What does a bridge router need to do?

[jamesmunns]

This is me "thinking out loud" about implementing the first bridge router profile. This will probably be std only first, then I'll figure out how to make it no-std friendly.

• Similar to direct-router, the bridge-router will need to maintain a list of connected devices.
• Unlike direct-router, the bridge-router will also have a single "upstream" interface as well. This upstream interface will act a bit like direct-edge: it should receive it's net_id assignment by waiting for a packet assigned to it.
• In general, for downstream interfaces, all enumerated connections should stay in the Inactive/ActiveLocal state until the upstream interface reaches the Active state.
  • TODO: How do these downstream interfaces "await" this state change? Do we need a top level WaitQueue for interface state changes? this would ideally be OUTSIDE the mutex, so it's easier to use them directly.
• Once the upstream interface has an assigned net_id, each downstream interface (who?) should attempt to discover a seed router, and request an assignment
• Once an assignment is successfully made, each downstream interface (who?) should move to the Active state, and should attempt to renew the assignment periodically
• If an interface is dropped, we should probably send some kind of "relinquish" message broadcast so that the seed router doesn't need to wait for a timeout.
• If the net_id assignment expires, we should move the interface to the Inactive/LocalOnly state, and do something (???) to tell all downstream networks to revoke their active state.

(there may be more, I'll probably come back and edit this)