Networking technologies have greatly enhanced the Internet with respect to the backbone ATM (Asynchronous Transfer Mode) network. The ATM multicast Tree (AMT) is the Mbone of video/audio conferencing and other multicasting applications in ATM networks [5]. Temporarily moving switches changing optical fiber connections and, tangible or intangible network failure on ATM networks causes service disruption and motirates us to consider more carefully the system¡¦s SQOS (Survivable Quality of Service) [7]. A backup protection on the ATM multicast Tree (AMT) is proposed here. This scheme supports a point-to-point preplanned backup route for each root-leaf pair (RL pair) of an AMT. Usually, a restoration message needs to travel over a long backup route to restore disrupted services and point-to-point backup routes may overlap each other and waste bandwidth resources. This motivates us to develop a tree- structured backup AMT to support economical protection. For the providence and proof of performance of these new schemes, we also formulate Bellcore¡¦s LATA model to simulate restoration in two schemes. The simulation results show that the preplanned scheme supports fast restoration; however, a dynamic scheme is needed to compensate for and restore the blocked parts.

Keywords: ATM, restoration, self-healing, multicast tree, and survivability

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Received November 23, 1998; revised May 3, October 19 & December 6, 1999; accepted January 14, 2000.
Communicated by Nen-Fu Huang.