Merge pull request #4 from ariard/2022-10-dual-funding-pr

Add dual funding messages PR

Author: dunxen

_posts/2022-10-25-#1794.md

@@ -0,0 +1,25 @@
+---
+layout: pr
+date: 2022-10-25
+title: "DRAFT: Dual funding messages"
+authors: ["dunxen"]
+pr: 1794
+components: ["funding"]
+host: ariard
+status: upcoming
+commit: b1d3eee
+---
+
+## Notes
+
+* Historically, the funding UTXOs have been provided by a single counterparty, leading to the [hard issue of bootstrapping inbound liquidity](https://lists.linuxfoundation.org/pipermail/lightning-dev/2018-November/001555.html) for services providers and nodes.
+* Few solutions have been developed in an attempt to palliate this issue: [submarine swaps](https://submarineswaps.org/), [liquidity ads](https://github.com/lightning/bolts/pull/878), [inbound channel request](https://github.com/BitcoinAndLightningLayerSpecs/lsp/blob/main/channel-request.md)
+* [#1754](https://github.com/lightningdevkit/rust-lightning/pull/1794) starts the support of dual-funding, a new funding flow enabling both sides of a channel to commit UTXOs.
+
+## Questions
+
+1. What's the message flow of [channel opening V1](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#the-open_channel-message) ? What the logically equivalent sequence of checks processed by both acceptor and initiator ? What are the policy checks realized ?
+2. What's the [dual-funding proposal](https://github.com/lightning/bolts/pull/851) ? How the mechanism works compared to single-funded channel and the `push_msat` setting ?
+3. What dual-funding bring as a liquidity tooling compared to a [swap](https://www.peerswap.dev/) ? What are the [trade-offs](https://zmnscpxj.github.io/clboss/01-inbound.html) ?
+4. Dual-funding builds on top of the interactive construction protocol, which introduces a collaborative fee-bumping [Replace-by-Fee](https://bitcoinops.org/en/topics/replace-by-fee/) mechanism ? What's the trade-offs in terms of cost/liveliness/key management/etc compared to [Child-Pay-For-Parent](https://bitcoinops.org/en/topics/cpfp/) ?
+5. What are the [downsides](https://lists.linuxfoundation.org/pipermail/lightning-dev/2021-May/003033.html) of dual-funding with "untrusted" Lightning counterparties, especially in multi-party context ?