Re: [Fwd: RE: 1000BASE-T PCS question]

[pbottorf@xxxxxxxxxxxxxxxxxx (Paul Bottorff)]

Tom:

OK, I'm out of line. The worst case BER standards for both 8/10 and SONET
fiber are the same.

Paul

At 11:32 AM 5/29/99 -0700, Thomas Dineen wrote:
>GentlePeople:
>
>	Wait just a minute here.
>
>"Infact, the equipment in production is much better than the BellCore
>specification with production error rate as low as 10^-15 making it far
>better than current 8/10 encoding systems."
>
>	I think you have gone to far on this one.
>
>	Normally standards are written with worst case numbers.
>For example a fiber optic physical layer standard may have a specified
>BER of 10E-12 worst case. Now a real instance of that physical layer
>running in the field will exibit a much better BER of say 10E-15.
>
>	I beleive that it is questionable engineering to compare typical
>BER values and conclude that one physical layer protocol is better
>than another.
>
>Thomas Dineen
>
>
>
>-------- Original Message --------
>Subject: RE: 1000BASE-T PCS question
>Date: Thu, 27 May 1999 09:35:02 -0700
>From: pbottorf@xxxxxxxxxxxxxxxxxx (Paul Bottorff)
>To: "Chang, Edward S" <Edward.Chang@xxxxxxxxxx>,Jaime Kardontchik
><kardontchik.jaime@xxxxxxxxxxx>,rtaborek@xxxxxxxxxxxxxxxx
>CC: HSSG_reflector <stds-802-3-hssg@xxxxxxxx>
>
>
>Ed:
>
>Though it is true that BellCore standards written before OC-192 specify
>a
>BER of 10^-10 the OC-192 SONET (~10 Gig) specification is for a BER of
>10^-12. Please refer to:
>
>GR-1377-CORE: SONET OC-192 Transport System Generic Criteria
>Section 4.2.1, page 4-3
>
>"All parameter values specified are worst-case, end-of-life values and
>are to be met over the range of operating conditions described in
>Section 7 of GR-253-CORE, with the exception of the follwoing: the
>parameters are specified relative to an optical system design objective
>of a BER not worse than 1E-12 for the extreme case of optical path
>attenuation and dispersion conditions for each application specified."
>
>Infact, the equipment in production is much better than the BellCore
>specification with production error rate as low as 10^-15 making it far
>better than current 8/10 encoding systems.
>
>Paul
>
>
>At 09:16 AM 5/27/99 -0400, Chang, Edward S wrote:
>>
>>Jami:
>>
>>We have been discussing scramble code versus block code, 8B/10B in
>>particular, for a while on the reflector. Many people have the same feeling
>>that scrambled code has run length much longer than desirable to cause
>>base-line wander, and PLL clock drift; as a result, it can not meet the BER
>>of 10^-12
>>
>>The SONET using scramble code has BER of 10^-10, which is not recommended
>>for the datacom file transfer.  I believe the BER of 1000BASE-T is 10^-10,
>>again, which is not recommended for file transfer.
>>
>>You can prove the BER is 10^-12 for the 4D symbol code to enable it to be
>>used for all purposes, or stay at 10^-10 BER to be used, as 802.3ab, for
>>less critical data handling. 
>>
>>Please clarify.
>>
>>Ed Chang
>>Unisys Corporation
>>Edward.Chang@xxxxxxxxxx
>>      
>>
>>-----Original Message-----
>>From: Jaime Kardontchik [mailto:kardontchik.jaime@xxxxxxxxxxx]
>>Sent: Wednesday, May 26, 1999 9:48 PM
>>To: rtaborek@xxxxxxxxxxxxxxxx
>>Cc: Jaime Kardontchik; HSSG_reflector
>>Subject: Re: 1000BASE-T PCS question
>>
>>
>>
>>Rich,
>>
>>For simplicity, I did not mention nor I did include in the
>>figures that the 4D encoded symbols are randomized before
>>sending them to the transmitters. This procedure is described
>>in the 1000BASE-T standard.
>>
>>The produce assures that the output levels send down the
>>wires (or the fiber) are DC balanced. However, you will not
>>get the nice extremely short running disparity that one could
>>get with the 8b/10b encoder, since the randomization is based
>>on the scrambler. The scrambler used is 33 delays long (much
>>longer than the scrambler used in Fast Ethernet) and it is
>>expected to produce a better short term balance than the one
>>obtained in Fast Ethernet.
>>
>>The clock can be recovered (in the same way as it is recovered in
>>Fast Ethernet). Many simulations were run during the development
>>of the 1000BASE-T standard and presented during its meetings
>>showing that this is the case. There is already a well known
>>company that has 1000BASE-T transceivers on Silicon, and
>>has shown that they work in the last Interop gathering.
>>
>>Jaime
>>
>>Jaime E. Kardontchik
>>Micro Linear
>>San Jose, CA 95131
>>email: kardontchik.jaime@xxxxxxxxxxx
>>
>>
>>
>>
>>Rich Taborek wrote:
>>
>>> Jaime,
>>>
>>> I have a question about the 4D 8-state Trellis code used by 1000BASE-T
>>> which I hope you may be able to answer:
>>>
>>> Is the 4D 8-state Trellis code A DC balanced code? If not, how difficult
>>> will it be for the receiver to recover the clock?
>>>
>>> P.S. I believe that the usual procedure for presentations is to send
>>> them to the chair or webmaster for placement on the IEEE web site. In
>>> this case, that means sending a copy to Jonathan Thatcher or David Law.
>>> (I would send it to both of them).
>>>
>>> --
>>>
>>> Jaime Kardontchik wrote:
>>> >
>>> > Jonathan,
>>> >
>>> > I sent a couple of hours ago the complete presentation on the
>>> > "10G-BASE-T" approach in pdf format, but I did not get it back from the
>>> > Reflector. The pdf file is not large (17 pages, about 70,000 bytes).
>>> > Should I resend it ?
>>> >
>>> > Jaime
>>> >
>>> > Jaime E. Kardontchik
>>> > Micro Linear
>>> > San Jose, CA 95131
>>> > email: kardontchik.jaime@xxxxxxxxxxx
>>>
>>> --
>>>
>>> Best Regards,
>>> Rich
>>>
>>> -------------------------------------------------------------
>>> Richard Taborek Sr.    Tel: 650 210 8800 x101 or 408 370 9233
>>> Principal Architect         Fax: 650 940 1898 or 408 374 3645
>>> Transcendata, Inc.           Email: rtaborek@xxxxxxxxxxxxxxxx
>>> 1029 Corporation Way              http://www.transcendata.com
>>> Palo Alto, CA 94303-4305    Alt email: rtaborek@xxxxxxxxxxxxx
>>
>>
>Paul A. Bottorff, Director Switching Architecture
>Bay Architecture Laboratory
>Nortel Networks, Inc.
>4401 Great America Parkway
>Santa Clara, CA 95052-8185
>Tel: 408 495 3365 Fax: 408 495 1299 ESN: 265 3365
>email: pbottorf@xxxxxxxxxxxxxxxxxx
>
>
Paul A. Bottorff, Director Switching Architecture
Bay Architecture Laboratory
Nortel Networks, Inc.
4401 Great America Parkway
Santa Clara, CA 95052-8185
Tel: 408 495 3365 Fax: 408 495 1299 ESN: 265 3365
email: pbottorf@xxxxxxxxxxxxxxxxxx