Based on a ripped-up and rerouted methodology,a multilayer area detailed router is presented by using simulated evolution technique.A modified maze algorithm is also performed for the single net.
A Single-Buffered （SB） router is a router where only one stage of shared buffering is sandwiched between two interconnects in comparison of a Combined Input and Output Queued （CIOQ） router where a central switch f...A Single-Buffered （SB） router is a router where only one stage of shared buffering is sandwiched between two interconnects in comparison of a Combined Input and Output Queued （CIOQ） router where a central switch fabric is sandwiched between two stages of buffering. The notion of SB routers was firstly proposed by the High-Performance Networking Group （HPNG） of Stanford University, along with two promising designs of SB routers： one of which was Parallel Shared Memory （PSM） router and the other was Distributed Shared Memory （DSM） router. Admittedly, the work of HPNG deserved full credit, but all results presented by them appeared to relay on a Centralized Memory Management Algorithm （CMMA） which was essentially impractical because of the high processing and communication complexity. This paper attempts to make a scalable high-speed SB router completely practical by introducing a fully distributed architecture for managing the shared memory of SB routers. The resulting SB router is called as a Virtual Output and Input Queued （VOIQ） router. Furthermore, the scheme of VOIQ routers can not only eliminate the need for the CMMA scheduler, thus allowing a fully distributed implementation with low processing and commu- nication complexity, but also provide QoS guarantees and efficiently support variable-length packets in this paper. In particular, the results of performance testing and the hardware implementation of our VOIQ-based router （NDSC~ SR1880-TTM series） are illustrated at the end of this paper. The proposal of this paper is the first distributed scheme of how to design and implement SB routers publicized till now.展开更多
Internet real-time multimedia communication brings a further challenge to Quality of Service(QoS).A higher QoS in communication is required increasingly.As a new framework for providing QoS services,Differentiated Ser...Internet real-time multimedia communication brings a further challenge to Quality of Service(QoS).A higher QoS in communication is required increasingly.As a new framework for providing QoS services,Differentiated Services (DiffServ)is undergoing a speedily standardization process at the IETF.DiffServ not only can offer classified level of services,but also can provide guaranteed QoS in a certain extent.In order to provide QoS,DiffServ must be properly configured.The traditional DiffServ mechanism provides classifier for edge router to mark the different traffic streams,and then the core router uses different Drop Packet Mechanisms to drop packets or transmit data packets according to these classified markers.When multiple edge routers or other core routers transmit data packets high speedily to a single core router,the core router will emerge bottleneck bandwidth.The most valid solution to this problem is that the edge router adopts drop packet mechanism.This paper proposes an Modified Edge Router Mechanism that let the edge router achieve marking,dropping and transmitting packets of hybrid traffic streams based on DiffServ in a given bandwidth,the core router will only transmits packets but won’t drop packets.By the simulation of ns2,the modified mechanism ensure the QoS of high priority traffics and simplify the core router,it is a valid method to solve the congestion of the core router.展开更多
文摘Based on a ripped-up and rerouted methodology,a multilayer area detailed router is presented by using simulated evolution technique.A modified maze algorithm is also performed for the single net.
基金the National High-Tech Research and De-velopment Program of China (863 Program) (2003AA103510, 2004AA103130, 2005AA121210).
文摘A Single-Buffered （SB） router is a router where only one stage of shared buffering is sandwiched between two interconnects in comparison of a Combined Input and Output Queued （CIOQ） router where a central switch fabric is sandwiched between two stages of buffering. The notion of SB routers was firstly proposed by the High-Performance Networking Group （HPNG） of Stanford University, along with two promising designs of SB routers： one of which was Parallel Shared Memory （PSM） router and the other was Distributed Shared Memory （DSM） router. Admittedly, the work of HPNG deserved full credit, but all results presented by them appeared to relay on a Centralized Memory Management Algorithm （CMMA） which was essentially impractical because of the high processing and communication complexity. This paper attempts to make a scalable high-speed SB router completely practical by introducing a fully distributed architecture for managing the shared memory of SB routers. The resulting SB router is called as a Virtual Output and Input Queued （VOIQ） router. Furthermore, the scheme of VOIQ routers can not only eliminate the need for the CMMA scheduler, thus allowing a fully distributed implementation with low processing and commu- nication complexity, but also provide QoS guarantees and efficiently support variable-length packets in this paper. In particular, the results of performance testing and the hardware implementation of our VOIQ-based router （NDSC~ SR1880-TTM series） are illustrated at the end of this paper. The proposal of this paper is the first distributed scheme of how to design and implement SB routers publicized till now.
基金supported by the National Natural Science Foundation of China:(No60572093)the Specialized Research Fund for the Doctoral Program of Higher Education(No20050004016)NSFC-KOSEF Joint Research Project of China and Korea,and the CDSN,GIST
文摘Internet real-time multimedia communication brings a further challenge to Quality of Service(QoS).A higher QoS in communication is required increasingly.As a new framework for providing QoS services,Differentiated Services (DiffServ)is undergoing a speedily standardization process at the IETF.DiffServ not only can offer classified level of services,but also can provide guaranteed QoS in a certain extent.In order to provide QoS,DiffServ must be properly configured.The traditional DiffServ mechanism provides classifier for edge router to mark the different traffic streams,and then the core router uses different Drop Packet Mechanisms to drop packets or transmit data packets according to these classified markers.When multiple edge routers or other core routers transmit data packets high speedily to a single core router,the core router will emerge bottleneck bandwidth.The most valid solution to this problem is that the edge router adopts drop packet mechanism.This paper proposes an Modified Edge Router Mechanism that let the edge router achieve marking,dropping and transmitting packets of hybrid traffic streams based on DiffServ in a given bandwidth,the core router will only transmits packets but won’t drop packets.By the simulation of ns2,the modified mechanism ensure the QoS of high priority traffics and simplify the core router,it is a valid method to solve the congestion of the core router.
