Quality of Service on Gigabit Ethernet for Event Builder

Congestion avoidance techniques for event builders using switching network technologies is a major issue. Traffic management of the data flow is an essential point to avoid congestion. Global traffic control is one of the mechanisms to manage the traffic. It uses global information of the switching network. While, traffic shaping technique is another mechanism not to use them. Quality of Service (QoS) is one of the solutions to avoid this congestion, because it provides the bandwidth allocation in the network. A Gigabit Ethernet technology, which is a major in the high performance network, however, has no functionality of the QoS while ATM has the functionality of the QoS on a hardware level. Recently, IP-based QoS is intensively studied in computer science. On Gigabit Ethernet with the QoS, it will be expected to avoid the congestion of the event builder traffic. We used Alteon network interface card, which can handle large Maximum Transmission Unit (MTU) called jumbo frame. Jumbo frame improves the transfer speed. We also used Linux-based PCs for measuring the performance. We chose several parameters such as device driver parameters, MTU, chipset for PC, bus width of PCI (64/32-bit) and so on, related to the performance. We found high performance chipset for PC and 64-bit PCI bus improved the transfer speed in TCP/IP up to 990Mbit/s with jumbo frame. We had the results that the overhead of the IP-based QoS is very small and the bandwidth allocation worked.