The evolutionary approach

Don't be in too much of a hurry to get rid of your existing PBX equipment in favour of voice over IP. A phased approach is the best way when migrating to VoIP technology. Antony Adshead reports


Don't be in too much of a hurry to get rid of your existing PBX equipment in favour of voice over IP. A phased approach is the best way when migrating to VoIP technology. Antony Adshead reports

Voice over IP is catching on. In a survey of more than 600 businesses carried out for BT last year, 37% of respondents said they had moved to a converged network in the past 12 months, with 43% using their local area networks for voice calls and 34% sending voice traffic over the wide area network.

Lower cost is a major motivation, as is the greater ease of management that comes with putting everything on one network. Reduction in total cost of operation comes from having only one network to support, no more PBX support costs, and no more call costs between sites. Considerable savings can also be made on cabling, as well as quicker and easier moves and changes.

VoIP brings flexibility too, with users able to log in from any location - even from home - and still be contactable via their internal direct-dial number.

Other productivity benefits include presence awareness to help identify who is available to communicate with, text-to-speech functionality and the integration of telephony capability into other applications, where contacts can be dialled from the PC or account details shown during calls. All these savings and features are enough to make you wonder why everyone has not migrated to VoIP.

The short answer is that traditional PBXs and telephony equipment are a considerable investment that cannot be written off before time without good reason. Is this a barrier to reaping the benefits of VoIP? Certainly not - it's just a case of knowing how to negotiate an evolutionary approach to adopting the technology.

Your first move in a migration should be to take a step back and determine what you have and how your business wants to utilise its telephony. Cisco's market manager for IP communications, Ian Sherring, says the key drivers for moving to IP telephony are impending events, the need to save cost, and the need for new applications.

"The typical impending event is the replacement of older technology, an existing PBX coming to the end of its supported life, for example, or the opening of a new site," says Sherring.

"Cost as a motivation comes into play where someone replaces existing technology on the basis of a return-on-investment case, for example, where a company with multiple sites can see they will save money by having no call charges between them and by centrally managing the network. New applications are a driver where existing equipment cannot be upgraded to meet the needs of the business, such as feature-rich contact centre applications."

All good reasons - but they needn't mean a complete rip and replace of your existing equipment. "Partial upgrades are most common," says Ovum research director Peter Hall, "especially with large companies that have PBXs at different stages of depreciation, so they can't justify complete replacement.

"Some companies go for complete upgrades to VoIP, but not many are likely to find the circumstances to justify it. Not all PBXs are likely to be fully depreciated, for example."

The key question to ask is: what is it that I cannot achieve with my existing system or as an upgrade to my existing PBX?

A number of upgrades are available, such as unified messaging, conferencing, and enabling IP extensions so that IP phones can be used. One of the simplest partial upgrades to PBXs and the public switch network between sites is to run voice on the data network and remove costs for internal calls.

But consider it carefully, says Hall. "For a lot of companies, this will save a lot of money, but it won't work for everyone. The savings are not always that huge if the company's traffic volume isn't that great. Call tariffs are competitive in the UK and you need a lot of voice traffic to justify it."

As with any projected upgrade to IT and communication systems, the basic sums involve comparing current costs with projected costs of the new converged network. Although IP-based telephony offers flexibility and ease of management unheard of in traditional telephone systems, there are some less obvious factors that may introduce unexpected cost.

Chief among these is the fact that a network running voice traffic will need a higher level of network assessment and testing. Voice calls on IP networks only need about 3% of packets to be dropped for voice quality to fall below public switch network standards.

"Nothing should be left to chance or guesswork," says Butler Group senior research analyst Mark Blowers. "The readiness of the network to cater for voice must be ascertained at the start of the project and IT managers need to be aware of the ongoing challenges of running voice services on the data network.

"The expectation will be that the phones are available 24/7, so it is no longer acceptable to have downtime - scheduled or otherwise. Network administrators need to be more proactive in identifying problems, and spotting and rectifying bottlenecks before they impact the VoIP traffic."

One company that is part-way down the road of migration to IP telephony is civil engineer Ove Arup. It has 7,000 employees in 73 offices in 32 countries and had a number of reasons for wanting to move from traditional PBX technology. High among these was cost - it was paying about 20% more for calls than it needed - and usability.

The company had implemented voice over Frame Relay, which offered free calls between sites, but the system was not user-friendly and required complicated dialling procedures that differed between offices. On top of this, the company had a mixed-supplier environment, which increased management costs.

So in 2001, Ove Arup embarked on a five-year plan to move towards a converged network based on Cisco equipment. About 4,000 of its users have migrated so far, with completion expected this year at its Australian, Asian, African and the rest of its US offices.

From the start, the upgrade was planned as a series of partial roll-outs of IP telephony technology. There were two main reasons for this - the first was that a 100% rip and replace across such a wide geographical area would have been a massive undertaking, and the second was that many existing assets were not yet amortised.

Arup's first step was to freeze all investments in Lan and PBX technologies globally. Then, having drawn up a masterplan which was bought into by regional and autonomously run offices, a policy of review and design was adopted that would be triggered by any new investment, such as staff growth, new feature requirements or office moves.

At the same time, a pilot project was carried out at the company's Leeds office and the first big upgrade was planned at Arup's new headquarters office in London, effectively a greenfield site.

"There are a number of reasons why a phased approach makes sense," says Keith Ali, global network manager with Ove Arup.  "There are situations concerning relocations, for example, where we intend to move location within 24 months, so in those cases we'd hold fire.

"Then there are times when the Lan infrastructure has been upgraded recently but not to support voice, which makes the case for upgrading again impossible. We have faced this a few times as our assets cycle is a four-year depreciation model, so we have to make sure both the Lan and the PBX have been amortised before we can even think about IP telephony."

With regards to benefits, Ali often has to point to intangibles such as corporate integration and standardisation, but he can also reveal reduced support requirements and improved efficiency.

Having carried out more than half of the company's global roll-out, he can now show that the London office migration, for example, brought full return on investment within 32 months and it is estimated cabling costs are being halved at all sites.

The network now offers a number of user-friendly advantages, too. Any employee can walk into any office in the world and use their own number. By linking to the company intranet, users can obtain contact details and profiles of colleagues and it is planned to link personnel to engineering drawings via phone or video conferencing.

Arup's roll-out is not just being carried out one office at a time. Partial bolt-ons of IP telephony (IPT) to existing PBXs are also part of the plan. This helps users get accustomed to the new technology for basic functions such as plain voice calling, as well as show off some of the more advanced applications, such as video telephony.

"It's important to ensure full on-net integration," says Ali, "ensuring the PBX and the IPT system can talk to each other over the data network free of charge. Then we typically use the conferencing facilities and collaboration facilities of the IPT system globally. We tend to deploy four or five IPT handsets in most PBX offices which are connected back to the nearest regional call manager server to get the local awareness level raised and to show off fancy apps.

"One of the other great features we deliver is the IP telephony home worker solution. Even if the local office is on PBX technology, this always goes down well."

Arup's roll-out demonstrates that an evolutionary approach make sense, and for most companies will be the only option. Its benefits include cashflow considerations, the gradual build-up of necessary skills, and the gaining of buy-in from branch offices. But in fact, for Arup it was Hobson's choice, says Ali.

"If we had migrated everything five years ago, it would all have come to end of life at the same time," he says. "Rather than a manageable asset replacement strategy spread over the organisation, we would have had a 'big bang' hardware upgrade every five years. We would have been supporting ageing equipment longer than we would have preferred while we sorted out the logistics again and again."

Steps for VoIP migration

  • Prepare a strategic vision and master plan for the organisation to align the convergence project with business goals
  • Implement a pilot with full integration to the existing PBX technology
  • Migrate your headquarters
  • Promote the successful migration to the business
  • Deploy home worker and mobile facilities
  • Deploy regional offices as required, focusing first on important regional headquarters locations
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