TODO: Write this out in more detail. Feel free to skip for now.

Physical network abstraction

The physical network abstraction layer is responsible for:

• Keeping and continuously updating routing tables mapping external identities and compositions thereof to IP addresses (and compositions thereof)
• Keeping and continuously updating routing tables tracking which agents are interested in which topics
• Efficient pub-sub topic broadcast (particularly for messages to the "all" identity)
• Frequently testing latency to other known external identities and providing this as a measure of physical entanglement which can be used by higher layers
• Routing messages to and from other agents, including those not destined for this agent (this will require some configuration from higher layers for anti-DoS)
  • Also, keeping track of "routing kudos" in some approximate fashion which doesn't incur too much overhead.