lightning network – Should the nodes of a channel have the same Time Lock Delta?


An HTLC passing from node 1 (here Caffeine) to node 2 (here HODLcat.com) will be added a 144 blocks time-lock.

An HTLC passing from node 2 (here HODLcat.com) to node 1 (here Caffeine) will be added a 10 blocks time-lock.

The channel operation does not depend of the CLTV deltas, it really is a pure personal setting as it defines the time a forwarding node has to redeem an HTLC on-chain in case it gets timed out down the route and your peer becomes unresponsive.

However, wallets take it into account when computing routes as they sum up along the route and determine how many blocks funds of the end-payer may be stuck in a worst-case scenario.

You can find more details in the specification (it’s called cltv_expiry_delta), which gives a really detailed explanation and some recommendations which have been updated lately with the discovery of the recent attacks.