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RE: Long distance links

Hi All,

Have we come to concensus yet? 

I keep seeing things flying across the reflector about how we need SONET
OAM&P, SONET's 9.58464 data rate at the MAC/PLS interface, etc...  I thought
that the initial issue was having SONET's signalling at the PHY PMD

For those who want a 10.0000 Gigabit Ethernet that operates as a "Local Area
Network" (LAN) and allows us to hook our switches together in wiring
closets, buildings, and campuses cost effectively, we have an architecture
that will work.

 [ 10 Gig MAC ]->10 Gig MII-> 10 Gig PHY (SMF/MMF/Cu)

For those who want their long-distance WAN solution

 [ 10 Gig MAC ]->10 Gig MII-> 9.58464 SONET PHY (SMF)

which uses HOLD as a mechanism to prevent overflow of the SONET PHY
on outbound traffic. Now, I have a few questions about this SONET PHY that
are due to my inexperience with SONET signalling. I am willing to
expose my naivete in the interest of gaining knowledge on the specific
problems with my vision on this matter.

1) Assuming the HOLD mechanism, what is essentially wrong with using a
10.0000 Gbps MAC/PLS interface?

2) Why can't OAM&P functionality be performed in the SONET "PHY" where
it renders the least impact on the overall system architecture?

 2a) Can't we use MDIO/MDC to allow management access to the necessary
     PHY parameters in case processing is required?

Now I totally realize that I am using the term "PHY" loosely as the SONET
PHY function may require extensive processing capability. But from an
architectural/specification perspective, it makes it much more clean than to
burden a short-haul system with the same complexities as a long-haul system.

Now, if I have a vision that is workable (subject to debate) why are we
continuing to discuss a 9.58464 MAC/PLS interface or OAM&P functionality in
the MAC?


Dan Dove
HP Workgroup Networks

PS: Is there a good white-paper on SONET signalling on the web?