Getting 7931 to power up with NM-ESW-16

hcgov · ‎03-24-2008

I am running CME v4.x on a 2821 with an NM-ESW-16. I plug a 7931 phone into one of the switch ports. The 7931 does not power up. I have shut and no shut the port and tried all other ports. I can get a 7941 to power up. Does anyone have any idea if the 7931 can be powered from the NM-ESW-16?

paolo bevilacqua · ‎03-24-2008

It should, matter is, that's not the first time similar problems are heard. What exact IOS do you have on the 2821 ? and which exact FW on the 7931 ?

hcgov · ‎05-02-2008

I am not sure what the FW for the phone is. The IOS version is 12.4(15)T3.

paolo bevilacqua · ‎05-02-2008

Can you try:

power inline delay shutdown 20 initial 300

under interface configuration.

Hope this helps, please rate post if it does!

Rob Huffman · ‎03-24-2008

Hi Tun,

I think that you have discovered the porblem here. The 7931 is a Class 3 PoE Device (requires 15.4W);

IEEE 802.3af PoE

Can receive power from IEEE 802.3af-compliant data switches (Class III)

http://www.cisco.com/en/US/prod/collateral/voicesw/ps6788/phones/ps379/ps7062/product_data_sheet0900aecd80534259.html

From everything I can find out about the NM-ESW-16 is that it only supplies Cisco Pre-Standard PoE for Class 2 Devices like the 7941 (7W)

Hope this helps!

Rob