Voice over Internet Protocol (VoIP) is a technology that handles the transmission of voice conversations over an IP network such as the internet.
According to research from Yankee Group, 25% of businesses are already taking full advantage of VoIP, and 75% are looking to install it within the next two years.
VoIP promises to reduce the cost of network and communications since a single network is used to transmit voice and data traffic.
Because they use IP, VoIP calls over the internet generally do not incur a charge beyond what the user is paying their ISP for internet connectivity.
VoIP requires hardware to convert a telephone conversation into bits and bytes that are then transmitted using the IP to and from a pair of computers running VoIP software. In its most basic incarnation, VoIP does not require a handset, and relies on the built-in sound card and software encoders and decoders to convert audio into data that can be transmitted via IP.
Services such as Skype run a software client on the computer to enable calls to be made over the network using a sound card and headset.
Since the two PCs are connected directly through the internet, there is no need for a separate telephone line. This avoids the costs of running a separate telephone network, which has made VoIP attractive to businesses that run extensive branch office networks. The wide-area network that connects the remnote offices or branches to the head office can be utilised to run VoIP. In fact, VoIP is often one of the first applications deployed on new wide area networks.
Abbey installed IP-based telephony at its five call centres and more than 800 of its high street branches in 2003. At the time, the firm's contract with BT was worth £125m, but Abbey estimates it will save millions of pounds by running its telephony and data over a single network.
Tesco is taking the idea of converged voice and data network and VoIP one stage further with the introduction of fixed-mobile convergence (FMC). FMC allows customers to use just one handset for all calls, switching between mobile and fixed-line calls seamlessly. Accessing an internal, fixed-line data network to carry the call provides better signal quality and lower call costs. Once outside the office, the handset then roams to a mobile network.
Voice over IP calls can present certain challenges for IT departments. The main issue is that users are accustomed to the simplicity of being able to pick up the phone and make a call. The ringtone is almost always available. Calls made between fixed phonelines do not usually suffer from breaks in the flow of the conversation. But limited bandwidth on network latency can result in packet loss, delays and jitter, which makes voice calls sound choppy.
A 2007 Vanson Bourne survey of 300 large enterprises across Europe found that 73% of IT directors are still worried about basic quality and reliability of VoIP, despite the strong industry trend towards converging voice and data traffic onto a single data network.
An IT manager responsible for managing a VoIP deployment should be aware that moving telephony to a data network means voice services will inherit the data network's security problems.
This could mean denial-of-service data attacks on voice devices, malware infection and the possibility that it may be easier to eavesdrop on VoIP calls than on conventional calls.
Systems administration interfaces that control telephone exchanges can be located at multiple locations and can be accessed by web browsers.
Although security tools are available for VoIP, they can conflict with voice quality.
The more barriers there are in the network and endpoints for security purposes, the more interference there will be with voice quality.
Voice packets that have been passed through security devices can cause added delay, jitter and packet loss during the call.
The security versus voice-quality conflict is difficult to resolve in any deployment. The voice manager, obviously, does not want poor-quality calls. If the calls are poor, then why have calls travel over the data network in the first place?
The security manager does not want to open the network and endpoints to security exposures that will not only compromise the voice services but also weaken data functions.
Navigating the challenge of call quality and security requires a great deal of negotiation and compromise. Security is important, but not at the cost of an unacceptable voice service.
Deploying VoIP: five things every CIO should know
Navigating the complexity of VoIP can be overwhelming, and it may seem like you need a degree in the subject to understand it. Below are a few recommendations from Yankee Group that can help:
- Be prepared and fully understand whether you are ready for IP telephony. Before embarking on the project, have a qualified convergence consultant perform a network-readiness assessment to determine the cost to upgrade. Understand all the components of the VoIP system and be prepared to explain to the business executives what the underlying costs are.
- It is about the applications, not the technology. Once the costs are fully understood, the CIO must be able to discuss the benefits in business terms, not technology terms. Simply put, business leaders really do not care about IP, SIP, telephony or other technical terms.
- Leverage existing technology wherever possible. This is always good practice, but was lost during the late 1990s. By bringing together all of the corporate applications and infrastructure, companies will recognise greater efficiency and reduce the amount of waste in many IT organisations.
- Sort out the internal politics. The CIO must strategically determine who owns the converged infrastructure. Companies should cease distinguishing between voice and data networking, and only concern themselves with corporate communications.
- Remember that one size does not fit all. Pick the VoIP system that fits the business best rather than trying to force the business to change to take advantage of the technology. In many cases, the latest and greatest technical solution is not the best thing for the business, and a slower, migratory approach would be more cost effective.