S12700 css-port

Hello everyone,

Why is there a (B) opposite ports css-port1/1 and css-port2/2?

<S12700>display css css-port all

B     : broadcast

*down : administratively down

(e)   : Error down

Logic Port          Num  Phy Port                      Status

(B)css-port1/1      1    100GE1/1/0/23                 up

   css-port1/2      1    100GE1/2/0/23                 up

Logic Port          Num  Phy Port                      Status

   css-port2/1      1    100GE2/1/0/23                 up

(B)css-port2/2      1    100GE2/2/0/23                 up

Please help me! Thank you!