The present document is to evaluate the feasibility of introduction of an InterWorking Function (IWF) between MAP-based and Diameter-based interfaces. This evaluation will be based on the study of various concrete interworking deployment scenarios for which an IWF can/could be used. For each scenario, it will be analysed how the IWF fulfils the specific interworking requirements and performs the mapping of procedures and the corresponding parameter handling. The present document will study the related mechanism for the interworking scenarios, e.g. addressing. The other mechanism, such as security, will also be described in this document as a part of the whole solution.