My company is evaluating replacing our current aging PBX system with a Voice over IP one. The latest vendor we have looked at came in with pricing that makes it appear that it is cheaper to run VoIP than it would be to replace it a 'conventional' system. Are there any 'gotchas' that we should be looking for?My company is evaluating replacing our current aging PBX system with a Voice over IP one.\u00a0 The latest vendor we have looked at came in with pricing that makes it appear that it is cheaper to run\u00a0VoIP than it would be to replace it a "conventional" system.\u00a0 Are there any "gotchas" that we should be looking for?--Via the InternetWithout having the specifics of your current system and the proposal(s) you are looking at, I will have to make a few assumptions and ask some questions.\u00a0 Will the new system have any way of support your current handsets (either digital or analog ones), either natively or through the use of some type of adapter? If so, what is the cost of the adapter and what does it take to get it running?\u00a0 If your current handsets are not supported, this will probably increase the cost of going to the new phone system because of you'll need to buy additional handsets.The next question is where it can really get expensive.\u00a0 How ready is your network infrastructure for handling VoIP?\u00a0 You will want to have Quality of Service (QoS) so that you can have the bandwidth on the network necessary to support the phones.\u00a0 QoS will mean going to a managed switch of some type.\u00a0 Do the switches support the latest Power over Ethernet standard?\u00a0 If not, you'll have to upgrade to switches that do, purchase VoIP phones with different power supplies or put up with "wall warts" (power supplies) all over your building to power the phones.You will want to examine your wiring closets and see what your current UPS situation is.\u00a0 If you aren't currently using a UPS, you will need to think about implementing this so that if the power goes, some or all of your phones will stay operational. With UPS, you'll also need to look at\u00a0 run-time capacity - to determine how long the phones will stay workin.\u00a0 Look at some type of inband or out-of-band signalling on the UPS so that if it is on battery it can signal a central system to alert you of a potential problem.Check with local phone company or emergency management in your area to see if your area is under Enhanced 911 (E911) regulations.\u00a0 This can also add some cost to your VoIP system as you will have to add some type of call-responder server that signals out the building, floor and room number of where the phone is located.\u00a0 Depending on how the E911 system is implemented in your area, you may have to arrange with the phone company to install the appropriate connection between your phone system and the E911 cloud in the area.You will also want to look at how the core switch on your network is configured.\u00a0 Although somewhat exspensive, going to a dual-core switch configuration and splitting your building across the two core switches will mean that if you have to take a switch down or one fails, that you haven't lost all of you network and phones at ones, at least some would be up on each building or floor.There are probably other questions that you need to ask your prospective VoIP vendors.\u00a0 Get them to give you references in the area of companies similar to you that have gone to VoIP so you can find out first hand what challenges they ran into and use that as a roadmap to a smoother VoIP installation if that is the path you choose to go.