Highly Available Lightning Channels Revisited – ROUTE OR OUT

In an effort to enhance the Lightning Network's efficiency and reliability, a novel approach has been proposed aiming at achieving a 100% success rate for transactions. This initiative seeks to move away from the current reliance on complex probabilistic scoring models, which are not only challenging to design but also difficult to validate. The essence of this new strategy is straightforward: nodes that experience a failure on a single channel would be temporarily bypassed for an extended period, potentially indefinitely. This method, dubbed "ROUTE OR OUT," implies that any node failing to successfully process a transaction could risk being excluded from future transactions for a significant time.

The transition towards this model suggests that senders might begin favoring connections that exhibit a high availability (HA) signal, indicating their reliability in processing transactions without failures. Consequently, senders may be inclined to pay higher fees for utilizing HA channels, valuing the increased probability of successful transactions. This preference could dramatically influence the network's topology and the strategies nodes employ to ensure they remain favorable options for routing payments.

Despite the potential benefits, several developers have raised concerns regarding the practical implementation of such a concept, debating its effectiveness and the potential unforeseen impacts it might have on the network's dynamics. Nonetheless, the possibility of signaling high availability is already within reach for routing nodes, thanks to the flexibility of existing protocols. Specifically, the htlc_maximum_msat parameter in channel updates, which currently contains unused bits, presents an opportunity for nodes to indicate their high availability. For instance, by adjusting the htlc_maximum_msat value to end in 555, a node could subtly communicate that it is highly available for handling transactions up to that specified amount. This mechanism underscores a broader discussion on whether formalizing and standardizing such signaling methods would be beneficial compared to allowing nodes to adopt unofficial modifications at their discretion.

This conversation about HA signaling and the suggested deployment mechanisms reflects a broader dialogue within the developer community on how to evolve the Lightning Network's infrastructure to support more reliable and efficient payment processing. For more detailed insights into the ongoing discussions and the various perspectives being considered, interested parties can refer to the initial proposal and subsequent debate here.