[c-nsp] Design Case

[Mohammad Khalil]

Hi all
I have 7 switches that will be connected as Ring topology
In the coming future , each one of these switches will be connected to other switches to form sub-rings 
Number of Vlans in use are within 3 - 5 Vlans
One of these switches will be connected to a firewall (each Vlan GW is a sub-interface on the FW)
Now , what I was thinking of , should I use REP ? will that cause a problem with the sub-rings ? 
Or
 should I implement routing on the main ring and keep Layer 2 active on 
the sub-rings ? or should I keep default STP running inside the network ?

Thanks

BR,
Mohammad