Lightning This Week | 603,944
Wumbo Channels, Draining & Rebalancing, and new Zap over Tor
Hello LN-ers, after 1,056 blocks we meet again. Let’s get right to it.
Wumbo Channels
While it has matured dramatically over the last 2 years, the Lightning Network is still in its infancy with regards to being an established protocol. In order to safeguard the ‘reckless’ users of the network, protocol developers have instituted from the beginning a maximum channel size of 0.16777216 BTC.
Nevertheless, with the many number of companies and services building on top of Lightning, there has been a need for establishing larger channels. Node operators can make use of Wumbo channels, or even patch their LN node software to remove the maximum channel limit. In May of this year we saw Bitrefill and ACINQ open the very first 1BTC channel on the network.
The exciting news is that we have since reached 10 public Wumbo channels on the network, with capacity as high as 1.8BTC (~$15,000 as of press time). This is great as it demonstrates companies are getting more familiar with the protocol and more certain of the capabilities and security aspects of the network.
One important bit to note is that these are all Wumbo channels that are publicly announced to the broader network. As Justin Camarena of Bitrefill points out, there’s no reason why there couldn’t be 10+ other Wumbo channels that are private to the two parties transacting — we’ll never know.
Drain Fill Rebalance C-Lightning Plugin
If you are a C-Lightning node operator and make use of their excellent plugins architecture, there’s a new plugin that adds 3 very useful commands: drain fill and setbalance.
This plugin drains or fills up the capacity of one of your channel using circular payments to yourself. This can be useful for:
- Liquidity management
- Cleaning up or reducing channels before closing
- Keeping capacity: pushing remaining balance into other lightning channels
- Reducing capacity: filling up a channel before closing to reduce capacity
- Accumulating dust before closing multiple channels
The most powerful command in my opinion is the new setbalance, which will fill up or drain your side of the a channel to a given total percentage (defaults to 50% — evenly balanced channel). This is really powerful as the plugin does all the math necessary to achieve that percentage, so you don’t need to worry about the specifics of the channel balance, but rather worry about the overall channel health.
In a channel that is 90% balanced to them and 10% balanced to you:
YOU ├───┼──────────────────────┤ THEMYou can now run: lightning-cli setbalance scid 50 where scid is the short channel ID and 50 is the percentage wanted. This will use circular payments to yourself and will rebalance the channel to 50% even balance.
YOU ├────────────┼────────────┤ THEMLND millisatoshi Discussion
A topic of discussion these past few days has been the support for millisatoshis in the protocol. While not-enforceable onchain (satoshis are the base unit of the Bitcoin blockchain), millisatoshis have always been a part of the Lightning Network specification. And while I can’t say I’ve seen many uses for millisatoshis in the past (the satoshi is already magnitudes smaller than a $ cent), some have begun to explore new services on the network which could make use of msats — and are therefore pushing this discussion. There are now a few PRs discussing this possible change in the LND repository.
PR: Lower default minimum HTLC amount
PR: Allow paying smaller amounts
As it is with most open source projects, any node operator is welcome to patch the existing node software to allow for lower default minimum HTLC sizes (below 1 satoshi), and even lower the minimum relay value to allow routing of HTLCs with less than 1 satoshi.
Zap iOS v0.5.0 Release
A new release of Zap for iOS has been posted. This version introduces some of the most wanted features by power users of the network. First of, Zap now supports connecting to your node entirely through Tor. This is a great privacy enhancement for users who can now easily connect their Tor-enabled clients to their Tor-enabled Lightning nodes.
Secondly, Zap now has full support for LNURL. LNURL is a bech32-encoded HTTPS query string aimed at improving payer — payee interactions such as requesting incoming channels, withdrawing funds and requesting invoices. The standard is becoming more popular in the community as it allows for better user experience for users and wallets.
Zap v0.5.0 iOS TestFlight: https://testflight.apple.com/join/elC3EXAK
Bolt-A-Thon2
Bolt-A-Thon, the Virtual Lightning Network Conference is returning for its second iteration. This one happening on December 6–8 of 2019.
The mission of the Bolt-A-Thon is to foster the global development of the Lightning Network by hosting virtual conferences and hackathons. By hosting it online, we are able to make the top Lightning Network developers available to anyone in the world through speaker sessions. We are also able to create opportunities for hackers to experiment building on Bitcoin’s layer two technology.
The first Bolt-A-Thon was hosted in April of this year and saw over 300 tickets sold with participants for countries from all over the world including Brazil, South Africa, Thailand, Nigeria, and the United States.
If you have a Lightning project you’ve been wanting to build and/or show off, this is a great chance to do just that.
That is all for Lightning This Week. As usual, if I’ve missed any major happenings in the Lightning stratosphere please let me know through the comments or on Twitter.
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