DCAN Approach to Open Switch Control 32 DCAN APPROACH TO OPEN SWITCH CONTROLFigure

This paper presents a novel approach to the control and management of ATM networks, by allowing diierent control architectures to be operational within the same network, and on the same switch. The resources available on an ATM switch are divided into switchlets, each of which encapsulates a subset of the physical ATM switch resources. A set of switchlets on diierent ATM switches combine to form a virtual ATM network. Each virtual network created in this way can potentially use diierent control and management mechanisms which are collectively called a control architecture. For example one virtual network might run ATM Forum signalling, another might implement an IP switching control architecture, while yet another can be reserved for an in house secure control architecture. In this manner a new control architecture can be introduced into a network without disrupting existing services and applications, thereby facilitating change management in an elegant way. Switchlets and a control architecture from a well known set can be created on demand to allow the dynamic construction of virtual ATM networks of predeened type. Alternatively the control architecture can be supplied (by a `user') after the virtual network has been created, thus allowing the dynamic creation of virtual ATM networks of arbitrary func-tionality. Finally, the paper presents a proof of concept implementation as well as ongoing work in this area.