topic Re: C9120AXI AP POE Power in Wireless

C9120AXI AP POE Power

viraj patil — Fri, 28 Jul 2023 10:40:17 GMT

Hello Team,

We have connected C9120AXI access points to WS-C2960X-24PS-L switch. It is consuming 30 Watts of power. Is there any way to reduce the function of AP so that it can consume power less than 30 Watts?

Below is the output for Show Power Inline

Gi1/0/37 auto on 30.0 C9120AXI-H 4 30.0
Gi1/0/38 auto off 0.0 n/a n/a 30.0
Gi1/0/39 auto on 30.0 C9120AXI-H 4 30.0
Gi1/0/40 auto off 0.0 n/a n/a 30.0
Gi1/0/41 auto on 30.0 C9120AXI-H 4 30.0

Re: C9120AXI AP POE Power

Flavio Miranda — Fri, 28 Jul 2023 10:49:59 GMT

Hi @viraj patil

Theorically it can work with 13.4W however, the wireless speed need to be reduced drastically. I dont believe it is a good idea considering the cost for an AP like that.

It would be more appropriate to buy a simple AP with limited speed which will cost much less.

Catalyst 9120AXI, 9120AXE, 9120AXP

PoE power consumption

2.4-GHz radio

5-GHz radio

Link speed

USB

LLDP

802.3af

PoE

1x1

13.4W

802.3af

PoE

2x2

13.4W

802.3af

PoE

2x2

13.4W

Re: C9120AXI AP POE Power

Leo Laohoo — Fri, 28 Jul 2023 13:35:08 GMT

Disable the USB port.

Re: C9120AXI AP POE Power

Rich R — Fri, 28 Jul 2023 13:48:30 GMT

Do you want to reduce the actual power consumption of the AP or the power it reserves from the switch? (hint they are not the same). Reducing the actual power consumption will not reduce the power it reserves from the switch unless you get it to switch to 802.3af like Flavio mentioned and you could do that by simply disabling CDP and LLDP on the port. Without CDP/LLDP it will default to 15.4W (not the 13.4W it consumes as per the datasheet Flavio quoted).

I have a long-running, unresolved argument with the wireless BU over this - the fact that the APs reserve 30W power regardless of what they're actually using, which is usually significantly less. Of course this impacts the power budget on the POE switch. They seem to be weak of mind when it comes to understanding the basic principles of this - I get the impression they have never had to run a network and plan power budgets across a large deployment.

Re: C9120AXI AP POE Power

viraj patil — Wed, 30 Aug 2023 13:19:22 GMT

Yes, I disabled the USB port and now It's consuming power of 23.2 Watts. So, It worked for me.

Re: C9120AXI AP POE Power

viraj patil — Wed, 30 Aug 2023 13:21:05 GMT

I disabled the CDP, LLDP Port and now it is started consuming the power of 23.2 Watts. It worked for me.