoIP application, consider using

encryption software for both your installation and for those you wish encryption software for both your installation and for those you wish to talk to. to talk to.

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The disadvantages of VOIP could be annoying, but their effects are The disadvantages of VOIP could be annoying, but their effects are relatively limited. The complaints of VOIP are usually tolerable if the relatively limited. The complaints of VOIP are usually tolerable if the callers are using a free service. As the technology is advancing, we will callers are using a free service. As the technology is advancing, we will expect the VOIP quality will match the traditional telephone technology.expect the VOIP quality will match the traditional telephone technology.

These are some of advantages and These are some of advantages and disadvantages of VOIP. All said and done, disadvantages of VOIP. All said and done, we could say that the advantages of VOIP we could say that the advantages of VOIP outweigh the disadvantages of it.outweigh the disadvantages of it.

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Name confusion Commonly used interchangeably:Commonly used interchangeably:

Internet telephonyInternet telephony Voice-over-IP (VoIP)Voice-over-IP (VoIP) IP telephony (IPtel)IP telephony (IPtel)

Also: VoP (any of ATM, IP, MPLS)Also: VoP (any of ATM, IP, MPLS) Some reserve Internet telephony for transmission across Some reserve Internet telephony for transmission across

the (public) Internetthe (public) Internet Transmission of telephone services over IP-based Transmission of telephone services over IP-based

packet switched networkspacket switched networks Also includes video and other media, not just voice.Also includes video and other media, not just voice.

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