We use the term slice authority to refer to both the

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we use the term ‘slice authority’ to refer to both the principal and the server that implements it. The PLC slice authority includes a database that records the persistent state of each registered slice, including information about every principal that has access to the slice. For example, the current PLC implementation includes: principal = (name, email, org, addr, key, role) org = (name, addr, admin) slice = (state, rspec) where role = (admin | user) state = ((delegated | central) & (start | stop) & (active | deleted)) The admin field of each org tuple is a link to a principal with role = admin (this corresponds to the person responsible for all users at the organization) and the user array in the slice tuple is a set of links to principals with role = user (these are the people allowed to access the slice). Evolution Note: The architecture is currently under-specified with re- spect to roles. The current implementation includes the roles outlined above, and while we recognize that certain set of standard roles will be necessary to support interoperability, we have not yet defined pre- cisely what they will be (and how they parameterize the operations 16
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given later in this section). However, we expect roles will remain an extensible part of the architecture. The SA provides an interface by which users register information about them- selves, create slices, bind users to slices, and request that the slice be instantiated on a set of nodes. This interface is described in a companion document, although we introduce some of the key operations below. The current implementation involves a two-level validation process for prin- cipals: PLC first enters into an off-line agreement with an organization, which identifies an administrative authority that is responsible for approving additional users at that organization. The SA then lets this admin approve a user at the orga- nization, create slices (this results in a slice record in the database), and associate users with slices. Those users are then free to define the slice’s RSpec , associate the slice with a list of users (references to principals ), and request that the slice be instantiated on a set of nodes. Evolution Note: Note that PLC’s slice authority implements two lev- els of naming authorities in a single database: the PLC authority and a set of organization-level authorities. These levels would seem to lend themselves to a distributed implementation. The RSpec maintained by the PLC slice authority is a superset of the core RSpec defined for use by the node manager. This lets the slice authority use the same structure to record additional information about the slice, and pass this infor- mation to the slice creation service running on each node. For example, the RSpec in the PLC slice database includes the slice name, the set of users associated with the slice, and the set of on which nodes the slice is to be instantiated. It also in- cludes a database identifier that can be used to determine when a slice is deleted and recreated.
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