Group members
1.najah saed Othman
2.Husri kadar aw daahir
3.Deek Mohamed nour
4.A/Rahman Othman muhumed
5.sayid-ali A/Rahman mohamud
6.Nasir A/Rahman muhumed
VoIP(voice over IP)
What is VoIP?
In a simple format, VoIP is packetisation and transport of classic public
switched telephone system audio over an IP network. It allows 2-way voice
transmission over broadband connection.
It is also called IP telephony, internet telephony, and voice over broadband,
broadband telephony.
VoIP, is a real-time transmission of voice signals using the Internet Protocol
(IP) over the public Internet or a private data network.
Motivations of this project
Because of the academic requirement, we should have to fulfil
university’s mini project and summit the project book.
The main reasons that encourage us to choose VoIP and present this
project are listed below briefly.
VOIP is the latest technology, so, it is very important as telecom student
to know more about it and search more and understand the concept of
VOIP. As telecomm engineers, its compulsory accept our role and
enhance our generation’s technology and pave the way to the next
generation.
Continue…
The availability of the resources that telecom engineers published from the
growth of the VoIP up to now, have enforced us to study and research this
technology. A lot of documents and research are available in internet and
even in libraries.
Importance of the VoIP(why VoIP)
Because of the globalization of the world, business manager’s international
enterprises may have many offices in different countries, so they need a
cheaper way to communicate through the world. VoIP provide the best route
for this necessity
VoIP offers you toll-free long distance voice and fax communication over an
existing ip network.
Evolution of the VoIP
There are several technologies that pave the way for the birth of VoIP
technologies, they contribute a great role for the invention and the
development of the VoIP. Some of these technologies are summarized below.
There are two fundamental technologies that are necessary for the existence
of VoIP.
The first, and most widely used, is the telephone. The second technology is
the Internet.
Continue…
Although the telephone and Internet were vital to the existence of VoIP,
there is an-other technology that is closely related, and just as important. In
1972 Dr. Vint Cerf was the man who invented Transmission Control Protocol /
Internet Protocol (TCP/IP) - the technical protocol that defines the form of
net data packets and how they travel to their destinations.
CONTINUE
in February of 1995 VoIP has been started by a small company in
Israel called Vocal Tec, Inc. Their product, Internet Phone, allowed
one user to call another user via their computers, a microphone and a
set of speakers. Additionally, this application/product only worked if
both the caller and the receiver had the same software setup. By
1998 some entrepreneurs started to market PC-to-phone and phone-
to-phone VoIP solutions. The phone calls were marketed as “Free”
nation-wide long distance calls
CONTINUE
In 1989, Tim Berners-Lee and a group of researchers at CERN (an international
scientific organization based in Geneva, Switzerland) created hypertext
transfer protocol (HTTP) and a text format code called hypertext markup
language. They also invented a universal resource identifier (later universal
resource locator, or URL) to identify document locations. These inventions
formed the foundation of the World Wide Web.
continue
When the caller would start the call he/she had to listen to advertisements
before the call was connected. Another development in 1998 was the
hardware’s foray into the market. There were three IP Switch manufactures
that introduced VoIP switching software as a standard in their routing
equipment. By the end of 1998 VoIP calls had yet to total 1% of all voice calls.
How does VoIP works
VoIP operates by transferring voice signals between IP
addresses, which means that these signals have to transform
into pieces of data small enough to transmit. Vocal samples
from the sender are broken down into voice “packets,” which
are given routing information and sent to the receiving end.
The packets transmit one-by-one, then re-form as close to the
original state as possible, creating one whole voice. This
process compresses the voice signal, and then decompresses
the signal for the receiver
Continue…
When you talk over normal PSTN phone, your voice is transported in an analog
way over the phone line. But with VoIP, your voice is converted into digital
signals. This conversion is technically called encoding, and is achieved by a
codec. When the digitized voice reaches its destination, it has to be decoded
back to its original analog state so that the other correspondent can hear and
understand it.
VoIP protocols
There several protocols that is used routing and maintaining processes in ip
telephony. The most common protocols are
H.323
SIP ( session initiation protocol)
MGCP ( media gateway control protocol)
RTP ( real time transmission protocol)
RSTP ( real time streaming transfer protocol)
VoIP codecs
A codec is an algorithm that is used to convert voice signals into digital data
to be transmitted over the Internet or any network during a VoIP call
Some ip private network use their proprietary codecs, but the following are
used globally
ITU-T G.711
ITU-T G.722.1
ITU-T G.722.2
MPEG4
Conclusion
VoIP is better replacement of the LANDLINES that were used circuit switched
system (PSTN)
People had difficulties with the international calls, it was too much cost when
calling outside the country, VoIP provide you toll fee free seamless voice
communication throughout the world
It is easy to install and scalable when compared to the public switched
telephone network
VoIP user can be independent from telecom operators, IP allows two users to set
up a call without the need for a telecommunication company to assist in
Signaling or routing of the media. All users need to know is the IP address of the
other.
Voip uses its own protocol for signalling protocols and routing processes as the
PSTN does.
According to PSTN, VoIP is less secure, it is prone to eavesdropping and hacking
Packet lost and small bit jittering is a moderate issue in VoIP
Future enhancement of the voip
The main points that are expected voip will changed are
discussed below
The growth of the smart devices in the market will increase the
growth of the VoIP services in the globe.
In the coming generations, the availability of high speed
internet will raise thus the adoption of voip will be increased.
service mobility, integrated applications, user control interface
and other rich features are expected to change in the next
generations
Technological advancement has enabled the network operators
to enhance their infrastructures. Thus ease use of voip will get
better
Lower data prices means more adoption of VoIP and cloud-
hosted solutions.