Technology interoperation in ATM networks: The REFORM system

This article addresses the applicability and interoperation of standards and emerging technologies for the operation and management of ATM networks. The issue is tackled from a practical perspective based on experiences gained through the design, realization, and experimentation of a system developed by the ACTS AC208 REFORM project. Assuming an ATM-based network infrastructure offering a range of services with distinct QoS guarantees, the REFORM system encompasses the required functions for ensuring cost-effective network survivability and availability; fast-responding reliable fault detection and self-healing mechanisms, distributed dynamic routing functions with inherent load balancing capabilities, efficient VP layer design, and dynamic network reconfiguration functions. A number of standards and emerging technologies were used for designing and realizing the wide spectrum of functionality incorporated within the REFORM system, including ITU-T OAM 1.610 and Q.2931, ATM Forum UNI 3.0 and PNNI v. 1, OMG CORBA and Component Model, TINA NRA and ISO/OSI, and ITU-T TMN. Based on the experience gained, the article discusses and draws conclusions on the applicability, coexistence, and interoperation of the adopted technologies. It is shown that these technologies can coexist, through careful design, to the benefit of network design and operation.