对Linux操作系统中TCP／IP网络协议的IP层排队分析

随着网络技术的快速发展，主机间的通信速率已提高到千兆数量级，同时多媒体应用还要求网络协议支持多种业务类型。因此对传统的TCP／IP协议栈进行研究，找出它们是否适于支持高速通信及提供QoS保障，并给出相应的改进方法具有重要的意义。基于这样的思路该文对Linux操作系统中的TCP／IP协议的IP层排队进行了分析，提出了一种基于检测点的对TCP/IP协议栈IP层排队进行检测的方法。经实验发现在100M的网络速率下IP层的输入侧没有排队现象发生，在IP层的输出侧的排队在大吞吐量时有周期性的变化现象。因此在Linux的TCP／IP协议栈中仅需要在IP层的输出侧引入相应的分组调度算法（如WFQ）以提供QoS支持。

Analysis of the IP Layer Queuing of the TCP/IP Protocol Stack of Linux

With the rapid progress of network technology, the communication rate between hosts has reached Gigabit per second, and the multimedia applications require the network protocols to support multi service. So it is important to investigate the traditional TCP/IP protocol stack to find out whether it is suitable for high speed communications and providing QoS. Based on this consideration, the queuing of IP layer of the Linux TCP/IP stack is analyzed in this paper. A probing node method is proposed to investigate the internal IP queuing of the stack. Our experiments show that there is no queuing at the receiving side of the IP layer when the rate is 100Mbps, and the queuing of the sending side of the IP layer has periodical behavior. More sophisticated packet schedulers such as WFQ are needed at the sending side of the IP layer to provide QoS in the future.