[Question] [Testnet] No receivable btc

[ParmuSingh]

I've asked this on reddit as well: https://www.reddit.com/r/lightningnetwork/comments/ay1thg/can_terminal_nodes_receive_payments/?utm_medium=android_app&utm_source=share

I wanted to test receive functionality so I tried the testnet app. I made a channel to ACINQ but it says my receive capacity is 0. Why is that? Does this mean terminal nodes cannot receive lightning payments?

[dpad85]

Hello,

Terminal nodes can receive payments, as long as they have enough incoming capacity, that is their channels are balanced in such a way that these channels can transport funds from the counterpart to them.

For example, if you open a channel for 10 mBTC: you'll be able to send 10 mBTC, and receive 0 mBTC since all the balance is on your side.

Then you send 3 mBTC, the balance will change to 7 mBTC on your side, and 3 mBTC on the counterpart's side. You'll be able to receive 3 mBTC.

Obviously this is not perfect since you have to pay first to be able to receive. This is why the LN specs propose a Dual funding mechanism (see lightning/bolts#184) which allow opening balanced channels. This is not ready yet, so in the meantime, some nodes propose a liquidity mechanism where they open a channel to you (hence giving you inbound capacity). For example, our testnet node offer such a solution, for a fee (see : https://medium.com/@ACINQ/enabling-receive-on-eclair-mobile-2e1b87bd1e3a#3865).

[ParmuSingh]

I get it now! I was trying out in testnet and turns out I didn't tick "request liquidity.." i didn't not know about the LIP (Lightning improvement proposal?). Thanks.