In a perfect world, you could implement the latest, greatest VoIP technology without regard to your existing equipment....
Unfortunately, that's rarely possible for a number of different reasons. However, many major vendors are creating solutions that allow you to leverage the legacy equipment instead of fighting it.
One of the best examples of this trend is combining the old and new into hybrid systems. These systems typically have a limited amount of traditional, modular, telephony hardware, combined with an Intel-based server running some variant of Windows NT or NT Embedded. All this is packed into a PC-sized, rack-mounted chassis.
If you're looking for a telephony system for a new office, you can probably do better elsewhere. But if you want all the advantages of IP Telephony and VoIP, but don't want the expense of replacing your existing phones or wiring, these solutions can offer a couple of surprising benefits.
The first is that they're more reliable than you may think. Only peripheral systems like TAPI and VRU and VM run on the PC side, so if Windows coughs up a lung, your basic telephone service won't be interrupted. The second is that they typically include all the bells and whistles, such as unified messaging, QoS features and support for lots of CODECs, but the device administration is remarkably similar to the legacy phone systems. This means that your learning curve can be reasonably short.
For some examples of these hybrid solutions, check out:
About the author:
Thomas Alexander Lancaster IV is a consultant and author with over ten years experience in the networking industry, focused on Internet infrastructure.