摘要
通常要传输的IP报文的大小超过链路层最大传输单元(MTU)时就会产生IP分片,大量的IP分片会对网络产生多种影响。针对IP分片现象,首先介绍了IP分片的基本原理,通过对报文分片的测试,分析了IP分片对网络丢包率和延时等网络性能参数的影响;通过对专网应用案例的分析,说明了IP分片会造成业务数据不能得到相应服务质量QoS等级的保障。通过虚拟专用网络VPN技术组网案例的分析,提出了网络设计应整体规划MTU以避免IP分片的观点。
The IP fragments are generated when the size of IP messages usually to be transmitted exceeds the Maximum Transmission Unit （MTU） of link layer. A large number of IP fragments will produce a variety of influences on network. Aiming at the phenomenon of IP fragment, this paper introduces the basic principles of IP fragment, analyzes the influences of IP fragment on network performance parameters such as network package loss rate, time-delay, etc. by testing the message fragment. The analysis on application case of virtual private network （VPN） show that the IP fragment may make the service data not get the corresponding guarantee of Quality of Service （QoS） level. Based on analysis on VPN technology networking case , this paper proposes the opinion that the network design should comprehensively plan MTU to avoid IP fragment.
出处
《计算机与网络》
2014年第9期64-67,共4页
Computer & Network
