• Designed by • Zohaib Hussain• University of Lahore• Bcs02123325

Voip(Voice over Internet Protocol)

Agenda

• What is VoIP and its Introduction.• History of VoIP.• VoIP Architecture.• How VoIP Work.• VoIP Protocols.• Comparison of Protocols.• PSTN Vs VoIP.• VoIP Requirements.• Pros and Cons of VoIP.

1. What is VoIP and its Introduction

VoIP stand for Voice over Internet Protocol.“VoIP is the ability to make telephone calls

over IP-Based data network with a suitable quality of service and superior cost.”

Also Known As IP Telephony Voice Over Broadband Internet TelephonyVoIP Technology emerged over Public Switched Telephone Network(PSTN).

2. VoIP History

• The first VoIP software was introduced in 1995 by Vocaltec.

Designed for home PCUses H.323 ProtocolUses Packet switching

3. VoIP Architectures

PC to PC.Phone to Phone.PC to Phone.

VoIP Architectures

• PC to PC

VoIP Architectures

• Phone to Phone

VoIP Architectures

• Pc to Phone

How VoIP Works?

1. The voice is converted from an analog to a digital signal.

2. The digital signal is broken up into packets.3. The packets are sent to the destination via

Internet Protocol(IP).4. The packets are reassembled into a digital

signal at the destination.5. The digital signal is converted to an analog

signal and played back through the receiver.

VoIP Protocols

Protocols of VoIP

1. H.3232. SIP(Session Initiation Protocol)3. MGCP(Media Gateway Control

Protocol)

Protocols of VoIP

H.323: The call setup protocol H.323 is standardized by the international telecommunications Union(ITU). In a VoIP environment, H.323 is a common protocol running on voice gateway to connect the VoIP network to the PSTN.

Protocols of VoIP

SIP: The SIP Protocol is a standard developed by the Internet Engineer Task Force(IETF) for establishing multimedia session such as voice instant messaging and video.

Protocols of VoIP

MGCP: The Media Gateway Control Protocol is a protocol for providing telecommunication services and controlling devices and transmitting calls via an Internet Protocol network.

Comparison of Protocols

Item H.323 SIP MGCP

Designed by ITU IETF ITU

Compatibility with PSTN

YES YES YES

Implementation Large and complex Moderate Moderate

Multiparty call Yes Yes Yes

Multimedia conference

Yes Yes In future?

PSTN versus VoIP: A Feature Comparison

PSTN• Dedicated Lines• Features such as call

waiting caller ID and so on are usually available at an extra cost

• Can be upgraded or expanded with new equipment

VoIP• All channel carried over

one internet connection• Features such as call

waiting caller ID and so on are usually included free with service

• Upgrades usually requires only bandwidth and software upgrades

Voip Requirements

• Which Equipment's are needed?1. A broadband(high speed internet)

connection.2. A computer, or specialized phone.

Advantage of VoIP

• Highly low cost communication.• Easy to use.• Easy to establish the network.• Communication possible through

laptop.• Unlimited user can be add• Free IP to IP

Disadvantage of VoIP

• Need always power supply.• Need a uninterrupted internet

connection.