Cisco AP 2700 with PWRINJ=5 or PWRINJ4 ?

[Nalin Singh]

Dear Team,

I have recently brought cisco 2702I-D series AP along with PWRINJ=5. and this order has been process 2 monhs back. that time i have checked that witch power injector will support to this AP.

today i have checked again 2700 series AP datasheet and there is mentioned PWRINJ=4 . 

My Question is what feature will loose now after this implementation.

Regards,

Nalin 

[Dhiresh Yadav]

Hi,

If it will provide required power ...there should be no functionality loss.

Regards

Dhiresh

[Nalin Singh]

   this Will give us 3x4 MIMO with three Spatial Streams Speed.

[Dhiresh Yadav · Accepted solution]

Hi Nalin,

As I said earlier , it will try to do best with the available power with 15.4 watt source.

"today i have checked again 2700 series AP datasheet and there is mentioned PWRINJ=4,this Will give us 3x4 MIMO with three Spatial Streams Speed."

You have checked it correct.PWRINJ=4 is written in the datasheet because this AP requires , I think 16.x watts for full operation and this INJ4 can provide more than 15.4 as it is 802.3at and if 15.4 watt is provided , there might be loss in the number of spatial SS.

if you are running 7.6  , and you provide 15.4 watt , then definitely there will be reduction in the number of spatial stream from 3 to a lower value , i think 2.

Since 8.0 is improved a lot on that front og power management , So if you are on 8.0 with 2700 powered by 15.4 watt , the there will not be any reduction in the number of spatial streams which  will still be 3.

Speeds/throughput etc depends on N number of factors so that is a separate discussion.

Alternatively you can also use 802.3at compliant switch to provide POE power.

Hope this explains all.

Regards

Dhiresh

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[ngtransge]

Hello,

Did you tested 2700 Aironet with PWRINJ=4  POE injector ? Can it deliver power sufficied for 3x4 MIMO ?

[mohanak]

The Cisco Aironet Power Injector (AIR-PWRINJ5) increases wireless LAN deployment flexibility of Cisco Aironet Access Points by providing an alternative powering option to local power, inline power-capable multiport switches, and multiport power patch panels.

The single-port Cisco Aironet Power Injector provides 802.3af power and data signal, sending both to the Cisco Aironet Access Point.

The power injectors provide up to 15.4 W over the unused wire pairs of a Category 5 or better Ethernet cable, supplying enough power for a distance of 328 ft. (100 m) on the Cisco Aironet 1040, 1140, 1260, 2600, and 3500 Series Access Points. While it can also support the Cisco Aironet Series 3600 Access Points when modules are not being used, it is recommended to use the AIR-PWRINJ4= power injector instead for the 3600 series, as it has sufficient power to supply to the AP and any installed modules.

[Moin Ilyas]

Apply power to the access point:

a. The access point is 802.3af (15.4 W) compliant and can be powered by any 802.3af-compliant device.

The recommended external power supply for the access point is the Cisco AIR-PWR-B power supply. The access point can also be powered by the following optional external power sources:

– Access point power injector (AIR-PWRINJ5)

– Any 802.3af compliant power injector

Source: http://www.cisco.com/c/en/us/td/docs/wireless/access_point/2700/quick/guide/ap2700getstart.html

Hope that helps.