We are looking at replacing our current legacy PBX with a VoIP based phone system. One of the things that we are deciding on is how to power the phones – power supply, Cisco proprietary or 802.3af. If we go with either of the two latter choices, we are looking at significant costs to replace our current network equipment with switches that can support VoIP phones. What would you suggest?
We are looking at replacing our current legacy PBX with a VoIP based phone system. One of the things that we are deciding on is how to power the phones – power supply, Cisco proprietary or 802.3af. If we go with either of the two latter choices, we are looking at significant costs to replace our current network equipment with switches that can support VoIP phones. What would you suggest?
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While you can certainly go with the power-supply option, that will incur additional expense per phone and give you yet one more thing to troubleshoot when there is a problem. This also means that you will have one more thing to plug into a wall at desks that may already have more things plugged in that what they probably should. While this is an option, I would take it as the last option.
As to Cisco proprietary or 802.3af, I would go with 802.3af for several reasons. The first is, at some point, vendors will begin to drop support for the “Cisco proprietary” way of powering phones over the network. By using 802.3af, you may not be locked in to what phones you can use because you went with the non 802.3af power method. While ideally, you will probably want to use the same brand of phones, there may be special purpose such as a conference call phone that may need to come from a different vendor. By using 802.3af, you won’t have to make the change later and possibly at greater expense, when support for the early method is dropped.
Two things to think about on powering the phones that you didn’t ask about. You don’t have to replace your existing switches to power the VoIP phones. There are several vendors that supply inline power devices that go in your wiring closets that sit between the network switch and the end wall jack to supply power over the network wiring. While this is an option, I would still recommend looking at going to a switch that natively supplies power over Ethernet to the phones. If you dont already have UPSes in your wiring closets, you will want to look at that now while you are making these changes. When you lose power to a wiring closet, you will automatically lose the phones at the same time when Power over Ethernet (PoE) is involved. The longer runtime you can buy in a UPS, the longer you can keep the phones running until power is restored to the closet. If your phone vendor cant help you size a UPS correctly for your wiring closets to deal with VoIP, talk directly to several of the UPS vendors who should be able to help you with this.
Another thing to consider is implementing Quality of Service (QoS). As your use of VoIP grows within the company, having a quality call becomes of paramount importance. This is where QoS comes into play by “reserving” for lack of a better word a certain amount of bandwidth when a VoIP call is going on so that packets dont get dropped or other latency issues dont cause a phone call to sound like you are talking to Donald Duck or are getting every other word and are having to “fill in” the blanks to get an idea of what one or both parties were saying.
It sounds like you still have some planning to do. Doing a little more research now can save you some headaches and regrets later when it could cost a lot more to get things working the way they need to be. Once you have made what you think is your final decision, have someone you know and trust who hasn’t been involved in the situation and who understands what you are trying to do look over your plans to see if they can find something that might have been missed before you start implementation.
