This document provides an overview of Voice over Internet Protocol (VoIP) including: - What VoIP is, how it works by converting voice to digital signals and transmitting over the internet instead of traditional telephone networks. Popular services like Skype are mentioned. - The main VoIP protocols and how VoIP allows calling from computers, phones, or phone adapters using an internet connection instead of dedicated phone lines. - Differences between VoIP and traditional PSTN networks in terms of required infrastructure, bandwidth usage, features, and costs. - Common VoIP devices like analog telephone adapters, software on computers, and IP phones. Popular VoIP providers and their typical costs are also outlined.

1. Assalam-u-alaikum 
Welcome Everyone!

2. WE ARE:
› Iffat Jahan
› Izamt Ara
› Mukhlesur Rahman
› Hasanuzzaman Dipu
› Minhajul Karim

3. TOPIC:

4. WHAT IS VOIP?
Voice over Internet
protocol

5. WHAT IS VOIP?
SKYPE,
HANGOUT etc
are VOIP for
personal use

6. THE IDEA
 To use the Internet as a
telephone network with
some additional
capabilities.
 Instead of communicating
over a circuit-switched
network VOIP
communicates over the
packet-switched internet.

7. HOW VOIP WORKS?
› VoIP protocols first converts your voice or
media into digital signal and travels over
the internet. At receiver side it decode in
its original format.
› It allows you to make a call from your
desktops/laptops or from IP phones
using internet. You can make a call from
your traditional telephones using special
type of phone adapter.

8. WHO USES VOIP?
› Microsoft is using VoIP for their ‘Xbox’
live service. Enabling customers to
be able to talk through a headset to
each other. However, they do charge
a small fee for the service.
› Skype also use VoIP. Skype is used
by 20% of American businesses.

9. VOIP PROTOCOLS
 H.323
 IMS [IP Multimedia System]
 MGCP [Media Gateway Control
Protocol]
 SIP [Session Initiation Protocol]
 RTP [Real-time Transport
protocol]
 SDP [Session Description
Protocol]
 IAX [Inter-Asterisk exchange]

10. WHAT IS PSTN?
› PSTN [Public Switched Telephone Network] is the network
of circuit-switched telephone network which is based on
telephone lines, fibre optics, cellular networks,
communication satelites etc.
› It is our conventional method of voice communication
which is based on circuit switching which are now
replaced by VoIP technique.

11. PSTN vs VOIP
Carrier Lines:
 PSTN : Dedicated lines required from telecom company.
 VoIP : Only an internet connection is required.
Bandwidth:
 PSTN: Each telephone lines require 64kbps in each
direction
 VoIP : Using compression, VoIP can use only 10kbps in
each direction

12. PSTN vs VOIP
Features :
 PSTN : call waiting, call conference, caller ID available at
an extra cost.
 VoIP : all features are generally free.
Upgrade and Expansion:
 PSTN : Very complex due to change in hardware and
wires
 VoIP : Sometimes just require more bandwidth and
software upgrade.

13. PSTN vs VOIP
Last but not the least, Rental :
 PSTN : Expensive compare to VoIP
 VoIP : About 1/4 times less expensive to PSTN

14. APPLICATION

15. DEVICES:
Most useful device for
VoIP is ATA (Analog
telephone Adaptor).
It helps you to
connect your standard
phone to computer
and lets you call.
ATA

16. DEVICES:
It’s the easiest way to make
VoIP calls.
We just need a software,
speaker and sound card
(and internet connection
obviously ! ! !).
There are not any
additional charges for this.
PC-TO-PC

17. DEVICES:
This is just a simple phone
with the headset and
different buttons.
IP Phones connect directly
to your router and contain
all the necessary software
and hardware to handle
the IP calls.
IP PHONE

18. PROVIDERS

19. USAGE:
› Plug the cord from your phone into
the ATA.
› An internet cord from the ATA into
your router or internet connection.
› And configure your ATA for first
time.
VoIP using ATA connector

20. USAGE:
> Register your account (Gtalk, Iptel,
Skype, etc.)
> First install same VoIP client on
both PC.
> Establish connection between two
PC through Internet connection.
VoIP using PC-PC

21. USAGE::
> First install the appropriate
software that creates PBX server.(i.e.
3CX,Asterisk OS etc.)
> Then configure the server
according to your need and
requirements.
> Then activate your VoIP account in
this server.
To establish a PBX server

22. ADVANTAGES:
› Lower cost
› Greater functionality
› Less maintenance
› Similar call quality if there is an appropriate internet
connection

23. COST:
Generally the cost is around $20 to
$30 per month with facilities like:
› Free local & long distance calling
› Ability to transfer & queue calls
› Have calls ring multiple lines
simultaneously.

24. COST:
› Price starts from around 50$.
› Extra 100$ for additional features
like screen for video calls
VOIP Handsets

25. CALL
QUALITY
Is dependent upon the speed &
stability of your INTERNET
CONNECTION.
A typical DSL connection will be able
to support 6 concurrent phone calls
with full quality audio.

26. DISADVANTAGES:
› One factor that is preventing VoIP from really taking off.
This is the fact that it is less reliable than the traditional
switched circuit method of telephone communications.
› Because of this some parts of the packet, that the voice
is sent in can be lost.

27. GOOD
NEWS
The market share of landline phones
is expected to be only 16% by 2015
VOIP is growing & the
number of traditional
telephone users are
shrinking.

28. Thank You All 