[c-nsp] gigabit ethernet ring for metro ethernet deployment

[Bill Wichers]

>> The goals that I was trying to achieve is to design and deploy metro
>> ethernet ring for MAN backbone with the smallest budget possible, and
>> I find that metro gigabit ethernet switch is quite cheap these days,
>> compared to the RPR and sonet/sdh-based solution.

You can also try using CWDM instead of just daisy-chaining switches. I
would't go SONET though, that just adds another layer of complexity and
cost, and it doesn't gain you anything for an all-Ethernet service MAN
anyway. CWDM would let you star all your switches from one point, and
while this would create a single point of failure at the central switch,
the CWDM rings would still be able to protect against fiber cuts. The
advantage of the star is that you limit the spanning tree problems you
could otherwise have, and your network performance will be more consistant
and predictable.

If you need out-of-band management (as suggested in another reply), I'd
suggest looking at a 1310/1550 WDM OADM and using the 1550 lambda for your
data path and the 1310 lambda for your OOB management link. 1310nm is
gigabit LX, 1550 is the "ZX", or any of the 70-125km links that don't say
they're CWDM or DWDM. The 1310/1550 OADMs are reasonably priced and let
you run out of band management on the same fiber pair you use for your
data which can save money over leasing more strands or buying another IRU
(assuming you don't own spare strands already).

      -Bill

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Waveform Technology
Systems Engineer