Re: Long distance links
Rich,
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
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