Chris Mouncey, services product manager, Networks First considers the issues of this ever increasing trend, VOIP

Voice over Internet Protocol (VoIP) – the routing of conversations over the Internet or through other IP-based networks – has been around since 1996, but it has really gathered momentum over recent years. Although the infrastructure for VoIP is still being built, there is no doubt that it is only a matter of time before VoIP is deployed extensively not just for business, but also for personal use. ISPs, for example, are already bundling broadband and voice together.

VoIP is the future of voice communication and has to be every bit as good as tried and tested traditional methods. We take for it for granted that when we pick up a phone there is always a dial tone and whoever we talk to will hear us clearly, and vice versa. In the early days of VoIP this was not always the case but the Quality of Service (QoS) issues have been largely solved, to the extent that Data Centre Managers (DCMs) can now rely on a resilient, fit-for-business service.

Considerations of VoIP

There are two main protocol standards that can be adopted – SIP (Session Initiation Protocol) and H323. Although neither one is better than the other, fortunately they can be run in parallel as long as the DCM considering adoption of VoIP ensures the company’s infrastructure has the technology to handle both.

SIP is similar to personal email while H323 is more structured and is orientated towards the business market place. The choice comes down to the end-user as to what functionality they require.

Prior Planning

Astute DCMs appreciate that, as with introduction of any new technology, advance planning for VoIP implemention is vital. They must have a clear idea about what they want to achieve from introducing VoIP and the service they want to provide. These decisions will help to detail the project and its deliverables. The data centre is a highly desirable location for a VoIP system, as the back-up systems are already in place, and running VoIP post-implentation should be straightforward.

They should also take into account whether VoIP is going to be offered as an internal service to users – and different locations and cost centres – and how VoIP will be billed accordingly.

The project plan needs to cover choice of protocol – H323 or SIP – encompassing elements such as quality of service and the type of voice packet, for example.

Quality of Service

Where IP packets are lost or delayed at any point in the network between VoIP users, there will be a momentary drop-out of voice. This is more noticeable in highly congested networks and/or where there are long distances and/or complex networking between end points. Advancing technology has improved the reliability and voice quality considerably and will continue to improve VoIP performance as time goes on. DCMs need to consider the quality desired when deciding on bandwidth and the size of the network.

It is important to decide how much bandwidth is needed – if too small, the service may incur delay. Too large and you may be paying for unused capacity. In this respect, Codec choice is a major consideration; codec’s are used to reduce traditional voice packets from pulse code modulation (PCM) to smaller more efficient packet sizes. For example a G.729 Codec, will reduce a 64k voice packet and squeeze it down to a bandwidth of just 8k, allowing more cost-effective use of bandwidth than would otherwise be the case. However, it is important to point out, that once the codec selection has produced the initial voice packet size, this packet will increase once it is added onto the IP network.

Increased Efficiency and Lessening Environmental Impact

There are key advantages to VoIP over a traditional telephony system, apart from increased efficiency and cost reduction -- especially over multiple networked sites -- also by lessening environmental impact.

Recent research from industry analyst Gartner, found that data centres account for almost a quarter (23 percent) of the 580 million tonnes of C02 released annually by the production and use of computer systems. The pressure on DCMs to address the impact their data centre is having on the environment is a serious issue and one that cannot be ignored. Like for like, VoIP requires less hardware then traditional telephone systems and therefore saves hardware manufacturing resources, space, power and heat.

Virtualisation

In this world of always-available communications, it is often essential for businesses large or small to remain in contact with colleagues and customers. VoIP’s virtualisation features allow one telephone number to be used over multiple sites – very useful for large organisations who want to cut down on ‘telephone tag’ with staff travelling between offices. It is also advantageous for smaller companies who may want to give the impression that they have more than a single location that they are in an alternative office, for example. In addition, a company no longer needs to be in London to have a London number.

Disaster Recovery

With increased risk of terrorist activity and the inevitability that kit will fail eventually, as the VoIP system is centralised but also distributed, disaster recovery can be fairly straightforward. At the touch of a button, the entire application can be automatically transferred to a new network, compared to the hours and hours that would be needed to switch a traditional system.

3rd party Companies

Depending on the service the data centre wants to implement, it may be an autonomous or internal closed service is not the best option. An alternative to consider is whether to outsource the varying degrees of VoIP capability through third-party companies. One option open to the DCM is to utilise external VoIP trunk services, as opposed to the traditional BT ISDN lines. This has a number of benefits, not only large cost savings, but also removes the geographic restraints of traditional line provision. i.e the option to have out of area dialling codes. It can also be a key consideration to resilient/redundancy plans.

Alternatively, the prospect of running VoIP services may be too much for the DCM directly. A 3rd party managed VoIP company could be an alternative, removing the complications of planning, implementing and continual management of the new service, and only charging a set monthly fee, mostly based around the number of users.

Security

Security is a key issue, not least of which is dealing with unwelcome ‘Spit’ – the voice version of spam, whereby a user’s voicemail box is filled up with sales messages. This problem is on the increase as there is no real transmission costs involved for the Spit originator, and it is considered an easy form of advertising.

A more traditional, but equally important consideration has to be based around external hacker compromising the system and making costly international or premium rate calls.

Vendors have built in a number of counter measures to both issues, but DCMs should ensure that some form of traffic monitoring and policing is built into the system to alert them to any problems, whether in-house or through an outsourced VoIP service provider.

Billing

Needless to say, whether the data centre runs a closed network or uses an outsourced service, the call billing must be absolutely accurate. The process for how this will be done must be decided before implementation and is crucial if the risk of over-paying for calls is to be avoided.

Conclusion

There is no doubt that VoIP will supplant traditional telephony over the coming years, to the extent that organisations will have no alternative as the major carriers switch over. Even at this stage, VoIP has a great deal to offer organisations, large and small and DCMs should give it very serious consideration – not least from the aspects of cost savings, increased efficiency and improved end user service.