An object-oriented implementation of B-ISDN signalling. 2. Extendability stands the test

The article discusses the extension to an existing object-oriented implementation for B-ISDN signalling. After a brief overview of the existing implementation it is shown where changes in the existing software were made to meet the new requirements (in particular, features for intelligent networks), what mechanisms were available or introduced to make this adaptation as easy as possible, and what experiences in software reuse resulted in this proceeding. The conclusions confirm the predictions concerning extendibility stated in an earlier article, giving reasons for emphasizing again the values and merits of the Call Model and an object-oriented approach.