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Power drawn on CISCO AP : AIR-AP1832I-D-K9

Dear Team,

 

Kindly help to understand the practical power drawn on CISCO AP : AIR-AP1832I-D-K9 when connected to a Huawei POE switch : S2700-9TP-PWR-EI.

As per datasheet it takes 15.4 however APs are getting mid power at WLC end.

 

Are these compatible to each other ?

2 REPLIES 2
Rising star

Re: Power drawn on CISCO AP : AIR-AP1832I-D-K9

what do you mean by "however APs are getting mid power at WLC end"?

the WLC does not supply power to the devices!, it only reports information retrieved from the AP.

The AP wants to negotiate PoE with the connected switch using CDP protocol.

as CDP is a Cisco proprietary protocol, the Huawei switch will NOT negotiate PoE with the AP using CDP,

and as a result, supply a default value.

 

maybe you can enable LLDP on the Huawei switch?

then negotiation uccurs using LLDP instead CDP.

PoE Negotiation

When the AP negotiates 802.3at (high power), it always tries first to negotiate using Cisco Discovery Protocol (CDP). If the negotiation fails, the AP will attempt to negotiate using Link Layer Discovery Protocol (LLDP). LLDP is a vendor-neutral method for advertising device identity and capabilities.

So, the AP 1850 first uses CDP to get 20.9 W and reserve that amount of power. If CDP fails, the same process starts using LLDP. So, a non CDP response time out (often approaching 60 seconds) would need to occur before the LLDP negotiation starts. In both cases, the requirement is obtain 20.9 W power.

If the AP has enough power, it shows Full Power in the PoE settings. See Figure 1.

 

Note: If the power source does not support Cisco Discovery Protocol, for example third party switch, then uncheck its usage.

To avoid waiting for timeouts from CDP protocol

Hall of Fame Community Legend

Re: Power drawn on CISCO AP : AIR-AP1832I-D-K9

The Data Sheet is very misleading.
There are two ways to power up the AP: PoE (15.4w) or PoE+ (between 20.0w to 30.0w).
If the power option is PoE then the USB port is disabled.
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