RE: [802.3ae_Serial] Support for 10GFC
Rich,
K28.4 is a "sequence" for the FC as well? The behavior of the Tx PCS layer
is identical to the behavior of the PCS layer in 10GE so far?
Thx.,
Boaz
> -----Original Message-----
> From: Rich Taborek [mailto:rtaborek@xxxxxxxxxxxxx]
> Sent: Thursday, December 20, 2001 4:59 AM
> To: THALER,PAT (A-Roseville,ex1); Vipul Bhatt; 802. 3ae
> Serial PMD (E-mail); Tom Lindsay; Craig Stuber; Bob Snively
> Subject: Re: [802.3ae_Serial] Support for 10GFC
>
>
>
> Pat, Vipul,
>
> On the protocol side of the issues presented here, 10 Gigabit Fibre
> Channel uses the special characters K28.2 and K28.4 through the XGMII,
> 8B/10B PCS and 64B/66B PCS. 10GFC does not use K28.6.
>
> We're still working the link budget issue but the direction of comment
> resolution thus far has been to reduce 10GFC PMD supported distances
> where link budget unallocated margin is not available. Since the
> difference is 2% between 10GFC and 10GE I believe that this solution
> will be acceptable to FC customers. One has to consider the 10G
> convergence where SONET OC-192, 10GE, 10GFC and FEC versions yield
> operating rates of 9.952 Gb/s though 12.5 Gb/s for serial and
> 2.488 Gb/s
> through 3.9 Gb/s for 4 lane (also includes InfiniBand). The 2% 10GFC
> variation from 10GE literally gets lost in the noise.
>
> Happy Holidays,
> Rich
>
> --
>
> "THALER,PAT (A-Roseville,ex1)" wrote:
> >
> > Vipul and Tom,
> >
> > The 10GFC draft says in an editor's note at the start of
> the specs for the
> > PMDs they have borrowed from Ethernet:
> > The 10GFC project intends to compensate for the higher
> speed by making
> > compensating adjustments in specifications relating to
> cable length and
> > optical link budgets.
> >
> > They are aware of the issue and have decided to deal with
> it by adjusting
> > the link rather than the transceiver.
> >
> > If you look at the specs for XGXS and PCS in 802.3ae, they
> actually do
> > include requirements to properly handle the reserved codes
> of K28.2 and
> > K28.6 (see Tables 48-2, 48-3, and 49-1). There was a brief
> period when one
> > of the tables in 48 indicated otherwise, but I submitted a
> comment to
> > correct that which was accepted. The physical layer
> components defined in
> > 802.3ae will handle the FC encodings. However, I think your
> statement is
> > partially incorrect as K28.6 is listed as reserved in the
> 10GFC draft. I
> > believe that K28.2 is the only code additional that 10GFC uses.
> >
> > I am in the process of reviewing the specs in 10GFC to see
> if there are any
> > deviations that would interfere with using the same
> transceiver or XGXS for
> > both standards. I encourage others to do the same.
> >
> > Regards,
> > Pat
> >
> > -----Original Message-----
> > From: Vipul Bhatt [mailto:vipul.bhatt@xxxxxxxxxxx]
> > Sent: Tuesday, December 18, 2001 10:06 AM
> > To: 802. 3ae Serial PMD (E-mail)
> > Subject: RE: [802.3ae_Serial] Support for 10GFC
> >
> > Tom,
> >
> > Good idea. From the standpoint of return on development efforts,
> > 10GFC is a low hanging fruit. The increase in power budget is
> > relatively small.
> >
> > I hope the designers of XGXS and PCS will do a similar exercise. My
> > (unreliable) recollection is that apart from the increased 2% speed,
> > the only thing a designer has to make sure is that K28.2 and K28.6
> > are supported. Support for these two characters is required in
> > 10GFC, but not in 802.3ae.
> >
> > Regards,
> > Vipul
> >
> > =================
> >
> > -----Original Message-----
> > From: owner-stds-802-3-hssg-serialpmd@xxxxxxxxxxxxxxxxxx
> > [mailto:owner-stds-802-3-hssg-serialpmd@xxxxxxxxxxxxxxxxxx]On Behalf
> > Of Lindsay, Tom
> > Sent: Monday, December 17, 2001 4:01 PM
> > To: 802. 3ae Serial PMD (E-mail)
> > Subject: [802.3ae_Serial] Support for 10GFC
> >
> > Folks - 10G Fibre channel intends to use 10G Ethernet PMDs but for a
> > rate that is 2% faster. For serial, this would mean 10.51875 Gbd;
> > for LX4, this would mean 3.1875 Gbd per lane.
> >
> > As a modeling approximation, I modified cell C4 in
> > 10GEPBud3_1_16a.xls to the FC rates. Margins stay positive for
> > all -S variants, but go negative for:
> > -0.05 dB for 1310 serial
> > -0.21 dB for LX4
> >
> > Possibly any of these are within spreadsheet margin for error, but
> > is there willingness to increase the power budget to drive these
> > margins back positive?
> >
> > Tom
> > Stratos NW
> > 425/672-8035 x105
>
> ---------------------------------------------------------
> Richard Taborek Sr. Intel Corporation
> XAUI Sherpa Intel Communications Group
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