Re: [10GBASE-T] PAR and 5 critters
George:
I strongly beleive what you said and the great potential of 10G over
Cat5e/Cat6 cables. We just need to discover some techniques.
Regards,
Walter Y. Chen
----- Original Message -----
From: "George Zimmerman" <gzimmerman@solarflare.com>
To: <sreen@vativ.com>; "DOVE,DANIEL J (HP-Roseville,ex1)" <dan.dove@hp.com>;
"Alan Flatman" <a_flatman@compuserve.com>; "Kardontchik, Jaime"
<jaime@integration.com>
Cc: "[unknown]" <stds-802-3-10gbt@ieee.org>; "Sterling Vaden"
<sterlingv@bellsouth.net>
Sent: Tuesday, July 29, 2003 3:15 PM
Subject: RE: [10GBASE-T] PAR and 5 critters
>
> Sreen & all -
> I believe some clarification is in order.
>
> What the presentation you reference from Portsmouth, New Hampshire
> showed was that with an assumption of a high-degree of alien NEXT and a
> further assumption that it could not be mitigated in any way, cat5e/cat6
> could not support 100meter operation at 10G. This is a different
> statement altogether as to whether cat5e/6 can support 10G either with
> alien NEXT mitigation, or at shorter reaches, both of which have been
> shown to yield sufficient capacity to allow 10G in numerous
> presentations by multiple vendors.
>
> The consensus proposal presented at San Francisco argued that even
> without alien NEXT mitigation, there was a sufficient portion of the
> installed base of 5e & 6 coverable to merit broad market potential (>60%
> installed base at 50m or less), and that in addition to SolarFlare
> showing both receiver-based (DSP) and installation-practices based alien
> NEXT mitigation examples, other companies have now shown significant
> alien NEXT mitigation through installation practices.
>
> These developments significantly change the capacity relations you refer
> to, making 10GBASE-T practical on the economically feasible installed
> base of cat5e & 6.
>
> On your technical points for implementation, I respectfully disagree,
> and we have put forward our requirements, and these have been confirmed
> by at least one independent presentation.
>
>
> George Zimmerman
> gzimmerman@solarflare.com
> tel: (949) 581-6830 ext. 2500
> cell: (310) 920-3860
>
> > -----Original Message-----
> > From: Sreen Raghavan [mailto:sreen-raghavan@vativ.com]
> > Sent: Tuesday, July 29, 2003 1:58 PM
> > To: 'DOVE,DANIEL J (HP-Roseville,ex1)'; sreen@vativ.com; 'Alan
> Flatman';
> > 'Kardontchik, Jaime'
> > Cc: '[unknown]'; 'Sterling Vaden'
> > Subject: RE: [10GBASE-T] PAR and 5 critters
> >
> >
> > Dan:
> >
> > We are really referring to the theory (Shannon Capacity) when we say
> > 10Gbps
> > cannot be achieved over CAT-5e or CAT-6 cabling. Theory shows that
> 10Gbps
> > can be achieved over CAT-7 cabling. Practical issues to accomplish
> 10Gbps
> > over CAT-7 cabling include (assuming PAM-10 modulation):
> >
> > 1. Building an 11-bit effective ADC at 833 MBaud,
> > 2. Performing large number (x8 relative to 1000BaseT) of DSP
> calculations
> > at
> > 833MHz,
> > 3. DDFSE critical path to be implemented in 1.2 ns
> > 4. Building a linear transmit driver with an 833MGz bandwidth & 40 dB
> SNR
> >
> > The above list by no means is exhaustive, but shows the implementation
> > issues that need to be considered.
> >
> > Sreen
> >
> > -----Original Message-----
> > From: DOVE,DANIEL J (HP-Roseville,ex1) [mailto:dan.dove@hp.com]
> > Sent: Tuesday, July 29, 2003 1:09 PM
> > To: 'sreen@vativ.com'; 'Alan Flatman'; 'Kardontchik, Jaime'
> > Cc: '[unknown]'; 'Sterling Vaden'
> > Subject: RE: [10GBASE-T] PAR and 5 critters
> >
> > Hi Sreen,
> >
> > One thing that occurs to me on this point is the difference between
> > theory and application. Specifically, how many process actions have to
> > take place within a baud time to close the loops on the DSP and what
> > process geometry would be required to make that timing closure?
> >
> > I know that with 1000BASE-T, the theory was rock solid long before the
> > processes to implement it were reliable.
> >
> > Dan
> > HP ProCurve
> >
> > > -----Original Message-----
> > > From: Sreen Raghavan [mailto:sreen-raghavan@vativ.com]
> > > Sent: Tuesday, July 29, 2003 11:52 AM
> > > To: 'Alan Flatman'; 'Kardontchik, Jaime'
> > > Cc: '[unknown]'; 'Sterling Vaden'
> > > Subject: RE: [10GBASE-T] PAR and 5 critters
> > >
> > >
> > >
> > > Just to clarify, Vativ, Broadcom & Marvell presented capacity
> > > calculations
> > > at the Portsmouth meeting and showed that worst-case CAT-7
> > > (Class F) cabling
> > > had sufficient channel capacity to achieve 10Gbps throughput
> > > at 100 meter
> > > distance. The reason for "may be possible" statement in the
> > > conclusions was
> > > that the 3 PHY vendors felt that more work needed to be done
> > > on practical
> > > implementation issues before the conclusion could be altered to a
> more
> > > definitive statement.
> > >
> > > In addition, we proved conclusively that there was NOT
> > > sufficient channel
> > > capacity on existing CAT-5e (Class D), or CAT-6 (Class E)
> > > cables to achieve
> > > 10 Gbps throughput.
> > >
> > > Sreen Raghavan
> > > Vativ Technologies
> > >
> > > -----Original Message-----
> > > From: owner-stds-802-3-10gbt@majordomo.ieee.org
> > > [mailto:owner-stds-802-3-10gbt@majordomo.ieee.org] On Behalf
> > > Of Alan Flatman
> > > Sent: Tuesday, July 29, 2003 9:51 AM
> > > To: Kardontchik, Jaime
> > > Cc: [unknown]; Sterling Vaden
> > > Subject: RE: [10GBASE-T] PAR and 5 critters
> > >
> > >
> > > Message text written by "Kardontchik, Jaime"
> > > >Was any reason given why it would not run on Class F ? Was it for
> > > technical reasons or for marketing reasons ?<
> > >
> > > The 3-PHY vendor presentation made in Portsmouth (sallaway_1_0503)
> > > calculated 49.36 Gbit/s capacity using unscaled Cat 7/Class F
> > > cabling. This
> > > figure was reduced to 37.71 Gbit/s with worst case limits. Overall,
> I
> > > thought that this was a refreshingly realistic presentation and I
> > > interpreted the summary statement "Capacity calculations with
> > > measured data
> > > indicate 10 Gigabit data transmission over 100m Cat 7 may be
> possible"
> > > (slide 16, bullet 3) as overly cautious engineering judgement.
> > >
> > > So, what has changed since the May interim? Not the laws of physics!
> > >
> > > Best regards,
> > >
> > > Alan Flatman
> > > Principal Consultant
> > > LAN Technologies
> > >
> > >
> > >
> > >
> > >
> >
> >
>
>