Bandwidth and currency

Look at a formula ：

$The\; amount\; of\; money=\alpha \times \frac{Total\; price}{The\; speed\; of\; money\; circulation}$

This is Mann's classic formula , Speed is efficiency ,“ The speed of money circulation ” The reciprocal of can be understood as “ Amount of currency required for unit price ”, Change the formula slightly ：

$The\; amount\; of\; money=\alpha \times The\; number\times The\; unit\; price\times Amount\; of\; currency\; required\; for\; unit\; price$

Suppose the quantity of goods is certain , namely ：

$The\; amount\; of\; money=\beta \times The\; unit\; price\times Amount\; of\; currency\; required\; for\; unit\; price$

For metal money , It also has value as a commodity , If the amount of money increases , Total value increase , Therefore, we can control “ The unit price ” unchanged , Only increase “ Amount of currency required for unit price ”, But it's heavy , So people will spontaneously converge to buy goods with the same unit price with less money , Thus reducing the amount of money , The extra money melts away at will , Bury the bottom of the box to preserve its value .

For paper money , As a credit symbol, it has no value , If you print too much , Not to increase the total value , Because it is the symbol of unit price , The amount of money required for a unit price is certain , such as 2 individual 1 Yuan is 2 Yuan , So in the case of paper money , If the currency is over issued , Can only cause “ The unit price ” Raise , This is inflation .

Look at another formula ：

$Link\; capacity(BDP)=Round\; trip\; delay\times Effective\; bandwidth$

Time is money , Round trip delay is the unit price in the currency formula , Bandwidth belongs to “ Valuable resources ”, At first, it increases with the increase of link capacity , When the effective bandwidth cannot be increased by increasing the link capacity , Bandwidth becomes a credit promise , That is, the nominal bandwidth is reached , Next bufferbloat Like inflation , Right and wrong .

bufferboat period , The additional link capacity is “ Worthless ” Of , but buffer It can promise the nominal bandwidth “ Just against ”, until buffer overflow, It must be damaging at this time . The question is how to deal with .

because bufferbloat As a result of RTT increase , Feedback is not timely , Retransmission caused by packet loss misjudgment will continuously reduce the feedback bandwidth , Retransmission can be understood as “ A run on a bank ”, Similar to the law of money , The more you issue paper money , The higher the unit price of goods , In order to buy goods , The more serious the run , This is a horrible positive feedback .

We were surprised to find out , If buffer infinity , It's not a good thing , infinite buffer Lead to infinite overload ,RTT The speed of continuous increase is greater than the speed of feedback , Retransmission run will eventually reduce the effective bandwidth to zero .RED AQM And van Jacobsen will AIMD introduce TCP It effectively solves the problem ,1986 The bandwidth hard landing event in has never happened again .

Monetary policy also needs RED AQM, From time to time, the losses will be tightened to avoid falling into the Ponzi scheme .

Look at the picture below ：

Monetary policy needs to stay buffer, But not too big . Time measurement CPI That is to say Vegas.

The silver standard of the Roman Empire and the gold standard of the British Empire are theoretically benign currencies , But it can't stop the emperor from mixing iron with gold and silver coins , Bad money drives good money , This is an inherent problem in any circulation phenomenon , Even benign bandwidth ,FEC Strategy can always attract people to win food and scenery , One after another , People always tend to “ Improve the effective bandwidth by reducing the effective bandwidth ”.

It's the same as melting gold and silver coins and hiding them and mixing them with iron , People try to improve their measured bandwidth by sending a packet twice , This is a game , Bad money drives good money , No win or lose .

This essay finally did not mention BBR, Of course , I mentioned it here .

Zhejiang Wenzhou leather shoes wet , It's not fat when it's raining .