Congestion control for packets sent on a network is important for DAQ systems that contain an event builder using switching network technologies.Quality of Service(QoS) is a technique for congestion control.Recent Lin...Congestion control for packets sent on a network is important for DAQ systems that contain an event builder using switching network technologies.Quality of Service(QoS) is a technique for congestion control.Recent Linux releases provide QoS in the kernel to manage network traffic.We have analyzed the packet-loss and packet distribution for the event builder prototype of the Atlas TDAQ system.We used PC/Linux with Gigabit Ethernet network as the testbed.The result showed that QoS using CBQ and TBF eliminated packet loss on UDP/IP transfer while the UDP/IP transfer in best effort made lots of packet loss.The result also showed that the QoS overhead was small.We concluded that QoS on Linux performed efficiently in TCP/IP and UDP/IP and will have an important role of the Atlas TDAQ system.展开更多
After having evaluated various H.323 products for these two years,KEK and Japanese HENP community started to move from ISDN(H.320)-based video conferencing environment into IP(H.323)-based one.Primary reason for the m...After having evaluated various H.323 products for these two years,KEK and Japanese HENP community started to move from ISDN(H.320)-based video conferencing environment into IP(H.323)-based one.Primary reason for the move is to cut down the ever increasing ISDN communication cost.At the same time the H.323 can offer us more powerful collaborative environment.In order to make KEK to be a center for the H.323-based collaborative environment in Japan,Picture Tel's LIVE GATEWAY as a H.320/H.323 gateway ,which is essential for the smooth transition,Cisco IP/VA 3510 as a H.323/MCU,and Cisco 2610 as a gatekeeper were installed at KEK in March 2001,And the transition started.In this paper,we'll describe the collaborative environment which our users can have,together with its operational results.展开更多
文摘Congestion control for packets sent on a network is important for DAQ systems that contain an event builder using switching network technologies.Quality of Service(QoS) is a technique for congestion control.Recent Linux releases provide QoS in the kernel to manage network traffic.We have analyzed the packet-loss and packet distribution for the event builder prototype of the Atlas TDAQ system.We used PC/Linux with Gigabit Ethernet network as the testbed.The result showed that QoS using CBQ and TBF eliminated packet loss on UDP/IP transfer while the UDP/IP transfer in best effort made lots of packet loss.The result also showed that the QoS overhead was small.We concluded that QoS on Linux performed efficiently in TCP/IP and UDP/IP and will have an important role of the Atlas TDAQ system.
文摘After having evaluated various H.323 products for these two years,KEK and Japanese HENP community started to move from ISDN(H.320)-based video conferencing environment into IP(H.323)-based one.Primary reason for the move is to cut down the ever increasing ISDN communication cost.At the same time the H.323 can offer us more powerful collaborative environment.In order to make KEK to be a center for the H.323-based collaborative environment in Japan,Picture Tel's LIVE GATEWAY as a H.320/H.323 gateway ,which is essential for the smooth transition,Cisco IP/VA 3510 as a H.323/MCU,and Cisco 2610 as a gatekeeper were installed at KEK in March 2001,And the transition started.In this paper,we'll describe the collaborative environment which our users can have,together with its operational results.
