by Maria Ingold
Note: This article is part of a series of technically focussed articles provided by onmedica.net for the healthcare community. The doctors who read this article have commented quite positively. Comments have included “Very well presented and explained” and “Comprehensive and very useful”.
What is VoIP?
VoIP stands for Voice over Internet Protocol and is typically referred to as Voice over IP. This simply means that the phone service is delivered over a broadband Internet connection rather than via the traditional phone company service. To avoid being confused by terminology, it’s useful to note that VoIP is sometimes referred to as Internet telephony or IP telephony and the traditional phone service is frequently referred to as PSTN (Public Switched Telephone Network).
VoIP is growing in popularity primarily due to its cost savings over PSTN phone calls. According to the International Data Group, up to 11% of UK broadband users will have VoIP by 2007. Even if individuals don’t all adopt VoIP, the infrastructure providers are certainly moving towards it. In 2009, BT intends to launch its next generation 21st Century Network, which means all BT phone calls will be VoIP calls.
Why use VoIP?
VoIP phone services can be used in addition to or, in some cases, instead of a traditional service. Most people use phone services via VoIP for two major reasons:
1) Lower cost (or free)
Domestic and international phone services that use VoIP are typically cheaper than traditional phone company services, or in some cases offered free as part of existing broadband services. This means that essentially free phone calls can be made to friends, family or business colleagues located anywhere in the world, although in general these calls are only free if the other party also has a VoIP connection and sometimes only if it is with the same provider.
Additionally, some added value services that are often charged for by normal phone companies are typically free with VoIP providers:
- Caller ID
- Call waiting
- Call transfer
- Repeat dial
- Return call
- Three-way calling
- Voicemail (via the web)
Travellers can take their home VoIP phone with them and receive incoming phone calls anywhere in the world as long as they are plugged in to a broadband connection.
VoIP phone lines can also be set up with some local (020) and lo-call (0845) numbers. This makes it possible to have, for example, a virtual London office with a London area code or to have a local rate phone number in the US.
What are the drawbacks of VoIP?
Reduced cost and flexibility are strong reasons to switch over to VoIP, but there are a few reasons why it hasn’t yet completely replaced traditional PSTN services. It’s good to be aware of these so you can find out how VoIP can fit in to your life. In general VoIP can be reliable and of good quality, but the PSTN system still provides a number of things that VoIP doesn’t.
1) Power failure protection
In the event of a power failure a non-cordless PSTN phones will still work, whereas a VoIP phone needs to be plugged in to the power grid to work.
VoIP can be more susceptible to viruses and hacking than PSTN phones, although security measures are continually being introduced.
It’s also possible that there may be more unwanted phone sales calls, known as SPIT (SPAM over IP Telephony).
Quality is highly affected by the bandwidth available and the CODEC or type of compression/decompression used to make the audio as small as possible. A VoIP phone call can use most of a 256KB broadband line, and even a 512KB broadband line doesn’t always deliver the QOS (Quality of Service) that PSTN phone services provide. This is becoming less of a problem as broadband providers are increasing the bandwidth of their services. However, normal broadband issues such as latency or packet loss will also affect the quality of the service.
Furthermore, calls made on a computer could be affected by the processing power being taken by another application or by the computer crashing.
4) Calls to special numbers
There has historically been a problem with VoIP services being unable to offer emergency services such as 911 in the US and 999 in the UK because VoIP phone numbers could be physically located anywhere. This is becoming less of a problem as providers such as Vonage now provide access to emergency service numbers in the UK.
Furthermore, some special numbers like directory services could not be available on VoIP. However, if the VoIP service is over the computer, a free online service like Yell could easily be used.
Many of these issues are already in the process of being resolved as the VoIP market aims to be competitive with, or as in the case of BT, looks to replace the PSTN market.
How do you use VoIP?
If you’ve decided that you want to use VoIP there are a number of options available which can meet your needs. The following is a general description of the main options.
1) Add VoIP software to your computer
The advantage of this method is that it can be low or no cost to set up, especially if you already have a recent computer and a broadband connection, however you need to be comfortable with sitting at your computer to make phone calls.
You will need the following:
- Computer with a sound card
- Broadband connection
- Microphone and speakers or a USB headset
- VoIP software
The disadvantage of this service is that to make and receive calls your computer needs to be on. If you don’t want to leave your computer on, the following options may be better for you.
2) Use an IP Phone
If you’re uncomfortable speaking at your computer, you can buy a self-contained IP Phone. This phone looks just like a normal phone but has a different adapter (a RJ45 Ethernet adapter) that allows it to connect to the Internet through an Ethernet router rather than directly to the PSTS phone system (through a RJ11 adapter).
The phone can be used independently of the computer and has all the software and hardware needed to make and receive calls.
Stand-alone IP phones are also available as cordless phones with the IP interface in the base station, and some can be hooked up to WiFi access points and GSM networks.
3) Extend your standard phone with an ATA
If you want to keep your existing phone, but take advantage of VoIP, you’ll need an ATA (Analogue Telephone Adapter).
There are typically two ways to use an ATA. One way connects your phone directly to the Internet through an Ethernet adapter. This means that you don’t need any additional hardware or software. The other way is to connect your phone to a USB connection and run the software on the computer.
How do I find out more?
There are many websites and articles available to find out more about VoIP. A selection of some useful ones is listed below.
Find out more information on VoIP:
- http://www.voip-info.org – A very thorough American reference site
- http://computer.howstuffworks.com/ip-telephony.htm – How VoIP works
Find, compare, and rank VoIP providers
- http://www.myvoipprovider.com/ – Top 100 and from selectable locations
A nicely researched comparison of the main UK software and ATA VoIP providers
An IP phone reseller website with clear product descriptions