Voice Over IP or IP Telephony?
<<<... and if you don’t have one, it’s going to add to the complexity and the cost — and trunk connections, via gateways, which can be either dedicated to the task or added to existing WAN hardware. These gateways could also connect your IP telephony system to your existing PBX, via one of its trunks, so you can bring in an IP telephony system without having to get rid of your existing phone system and migrate slowly from one to the other over time. All of these are connected via standard LAN switches and cabling. We’ll look in detail at some of the configuration and tuning you’ll need to do in the next article. This does mean, however, that your two redundant softswitches can be deployed in two separate comms rooms at opposite ends of the building for physical separation in case of say a flood in one comms room.
Because they’re only involved in call set up and tear down (in fact, once a call is established, the softswitch could fail completely and the people on the call wouldn’t know about it), softswitches don’t require the massive processing power of PBXs designed for similar numbers of users/calls. Hence the reason most softswitches are server-based — a one rack unit (RU) high server that can handle several thousand users isn’t uncommon — which is handy if you’re tight for space. It also makes the relative cost significantly less — though always remember that that has to be offset against the cost of handsets. It’s important you understand the differences between basic VoIP and IP telephony, and also some of the comparisons between PBX-based telephony and its IP alternative. Now we can start delving into the subject a bit deeper.