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Author Topic: Question about POE  (Read 2520 times)

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Offline subnet11

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Question about POE
« on: May 31, 2013, 11:05:16 PM »
Hello All,

Long time....It has been almost 8 months after our implementation and everything works excellent. I have a small question :
We have one location where we have a avaya ers 5520 switch configured. There are 44 phones and the pc are connected to the phone.  Right now we have a issue that some phones automatically restarts and after that it doesn't comes up again. The only thing we can do is to remove the cable from the jackbox and connect it again, then it works again. We get is at random times during the day.

What could it possible be ?

Offline Flintstone

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Re: Question about POE
« Reply #1 on: June 01, 2013, 05:43:59 AM »
Hi subnet11,

Try setting the maximum wattage on the port in case the IP phone is not drawing enough power.  If you haven't already done so?


Offline cacids

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Re: Question about POE
« Reply #2 on: June 02, 2013, 09:39:27 PM »
I experience similar issue recently and found that it was due to Avaya Energy Saver [AES]. The AES configuration was enable on certain ports which I had to exempt.

Offline Johan Witters

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Re: Question about POE
« Reply #3 on: June 03, 2013, 10:33:46 AM »
You might also want to check the firmware of the phones.. Or try to connect a phone to a power injector for a while..

As a system integrator we also install PBX's and phones, and I've had my share of misery with buggy software on the phones cutting off pc's, rebooting, crashing, etc...
Kind regards,

Johan Witters

Network Engineer

Offline tbigby

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Re: Question about POE
« Reply #4 on: June 03, 2013, 05:55:04 PM »
Also you might be over-driving the 5520 for total POE power. You can only provide up to 320W of power across all phones- since you have 44 phones, that leaves only 7.2W available for each phone.

If the phones that you are using take more power than that, you will start having this sort of problem.

Have a look in EDM at the Power Management - POE tab and see how much power each phone uses.

I think that if you use the redundant power supply module, you can get more total power available than 320W- it would be worth checking that out. Otherwise you would need a second switch or another POE injector to run some of the phones.
Tony Bigby

Offline Michael McNamara

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Re: Question about POE
« Reply #5 on: June 04, 2013, 09:08:35 AM »
I would start with basic troubleshooting... is the IP phone making a DHCP request? Is it getting a DHCP IP address? If so what other traffic is the IP phone sending (packet trace required).

Additional questions...

- What model IP phone?
- What software release is on the switch?
- Are you using ADAC/LLDP-MED or just statically configuring the IP phones?
- What software/firmware are you using on the IP phones?

Good Luck!
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