Routing
Also · Pathfinding · Routing fees · Routing node
Lightning routing finds a path of channels to carry a payment between 2 nodes that share no channel. Each hop charges a small fee and forwards without holding the funds.
Most Lightning payments go to someone you have no channel with. Your node builds a map of public channels from gossip messages, then looks for a path with enough capacity, acceptable fees and a reasonable number of hops. It sends the payment as a chain of HTLCs along that path. Each intermediate node earns a fee, usually a fixed base plus a share of the amount.
The map shows capacities but not how balances sit inside each channel, so a path that looks fine can fail for lack of liquidity at 1 hop. Wallets retry other routes or split the payment into parts. Routing nodes make a business of placing liquidity where payments want to flow.
In French · Routage