Resilience on pre-assigned ATM multicast tree

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.