VoIP for Business: The Converged Network
For decades now, businesses have come to rely on their Local Area Networks for file transfers, data storage and communication. Since the explosion of the Internet in the 1990's and the subsequent building of infrastructure, merging data networks with voice has become a viable reality. The concept of the Converged Network has been around since the eighties, when many of the ideas were conceived during the development of the Integrated Services Digital Network (ISDN), a project of the International Telecommunications Industry. Originally, the idea was to merge data, voice, and other applications onto a circuit based network, or the existing telephone network.
With the wide acceptance of the Internet Protocol, and the technological advances made in VoIP, better solutions became available. To better understand how this came about, a basic understanding of the differences between a data network and the telephone network is needed.
The legacy telephone network is based on a circuit switching technology. Put simply, both parties involved are connected via a telephone line that uses circuits to connect multiple spans of wire over long distances. The telephone switchboard operator is closing the circuit that connects one line to another, the end result being similar to two tin cans and a string, albeit the string may be spliced together by other strings.
The Internet Protocol on the other hand, is a packet switching technology. Through the science of VoIP, the analog voice is converted into digital IP packets that are sent to their destination over the Internet, not necessarily following the same path.
IP is a connectionless protocol, and therefore less reliable that a circuit switched network. To overcome the difficulties in transporting time sensitive data such as voice and video over IP, traffic engineering must be done to give these packets priority over less sensitive data, such as file transfers or email. If we were not able to prioritize, voice transmissions would suffer from such acoustical degradation as jitter, echo and delay, and most certainly result in dropped calls. For VoIP to work successfully, a group of protocols collectively known as Quality of Service (QoS) was developed to ensure that these packets arrive without delay and in sequence at their destination.
The advantages of a converged network are many for all types of businesses. Among the benefits include the economical savings of maintaining one network instead of two, newly developed e-commerce applications such as interactive voice enabled websites, and of course the huge economic benefit of sending voice packets over the Internet instead of using the expensive telephone company land lines.
Legacy PBX systems rely on the telephone company's circuit switching technology and in themselves are their own network, complete with all the hardware involved. An IP PBX can be as simple as a softphone downloaded free from Skype, to smart IP phones that have PBX software built in and can automatically configure themselves on the network, or a hardware based solution such as Cisco's CallManager installed on a Cisco IOS Router or Linux server, servicing up to 30,000 SIP enabled IP Phones.
One IP PBX solution gaining in notoriety is Asterix, an open source software solution that runs on the Linux operating system and can be downloaded for free. The newest release, AsterixNOW, has a new user interface for much easier configuration. Asterix includes many features associated with the higher end PBX systems, and supports a variety of hardware. The Asterix Business Edition scales to up to 240 simultaneous calls, and sells for just under $1000.
Today, Converged Networks are a reality. With fiber optic networks carrying
voice packets around the world at the speed of light, voice over IP technology
has risen to the task of providing businesses large and small with a much more
cost effective way to communicate between branch offices, vendors, and potential
customers worldwide.
