BBFS routing

[michielbdejong]

• when a new link is added, the peers assign it an identifier (8 hex chars), and tell their neighbors about it
• if you want to trade from a neighbor to the new link, announce the link identifier with "rev"
• if you want to trade from the new link to a neighbor, announce the link identifier with "fwd"
• message format for this:

  {
  msgType: 'PROBE',
  fwd: [ 'ae645128', ... ],
  rev: []
  }

• incoming fwd-probes get forwarded once a second to higher neighbors
• incoming rev-probes get forwarded once a second to lower neighbors
• if you have seen a probe in both a forward and a reverse direction on the same link, you can start using it as a routing hint for PROBE messages.
• forget probes after 60 seconds (can't find loops longer than 60)

[michielbdejong]

BBFS stands for bi-directional breadth-first search.

[michielbdejong]

the person sending the ADD sends a single fwd probe along with it, and sends rev probes to all lower neighbors. They store it as if a rev was received over the new link. Before forwarding a probe, see if it's stored for the opposite direction. Eventually, probesSeen will just be lists of reachable links.

[michielbdejong]

done