VoIP - PoE Switches vs. phone adapters

lapavoni used Ask the Experts™
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 ?

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It depends from switch to switch how many POE ports they have. I have Cisco's 24 port cisco's and all 24 are POE and I have a 16 port and a 8 port where only half is POE.

I would use phone adapters if it is 10 or less phones but with 75 phones I would use POE switches. If you already have power supplies for the phones there is no real advantage to move to POE switches besides that the offices will be neater with less cabling.

POE switches is also advantageous to have for other equipment like wireless access points, cameras etc.
better to go for second options..... cisco  POE switches.
cisco have switches where all the ports are POE.

because in first option , you need to give power adapter for every phones, need to have additional power socket to each and every desk. need to have extra adapter(if one/ two is not working suddenly)

but if you purchase POE switches with 24 x 7 warranty...then you are safe...
power will be supply by switch. if  switch goes down..you will get replacement.

you need to concentrate only on 2 switches , not all 75 phones/a adapters.

I would look at replacing the switch with a PoE switch. Power adapters are pretty expensive and it doesn't take a too many to make the PoE switch the more cost effective solution


Good advice and good points. Thank you both.  Studying Cisco 2960 PoE switches, I learned that the 370 watt powers 24 of the 48 ports. The 740 watt powers them all.  It is a significant investment at $3k to $4k each, but probably worth it in the long run.

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