This read-write INTEGER (1..15) specifies the cost associated with the trunk for routing connections, which only has effect when cost-based routing is enabled via parCmParmsCostBased. An administrator raises this value to make PAR's routing engine avoid the trunk unless necessary, typically for expensive or lower-quality links. For example, setting a satellite trunk's routing cost to the maximum value of 15 ensures PAR only routes connections over it as a last resort compared with cheaper terrestrial trunks.