I found information about it, here's an explanation from ldk: https://lightningdevkit.org/blog/zero-confirmation-channels/

There is counterparty risk with these channel openings, but they make it possible to pay a minimal fee to open a channel if the counterparty can be trusted to not double spend the transaction before it gets included in a block.

Indranet requires a low friction onboarding process for users, who may have minimal technical ability, and likely more used to trust based systems like the centralised banking services they probably use every day.

This capability makes it possible for users to get started using Indranet for maybe as little as 30,000 sats, around $6 at current prices, and enables them to establish sessions with an Indra seed node which they can then use to open sessions with relays and the Indra client will be able to generate invoices that they can use to top up the balance of their channel when it runs down and cannot make any more payments out to relays. Typical session fees can be as little as $0.05 which would give them like 50-100mb through a given relay or so, just plucking numbers out of the air, of course they will also be able to set maximum bandwidth prices for relays their client selects.