Abstract: the development of worldwide networks, open systems and new technology trends a new type of computing where computational power is provided similar to utilities like water, gas or electricity. Cloud computing refers to the concept of grid computing, utility computing and virtualization. It elevates knowledge management to newer heights by providing huge data storage and computational power with feature of elasticity and scalability. It has a lot of advantages but still this field in its infancy as far as implementation and usage are concerned. The lack of security in cloud represents an obstacle for most enterprises for moving into the cloud. The purpose of this paper is to address the challenges and threats in deployment models and discuss obstacles in implementation of cloud computing. So researcher need to work at this high developing paradigm’s highlighted areas.

• Publication Date: 03-Jun-2011
• DOI: 10.15224/978-981-07-1847-3-1027
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Abstract: In this paper we describe a ns based simulation analysis of TCP performance over a hybrid network with first link as a wireless link. The latter choice is for understanding performance issues with better clarity. The effect of wireless errors on different TCP parameters resulted into end to end performance degradation of TCP is investigated. Based on the analysis of the basic MAC loss recovery mechanism, we are able to show impact of delay introduced by MAC loss recovery over the performance of TCP. With increased MAC loss recovery duration TCP is unable to conceive maximum of available bandwidth over a network. In addition, it also describe that adaption in CWND will improve the performance of wireless networks. All above simulation results clearly show a) scope for improving MAC loss recovery and b) requirement of tuning between TCP and MAC loss recovery, particularly for retransmission mechanism.

• Publication Date: 03-Jun-2011
• DOI: 10.15224/978-981-07-1847-3-1027
• Views: 0
• Downloads: 0