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Forum Discussion
mcsweeney
Jul 07, 2019Aspirant
GS108PEv3 PoE Mode A capability ?
Hi, we are contemplating buying some GS108PEv3 switches, or the bigger-port equivalents for our building. We have a number of IP security cameras which are PoE powered. However, many of these are usi...
- Jul 11, 2019
I just got a feedback from the higher tier of NETGEAR Support. The NETGEAR 802.3af/at PoE switches supports ALT-A mode (Ethernet 1,2,3,6 pair) and will deliver power to PD’s (power devices), that should cover 10/100Mbps devices like the the IP camera you have mentioned. If only using 2 pair cable, the you must make sure that the PD supports ALT-A and must use CAT5 for 10/100M, or CAT5E for 1000M (4pair).
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schumaku
Jul 08, 2019Guru - Experienced User
Please not that a connection with just to pairs can only reach a max link rate of Fast Ethernet (100 Mbit/s). With Gigabit Ethernet, there are no spare pairs, all foir pairs (eight strands) are used for communication.
We have done some tests in the past with various Netgear PoO and PoE+ switches (like GS510TP, GC110PP, GC510PP, ...) and found e.g. an Arlo Q Plus connected by a patch cable with just the (right) two pairs is powered and an Ethernet link is established to working camera conditions.
In my opinion, a standards compliant PoE(+) switch can negotiate power requirements and operate both Mode A and Mode B PDs.
mcsweeney
Jul 08, 2019Aspirant
Hi, thanks for the reply. I was aware with this configuration I would only get 100MBPS but I think that's ample for our cameras.
I suppose the next question is, is this switch (GS108PEv3) PoE+ (both 803.11at + af compliant), as it is simply described as PoE.
I'd imagine this configuration I am suggesting, though technically compliant with the standard may be rarely enough used to have had its support dropped.
- schumakuJul 09, 2019Guru - Experienced User
Any standards compliant 802.3af or 802.3at PSE (endspan [integrated with the PoE switch] or mid-span [PoE injector]) must be able to detect, power and work PDs with alternative A or alternative B versions. The power alternate to be used is defined by 25kOhm resistors on the PD side.
PS. The IEEE standards talk of alternative A and B, not mode A and B.
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