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

[Fetzer, Bryan]

Affan,
Are you locked into a Cisco based solution? EAPS does exactly what you
are asking of it and won't introduce the myriad of issues you'll have
attempting to make STP do something it was never intended to do (a
ring). It will also do it more reliably and MUCH faster protection in
the event of a failure. 
EAPS will scale as large as you want it to, and you can start out with
very cheap switches to get the job done.
RPR is a technology I feel needs to be implemented in Cisco's switch
lineup. At this point RPR is not where it needs to be, I have queried
Cisco about when they plan on implementing RPR in their switching
platforms and they have stated they need input from users that they
actually want to do this. To me, RPR is intended to be "SONET on
Ethernet". EAPS accomplishes this but is one vendor centric (Extreme
Networks)
We are running multiple 1 gb and 10gb Extreme Networks EAPS based rings
and they do L2 great (we are only asking them to do L2, we do L3 with
Juniper and Cisco). 

http://www.extremenetworks.com/libraries/whitepapers/WEAPS_1293.pdf

Extreme EAPS domains are simple to setup and maintain, might be worth
looking into because it fits your situation perfectly and you won't have
the STP management nightmare on your hands. 

Bryan F