VoIP

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.

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.

How VoIP works?

VoIP Protocols

Some proprietary and open-source 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]

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.

VoIP vs. PSTN Carrier LinesPSTN : 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

Continue . . . Upgrade and Expansion PSTN : Very complex due to change in hardware

and wires VoIP : Sometimes just require more bandwidth and

software upgrade

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

Application

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.

Some Application

Advantages of VoIP Cost is very less compare to conventional

telephone lines Upgrading and maintenance is easy PC-PC free calls and PC-Mobile/Landline

nominal charge You can obtain concurrent data, voice and

video calls Very less hardware requires because is

use the internet connection Portability is achieved if you are using Wi-

fi or wireless connection Call waiting, caller ID, call conference are

free

VoIP Devices[1] 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.

Continue

[2] 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.

Continue

[3] 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.

Extra Information

List of websites that works on VoIP Www.evaphone.com Www.voipbuster.com Www.freeipcall.com Www.s-unno.com

Or you can create your own VoIP server using AsteriskNow operating system or some software