IP Phone 8861 with Expansion Module keep disconnecting and Reseting .

[Hk15]

Hi , 

I'd like to know if there's anyone who can help or have seen this in the past.

8861 phones with expansion still disconnecting and cannot boot  since  the parameter " Power Negotiation "  disabled on the phone.

if the parameter is enabled , the expansion cannot turn on .

all the phones impacted are running on the same switch 

cucm 10.5.2 

Firmware sip88xx.12-5-1SR2-2

many thanks for your help 

[Mike_Brezicky]

Do you know how much PoE is being allocated form the switch? If its not sufficient, you may need an external power brick to supplement.

[Hk15]

Hi Mike,

i can see the AdminPwerMax and AdminConsumtipn is 15.4 W on the switch int : 

Available:3537(w) Used:1006(w) Remaining:2531(w)

Interface Admin Oper Power(Watts) Device Class
From PS To Device
--------- ------ ---------- ---------- ---------- ------------------- -----

Fa2/20 auto on 15.9 14.2 IP Phone 8861 4

Interface AdminPowerMax AdminConsumption
(Watts) (Watts)
---------- --------------- --------------------

Fa2/20 15.4 15.4

I do not know exactly what the requirements are for a Cisco 8861 + 1 expansion module . where I found that the expansion alone needs 5 w

[Mike_Brezicky · Accepted solution]

Check out the datasheet for KEM.
https://www.cisco.com/c/en/us/products/collateral/collaboration-endpoints/ip-phone-8851-8861-key-expansion-module/datasheet-c78-739846.html

8861 + KEM x 1 - compatible with 802.3at PoE or Power Brick. If your switch is delivering 15.4 watts, then its only sending 802.3af which is not compatible. If you can increase the max power to 25.5 or 30, it should be fully functional.

[Hk15]

Thank you very much,

we are using a WS-X45-SUP7 line-card wich support only RJ-45 PoE IEEE 802.3af and Cisco prestandard .

i am not sure that we can increase the max power with this type of line-card.

for the moment, a colleague is forcing the "AdminConsumption" directly on the int to 14.2 and it works but I doubt very much that it's not the best practice and i ignor the impact that this workaround can cause .