Voice over Internet Protocol (VoIP)

Elaborated by :Raed AMMARMarouen ARFAOUI

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Plan

• Introduction• VoIP definition• Architecture• VoIP Protocols• VoIP Security• Future of VoIP• Conclusion

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Introduction

Problem:

• Reduce the communication cost within enterprises

Solution:

• Communicate using the internet

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VoIP definition

Voice over IP (VoIP) is the process of sending an audio signal (usually voice) over a network using internet protocol.

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Architecture

How it works?

To implement voip, we need some equipments:• IPBX• VOIP server• VOIP client• Gateway

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Architecture

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Architecture

PBX

PBX (Private Branch Exchange) is a system that links individual telephones to telephone lines and external mobile networks.

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Architecture

IPBX

Private telephone exchange using the Internet Protocol (IP) to manage telephone calls from a company in its internal local area network (LAN)

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Architecture

VOIP ServerThey can now act as IPBX Systems and connect the clients connected

The ways to get this service are:- Use a service on the internet- Buy a physic equipment- Use a software (Asterisk, Elastix)

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Architecture

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Architecture

VOIP Client

There we have softphones and headphones:

• Softphones are computers that looks as telephones used for VOIP communication

• Headphones are software that can be installed in a computer, or a PDA that allows the device to use the VOIP

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Architecture

General Softphone clients :

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Architecture

GatewayEquipment used to connect the VOIP system to a real telephone lineIt is used in enterprises to call distant branches

It can also connect different type of communication infrastructures (Skype to SIP, SIP to telephone, telephone to SKYPE)

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VoIP Protocols

• H.323 or SIP• RTP, RTCP, RSVP, RTSP• Transport Layer (UDP, TCP)• Network Layer (IP, IP Multicast)• Data Link Layer• Physical Layer

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VoIP Protocols

• Call Manager / SoftwareApplication• CodecsPresentation• SIP/ H323Session• RTP/ UDP/ TCPTransport• IPNetwork

Data Link

Physical

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VoIP Protocols

H.323 is a multimedia standard that provides a foundation to transport voice, video and data with a concern for real-time data.

H.323 defines several network elements:• Terminals (LAN Endpoints)• Gateways (Optional but really useful)• Gatekeepers (Also optional)

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VoIP Protocols

SIP (Session Initiation Protocol) is an application-layer protocol for creating, modifying and terminating VoIP sessions.

Allows registration, authentication, initialization and call control. It also allows the negotiation on how to encode information was exchanged.

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VoIP Protocols

Transport Protocols (RTP / RTCP)

RTP (Real_Time Transport Protocol) aims to provide a uniform way to transmit IP data subject to constraints of real-time beginning to end, (audio or video streams) .Integrated with RTP, RTCP (Real Time Transport Control Protocol) allows you to have information on the quality of the data transmitted.

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VoIP Security

VoIP Security Issues:• Interception of calls• Denial of Service Attacks• Theft of Service• Exfiltration of data via media session• Malware embedded in signaling and media

session

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VoIP SecurityEnsure Secure VoIP

• Encrypt VoIP traffic • Properly configure firewalls. • Consider segmenting voice and data traffic by using

a virtual LAN. • Use proxy servers in front of corporate firewalls to

process incoming and outgoing voice data.• Make sure that server based IP PBXs are locked down

and protected against viruses and DoS attacks.

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Future of VoIP

Regulation:

Regulation and taxing can define the future of VoIP

Network Convergence:• The future is Triple Play! Voice, Video, and Data• Big competitors are Hybrid Fiber-Coax (cable

companies), and Fiber to the Home (phone companies)

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Conclusion

VoIP technology will be the trend of future. Already, more than 50 million people and businesses have begun to subscribe to a VoIP phone provider

Achievement

Questions??