In order to promote competition in the field of communication, efficient regulations are required. Interconnection is one of the most important issues in regulation of communication sector. In communications sector, the subject that operators and regulatory authorities mostly encounter is about the interconnection rates and indirectly the interconnection costs. There is a big dispute about optimum interconnection price especially in some countries where calling party pay principle is applied. Bill and Keep has become a current issue as an alternative to the currently used regime Calling Party Pays. Also choosing the interconnection charging mechanism to be applied and determining the level of call termination rates is very important. In this context, optimum