RE: [10GBASE-T] PAR and 5 critters
George:
I have gone thru' these presentations. I do not see any of these
presentations verifying your claims on:
1. Receiver ANEXT mitigation techniques,
2. MIMO somehow collapsing the DSP complexity (a claim Solarflare made
during Nov 2002 IEEE meeting).
You claim that above techniques are essential to the feasibility of 10G over
CAT-5e, but you never provided any MATLAB models to the group to verify. In
addition, you said in November 2002 that 10G was feasible over 100 meters of
CAT-5e. Due to careful mathematical analysis done by Vativ (and made
available to the group MATLAB models to verify) and other companies over
past 9 months, majority in the group are now convinced that your claim is
false.
I believe that you must adhere to due scientific process to support your
claims.
Sreen
-----Original Message-----
From: George Zimmerman [mailto:gzimmerman@solarflare.com]
Sent: Tuesday, July 29, 2003 5:52 PM
To: sreen@vativ.com; DOVE,DANIEL J (HP-Roseville,ex1); Alan Flatman;
Kardontchik, Jaime
Cc: [unknown]; Sterling Vaden
Subject: RE: [10GBASE-T] PAR and 5 critters
Presentations are given by individuals, not companies, but you can find
them on the 10GBASE-T study group site. Among those of note are a
January presentation from Stephen Bates, up to one just in July by Shadi
AbuGhazaleh & Rehan Mahmood (there are more on mitigation and on
feasibility studies, Ron Nordin & Vanderlaan, Albert Vareljian, Bijit
Halder all come to mind).
There really isn't any mystery here - going to shorter distances
increases the received signal proportionally, and mitigating alien NEXT
decreases the noise, hence, more capacity. What is more, because the
crossover point (signal/noise=1) occurs at a higher frequency, only
increasing the capacity further.
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 4:24 PM
> To: George Zimmerman; sreen@vativ.com; 'DOVE,DANIEL J
(HP-Roseville,ex1)';
> 'Alan Flatman'; 'Kardontchik, Jaime'
> Cc: '[unknown]'; 'Sterling Vaden'
> Subject: RE: [10GBASE-T] PAR and 5 critters
>
> George,
>
> Please indicate which company's presentation has independently
confirmed
> your claims, and where I can find such a presentation.
>
> -----Original Message-----
> From: George Zimmerman [mailto:gzimmerman@solarflare.com]
> Sent: Tuesday, July 29, 2003 3:16 PM
> To: sreen@vativ.com; DOVE,DANIEL J (HP-Roseville,ex1); Alan Flatman;
> Kardontchik, Jaime
> Cc: [unknown]; Sterling Vaden
> 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
> > >
> > >
> > >
> > >
> > >
> >
> >
>
>