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Re: Please help to clarify some things!


Where does the idea come from that developing a new technology that operates as a
higher signaling rate, with more active bytes per data traffic payload, will be less
expensive than a technology that has already been developed, operates at a lower
signaling speed, and has 4 bytes of active overhead per 15000 bytes of data traffic
payload?  I am confused, when does lower processing, and lower speed become more
expensive?  Unless the interface price is artificially inflated, a native data 10GbE
WAN compatible PHY should not be more expensive than a block encoded LAN only PHY at
the same laser output.

Thank you,
Roy Bynum
MCI WorldCom

Dae Young KIM wrote:

> Roy,
> My point is this:
>     1) If 10GbE should operate over (private) dark fiber, block coding can provide
> exta line symbols for exchanging OAM information. If current 1GbE OAM(if it can be
> called so) is not enough, 10GbE committe can consider extending the feature to
> better work with long-distance dark-fiber WAN envorionment.
>     2) If 10GbE should ride on SONET, why should 10GbE bother itself with the WAN
> OAM feature which would be inherently supplied by the SONET itself, say SONET PATH
> OAM? It is not the line coded stream (hence at the rate of 9.58 x 1.25 =
> 11.975Gbps in case of 8B10B) but the uncoded payload data (hence at the rate of
> 9.58Gbps, and that in NRZ) that would ride the SONET. Therefore, there is neither
> need nor means to signal Ethernet inherent OAM features in the SONET overhead.
> SONET will do its QAM by use of PATH, LINE, SECTION overhead while Ethernet will
> do its own end-to-end outside the PATH ingress and egress points.
> In the case of (2), SONET OAM and Etherent OAM are independent and decoupled. Why
> should Ethernet or its PHY bother with SONET OAM features?
> Roy Bynum wrote:
> > Dae, Henry,
> >
> > Can you provide a block coding scheme that will work with existing transport
> > services outside of private dark fiber or private dark wavelengths?
> Dae Young