Putting voice into the net

Published: 7 Nov 2008 (ICT Update - Rural Telephony, ICT Update)

Leiden, The Netherlands.

Do you need a computer to make VoIP (voice over internet protocol) phone calls?

No, you don’t need a computer. An analogue phone connected to an ATA (analogue telephone adaptor) is the minimum hardware required. An ATA is a small piece of equipment that can convert the signal from a traditional analogue phone into the digital signal needed to transfer data over the internet. So you still need an internet connection but the ATA turns your old phone into an IP phone. ATAs are available from about US$30.

Is a broadband connection essential for carrying a telephone conversation over the internet?

No. In fact, the bandwidth requirements for VoIP are as little of 15–20 kbps per call. The main challenge is the ‘stability’ of the network connection, and the fluctuations in quality (known as jitter).

How useful is VoIP for a rural community with only limited internet bandwidth?

Local telephony is always possible. It is simple to build a local wireless network that could carry several hundred calls and would act like a local telephone service. For non-local calls it is possible to use a satellite connection with 32 kbps guaranteed bandwidth. Satellite connections, however, can become quickly oversold, meaning that many users end up sharing the limited bandwidth. If a lot of people make calls at the same time the quality of the connection, and the calls, could suffer.

There are several well known brands of software that are free to download and use to talk with someone over the internet (Skype, Google Talk, etc.). What are the restrictions and disadvantages with this type of software?

Open source solutions, such as Asterisk and OpenSIPS, provide greater flexibility as they can be adapted to local needs. These are software applications that let you set up your own PBX (private branch exchange), which is basically a telephone exchange that serves a small network such as an office. The four main reasons to use an open source technology for local VoIP calls are:

  • Flexibility: you do not need to be connected to the internet to run your local telephone system. Such a local network could range in size from a single house, to a village or a region.
  • Ownership: local business models can be created instead of using a third-party solution where the community has to adapt to the product rather than adapting the product to suit the community’s needs.
  • Opportunity: it allows the creation of new added value services, such as accessing weather and market information services, voicemail, messaging, interactive voice services and even developing call centres.
  • Sustainability: relying on third-party solutions means that local knowledge is not created. To ensure that the phone network continues to operate long term it is better that the infrastructure is designed, built and maintained locally.

After the initial investment and installation of the hardware and software, is every phone call free afterwards? Are there any ‘hidden’ costs?

It depends on the business model that you want to use. Internet, electricity and the wireless network have to be created, all of which cost money. This infrastructure also implies people; there needs to be personnel to bill the customers, manage the cash and maintain the system. Calls within the network could be free, but linking beyond that to the traditional telephone network also means you would need to pay connection costs to the telephone company. Calls can definitely be cheaper, and a possible business model is to make local calls free.

What still needs to be done to make VoIP more widely available, especially to rural communities?

Training is the most important. And we need to learn from each other. Anyone using the technology should document their experiences and tell others what problems they came across and how they were solved. Improvements in local infrastructure would also help, of course. That means providing better access to electricity, building more local wireless and cable networks and improving tools and support to communities and individuals to help them develop workable business models.

How is VoIP likely to develop in the future?

VoIP is set to become more widely available and easier to use. Most telephone networks run ‘IP’ already. But many regulators are still cautious about VoIP, with some governments restricting access to equipment and knowledge and even making it illegal to make VoIP phone calls in their country. This is simply because VoIP allows more players into a market that has been traditionally controlled by just a few, often state-owned telecoms companies. It is no surprise that governments do not want other people to have access to that revenue.


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