Why 4506E POE Switch cannot use 568a-568b cable to connect to 7911 IPphone?

[greensubmarine2009]

recently my coustomer bought a 4506E switch(SUP6L-E;WS-X4548-RJ45V+;PWR-C45-2800ACV) .when use their old cables(568a-568b),they found that the 7911 phones(no standalone power) displayed :"ethernet not connect",and the switch console (show power inline) said "ieee PD".also cdp found nothing.using 568b-568b cable,they worked well.

But,when i use 3560-48PS-S,and the same cables,the phones worked well.

Why 4506E POE Switch cannot use 568a-568b cable to connect to 7911 IPphone?

[Fabienne Stephanoff]

EIA/TIA 568B (T568B for short) is the most common wiring today.

http://cisco.com/en/US/products/hw/optical/ps2006/products_tech_note09186a008043af97.shtml#topic1

The sup6-E and type of linecard you are using on the 4605E are simply more recent.

Fabienne