Like Dexman said, Alarm systems are really finicky and I can't get mine to tolerate anything but a clean POTS line - if there is anything on the line (PairGain, Load Coils, etc) it will have intermittent troubles that drive the staff nuts when the beeper goes off.
I work in a moderate sized healthcare system representing about 1800 devices at 7 sites that's set up with hub and spoke for internal local calls and each site has it's own external lines - usually a PRI and a few copper COs for backup. I have successfully fought off 3 different IS leaders or vendors who want to do a rip & replace on these systems and put in Cisco or something just because IS likes Cisco products. I *DO* want VOIP in my network, but my plan is to install a VOIP system alongside what I have now and slowly migrate over a few years rather than all at once. Cough and choke all you want, but I can install Siemens Hybrid systems right next to my Siemens PBX's and I can tie the two of them together seamlessly. In some cases I can keep all the phones I'm using now and just add new devices with more current products, and in other cases I will have to migrate the users to new phones, but I can do it over a few years rather than in one big blast and have no down time at all while doing it. Also as the years progress the cost of the hardware will decrease as it becomes more mainstream and I'll save money that way too.
The funny thing is that even though I WANT to embrace the technology and I'm not afraid of change, I can only think of about 50 phones out of 1800 that would really NEED to be VOIP. Most of those are home-based transcriptionists who could really use a company extension at their homes and I could facilitate that using their company-supplied internet connections. The calls would be seamless and no one would ever know they are calling a house rather than an office. Of course the CEO and the Veeps, plus Myself and the MIS geeks would get them, and maybe the call centers would benefit but that's about all that really need it, and it's much more cost effective to keep buying the $100 or less refurbished phones vs the average $200+ for an IP phone or even more if they want a headset in some cases....
Not to mention I have 100 years worth of CAT3 or worse voice wiring with IDFs in the smallest little places, and all the little closets they have tried to stuff the IS infrastructure into just can't hold anymore and can't take the heat - plus the cost of all the recabling that would be needed. The IS people just don't think of all this. They just say how cool it would be to do it but haven't given a moment's worth of though to the millions of $$ it would take to implement it across our organization... As it stands I have a nearly million $ investment in hardware based on purchase cost...
The cost really needs to come down yet. And people really need to get a clue about how much bandwidth it needs, rack space, heat dissipation, reliability of our IS network and everything else, the cost of the hardware, etc before I'll support just jumping in and doing it.
Those 20+ person legal offices and clinics need to stop and think about having switches that can handle the load and are ready for POE, how big of an outside pipe they will need for their communications and what it will cost, the expensive phones if they want something decent, and lots of other stuff - not just that we have this cool Microsoft server that can run this software and we're going to just hook it all up and have it work. What happens if big documents and graphics are being passed around the network - like PACS images of X-Rays and stuff like that - voice has to get priority or their calls will sound like Max Headroom or like they are in an echo chamber - so when voice is busy and the network slows to a crawl how much whining is there going to be that they can't get their work done???
oops... guess this got just a little long... but all things they should be thinking about....
