With larger trunk carriers it is common to have different pricing for inbound and outbound calls. There are also many opportunities for calls to get routed through different rate decks depending on route reliability and availability.
With these large carriers where a call could go through a number of different rate decks, there isn’t really a way in Sonar to accurately account for and calculate correct costs. It would be ideal if on CDR import a cost parameter could be included. A lot of the better trunk carriers offer prices per call in the call detail records so being able to optionally add that item for the import and bypass the rate deck lookups would makes things much more flexible.