It's also the model of internet peering, but it requires an even exchange otherwise the imbalances lead to failure. As an example, the current dispute where th

It's also the model of internet peering, but it requires an even exchange otherwise the imbalances lead to failure. As an example, the current dispute where the US is leaving the Universal Postal Union (a month from today) because the exchange is unbalanced due to e-commerce from/to China.