F5F Stay Refreshed Power Users Networks Discussing PoE switches and PD queries.

Discussing PoE switches and PD queries.

Discussing PoE switches and PD queries.

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Mister_Token
Member
202
02-01-2016, 08:09 AM
#1
I'm evaluating the setup of IP cameras and decided PoE would be a practical choice for powering them. However, I haven't directly worked with PoE equipment before, so I've been researching extensively and feel confident about my approach. My main concern is replacing a 4-port gbit switch with an 8-port switch that supports PoE+ and non-PoE, to prevent extra complexity and unnecessary chaining. From what I've learned, PoE is delivered through various configurations depending on the connection type. Typically, gbit switches provide power to all pairs, but the cameras I'm considering are 100Mbps PDs that only require two pairs for PoE. While 802.3af and 802.3at compliant devices can negotiate power needs, I'm unsure if the switch and PD will also coordinate power delivery. So, can a gbit switch that normally supplies power to all pairs still function for just two pairs as the PD expects? Please advise if this seems like a reasonable assumption. I appreciate any guidance you can offer. Thank you ahead of time.
M
Mister_Token
02-01-2016, 08:09 AM #1

I'm evaluating the setup of IP cameras and decided PoE would be a practical choice for powering them. However, I haven't directly worked with PoE equipment before, so I've been researching extensively and feel confident about my approach. My main concern is replacing a 4-port gbit switch with an 8-port switch that supports PoE+ and non-PoE, to prevent extra complexity and unnecessary chaining. From what I've learned, PoE is delivered through various configurations depending on the connection type. Typically, gbit switches provide power to all pairs, but the cameras I'm considering are 100Mbps PDs that only require two pairs for PoE. While 802.3af and 802.3at compliant devices can negotiate power needs, I'm unsure if the switch and PD will also coordinate power delivery. So, can a gbit switch that normally supplies power to all pairs still function for just two pairs as the PD expects? Please advise if this seems like a reasonable assumption. I appreciate any guidance you can offer. Thank you ahead of time.

T
TheCryzzHD
Junior Member
44
02-01-2016, 05:01 PM
#2
Which switch are you checking for? If it's passive PoE, it won't engage in negotiation at all, but with active PoE it should properly negotiate provided it's correctly implemented.
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TheCryzzHD
02-01-2016, 05:01 PM #2

Which switch are you checking for? If it's passive PoE, it won't engage in negotiation at all, but with active PoE it should properly negotiate provided it's correctly implemented.

F
Fjellberg
Junior Member
15
02-01-2016, 11:53 PM
#3
It's a Linksys LGS108P I've been checking out since it looked like a solid option for my needs. I already have a 4-port switch that can be reconfigured to use the non-PoE ports on this device. Right now I only require two PoE ports, but it's possible I'll need more IP cameras later. That's why I chose a switch instead of injectors.
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Fjellberg
02-01-2016, 11:53 PM #3

It's a Linksys LGS108P I've been checking out since it looked like a solid option for my needs. I already have a 4-port switch that can be reconfigured to use the non-PoE ports on this device. Right now I only require two PoE ports, but it's possible I'll need more IP cameras later. That's why I chose a switch instead of injectors.

T
TabZitha
Junior Member
4
02-06-2016, 04:31 AM
#4
The product page indicates backward compatibility between PoE+ and PoE, suggesting automatic power negotiation works correctly.
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TabZitha
02-06-2016, 04:31 AM #4

The product page indicates backward compatibility between PoE+ and PoE, suggesting automatic power negotiation works correctly.