LN routing and caveats

It begins with Alice needing to open a channel on the LN, typically with the ACINQ node, which acts as a Trampoline Node. This node possesses a comprehensive map of LN nodes, facilitating routing decisions, including the application of Dijkstra’s algorithm for pathfinding across the network's open channels. Once Alice funds this entry channel, she effectively integrates into the LN, likened to joining a mesh network.

The process proceeds with Alice initiating a payment through Electrum by entering Bob’s LN invoice and sending the transaction. This action triggers the creation and signing of a contract between Alice and ACINQ, which commits 1 BTC to ACINQ contingent upon the invoice's settlement. The ACINQ node, leveraging its role as a Trampoline Node, determines the optimal route (P0) for the transaction to reach Bob. This involves sequential contracts with intermediary nodes (N1, N2, etc.) along the chosen path, each agreeing to forward the transaction towards Bob in a cascading manner.

Several questions are raised concerning this procedural outline, including the possibility of ACINQ or intermediary nodes refusing to open a channel with Alice for various reasons, such as anti-money laundering (AML) concerns. The query also explores whether the sender or an intermediary node has authority over the choice of routing path, given the potential for multiple viable routes.

Furthermore, the concept of "capacity" within the LN is interrogated, specifically how it relates to the total sum of all opened channels linked to a node (e.g., ACINQ’s ~424 BTC capacity). Questions probe how this capacity translates into practical considerations, like the likelihood of successfully routing large transactions, the implications of node connectivity (or lack thereof), and the efficacy of sending substantial sums either as a single transaction or in smaller increments to ensure delivery.

The sender expresses uncertainty regarding the technical feasibility and constraints of regularly using the LN for business-to-business (B2B) transactions, especially when dealing with varying amounts that could exceed 1000 BTC. This encompasses concerns about determining the minimum necessary entry channel capacity, anticipated fees, and transaction times, highlighting a quest for clarity on the technical limitations and requirements for efficient utilization of the LN in a commercial context.