Cogen, a division of power company Innogy, is using 3Com's NBX 100 Communications System at its Solihull headquarters to trial a voice over IP (VoIP) system. It is likely that if the trials are successful the system will form the basis for a new communications infrastructure aimed at cutting costs, boosting efficiency and improving customer service across the entire Innogy business.

The Cogen site is being used as a LAN/IP telephony test area for the whole Innogy group. While there are as yet no firm plans for a mass rollout of IP private branch exchanges (PBXs) across the rest of the group, it is probable that these will be used to replace its traditional PBX systems as they come to the end of their useful lives.

Cogen employees are using VoIP over their LAN through the NBX 100. About 80 3Com IP handsets are being used for voice calls over the LAN at present, these being attached to a single NBX 100 system that is in turn attached to a 3Com LAN Switch 3300.

Currently, the system is set up to route calls via the PSTN through an ISDN connection, with the main trunk in and out of Cogen headquarters being based on a 30-channel ISDN Primary Rate Interface (PRI) card running the Q.931 signalling protocol for inter-PBX signalling. The next phase is to connect the NBX to Cogen's voice virtual private network (VPN). When this occurs, Cogen will be able to activate the all-important least-cost routing feature, designed to minimise the cost of voice calls.

In conjunction with the NBX, computer telephony integration (CTI) applications are also being deployed for the first time at Cogen. Users can call their contacts from desktop applications such as Microsoft Outlook, for instance, and also have the ability to receive voice messages via their email. Cogen is also using Imap4 unified messaging. The NBX acts as an Imap4 server, which is polled every few minutes by Microsoft Outlook. While this is only marginally useful for office-bound desktop PC users, it offers much bigger benefits to mobile users who have to travel between several sites. This advantage will become increasingly apparent when the use of IP PBXs grows more widespread.

'Much of the functionality we are already using is also available from competing systems, such as unified messaging, CTI and off-site notification,' says Chris Legge, Innogy's project manager. 'However, with the 3Com package these are integral rather than bolt-on extras. In addition, we expect overall cost reductions as more NBXs are rolled out.' Legge adds that the 3Com PBX had a lot more features than the other two IP PBXs that he considered, which were from Cisco and Nortel.

Legge says there were difficulties at the start of the NBX implementation. 'We had a couple of hardware problems with the IP handsets, but 3Com swapped these out,' he says. 'One of the reasons for choosing the 3Com NBX was because it had more of the features of our [existing] Siemens ISDX than its competitors. However, there were a few features missing. The one that was really lacking in the NBX was the ability for a caller to 'camp' on someone else's phone. There were a few other missing features, but these could either be worked around or were deemed not to be key features.'

The project explained

The first stage of the project was to install a business telephone system to meet the requirements of Innogy and Cogen. The aim was simply to deliver standard telephony to all users together with new CTI applications.

One of the early project goals was to ensure that the system was as reliable and effective as Cogen's preferred PBX, the Siemens ISDX. In addition, the system needed to be capable of being managed both locally for first-level support, and remotely by Innogy's central team for second-level support.

Another of the project's main aims was to deliver a communications solution that was more cost effective than the ISDX. 'On the surface, the NBX is quite cost-effective compared with the ISDX. But when you consider the cost of 3Com IP digital handsets, at about £200 each compared with between £30 and £40 for an analogue handset for the ISDX, some people are going to question whether VoIP is economically viable,' says Legge.

However, Legge estimates that in terms of overall capital costs, an NBX plus digital handsets costs around the same as an ISDX plus analogue handsets. Even so, he believes that for smaller sites with few engineers, £1,000 to connect five people and their handsets to a voice VPN is a negligible cost compared with putting in an ISDX for five staff.

Legge believes the main savings for Cogen will come from a reduction in its annual PBX maintenance bill, which is typically high. His team is investigating the costs of maintaining 3Com NBXs. 'At the moment, all our ISDXs ­ about 30 ­ are on a huge five-year maintenance contract with Kingston Telecommunications. Deploying a single NBX instead of an ISDX doesn't make much difference to the overall maintenance cost, but I need Kingston to break out the cost of maintaining the NBX from the main contract,' he says.

Legge, who intends to put the NBX maintenance out to tender with a couple of other companies to compare quotes, expects maintenance will be very much cheaper than with the ISDX. 'We think it will be about the same as maintaining data networking equipment, about 10 to 15 percent annually of the capital equipment cost,' he says.

The second phase of the project­ due to start this month­ is to connect the phone system to Cogen's voice VPN, which Innogy has interconnecting all its sites. While the voice VPN works well with the traditional systems, the choice of a LAN/IP telephony system means the IP PBX needs to integrate seamlessly with the existing voice topology. The company also needs the new system to be part of the existing dial plan for users.

The third major phase, likely to begin in the latter half of 2001, is to link the architecture to customer sites via the company's WAN, again deploying 3Com NBX 100 chassis and IP handsets rather than a Siemens ISDX. The goal is to enable easier cost-effective communications with smaller on-site teams over the voice/data network. The WAN deployment will also make it easier and cheaper for customers to contact Cogen.

The intention is for Cogen/Innogy staff to remain within contact at whichever site they are located, and to provide the flexibility to transfer voice communications with Cogen staff as they move between existing locations or to new sites.

'At the moment, our ISDXs each have a different site-based identifier code. This makes our internal dial plan more complex than one built around the 3Com NBX,' says Legge. Today, when an engineer moves from one Cogen site to another, there is no guarantee that he will have the same extension, for instance. It also means the ISDX has to be reconfigured with additional extensions as engineers move from site to site.

When NBXs are widely deployed, because the extension is based on IP addressing, it remains the same as the engineer moves from site to site. Also, since all NBXs and IP handsets will be identified as belonging to the same Cogen IP domain, no PBX reprogramming is needed. The engineer simply plugs his IP phone into the nearest socket and it works immediately.

The fact that the administration of the NBX system can be managed locally by Cogen people, rather than by central Innogy staff, will become key in the third phase. It will save time and effort when simple changes must be made ­ such as adding staff details ­ since no engineer needs to visit the site.

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