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  1. #1

    TL-SG1016PE support for 802.3af?

    Model :

    Hardware Version :

    Firmware Version :

    ISP : [/COLOR]

    I am testing out this switch and have a question about the specifications on the web site vs. the specifications in the manual.

    In the manual that came with the switch, it indicates several 802.3x specifications were valid across multiple switches, but it calls out 802.3 af and 802.3 at specifically for TL-SG1016PE.

    Online, it only references 802.3 at compliant.

    Is there a discrepancy between the manual and online?

    Is this configurable?

    I am trying to use this switch with Ubiquiti AP Lite Access Points which are only 802.3 af compliant. Based on my tests, it appears the switch only supports 802.3.

  2. #2
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    Since 802.3at is an extension of 802.3af, the TL-SG1016PE supports both, 802.3at (PoE+) and 802.3af (PoE) as does any other 802.3at switch. There is no 802.3 (without af or at) PoE standard. 802.3 is the name of the IEEE standardization group defining all those related standards.

  3. #3
    OK, thanks for the clarification. If this switch does support 802.3 af, can you provide any other insights as to why the access points are not powered? I have set the ports to auto, as well as the 4 preset options.

  4. #4
    Members R1D2 is on a distinguished road
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    Quote Originally Posted by tbuzzell View Post
    OK, thanks for the clarification. If this switch does support 802.3 af, can you provide any other insights as to why the access points are not powered? I have set the ports to auto, as well as the 4 preset options.
    Could be an incompatibility of the devices in regard to the IEEE 802.3af sub-standards: mode A and mode B.

    First, read this about modes A/B: http://duncansonline.ca/FAQs/WhatisPoEModeAModeB.htm

    As written in the document, PDs (powered devices) must accept both modes, be it A or B, while PSEs (power source equipments) are standard-compliant if they implement either mode A or mode B. If all vendors would obey this standard rule, there will be no problems.

    But: when looking at the data sheet of UBNT AP AC Lite (are this your APs?) they use either passive PoE (24v, not standardized) or (quote) "IEEE 802.3af/A".

    I guess with 'A' they mean mode A. If my guess is correct, the UBNT AP AC Lite supports only 802.3af substandard mode A (or even only cabling alternative A). Although this violates the standard insofar as their PDs don't accept mode B, vendors are free to do so. As for the alternatives (regarding cabling) there is no way to provide compatibility between cabling alternative A or alternative B. Unfortunately, this can lead to much confusion if choosing the right devices.

    It seems that their UAP-AC PRO and UAP-AC EDU model variants indeed support both modes A and B if I interpret their data sheet correctly:

    See https://dl.ubnt.com/datasheets/unifi..._AC_APs_DS.pdf

    I guess if they mean cabling alternatives, all device would have an /A or /B appended, so my guess is they mean mode A. To make sure about this, please ask in the UBNT forum - I'm not used to their devices except for some of their passive PoE routers.

    I recommend to either stick with the same vendor for the APs and PSEs or to just test their inter-operability. If they don't play together, you might find out what causes the incompatibility and RMA this device and try another one.
    Last edited by R1D2; 12-12-2017 at 23:14.


 

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