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Re: Long distance links


The processing between a WAN compatible PHY with minimal operations
support will have perhaps less than 1% additional active processing over
a LAN only PHY that has no operations support.  How much will that add
to the cost of the WAN compatible PHY over a LAN only PHY?  How much
will it add to the available market of the interface?

Thank you,
Roy Bynum
MCI WorldCom

Rich Taborek wrote:

> Brad,
> I completely agree with you. I was only pointing out that the SILICON
> GATE COUNT argument for an OC-192 PHY vs. a straigtforward 10 GbE PHY
> (simple 10X speed-up of 1 GbE PHY) is probably not effective because
> its such a small piece of the total 10 Gbps PHY cost.
> I agree that there are significant additional overhead processing
> costs incurred in a LAN which is forced to meet all of the
> requirements of a WAN PHY.
> Best Regards,
> Rich
> --
> "Booth, Brad" wrote:
>> Rich,
>> I agree that there are a lot of other things that can impact the
>> cost other than silicon gate count.  If all other components of the
>> two systems were equal, the WAN would still cost more (in silicon or
>> in processing cycles) than the LAN due to the requirements to
>> process the overhead.
>> Thanks,
>> Brad
>>      -----Original Message-----
>>      From:   Rich Taborek [SMTP:rtaborek@xxxxxxxxxxxxxxxx]
>>      Sent:  Monday, September 06, 1999 1:12 PM
>>      To:    HSSG
>>      Subject:       Re: Long distance links
>>      Brad,
>>      That's (cost) a dangerous pedestal to get on. The cost of a
>>      multi-gigabit PHY is primarily governed by its opto-electronics
>>      and associated high-speed and Tx/Rx electronics such as the Tx
>>      Laser Driver and Rx Photo Diode Pre-Amplifier, Trans-Impendence
>>      Amplifier, Post Amplifier, whichever are applicable times their
>>      quantities and in consideration of the level of integration.
>>      At multi-gigabit rates, the connection between Tx/Rx
>>      opto-electronics and associated Tx/Rx electronics are critical
>>      and packaging gets expensive depending on the architecture of
>>      the PHY.
>>      I believe that, in general, silicon gate count for any
>>      multi-gigabit PHY gets lost in the noise.
>>      My argument is that the architecture of the SONET OC-192 WAN
>>      PHY is far from the cheapest possible for 10 GbE based on its
>>      requirements for the highest speed opto-electronics and
>>      associated high-speed and Tx/Rx electronics. I don't want to
>>      see all 10 GbE connections encumbered with this unnecessary
>>      cost.
>>      Best Regards,
>>      Rich
>>      --
>>      "Booth, Brad" wrote:
>>           I'd like to address the cost issue.  In a silicon gate
>>           count, the MAC for a WAN or a LAN should be the same
>>           cost.  As for the PHY, a WAN PHY is going to be more
>>           costly than a LAN PHY if you look at the silicon gate
>>           count.  The reason for the WAN PHY being more expensive is
>>           that the PHY is not only an encoder, it is also a framer.
>>           Where a LAN PHY would perform encoding/decoding and
>>           translation from serial-parallel, the WAN PHY must perform
>>           all that plus add overhead and perform framing, which adds
>>           complexity and cost.
>>           I feel that a WAN PHY and a LAN PHY are required so that
>>           LAN implementations are not burdened with the added cost
>>           and complexity of overhead and framing that are required
>>           to utilize the installed WAN OC-192 base.
>>           Thanks,
>>           Brad
>>           Brad Booth
>>           Austin Design Center
>>           Intel Network Interface Division
>>            (512) 407-2135 office
>>           (512) 589-4438 cellular
>>           -----Original Message-----
>>           From:   Roy Bynum [SMTP:rabynum@xxxxxxxxxxx]
>>           Sent:  Sunday, September 05, 1999 4:57 PM
>>           To:    NetWorthTK@xxxxxxx
>>           Cc:    stds-802-3-hssg@xxxxxxxx
>>           Subject:       Re: Long distance links
>>           Ed,
>>           I have seen and heard a lot of issue about the WAN
>>           compatible MAC/PHY being more
>>           expensive than a LAN only MAC/PHY.  Has anyone done any
>>           actual cost analysis?
>>           Having done development work before, even if it was some
>>           time ago,  the ability to
>>           use existing technology and chips was always less
>>           expensive for initial
>>           deployment. A lower frequency signal encode and decode was
>>           always less expensive
>>           over the long term.  Semi-static information processing
>>           was always less expensive
>>           was less expensive than active information processing.
>>           Unless it is legacy WAN
>>           vendors trying to protect their control and high profit
>>           margins for WAN
>>           interfaces, I can not see why a WAN compatible PHY should
>>           be more expensive than a
>>           LAN only PHY at the same laser powers.  I have seen
>>           nothing to support it that
>>           assumption.  As a customer, I would like to see the WAN
>>           comparable costs to the
>>           LAN interfaces.  As a customer, I would like to be able to
>>           take the same type of
>>           interface and use it where ever my implementation
>>           architecture requires.  As a
>>           customer I would like to be able to have unmodified 802.3
>>           frames delivered from
>>           any one place to any other place with the least expense,
>>           in both equipment and
>>           support costs.
>>           Thank you,
>>           Roy Bynum
>>           MCI WorldCom
> -------------------------------------------------------------
> 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   
> Palo Alto, CA 94303-4305    Alt email: rtaborek@xxxxxxxxxxxxx