An object-oriented implementation of B-ISDN signalling

The implementation of the September 1992 version of CCITT Draft Recommendation Q.93B for B-ISDN Signalling is described after a brief overview of the architecture of the Siemens ATM Pilot System is given. It is shown how the software for dial-up connections has been integrated into the pre-existing object-oriented software for permanent virtual channel connections and permanent virtual paths exploiting the features of object-oriented technology. A call model is derived considering the call model for N-ISDN and the particularities of object-oriented design. The implementation of this call model is subsequently discussed. A very modular and clear structure of call-processing software has been achieved. By means of an example the extendability of the call model with respect to modifications is demonstrated. The impact on existing software is minimal due to the structure of the call model and also due to features of object-oriented technology