@
txydhr Following an earlier post Peering into Peering , the definition of peering is settlement-free, "bill-and-keep," or "sender keeps all," meaning that neither party pays the other for the exchange of traffic.
Based on the definition, peering appears to be free of cost. However, that doesn ’ t mean peering is completely free. There are costs involved such as co-location, power, equipment (routers and switches), capacity, cross-connects, local loop, effort to manage the peering and so on.