IP Telephony (VOIP) Presentation

Group D:

Thomas Chen

Pedro Hernandez

Tawana Murphy-Burnett

Mehul Vora

Table of contents

·       Introduction

·       How IP Telephony Works

·       Calling Applications

·       Service Providers

·       The Future

·       Web Links

INTRODUCTION

IP telephony is a category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls. For users who have free or fixed-price Internet access, Internet telephony software essentially provides free telephone calls anywhere in the world. To date, however, Internet telephony does not offer the same quality of telephone service as direct telephone connections.

There are many Internet telephony applications available. Some, like CoolTalk and NetMeeting, come bundled with Web browsers. Others are stand-alone products like Skype and net2phone. Internet telephony products are sometimes called IP telephony, Voice over the Internet (VOI) or Voice over IP (VOIP) products.

HOW IP TELEPHONY WORKS

IP telephony, known in the industry as Voice-over IP (VoIP), is the transmission of telephone conversations over a data network like one of the many networks that make up the Internet. While you probably have heard of VoIP, what you may not know is that many companies are already using this technology in the connections between their regional offices worldwide.

CALLING APPLICATIONS

There are four ways that you might talk to someone using VoIP. If you've got a computer or a telephone, you can use at least one of these methods without buying any new equipment:

1.      Computer-to-computer - This is certainly the easiest way to use VoIP. You don't have to pay for long-distance. There are several companies offering free or very low-cost software that you can use for this type of VoIP. All you need is the software, a microphone, speakers, a sound card and an Internet connection; preferably a fast one like you would get through cable or DSL. Except for your normal monthly ISP fee, there is usually no charge for computer-to-computer calls, no matter the distance or duration.

2.      Computer-to-telephone - This method allows you to call anyone (who has a phone) from your computer. Like computer-to-computer calling, it requires a software client. The software is typically free, but the calls may have a small per-minute charge.  Your voice will be transmitted as data packets and then converted to ride over regular phone lines, unless the person at the other end is using an IP telephone.  Conversely, if that person is using a regular telephone, at some point, her voice will be “digitized” and you will receive the corresponding signal.  IP telephony equipment resides between the two of you that performs the conversion automatically.

3.      Telephone-to-computer - A few companies are providing special numbers or calling cards that allow a standard telephone user to initiate a call to a computer user. The caveat is that the computer user must have the vendor's software installed and running on his or her computer. The good news is that the cost of the call is normally much cheaper than a traditional long-distance call. The vendor will maintain the telephone number and associate an IP address or some other unique identifier with it that corresponds to your machine so that it can route the incoming call to you.

4.      Telephone-to-telephone - Through the use of gateways, you can connect directly with any other standard telephone in the world. To use the discounted services offered by several companies, you must call in to one of their gateways. Then, you enter the number you wish to call, and they connect you through their IP-based network. The downside is that you have to call a special number first. The upside is that the rates are typically much lower than standard long distance.  Again, special equipment resides with the company that provides the bridge from the regular phone network to the IP network.

SERVICE PROVIDERS

There providers of calling applications can be grouped in a similar fashion:

1.      Computer-to-computer - The most widely used are AOL, MSN and Yahoo! Instant Messengers.  Skype (founded by ex-KaZaA professionals), is arguably of superior sound quality.  The company asserts its quality outperforms a regular phone.  Launched in September 2003, the software has already been downloaded by 3 million users.

2.      Computer-to-telephone - The most successful player is Net2Phone (NASDAQ) with 2003 revenues of $91.8 million, down from $137.9 million from 2002 due to fierce price competition.

3.      Telephone-to-computer - Because the computer called must have the vendor’s software installed, this is the least popular and few companies are providing this service.

4.      Telephone-to-telephone - The most common method is calling from a conventional phone to a gateway.  This gateway then forwards your call via the IP network and can be routed back into the corresponding local phone network of the call destination.  Leading provider Vonage goes one step further by hooking up an IP-enabled phone directly to your cable or DSL modem through an adaptor making your analog line obsolete.  Moreover, your Vonage phone number travels with you as long as you have Internet access.  This is one of the most advanced services and currently is facing regulation issues in congress.

THE FUTURE

Just a few years ago the debate over packet-switched voice transmission centered on the protocol used to ship the packets: IP, ATM, frame relay or others.  The verdict is still out on the best protocol, though each one has its set of strengths and weaknesses.  ATM gained initial popularity due to its bandwidth-use efficiency.  However, given that IP is the de-facto standard for most of the Internet, VoIP has proliferated as of late.  The real challenge lies in integrating packet-based voice over the plethora of networks: IP, ATM, etc.  Internet telephony must achieve quality, reliability, scalability and manageability equivalent to the public switched telephone network.  Furthermore, it must do so at a cost reduction.

As you envision a VoIP solution that delivers high quality, reliable, latency-free voice transmission, let your imagination run free and think of the possibilities.  A Wi-Fi enabled IP phone could let you make free calls from any Wi-Fi hotspot.  Need to call China?  Just stop in at your local Starbucks.  Have DSL or Cable at home?  All calls are free from home – to anywhere in the world.  This future is closer than you think.  In July, Agere Systems announced a Wi-Fi VoIP chip and its first customer in Japan’s NTT, the powerhouse behind DoCoMO.  Now, the providers of your Internet access, local phone service, cable TV, and cellular service will each compete to offer you VoIP and at cheaper rates than ever seen before.

WEB LINKS

Background / White Papers:

VoIP Howto (www.tldp.org/HOWTO/VoIP-HOWTO.html)

IP xStream (www.iptelephony.org)

Current News:

Business Week: Why the Bells Should Be Very Scared

(http://www.businessweek.com/technology/content/nov2003/tc20031111_3523_tc047.htm)

CNET News.com: Cablevision adds VoIP to broadband menu

(http://news.com.com/2100-7352-5106133.html)