Polycom CX Phone reboot issue - Resolved

During Lync Pilot, users complained that the CX600 Lync Phones would completely reboot after being awaken from sleep mode. After engaging Cisco, it was determined that this was an issue with the 3750-X series switches that were in use.

Here are the notes from the Cisco Engineer that assisted with troubleshooting this issue,

"You have class-2 PoE IP telephones that are using approximately 2.6 -

3.0 Watts when in sleep mode.  When resuming operation, the devices

request a power value of 65 via LLDP.  During this transition, the

phones are being reset by the Cisco switch.  Debugging this issue on the

switch we found the following:

014173: May 16 16:21:32.550: ilpower_powerman_request_from_lldp: rx lldp

power class tlv from port GigabitEthernet0/19

014174: May 16 16:21:32.550: Shut down interface (Gi0/19) since

consumption power 6500 is greater than allocation 3000

Power value of 65 allows utilization between 3.84 and 6.49 W.  The

problem isn't that the device is requesting more power than allowed by

the class, rather that it is attempting to use LLDP to request higher

power.  According to the ANSI standard, this type of request requires a

reload of the device.

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http://www.tiaonline.org/standards/technology/voip/documents/ANSI-TIA-10 57_final_for_publication.pdf

10.2.5.4 Power value

The Power Value field shall represent the maximum power consumption of

an Endpoint Device or the minimum power available from a PSE port of a

Network Connectivity Device when the LLDPDU is transmitted. It shall not

be used to indicate instantaneous variations of power required or

offered at the time of transmission of the LLDPDU.

A PD Endpoint Device that requires more power than previously

advertised, due to a hardware reconfiguration, shall not advertise a

higher power value than is currently advertised by the PSE Network

Connectivity Device it is connected to on that port.

If the PD Endpoint Device requires power greater than either the power

value currently advertised by the PSE Network Connectivity Device or the

upper power limit of the corresponding IEEE 802.3af power class, then it

must renegotiate this new power limit by resetting the port (i.e. by

triggering renegotiation of power at the IEEE 802.3af level).

################### "

Therefore, the reboot is expected behavior.  As a workaround to the

issue, the power TLV was disabled from the LLDP field as the Cisco Engineer suggested. 

RESOLVED with Lync Server CU4 (Novemeber) patch!!!