[802.3ae] ask some question

[??? <tsaiws@xxxxxxxxxxx>]

1.10GBASE-R support a BER objective of 10E-12.

   Does the BER calculation accmplish by "BER monitor" of PCS,

   and how does it work to support a ber of "10E-12"?

2.(1)In the 802.3ae spec.(Draft3.0 March 2001), I have some problems 
with the figure 49-13.

   when  ber_cnt exceeds "16" , it indicates a bit error rate>10E-4, why...?

   this parameter "16" is how to choose?

  (2) the 125us_timer is how to choose?



3. (1)In the 802.3ae spec.(Draft3.0 March 2001), I have some problems 
with the figure 49-12.

   sh_cnt: count the number of sync headers checked within the current 
"64" block window,

   the parameter "64" is how to choose?

  (2)test_sh: boolean value which is set true when a new sync header is 
available for testing and

      false when TESH_SH state is entered.

     a.  how does it know that the two bits are sync header? does it use 
the first two bits of each

          of the 64 block(66bits) window as sync header, right?

     b. if test_sh is false, then do what..?

   (3)It makes me confuse, after "VALID_SH(sh_cnt++)" state, if the 
condition is

        "sh_cnt=64 and sh_invaild_cnt>0), then jump to "RESET_CNT" state.

        what is sh_invaild_cnt, I mean in VALID_SH state , "sh_vaild is 
true", so what does

        sh_invaild_cnt mean?

   (4) why the lock state macnine is always running, it always jump to 
"RESET_CNT" state finally?