摘要：Optical network introduction has been one of the most significant changes in the telecommunications industry in recent years. With the increasing deployment and growth in optical transport networks, solving the classic network design problem of optimizing quality and scalability becomes ever critical. The fundamental designing objectives in an optical network concern the optimizations regarding the following two metrics: The first one is to minimize the network total cost. The second one is to maintain an acceptable quality of service (QoS). SDH (synchronous digital hierarchy) is a strictly planned system in optical backbone network. The SDH deploy the multiple section shared protection ring (MS-SPRing/2) architecture. The synchronous transport module (STM) is the fiber optic network standard and the currently supported levels are STM-1, STM-4, STM-16, STM-64, STM-256. One of the problems behind in the STM-16 under the MS-SPRing is that it supports only 16 nodes in primary ring connection. One of the top internet service providers in INDIA is Bharat Sanchar Nigam Ltd; they use the back bone topology as ring topology with various numbers of nodes. So, this paper proposed the analysis that increases the number of nodes in the STM-16 up to 24, 32 and also analyses the network parameters such as throughput, packet delivery ratio and end to end delay of the network
关键词：SONET/SDH; optical back bone network; Ring topology; Network parameters; STM
