The Lightning Network FAQ

[franky1]

But it’s NOT the same. No one signed, and issued a worthless piece of paper in Lightning, trusting the counterparty’s ability to pay. In Lightning, you literally need an onchain transaction to open/fund a channel, so you are not sending anything worthless to the counterparty.

you mention words like trust and signed.
there are LN walets out their that create channels before a bitcoin transaction is confirmed and locked
there are probably wallets that are using elthree where the channels 'collateral' are not bitcoin transactions
but just purely a balance authorised by a factory where users have to request that balance to be converted to a bitcoin if they ever want to truly exit LN

friends in my neighbourhood know i have lots of funds and am good for it to give them money.
but i can sign anything and show them a bank statement that proves im worth it.
but what im signing is not actually the bank account.
there is still the trust that LATER i will pay what thy are OWED

a contract of whats owed is not the same as a confirmed settled onchain transaction

signing something measured in millisats is not signing a bitcoin transaction

you really do not know all the flaws do you.

devs can make LN wallets that can agree on any silly thing or ignore any silly thing they like. as LN is not a network wide audited payment system.. its just an agreement within the 2 individuals. where those and only those 2 individuals agree on their own terms

i could have channels of(im B)
     C  D
     | /
A--B--E
     | \
     G  F
where BA uses one protocol. where our agreements are measured in millisats
where BC uses another protocol where our IOU are measured in sats
where BD uses another protocol where our IOU are measured in bits
where BE uses another protocol where our IOU are measured in L-btc
where BF uses another protocol where our IOU are measured in furballs
where BG uses another protocol where out IOU are measured in memes

where by when its time to settle/exit LN then we convert the HTLC into a bitcoin transaction
much like HTLC converts millisats to sats

please learn about HTLC's it might really help you out

also each channel can do as many silly or trusted things between us as we can imagine.
as long as we agree on it.
heck it doesnt even matter if the 12 decimals are called millisats or kitten furballs..
it doesnt even have to be 12 decimals. we could use 24 if we wanted.

we dont even have to sign a htlc. we can instead decide to agree on using cat emoji's
the LN network of 32k peers is not auditing our payments within the channel
heck we could be using units of measure of kittyfluff if we want to.

secondly you obsess about the blockchain locks but you dont wish to understand the stuff happening inside LN


the in channel HTLC is not a bitcoin transaction. the denominations the format just dont fit into bitcoins onchain rules. try to understand that then all previous posts might make sense to you
HTLC do not and cannot be broadcast to the bitcoin network
please for the hundredth time.. learn this stuff

the other thing is take any historic IOU. 1890's bank notes dont need countersigning. but were an iou of gold
a cheque doesnt need countersigning. but until its cleared its not settled and thus an iou
even a unconfirmed bitcoin transaction is an IOU(spoiler dont accept zero confirms)

heck i have a raw TX here with gmaxwells address on it..
i signed my transaction..
but its not actually in any mempool or blockchain. soo the question "does it really exist and will gmax ever actually get it" (spoiler:no)
i know he might like to argue that on this forum i have just announced he is owed something.
but .. ofcourse.. not on blockchain=not real

lastly HTLC's get renegged all the time. thats the point. people renegotiate how much each other owes them without actually settling

im surprised it takes you years to even understand these basic concepts of trade, negotiations, contracts.. as its pretty common life stuff

[DooMAD]

doomad can say all the BS he wants but i quoted something from the devs of a LN wallet from the LN wallet github that counters doomads fluff

so get the hint.. from the LN devs themselves: read it and weep

// MilliSatoshi are the native unit of the Lightning Network. A milli-satoshi
// is simply 1/1000th of a satoshi. There are 1000 milli-satoshis in a single
// satoshi. Within the network, all HTLC payments are denominated in
// milli-satoshis. As milli-satoshis aren't deliverable on the native
// blockchain, before settling to broadcasting, the values are rounded down to
// the nearest satoshi.

No one is disputing the existence of millisats.  You aren't "countering" anything.  We're disputing your total lack of logic in jumping to the completely flawed and asinine conclusion that a difference in the number of decimal places = IOUs.

Get hold of some Uzbekistani Som or Burmese Kyat and then try exchanging it for a more valuable currency.  Watch the rounding occur because there aren't enough decimal places to cope with the conversion.  Try and apply your same broken thinking there and your argument completely falls apart.

[franky1]

signing a contract that is measured in millisats is not signing a bitcoin transaction

having a bank note saying "we promise to pay the bearer 10pounds of silver" is not actually silver

but as you say doomad
having Kyat and exchanging it for a more valuable currency
is what happens in LN
have millisats and then exchange it for bitcoin
(converting a htlc into a close session bitcoin transaction)

when you can understand the concept of an payment in millisats(htlc).. being a separate thing to an exchange to a bitcoin transaction at a different time. then you might understand that the HTLC(msat) payment (agreement of who owes what) is not the same as a bitcoin transaction.

you seem soo obsessed to the point of being misleading by only wanting to point at the close session exchange and broadcast part.. and completely arrogantly and ignorantly not thinking about the IN LN payment part

but for once. accept this topic is about what happens WITH IN LN at the payment of HTLC

seems you have been mis-informing windfury about the onchain(btc) gold. being exchanged for an offchain
token(msat)
where a protocol is 'trusted' to convert/exchange.. however.. as with all bitcoin principles:
unconfirmed transactions are never guaranteed. never accept zero confirms..
definitely dont trust(think its guaranteed) payments in converted/exchanged units of measure bitcoin does not even understand

..
its actually much safer to tell people the truth about the flaws and isssues and risks of LN so people can make informed decisions about using it. rather then being hyped up to use it and learn the hard way
telling people the risks and letting them try it. is more trusting than fluffing up and misguiding them and seeing them fall fowl to the risks

[Timelord2067]

The man is Hyperventilating - give him a brown paper bag and some room to breathe!


I'm pretty sure the whitepaper for Bitcoin alludes to having the capacity for more zeros being added onto the number (already at eight decimal places) that bitcoin can have.

Exchanges have for a while now have enabled traders to trade in bitcoin for alt crypto at nine and even ten decimal places - have you ever noticed those evil exchanges doing such a terrible thing??

Have you ever received a letter in the mail (usually from a council or utility (power/water etc)) and noticed that even in this day and age their franked stamp is in a tenth of a cent postage paid?

I'm sure there's other pesky examples out there how you're being diddled by extra zeros without even knowing it's occurring.

[franky1]

to anyone(sems theres a few above) still confused about a few truths of LN
lets just use one bit of code example that debunks their thoughts and clears up the issue quick

confusions of some people
a. LN is for bitcoin only 'cos bitcoin'
b. values in LN are measured in things that bitcoin recognises

// DefaultBitcoinStaticFeePerKW is the fee rate of 50 sat/vbyte
   // expressed in sat/kw.
   DefaultBitcoinStaticFeePerKW = chainfee.SatPerKWeight(12500)

   // DefaultBitcoinStaticMinRelayFeeRate is the min relay fee used for
   // static estimators.
   DefaultBitcoinStaticMinRelayFeeRate = chainfee.FeePerKwFloor

   // DefaultLitecoinStaticFeePerKW is the fee rate of 200 sat/vbyte
   // expressed in sat/kw.
   DefaultLitecoinStaticFeePerKW = chainfee.SatPerKWeight(50000)

   // BtcToLtcConversionRate is a fixed ratio used in order to scale up
   // payments when running on the Litecoin chain.
   BtcToLtcConversionRate = 60

first note that it allows both pegging iou tokens to bitcoin and litecoin
then note that for:
bitcoin pegged iou
the measure of 50sat/vbyte is 125sat/byte = INSIDE LN 12500 msat tokens

litecoin pegged IOU
the measure of 200sat/vbyte is 50sat/byte = INSIDE LN 50000 msat tokens

heck github has soo many examples of the network being separate and functional for many pegs
and hundreds of examples of the tokens being a different denomination to the peg

..
atleast the liquid network can admit their tokens(L-BTC) are pegged tokens and not play the silly promo fluff of LN which pretends to be bitcoin itself

edit to respond to below
its not just that HTLC are in a different denomination.
but also requiring a separate contract(comitment) to make funds bitcoin network recognisable. where there is a separation between a 'commitment' and a 'HTLC'. where the HTLC is completely different and not bitcoin.

and then also the whole point of the 'dont trust zero confirms' of the commitment(settlement)
meaning a HTLC is 2 'layers' away from being a guaranteed settlement, and just a 'promise of 'i owe you x''

the funniest part is. i am a bitcoin(btc) maximalist. i dont want to go playing on other networks or made/forced to use other networks just to spend my value FAIRLY.
but the few trolls that think LN is bitcoin have also been saying that other altnets(crapcoins) which do have bitcoin compatible transactions that CAN BE REPLAYED on the bitcoin network, have been deemed NOT bitcoin.. very hypocritical and reveals they have no clue. and just trolling their hypocrisies by saying an altnet that CANT be direct replayed.. is bitcoin!!?.

[Rath_]

Let me throw in my two cents.

franky1 makes some good points. I am also a little bit concerned about large nodes which set the minimum channel funding value to ridiculously high values.

I don't agree with the statement that the Lightning Network as a whole consists of IOUs. I do agree that milisatoshis are backed only by trust, but...

I don't think that's a major issue. Putting the msats value aside, if you are the channel founder then you do not lose any money. The moment you decide to close the channel both balances are rounded down to whole satoshis and the remaining 1 satoshi is added to the transaction fee, which as a channel founder you have to pay anyway. If you are not the channel founder then... well, that's a negligible loss for you. By the time msats become valuable, the number of on-chain decimal places might have been already changed as a result of some hardfork.

when you can understand the concept of an payment in millisats(htlc).. being a separate thing to an exchange to a bitcoin transaction at a different time. then you might understand that the HTLC(msat) payment (agreement of who owes what) is not the same as a bitcoin transaction.

While it's true that HTLCs are denominated in msats, they are still enforceable on the blockchain. The moment you send/receive an HTLC to/from someone, you also need to sign a new commitment transaction. Commitment transactions can include not only the current balance of both parties but also offered and incoming HTLCs. Both of these (locked) outputs obviously need to be rounded down to whole satoshis in order for the transaction to be valid.

I think that we have had enough. Please, move to some other thread if you wish to discuss it further. Feel free to quote me there. I will be removing any IOU related posts from now on.

[garlonicon]

By the time msats become valuable, the number of on-chain decimal places might have been already changed as a result of some hardfork.

Soft fork solution was rejected, so hard fork solution will be instantly rejected: https://bitcointalk.org/index.php?topic=5330102.0

The problem however is that the following statement is not correct:

In the future, sooner or later, introducing fractional satoshis would be needed.

Edit: The only "fractional" satoshi solution accepted by developers is decreasing transaction fee, for example to one satoshi per kilobyte (or one satoshi per transaction later if needed). But as there are no developers treating fractional satoshis on L1 seriously, they will never be introduced and if they would exist on L2, then they would exist on L3, L4, and so on, so they would never be needed on L1.

[franky1]

though bitcoin even since 2009 has always been denominated in satoshis. where every raw tx on the blockchain has always been in sats.
which is not easy to break out of, while remaining 'backward compatible'
(there are many ways but that involves having old nodes ignore/accept without validation new tx formats)

by the time it gets to about 2045 there may then and only then be a case to change the value denomination to sub satoshi levels as the block reward would soon then become
sats:                 year:
4882812.5   2049
2441406.25   2053
1220703.125   2057
610351.5625   2061
76293.94531   2073
9536.743164   2085
596.0464478   2101

however that then plays into  the 'shareable' units (scarcity) debate. of adding more shareable units available at the bottom end

[BlackHatCoiner]

Edit: The only "fractional" satoshi solution accepted by developers is decreasing transaction fee, for example to one satoshi per kilobyte (or one satoshi per transaction later if needed). But as there are no developers treating fractional satoshis on L1 seriously, they will never be introduced and if they would exist on L2, then they would exist on L3, L4, and so on, so they would never be needed on L1.

Hi, would you, or anybody else, mind explaining me why there are so many layers of the lightning network? I googled it, but as always, I wasn't assisted properly. I'm a LN newbie BTW and willing to dive into the details now that I have some available time.

however that then plays into  the 'shareable' units (scarcity) debate. of adding more shareable units available at the bottom end

Actually it doesn't; it'd have the same scarcity after all, whether we hard forked msats in the source code or not. The number 21,000,000 BTC would never be exceeded. It wouldn't even touch it.

the funniest part is. i am a bitcoin(btc) maximalist. i dont want to go playing on other networks or made/forced to use other networks just to spend my value FAIRLY.

Why is this the funniest part and why are you forced to “spend your value” with LN?

[franky1]

however that then plays into  the 'shareable' units (scarcity) debate. of adding more shareable units available at the bottom end

Actually it doesn't; it'd have the same scarcity after all, whether we hard forked msats in the source code or not. The number 21,000,000 BTC would never be exceeded. It wouldn't even touch it.

sats have always been a shareable unit.
there have always been a rule that the circulation from 5000000000sats per block will halv after 210k blocks and cause a result near on 2100000000000000 sat total cap eventually
yep since day one only 2100000000000000 shareable units.
thats the real scarity

something is not more scarce because redefining 2100000000000000 parts into a buzzword for human eyes as 21m..
because sharing divisions of this buzzword has always been possible. the shareable potential still remains

heck if i created a new buzzword of just 21,000megabitcoins does not make it more scarce
because there is still currently still only 2100000000000000 shareable units (sats limit of future circulation)

however to increase the sharability reduces the scarcity.

imagine something is set in stone.. a round whole pizza can only be shared as a round whole pizza. a pizza is the smallest unit..
ordering 10 pizza's = only 10 people max can share
but but inventing sliced pizza..
means more can share and suddenly pizza is not as scarce as more then 10 can get a slice
(research share dilution.. same company. but more shares)
..
many people think bitcoin was invented from btc with decimal divisions being the temporary flimsy buzzwords that can change

when reality it was built from satoshi mutliples up where btc is the empty buzzword of just human visual
changing the 'must consume sats in whole units' sats rule.. to allowing slices of sats. is allowing more sharing and thus less scarcity

the funniest part is. i am a bitcoin(btc) maximalist. i dont want to go playing on other networks or made/forced to use other networks just to spend my value FAIRLY.

Why is this the funniest part and why are you forced to “spend your value” with LN?

the coding decisions making using bitcoin less useful and less fair, was done purposefully just to promote new features by swaying people "they save money by using new features".. while at code level its purposefully making old standard features more expensive and NOT making the new features cheaper then ever before... but just cheaper then the new recently added extra premium added to old feature

.take the vbyte to bytes that put legacy transactions at a premium 4x fee
 its never been a segwit is 4x cheaper then fee formulae of 2016
 its legacy is 4x more then 2016 and segwit is less then new legacy high premium

.take the lack of any tx fee formula to actually accurately gauge value/age of coin to set true
 premium/discount that has real purpose
 EG coins under 10 confirms should for efficiency purposes cost more then coins over 144 confirms..
 (as it makes spamming tx more expensive)
 someone moving $1billion pays the same fee as someone moving $20.. (thats bad methodology)
 someone moving a coin every block pays same as someone moving once a month (thats bad too)

.take having everyone pay more than 2016 levels .. as a lame excuse to deter spammers just makes everyone not want to use it as much

there are many websites that have turned off bitcoin support and moved to accepting altnet currencies just due to the fee cludgy decisions

after all if paypal started saying that people gotta pay $2+ each time they do something on ebay. people would pay for things using a different payment service

i avoid any ATM that has fees when there are other ATM's that dont. and thats the point

[BlackHatCoiner]

changing the 'must consume sats in whole units' sats rule.. to allowing slices of sats. is allowing more sharing and thus less scarcity

Why “thus less scarcity”? I don't get that. If I gave you 0.999999999999 ounces of gold, I wouldn't make 1 ounce less scarce just because I can cut it in smaller pieces.

[garlonicon]

Hi, would you, or anybody else, mind explaining me why there are so many layers of the lightning network? I googled it, but as always, I wasn't assisted properly. I'm a LN newbie BTW and willing to dive into the details now that I have some available time.

Simple, because when L1 does not work as intended, people created L2. When L2 still has problems, people will create L3. And when L3 will have another issues, people will create L4. If L1 would be good enough, people would never create L2, because it would never be needed (as you can see on many altcoins where you don't have L2 or where you will never see L2 by design).

L1 does not work as intended, because if you use BTC extensively and make many transactions, then they have to be stored forever. There is block size limit, so mempool is sometimes congested when there are too many transactions. For that reason L2 is needed. On BCH you have no L2, because they decided to do everything on L1 and they promise to never introduce L2.

L2 does not work as intended, because when L1 is congested, then you cannot settle your L1 transactions. You cannot open and close channels without L1. You cannot send coins to someone who never used BTC when L1 is congested. You cannot close your L2 channel for one satoshi per byte when there are 100 MB other transactions waiting in mempool.

L1 does everything on-chain. L2 does channel opening and closing on-chain and everything else off-chain. I guess L3 would batch matching channel opening and closing on-chain transactions into single on-chain transaction. From L1 it would look like channels will be closed before opening transaction will settle on-chain. I guess L4 would push some kind of 256-bit commitment to the nearest block and everything would happen off-chain. From L1 it would look like some coins are still part of the chain, but no L1 miner knows who owns what in L4 and how many channels are there, the only visible thing would be that there is X BTC locked in the whole L4 layer. But of course L3 and L4 design is just guessing and I am not 100% sure how it will work in practice.

[BlackHatCoiner]

meaning all 8 billion people can now hold ~23 units of gold

But, still, only 6.77 billion can hold 28 grams of gold. No matter the number of people who own gold, the 28 grams' scarcity will remain the same. Only if the supply increased, the scarcity would decrease.

L2 does not work as intended, because when L1 is congested, then you cannot settle your L1 transactions. You cannot open and close channels without L1. You cannot send coins to someone who never used BTC when L1 is congested. You cannot close your L2 channel for one satoshi per byte when there are 100 MB other transactions waiting in mempool.

So L1 is the block chain and L2 is the Lightning Network, okay I got it. In order to use L2, you need L1; does the same apply for L3 & L4? Would L3 need L2 to operate? To me, it seems that, by the way you wrote it, L3 is a L2 update (?).

[vjudeu]

In order to use L2, you need L1; does the same apply for L3 & L4?

I think so. In order to use L3, you need transaction batching feature, so some kind of Pedersen Commitments or things like that are needed. I guess in L3 you cannot join any transaction with any script type, just that transaction types when it will be enabled, for example only those with some kind of future Segwit version address or those with some kind of future-tapscript (because taproot is self-upgradeable).

Would L3 need L2 to operate?

Yes, because in other case it won't be L3, but just another L2.

To me, it seems that, by the way you wrote it, L3 is a L2 update (?).

I guess that garlonicon's way of thinking is "what needs to be outside". In Segwit, signatures are outside. In taproot, signatures are batched. In L2, transactions are outside. In L3, transactions will be batched. In L4, everything will be reduced to single commitment. So I guess in L5, commitments would be batched, for example instead of using one commitment per block, it could be one commitment per 2016 blocks.

If you want to create L3, you have to "push something outside" and because channel creation/destruction transactions are the only things that are present on-chain, then something related to that should be "outside". And batching is "pushing things outside", because in that case you can open some channel, you broadcast channel opening transaction to the "L2 mempool". Then, you do your L3 transactions, but "L2 mempool" is very congested. Finally, you close your L2 channel, but your channel opening transaction is not yet settled on L1. So, it can be reduced by using Pedersen Commitments or some other kind of transaction batching. Of course, to avoid double-spending, some kind of "honest batching proof" will be needed, because if Alice opened a channel with Bob, and Bob opened a channel with Charlie, it should be possible to close all channels and create a payment from Charlie to Alice without worrying if it should be from Charlie to Daniel.

Going further, if you have batched transactions on L3 and it is still not enough, then you have to "push something else outside". And the only thing I can think of is pushing transactions outside. For that, you collect all L3 transactions and create a 256-bit commitment. Going even further from L4 to L5, you have to "push something else outside". You have single 256-bit number per block. How to reduce that? Make one commitment per 2016 blocks. I still wonder how to create L6 by using that kind of logic, but it seems that L5 will be sufficient for a long time.

[Wind_FURY]

But it’s NOT the same. No one signed, and issued a worthless piece of paper in Lightning, trusting the counterparty’s ability to pay. In Lightning, you literally need an onchain transaction to open/fund a channel, so you are not sending anything worthless to the counterparty.

you mention words like trust and signed.

there are LN walets out their that create channels before a bitcoin transaction is confirmed and locked
 
there are probably wallets that are using elthree where the channels 'collateral' are not bitcoin transactions

but just purely a balance authorised by a factory where users have to request that balance to be converted to a bitcoin if they ever want to truly exit LN

Can anyone confirm this? Rath_, achow, gmaxwell? If it’s true, then it’s true, and we would need to review our standpoint/opinions. BUT if it’s not true, and franky1 is caught with disinformation/gaslighting again, then what are you doing franky1?

[LoyceV]

there are LN walets out their that create channels before a bitcoin transaction is confirmed and locked

Can anyone confirm this?

I can confirm this has happened to me, but it's because channel opening in Phoenix Wallet is custodial, and since it only connects to their own node (which they trust), they're not risking anything and I can already make transactions before the on-chain transaction is confirmed.

If it’s true, then it’s true, and we would need to review our standpoint/opinions.

It's true. But even though I didn't expect it, it makes sense, I don't think it's a terrible thing in this case.
See Opinions on Phoenix Wallet? (and later posts).

To answer TangentC's post: to the rest of the LN-network is doesn't matter that my transaction isn't confirmed yet. My channel is with a node, and that node has confirmed channels to the rest of the world. So as far as the rest of the world is concerned, they don't risk any funds by accepting my transaction.
Opening a channel in Phoenix Wallet is custodial, which means I trusted the wallet with my money already. It's a smart way of making channel opening more user friendly when on-chain fees rise.

[franky1]

meaning all 8 billion people can now hold ~23 units of gold

But, still, only 6.77 billion can hold 28 grams of gold. No matter the number of people who own gold, the 28 grams' scarcity will remain the same. Only if the supply increased, the scarcity would decrease.

to save more meandered off topic rebuttles from certain people. have scarcity debate here
https://bitcointalk.org/index.php?topic=5346487.msg57340802#msg57340802

In order to use L2, you need L1; does the same apply for L3 & L4?

I think so. In order to use L3, you need transaction batching feature, so some kind of Pedersen Commitments or things like that are needed.

custodial services take the deposits and funds become theirs. (like exchanges do)
they can then using their app have their customers be giving HTLC millisat balance that never need to broadcast onchain. whereby the HTLC get re-aggregated by the service when users want to close channels
so its not that complicated to do "elthree" stuff
after all channels are not network wide audited so only need to be agreed by the counterparties within the channels (a level below the service) where the service manages any disagreements. thus no special onchain rules need apply
much like bitcoin does not need to fork due to an exchange changing how it saves its customers MYSQL balance in their database
much like how MTGox-BTC-e years ago didnt need to request a bitcoin fork to allow mtgox/btc-e to have 'payment codes' for their in exchange payments between customers

heck people can make elthree stuff where the HTLC balance of all service customers is measured in kittens cats and tigers. where the aggregation converts it into sats by the service at close session

[garlonicon]

so its not that complicated to do "elthree" stuff

If that "elthree" is centralized, then yes, sure. But if you want to use your "elthree" across many exchanges or across any parties, then that thing should be somehow standardized and it should have an option where you control your funds all the time. For example: you can do "eltwo" by depositing funds to exchange (instead of channel opening), trading (instead of "eltwo" transactions) and withdrawing them (instead of channel closing). Is it "eltwo"? Yes, it is on the same level as LN. Is it centralized? Yes. You cannot control your coins directly and that's the difference between "globally recognized and standardized elthree" and "exchange/wallet centralized elthree". The former will be created, the latter exist today in custodial LN wallets.

[Wind_FURY]

there are LN walets out their that create channels before a bitcoin transaction is confirmed and locked

Can anyone confirm this?

I can confirm this has happened to me, but it's because channel opening in Phoenix Wallet is custodial, and since it only connects to their own node (which they trust), they're not risking anything and I can already make transactions before the on-chain transaction is confirmed.

If it’s true, then it’s true, and we would need to review our standpoint/opinions.

It's true. But even though I didn't expect it, it makes sense, I don't think it's a terrible thing in this case.
See Opinions on Phoenix Wallet? (and later posts).

To answer TangentC's post: to the rest of the LN-network is doesn't matter that my transaction isn't confirmed yet. My channel is with a node, and that node has confirmed channels to the rest of the world. So as far as the rest of the world is concerned, they don't risk any funds by accepting my transaction.
Opening a channel in Phoenix Wallet is custodial, which means I trusted the wallet with my money already. It's a smart way of making channel opening more user friendly when on-chain fees rise.

Just to make it absolutely clear, the unconfirmed transaction is only a “problem” between you and Phoenix wallet which is your custodian to use Lightning, and that Phoenix wallet itself cannot open a channel in Lightning without a confirmed transaction. Because I’m made to believe that it’s possible to open a channel WITHOUT an onchain transaction.

[Rath_]

Just to make it absolutely clear, the unconfirmed transaction is only a “problem” between you and Phoenix wallet which is your custodian to use Lightning, and that Phoenix wallet itself cannot open a channel in Lightning without a confirmed transaction.

In this case, Phoenix Wallet (or more precisely ACINQ) initiates the payment from their node rather than route it from you. They expect you to pay them back once the channel between you and them has become active. How can they trust you? Well, you are using their software which was programmed to do that automatically.

Because I’m made to believe that it’s possible to open a channel WITHOUT an onchain transaction.

Under normal circumstances, it would not be possible. If you set up your own node then it's impossible for someone to open a channel to you without a valid on-chain transaction. In fact, by default, that transactions needs to have either 1 or 3 confirmations (it depends on the implementation) before the channel becomes active.