Internet telephony
Summary Description Newswire's 5 Minute Guides looks into the evolution of voice over IP.
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Roullas Top10 Simon Vandore

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Editorial InformationArticle Location
Article Topic 5 Minute Guides
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Story Group 001112
Post Date 06/11/2000 08:10 AM Status Posted Entered by Simon Vandore on 03/11/2000 11:49 AM


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What's all this about making phone calls over the Internet?
Internet telephony, also known as voice over IP (VoIP or V/IP) or IP telephony, is aimed at using the Internet protocol (IP) to carry calls that would otherwise use ordinary public phone networks. The calls are digitised, carried as packets of data and routed just like other IP traffic.
What types of IP telephony exist?
It's important to make a distinction between computer-to-computer Internet calls, using software installed on each user's PC in the manner of two-way radio, and the commercial wave of VoIP development where Internet protocol is used to carry large numbers of calls that would otherwise use regular telephone lines.
The PC-to-PC variety is a small-time affair where quality varies and users require compatible software (such as those using technology from Net2Phone, Dialpad and PhoneFree). Large-scale VoIP, conducted by businesses and telecommunications companies, can provide call quality that is indistinguishable from those using the everyday phone network.
Today's VoIP products are usually integrated in some way with the traditional phone system, allowing a user to make a voice call from their computer to a regular telephone number, via a company which provides a gateway between the two networks.
Why make calls over the Internet when you could just make a normal phone call?
It's cheaper. Calls over public telephone networks attract tolls which are usually based on duration and distance, while charges for Internet traffic are usually not affected by these factors. If you already have an Internet connection or a private IP network between you and the person you want to call, using it for voice communication will not attract any additional charge.
At the PC-to-PC end of the scale you can access the Internet at local call rates and conduct international conversations which are invisible to your telephone service provider. If both parties are comfortable with this method and experience adequate performance, it is ideal when regular communication is required. Large-scale VoIP opens up opportunities for Internet service providers (ISPs), cable TV companies, wireless communication providers and networking companies to compete with established telephone networks.
Why is Internet telephony controversial?
Obviously the powerful, established international telephone companies are worried about VoIP. It undercuts their traditional revenue sources and threatens to shake up the telecommunications market. They want governments to regulate it as they do other phone services, but often the authorities refuse to do so, favouring as much competition as possible. In the US, to howls of protest from VoIP companies, legislation has been passed which theoretically allows the Federal Communications Commission (FCC) to impose fees on IP telephony. However, the authority says it has no plans to do so.
The alternative for existing phone companies is to beat their rivals to the punch and make their own investments in VoIP. Companies such as Telstra, AT&T and MCI WorldCom have all conducted VoIP trials.
What are the major problems with VoIP?
The first VoIP application was Internet Phone, released in early 1995 by Vocaltec. It offered scratchy sound quality and, like a CB radio, it was half-duplex meaning sound could not be sent and received at the same time.
However, today's VoIP is full duplex and sounds much better. The technical challenge is to provide a dependable service comparable with old-fashioned telephone traffic. Latency (lag) is a problem on the Internet, causing transmission delays for international calls which are more significant than those experienced on regular phone calls. Latency affects the time between the sender speaking a word and the receiver hearing it. The solution is to give it priority over less time-critical traffic (such as email) on routers, but outside private networks this is easier said than done.
The biggest problem for the future of VoIP is compatibility between technologies, as it is only recently that efforts towards interoperability have begun. Various standards bodies will be involved, such as the DSL Forum, Asynchronous Transfer Mode (ATM) Forum, the Internet Engineering Taskforce (IETF) and the International Telecommunications Union (ITU). For example, the IETF developed SIP (session initiation protocol) last year as a common means of initiating a connection.
What's happening in Australia and Asia?
Newswire has covered various local VoIP developments in the past 12 months. For example, Telstra is working on a project called DMO (data mode of operation) to integrate services based on IP, frame relay and asynchronous transfer mode (ATM) into its network. The technology has also proved useful to franchised Internet cafes which offer cheap international calls to backpackers at much lower rates than other phone companies.
In Asian countries where the telecommunications infrastructure is still in development, such as China, companies are actively trying to implement VoIP as a means of expanding telecommunications availability. There is also speculation about a VoIP boom in India if that country deregulates its phone system.


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Newswire's 5 Minute Guides looks into the evolution of voice over IP.

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