Re: Link Status encodings
Pat,
I agree. Pulse is a brand new ordered-set and I will propose it as well
as all of Link Status reporting and initialization for 10GFC use at the
next T11 meeting in Austin the week of 12/4. Using the singaling in
Pulse as a replacement for that in Sequence for Fibre Channel is a good
idea.
I don't see a problem with sharing the code space between 10GFC and
10GE. A 24-bit code space is available and both FC and 10GE together
would share but a few and use but a small handful in totality.
I haven't heard a better name than Pulse yet so I'll stick with it.
"Phy" and "Link" are completely non descriptive. "Link Status" describes
a particular application and would be too restrictive. I see a strong
possibility of using the Pulse ordered-set signaling to replace that of
the 10GFC Sequence ordered-set. In that case, Pulse goes away and we end
up with Sequence. How does this sound?
Best Regards,
Rich
--
pat_thaler@xxxxxxxxxxx wrote:
>
> Rich,
>
> There are fairly few control codes available in the 10B space. Before we
> decide to burn another one for ordered sets, I would like to see Fibre
> Channel figure out whether they can use the "Pulse" style insertion in place
> of the sequence ordered sets. As I said at the meeting, it is not obvious
> that the sequence insertion that you have proposed to Fibre Channel yields
> acceptable EMI spectrum. We could divide the code space of the pulse ordered
> sets between Ethernet and FC usage. For instance, we could give half the
> values of the first data byte to each.
>
> Also, I agree with Birdy that the name Pulse Ordered-Set does not denote its
> operation and is confusing because of the normal physical meaning of pulse.
> Other possible candidates:
>
> Phy Ordered Set
> Link Ordered Set
>
> Pat
>
> -----Original Message-----
> From: Rich Taborek [mailto:rtaborek@xxxxxxxxxxxxx]
> Sent: Friday, November 17, 2000 11:42 AM
> To: HSSG
> Subject: Re: Link Status encodings
>
> Birdy,
>
> I called the Ordered-Set Pulse instead of Link Status because Link
> Status represents only the two messages defined for transport, namely
> Local Fault and Remote Fault. A third message Break Link, is proposed
> but not accepted. It is not a Link Status, but rather a Link Request. In
> the future 10GE may have a use for Pulse Ordered-Sets for some reason
> perhaps having nothing to go with Link Status. I wanted to chose a
> generic name to prevent a potential future naming conflict.
>
> As far a running disparity goes, I see a potential desire for 10GE
> implementations to replace an ||R|| with a ||P|| at the 10b level. This
> would not be possible if I chose a non-neutral disparity special
> code-group for the /K/ of ||P||. All data code-groups associated with
> ||P|| would need to observe the same rules. However, we're quickly using
> up the 12 special code-groups and the /D/ codes are much easier to
> change down the line if required. Yes, it's half-baked, but it provides
> flexibility and affects nothing. You are 100% correct none of this
> discussion is applicable to ||P|| inserted at the 8b level.
>
> In November a liaison letter was forwarded from the chair of NCITS T11
> to the chair of IEEE P802.3ae requesting cooperation between 10GFC and
> P802.3ae efforts. One of the proposals I will be making to P802.3ae is
> the reservation of certain codes for 10GFC usage. This applies to the
> 10GFC Signal and Sequence Ordered-Sets.
>
> Best Regards,
> Rich
>
> --
>
> "Bharadwaj S. Amrutur" wrote:
> >
> > Rich,
> >
> > Pulse ordered sets - is semantically extremely confusing.
> > I would prefer the simpler LS : Link status
> >
> > You mention a desire to keep the running disparity of the D octets
> > in the K/D/D/D 0. If we make sure that the LS code is inserted
> > prior to XAUI encoding and deleted after XAUI decoding,
> > running disparity shouldn't be a problem, right?
> >
> > You also mention a new ordered set K28.6/D/D/D and its translation into
> > 0x0101 for 64/66. Was this proposed in the November plenary?
> >
> > regards
> > Birdy
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