Broker Discovery

[htdvisser]

I'm opening this issue to start discussing the way a TTN router will discover TTN brokers.

Current situation

Upon reception of a packet, a router either

• Broadcasts a packet to all known brokers
• Forwards the packet to brokers that previously accepted the devAddr (routing tables)
  • If rejected, then broadcast.

This system obviously isn't very scalable, because:

• Routing tables will grow and become useless
• Broadcasting to a couple 100s brokers is just insane
• There are security issues (many possibilities of DoS)

Long term

For a long-term solution, we're working with a group of experts that will help us define a perfect solution.

Short term

For the short term, we need something that is better than the current situation.

Initial option to start the discussion:

• Registry Service: Brokers register address range (prefix) with a TTN registry service, so routers only have to broadcast to a smaller number of brokers.

[htdvisser]

Great discussion. We'll go with the Registry service! 🎉

[tftelkamp]

With a simple registry we'll get some experience for a long-term scalable solution, like how to deal with changing prefixes, etc.

[htdvisser]

The central discovery service has been implemented in the refactor branch. See #199 for more info.