I know there is a RFE for some type of location mechanism when using multiple RADIUS servers across many sites. I'm not sure if this is on the roadmap or the status of it. You may want to reach out to your local Aruba team to see if they can offer more assistance.
One possible workaround is maybe create multiple server groups pointing to the same server, then have multiple derivation rules for each server group. The derivation rules would be the same with the exception of pointing to a role unique to each site, which would have the bandwidth contract.
Example: 2 sites
- servergroup1 has a derivation rule that points to site1_role
- servergroup2 has a derivation rule that points to site2_role
Each role (site1_role and site2_role) would have a unique bandwidth contract based on the site's capabilities. Users can login to each site pointing to the same RADIUS server but depending on the site based on the server group, a unique bandwidth contract will be applied.
-Mike