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.'
