VoIP -Voice over Internet Protocol

COE 341 Self-Learning Assignment

By: Ayman Al-Bassam 232101 Amar Farouk Merah 237925

Agenda for today:

Introduction Historical Background How Does VoIP work? Advantages of VoIP Implementation Challenges:

– Security and Privacy– Reliability of Service– Delays and Jitters– Emergency Calls Routing– Integrations with Current Circuit Switched Networks– Legal Issues

Conclusion

Introduction

VoIP – revolutionary technology

Its purpose: analog audio to digital signals conversion

Main Benefits: cost-effective and portability

Historical Background

Dates back as far as 1973 Available for end-users in the 1990’s Examples of the first VoIP services include:

– Vocaltec Internet Phone Release 4 (1996)– Level 3 (1997)

Problems in Vocaltec resolved in Level 3

How Does VoIP Work?

Different than standard telephony systems Use of packet-switching instead of circuit switching Data split into packets and sent through many

connections Packets contain destination address and a sequence

number Packets are compressed and de-compressed

through CODECs which have sampling algorithms.

Solar Concentrators and Solar Concentrators and Stirling EnginesStirling Engines

Overview of how a VoIP system works

How Does VoIP Work? (Cont’d)

VoIP makes use of Media Gateways and Media Gateway Controllers

Three different types of VoIP services:– Analog Telephone Adaptors– IP Phones– Computer-to-Computer

Requirements:– Broadband Internet Connection (Cable, DSL, T1, T3, etc)– VoIP box– VoIP subscriber’s account– Wi-fi enabled phone (if you want to make use of mobility)

Advantages of VoIP

Cost-effective and no geographical limits Mobility Use of existing networks Efficient utilization of bandwidth

Implementation Challenges

Like any emerging technology many challenges are faced.

Some of which have been overcome and some are not.

Security and Privacy

Eavesdropping and packet interception. Continents could be altered. Compression makes it harder but not

completely safe. SRTP & ZRTP standards in PSTN and lack

of standards in VoIP. Some implementations, Skype. Easy to implement because of IP networks.

Reliability of service

Depends on internet connection quality.

Power outage.

Delays and Jitters

Packets and different routes !! Resulting jitter and delays in voice. Use of play-out buffers. Assigning priorities to packets.

Emergency Calls Routing

The difficulty of assigning IP’s to geographical location.

Dynamic IP’s !! Registration process for some VoIP

providers.

Integration with current PSTN

Numbers assigning system (E.164) Again hard to tie an IP to a specific locations. Some providers use the same E.164

standard (Skype).

Legal issues

PSTN companies operated by governments. Different laws in different places i.e. India,

UAE and Europe.

Conclusion

Summing up VoIP is the future Has many advantages, but is not 100%

reliable yet

Thank you for your time

Q&A

Session

References

1. “How Does VoIP work?”.< http://www.voip-sol.com/how-does-voip-work/>

2. “How Does VoIP Work?” 1-3 http://www.packetizer.com/voip/papers/understanding_voip/how_voip_works.html

3. Valdes, Robert. “How VoIP works?”< http://communication.howstuffworks.com/ip-telephony.htm/printable >

4. “Voice over Internet Protocol”. Wikepedia.< http://en.wikipedia.org/wiki/Voice_over_IP >

5. Schueneman, Thomas. “The Advantages and Disadvantages of using VoIP”< http://ezinearticles.com/?The-Advantages-and-Disadvantages-of-Using-VoIP&id=147921>