Trampoline Routing
lightning · advanced
Outsourcing route construction to a well-connected node. The sender just picks a trampoline node; the trampoline figures out the rest.
Classic Lightning routing requires the sender to know enough of the network graph to construct a full path to the recipient. For mobile wallets with limited storage and bandwidth, holding and gossip-syncing the entire graph (tens of thousands of channels) is impractical.
Trampoline routing solves this by treating intermediate routing as a service. The sender builds a short onion: "trampoline node T, please deliver this payment to recipient R." T expands that into the actual multi-hop route. If the route fails, T can retry with a different path without bouncing failure back to the sender.
Eclair pioneered trampoline. Phoenix wallet uses it heavily to keep client-side overhead minimal — the wallet only needs to know about its channel to ACINQ's nodes, not the rest of the graph. The tradeoff is a small trust assumption: the trampoline node sees the payment amount and the destination region.