Cloud computing can significantly improve efficiency in Internet utilization and data management.Several cloud applications(file sharing,backup,data up/download etc.) imply transfers of large amount of data without re...Cloud computing can significantly improve efficiency in Internet utilization and data management.Several cloud applications(file sharing,backup,data up/download etc.) imply transfers of large amount of data without real-time requirements.In several use-cases cloud-computing solutions reduce operational costs and guarantee target QoS.These solutions become critical when satellite systems are utilized,since resources are limited,network latency is huge and bandwidth costs are high.Using satellite capacity for cloud-computing bulk traffic,keeping acceptable performance of interactive applications,is very important and can limit the connectivity costs.This goal can be achieved installing in the Set Top Box(STB) a proxy agent,to differentiate traffic and assign bandwidth according to priority,leaving spare capacity to bulk cloud computing traffic.This aim is typically reached using a specific QoS architecture,adding functional blocks at network or lower layers.We propose to manage such a process at transport layer only.The endpoint proxy implements a new transport protocol called TCP Noordwijk+,introducing a flow control differentiation capability.The proxy includes TPCN+ which efficiently transfers low-priority bulk data and handles interactive data,keeping a high degree of friendliness.The outcomes of Ns-2simulations confirm applicability and good performance of the proposed solution.展开更多
On the basis of studying the standard TCP retransmission mechanism, this paper proposes a method to adopt the theory of adaptive filtering in the field for the estimation of round trip time （RTT）. Then this method i...On the basis of studying the standard TCP retransmission mechanism, this paper proposes a method to adopt the theory of adaptive filtering in the field for the estimation of round trip time （RTT）. Then this method is embedded in TCP for estimation of RTT, and defined as RTT-AF TCP. In the schemes with Only-TCP flow and with TCP and UDP flow fighting for the link, the experiment results were made and analyzed by using the standard TCP and the RTT-AF TCP. The experimental results show higher throughput and lower loss rate of packets by using RTT-AF TCP for data transmission, and achieve excellent effect.展开更多
文摘Cloud computing can significantly improve efficiency in Internet utilization and data management.Several cloud applications(file sharing,backup,data up/download etc.) imply transfers of large amount of data without real-time requirements.In several use-cases cloud-computing solutions reduce operational costs and guarantee target QoS.These solutions become critical when satellite systems are utilized,since resources are limited,network latency is huge and bandwidth costs are high.Using satellite capacity for cloud-computing bulk traffic,keeping acceptable performance of interactive applications,is very important and can limit the connectivity costs.This goal can be achieved installing in the Set Top Box(STB) a proxy agent,to differentiate traffic and assign bandwidth according to priority,leaving spare capacity to bulk cloud computing traffic.This aim is typically reached using a specific QoS architecture,adding functional blocks at network or lower layers.We propose to manage such a process at transport layer only.The endpoint proxy implements a new transport protocol called TCP Noordwijk+,introducing a flow control differentiation capability.The proxy includes TPCN+ which efficiently transfers low-priority bulk data and handles interactive data,keeping a high degree of friendliness.The outcomes of Ns-2simulations confirm applicability and good performance of the proposed solution.
基金Supported by the National Natural Science Foundation of China （No. 60775058） the Key Project of Ministry of Education of China （No. 107028）.
文摘On the basis of studying the standard TCP retransmission mechanism, this paper proposes a method to adopt the theory of adaptive filtering in the field for the estimation of round trip time （RTT）. Then this method is embedded in TCP for estimation of RTT, and defined as RTT-AF TCP. In the schemes with Only-TCP flow and with TCP and UDP flow fighting for the link, the experiment results were made and analyzed by using the standard TCP and the RTT-AF TCP. The experimental results show higher throughput and lower loss rate of packets by using RTT-AF TCP for data transmission, and achieve excellent effect.
