This article IPFS, Again - macwright.com
being discussed here: IPFS, Again | Hacker News
lead to this comment:
whyrusleeping
We actually find NAT to be a pretty big problem still. Even using NAT-PMP, upnp, and hole punching, we still see a roughly 70% (sometimes much higher) undialable rate. Especially for people running ipfs in China (though high failure rates are also observed in other countries).
We’re pushing hard on getting libp2p relays up and running to help get through this. The idea is that we can use a relay to make the initial connection, then ask the remote peer to try dialing back (assuming that both peers involved arent undialable).`
I fear we like to ignore questions of dialability. However, if there is such a huge imbalance between nodes that can be connected to and ones that cannot, then certain assumptions about our connection topology do not hold. For example we always assume that most proximate nodes are fully (well enough) connected.
If this cannot be guaranteed, this has important implications for both syncing/retrieving as well as PSS message routing.
The only workaround I can think of right away is increasing the size of the ‘most proximate bin’ until you get a set of connected peers, but this seems clunky, inefficient, and fragile.
I open this topic so that we can discuss below.