Cisco 3911-Keeps Rebooting when connected to POE switch

[divyaramuu]

Hi All,

        Cisco 3911 model ip phones,which when connected to an external adaptor is working properly and getting registered to CUCM and the it has latest firmware version as SIP3951.8-1-4a loaded in it.

But when the same is connected with the  POE switch it is continuously rebooting.After downgrading the firmware version for the specific 3911 model to SIP3951.8-1-2SR1,when the same is connected to POE switch then the ip phone is properly booting and working as well as registered to CUCM as well.The Call Manager version is 9.1.2.12900-11.

          Is there some caveats with regards to SIP3951.8-1-4a,if it is then how the same is booting and working properly when connected to external adaptor.Pl suggest.

            Response appreciated

Thanks

[Aman Soi]

Hi,

there does not seem to be any bug related to POE issue on 3911 phones.

these phones are  IEEE 802.3af and use Class 2 (7W).

can u run the command show power inline and show power inline on the ethernet port on which 3911 is connected and share the output?

regds,

aman

[divyaramuu]

Hi Aman,

        Thanks for the response,we have already tried the above possibility and the POE switch is giving sufficient power to the phone and there are enough power(in watts) remaining as well.

Checked the configuration of the switch with respect to that port.All the other phone model is working properly except for 3911.Did a soft reset as well.

Then tried to load the firmware load in Phone configuration>Phone Load Name  in order to check whether this is leading to proper registration with CUCM but then also the phone is going up and down.

 Tried in different Ethernet ports as well so that to confirm the I/O port is not having any problem.

Thanks

[Aman Soi]

I think u have tried almost every troubleshooting step.

You can open a case and take their help or if somebody has faced this issue can share inputs.

regds,

aman