Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Remote Faults in RS




Hello everyone,
   I would like some clarification regarding the format of remote faults
that are generated during transmission in the reconciliation sublayer and
presented to the 64b/66b 10GBase-R PCS.

Referring to an excerpt from a previous IEEE reflector discussion by Stephen
Finch on Fri, 29 Dec 2000, he states...
----------------------------------------------------------------------------
---------------
3.  The RS layer is where the Local Fault Pulse Ordered Set is
    processed.  The RS layer is the only place that a Remote
    Fault Pulse Ordered Set can be generated.  If an RS receives
    a Local Fault Pulse Ordered Set it must stop sending packets
    and begin sending alternating columns of Idles and Remote
    Fault Pulse Ordered Sets.  If an RS receives a Remote Fault
    Pulse Ordered Set, it must stop sending packets and send
    only Idles.

----------------------------------------------------------------------------
---------------

Is the underlined statement still valid?  If a LF is received at the RS, is
it then translated to a RF during TX and flagged by sending a stream of
altermating columns of Idles and Sequence Ordered Sets?

such as,     /I   /Q   /I   /Q   /I
                 /I   /Q   /I   /Q   /I
           	     /I   /Q   /I   /Q   /I
                 /I   /Q   /I   /Q   /I

If this is a correct assumption, for WIS rate control methods, is it correct
that after the minimum IPG, it is only valid to delete Idles and pass on the
Sequence Ordered Sets? 

   The previous question is pertinent only if the above data stream can
occur as a possible input to the TX 64b/66b PCS.  If, instead, a RF triggers
a "relatively long" string of consecutive Sequence Ordered Sets, 

such as,    /Q   /Q  . . . .   /Q   /Q
      	    /Q   /Q  . . . .   /Q   /Q
                /Q   /Q  . . . .   /Q   /Q
                /Q   /Q  . . . .   /Q   /Q

then WIS rate control would be much easier to design for.

I would appreciate any input regarding these detailed matters.

Thanks,
Jennifer Sanati
jennifer.sanati@intel.com