We're in the early stage of looking to replace our aging phone system with VoIP.
Our 5 switches are Cisco 2960G ... Not PoE.
Aside from no 9-1-1 in a power failure, is there any disadvantage to using power adapters on each VoIP desk phone vs. replacing two or more of our switches with expensive new ones ? We have maybe 75 phones. I also read that a Cisco PoE switch may have 48 ports, but only 24 of them can provide PoE power. Is this generally true or just for certain switches ?