Re: Remote Faults in RS
All,
Apologies if this comment is somewhat "fringe".
There are some application environments in which it would be useful to
keep the TX link "up" even when LF is detected at RS.
This is *non-conforming* and out of scope of 802.3ae. However if silicon
vendors make it possible to disable the normative 46.3.4, etc behavior,
it would be helpful to these applications.
Just FYI.
Cheers,
Chuck Harrison
Far Field Associates, LLC
+1 360 863 8340 (voice) GMT-0700
Sanjeev Mahalawat wrote:
>
> Hi Jennifer,
>
> Your second assumption is correct. Clause 46.3.4 last
> last para bullet "b)" states that link_Fault = Local Fault then
> RS shall continously generate Remote Fault Sequence ordered_sets.
>
> And then in Clause 49.2.4.10 the last para allows Sequence
> ordered sets to be deleted but only if PCS receives 2 consecutive
> Sequence ordered sets. Now, since RS is sending continously
> RF Sequence ordered sets the PCS should not have any issue
> getting two consecutive RF Sequence ordered sets and deleting one.
>
> Thanks,
> Sanjeev
>
> At 03:15 PM 06/05/2001 -0700, Sanati, Jennifer wrote:
> >
> >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@xxxxxxxxx
> >