VoIP stands for Voice over Internet Protocol. It allows users to make voice calls via a broadband internet connection instead of a regular phone line. There are several VoIP protocols that convert voice into digital signals to transmit over the internet, like SIP and H.323. Users can make VoIP calls from their computers using softphones, or through an Analog Telephone Adapter connected to a regular phone. Setting up a PBX server allows creating a full-featured VoIP phone system. VoIP provides advantages over traditional PSTN phone networks like lower costs and additional features included free of charge.

2. WHAT IS VOIP?
•VoIP [Voice over Internet Protocol] is family of
communication protocols and transmission
technique which is used in delivery of voice
communication or multimedia sessions over
internet.

3. 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.
 VoIP 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 spceial type of phone adapter.

4. HOW VOIP WORKS?

5. VOIP PROTOCOLS
•Some 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]

6. WHAT IS PSTN?
 PSTN [Public Switched Telephone Network] is the
network of circuit-switched telephone network which is
based on telephone lines, fibre optics, celluler 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.

7. 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
Features
 PSTN : call waiting, call conference, caller ID available at an
extra cost
 VoIP : all features are generally free

8. CONTINUE . . .
Upgrade and Expansion
 PSTN : Very complex due to change in hardware and wires
 VoIP : Sometimes just require more bandwidth and software uprade
Rental
 PSTN : Expensive compare to VoIP
 VoIP : About 1/4 times less expensive to PSTN
Remote PABX extension
 PSTN : Very costly and require each dedicated line for each
VoIP : It is a standard feature of VoIP

9. APPLICATIONS
 Some application that you used in your daily life is
based on VoIP.
 Like Skype, Gtalk, Yahoo Messenger, Fring, E-buddy,
Nimbuzz, Twinkle, Brosix, SIPSet, Gizmo, iChat, iCall
that are used on various platform like Windows, Linux,
MAC OS X, Android and many mobile platforms.

10. SOME APPLICATION

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

12. CONTINUE…
Computer-to-computer : Its the easiest way to
make VoIP calls. You just need to have a software,
microphone, speaker and sound card (and internet
connection obviously ! ! !).There are not any
additional charges for this.

13. CONTINUE…
IP Phone : This look like 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.

14. HOW TO USE VOIP ?
There are three ways of using VoIP.
1) Using ATA connector
2) PC to PC
3) By creating PBX server

15. VOIP USING ATA CONNECTOR
Steps:
1) Plug the cord from your phone into the ATA.
2) An internet cord from the ATA into your router or
internet connection.
3) And configure your ATA for first time.

16. VOIP USING ATA

17. VOIP USING PC-PC
Steps:
1) Register your account (Gtalk, Iptel, Skype, etc.)
2) First install same VoIP client on both PC.
–(Jitsi, Twinkle, Gtalk, Yate etc.)
1) Establish connection between two PC through Internet
connection.

18. TO ESTABLISH A PBX SERVER
 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.
[live demo using Asterisk OS]

19. PBX
Yesterday’s Networks
Circuit Switched Networks (Voice)
CO
PBX
CO
CO
Packet Switched Networks (Data)
Router
Router
Router
Router
Router
• Separated networks
• Separated applications/services

20. PBX
IP Phone
Converged Network
PSTN
CO
Gateway
Router
Router
Router
Router
• Converged network
• Separated or integrated applications
PBX
IP Phone

21. VOIP NETWORK

22. IP-PBX SERVERS
• Windows Base
• 3CX PBX
• Linux Base
• Asterisk
• TriBox
• Elastix

23. ELASTIX HARDWARE SERVER

24.  Server > Elastix OS (Base on CentOS)
 Client > 3CX, SIPDroid, CSipSimple . . .

25. SIMPLE LAB