New fee structure proposal for rebalancing channels

[LNBIG-COM]

New fee structure proposal for rebalancing channels

Preamble

Now I am experimenting a lot with the rebalance of channels through the regulation of commissions (fees).
This scheme works. But I really miss the flexibility of the existing commission calculation scheme. I want to make a proposal that can change the protocol. But in light of the discussion of version 1.1, I think this proposal can be very useful. In addition, it is possible to apply it to version 1.0.

Briefly

Since the sender's software is oriented when choosing routes on commission and only the channel capacity I could through flexible fee scheme suggest choosing the best channels for routes. Senders do not know the real balances on each side of the channel and if the channel is not balanced, the senders are forced to try different routes.
For example I have channels that are exhausted (for example local balance < 30%) and balanced (30-60%) for example. Through the fee scheme I want to suggest to external senders to choose exhausted channels for small payments and to choose balanced channels for middle/big payments. The existing scheme allows you to increase the final percentage of the commission while reducing the amount of payment (through the base). But there is no reverse mechanism - to increase the final percentage of the commission with an increase in the amount of payment. This is what I want to offer.

Below there are a following terms:

• Fs - fee of satoshies
• sum - the sum of payment, Fp - the finish fee in percents from payment
• base - a base in millisatoshies
• rate - one per millions part from payment sum
• Fp - the final fee as part of payment.

So now there is a scheme:

Fs = base / 1000 + sum * ( rate / 1000000 )

We got

Fp = Fs/sum

It's final percent for payment. So if the base will grow the Fp will grow for small payments. But if the base will be zero the final Fp will be constant for both different volume payments.

I want to suggest next formula:

Fs = base / 1000 + sum * ( rate / 1000000 ) * ( 1 + sum / step )

Here is new step parameter. It multiplies the percent of fee by each stepth satoshies times. If step defined as 0 (zero) the 1 (one) is applied instead (1+sum/step). So default step is 0 and this formula turns into the one that is now. Of course, the step is defined by owner of node together with base and rate.

P.S. May be this issue is related: #587

[t-bast]

Closing for the same reasons as #587