Layers 2 and 3 ISDN Recommendations

The main feature of an ISDN user-network interface is the support of a wide range of service capabilities, including voice and nonvoice applications in the same network by offering end-to-end digital connectivity to a user. To handle the wide range of applications, a number of new features were developed and incorporated in the ISDN user-network interface layers 2 and 3 Recommendations. This paper reviews the current status of the ISDN user-network interface layers 2 and 3 Recommendations, with a special emphasis on new features developed and incorporated in these Recommendations.