Re: Long distance links
Ed,
Where do you get the idea that the WAN to LAN conversion will occur at every
terminal? The common denominator for the WAN PHY and the legacy LAN is the 802.3
frame. Existing LAN technology and future installations will in no way be
effected by a WAN compatible PHY interface on the other side of a data switch.
Where does the idea that Ethernet's common denominator is 10/100/1000/10000mb come
from. Ethernet started at 2.4mb, not 10mb. The common denominator is the
802.3/Ethernet frame, which is not changing.
Do we need a LAN only PHY, yes. Will a LAN only 500m MMF PHY, at 10.00mb traffic
data rate, be less expensive than a 500m MMF WAN compatible PHY; maybe not. No
one has done an economic model yet. Most of the development of a WAN compatible
PHY has already been done. That cost was absorbed by the telephony vendors. It
is almost a "freebie". All that is left is the cost of the MAC to WAN compatible
PHY interface development. Time to market for the WAN compatible PHY is dependent
only on the standardization of that interface. Development on a LAN only PHY has
not fully started yet, and has been paid for yet.
As for saving cost, both in equipment and support requirements, I am adamantly
committed to just that! In addition to the inexpensive interfaces, Ethernet has
gained dominance in the market because of its low-tech, plug and play support
architecture. This is exactly what I want to continue in the LAN and extend it to
the WAN/MAN!
Where does everyone keep keep coming up with the idea that a 10GbE WAN compatible
PHY will have SONET OAM&P on it. It will NOT have SONET OAM&P. Most, almost
99.7%, of the SONET OAM&P functionality will not exist in a 10GbE WAN compatible
PHY. Of the 1755 overhead bytes that exist in SONET OC192, only 4, maybe 5, will
be active in a 10GbE WAN compatible PHY. That is the reason that I refer to it as
a WAN compatible PHY, NOT as an Ethernet mapped SONET PHY.
The global WAN/MAN/LAN data market is a multi trillion dollar market, not a 280
billion dollar market. The 280 billion dollar figure is for the USA only. If the
10GbE WAN compatible PHY is done properly, it will be compatible to all
transmission/DWDM systems on a global scale.
Thank you,
Roy Bynum
MCI WorldCom
NetWorthTK@xxxxxxx wrote:
> Roy:
>
> In spite of differences, we all have one thing in common, which is to connect
> all the global Ethernet LAN sites together through WAN at the most
> cost-effective method. LAN people are determined to extend their $28 billion
> market into the $230 billion WAN market. So far, we are trying to achieve
> the same goal by making the conversion from LAN to WAN, simple, and low cost.
>
> I tried to find out where is our difference? The difference is whether we
> should be responsible for "LAN to WAN conversion" only, or we should also
> extend our responsibility to assure the installed bases are preserved without
> added cost.
>
> I believe the objective is clear -- the latter one is correct.
>
> Your proposal of "WAN compatible PHY" is to make 10GbE PHY = WAN PHY, which
> will impose 9.58..Gbps, NRZ scramble code and SONET OAM into IEEE 802.3 10GbE
> standard. I think we like to keep IEEE 802.3 an Ethernet standard, but not a
> SONET standard.
>
> In order to make this "WAN compatible PHY" to talk to the rest of Ethernet
> LANs, the "LAN to WAN conversion" will take place in every individual
> Ethernet terminals, which add unnecessary cost to the installed bases.
>
> I am not reasoning the WAN/PHY is much more expensive than a LAN/PHY, but I
> am reasoning the unnecessary cost added to each terminals. They should be
> tranparent from the LAN-to-WAN conversion issue -- no change.
>
> Why we cannot locate your "WAN compatible PHY" at only one location at the
> LAN entering point from WAN. That will do exactly what you want to do --
> Ethernet Frame, 9.584. Gbps, some kind of OAM to deal optical fault issues.
> I have not seen any good reason to insist that the conversion should be
> located inside the LAN.
>
> We need a LAN/PHY to keep 10/100/1000/10000 Mbps compatible. We definitely
> need WAN/PHYs to interconnect all Ethernet LANs together, which the strong
> market demand will create, with or without us anyway. I believe what you are
> proposing is that HSSG is the logical body at the right moment to create it.
> I would agree.
>
> Therefore, we need both LAN/PHY and WAN/PHY?
>
> Regards,
>
> Ed Chang
> NetWorth Technologies, Inc.
> EChang@xxxxxxxxxxxxxxxx
>
>
>
>
>
> > 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
> >
> > NetWorthTK@xxxxxxx wrote:
> >
> > > Additional Comments:
> > >
> > > I think we all brought up good discussions to nail down the specifics to
> > > enabling decision making.
> > >
> > > I agreed Paul's light SONET/PHY (WAN/PHY), which is the necessary
> > > requirement to let 10GbE extend its market share into the Global market,
> > and
> > > to become the dominant force in the marketplace. A private GbE user in
> US
> > > talks to another private GbE user in another continent without slowing
> > down
> > > to 56K bps, or 112 bps, but at the similar cost, will ultimately
> wide-open
> > > the Ethernet market.
> > >
> > > However, light SONET/PHY is a low-cost, intermediate range covneter,
> > which
> > > is good enough to reach the closest SONET terminal (or DWDM). The
> > distance
> > > could be MAN distance, or up to 40 km, which fits Roy's proposal for
> "Line"
> >
> > > OAM needs. The light SONET/PHY data will be retransmitted; as a result,
> > it
> > > does not have to be responsible for those jitter-tolerance, jitter-
> > transfer,
> > > ... requirements -- making it as cost-effective as possible.
> > >
> > > I believe FP laser can reach 40 km with some good design practices, but
> > not
> > > much of cost increase from 10 km devices. Many LAN vendors are
> supplying
> > 40
> > > km range without any big-deal, and why we make it so difficult for
> > ourselves?
> > >
> > >
> > > On the other hands, there is no reason at all that MAC/Plus should adapt
> > > anything other tahn 10.000 Gbps as Dan is screaming to all of us. Leave
> > it
> > > as a true Ethernet for backward compatibility, and keep all Ethernet
> > > advantages.
> > >
> > > Some where in the link, the data rate has to be converted. The light
> > > SONET/PHY is the most logical and cost-effective location to convert data
> > > rate and do framing. We still can make it cheep and works well, because
> > only
> > > one light SONET/PHY chip is needed at the entering LAN point.
> > >
> > > I still do not see the justification of everyone has to be 9,58... ,
> > instead
> > > of 10.000 and 9.58... for the sake of fairness to both LAN and WAN
> camps.
> > We
> > > are an equal opportunity committee -- I believe.
> > >
> > > Regards,
> > >
> > > Ed Chang
> > > NetWorth Technologies, Inc.
> > > EChang@xxxxxxxxxxxxxxxx
> > > >
> > >