嵌入式网络设备TCP高可用技术研究  

Research on TCP High Availability Technology for Embedded Network Device

作　　者：程友清[1,2] 余少华[1,2] 

机构地区：[1]华中科技大学计算机学院,武汉430074 [2]武汉邮电科学研究院,武汉430074

出　　处：《小型微型计算机系统》2013年第2期199-204,共6页Journal of Chinese Computer Systems

基　　金：科技部2008科研院所技术开发研究专项资金项目资助;国家发改委2008电子信息产业振兴和技术改造国家项目资助

摘　　要：对数据网络中嵌入式双主控设备和虚拟集群交换系统的TCP高可用技术进行了研究.提出一种新的TCP高可用方案,该方案对TCP/IP协议栈和TCP应用软件做少量改动.主用设备只需在TCP连接建立或关闭时向备用发送TCP连接同步信息,备用设备上TCP/IP栈收到同步信息后强制创建或关闭TCP套接字并将相应信息保存到TCP控制块,同时将TCP套接字信息通知TCP应用做相应处理;主用故障时备用切换为主用,转主用后TCP同步连接根据收到的第一个TCP包初始化TCP连接的发送和接收序列号等信息并完成TCP连接的倒换.该TCP高可用方案在实际设备中得到了应用,测试和实际工程应用表明,主备间只需要很少的通信量就可以实现TCP连接同步,且主备倒换时TCP连接能在毫秒级的时间成功切换.This paper focus on research of TCP high availability technology for embedded double controller network device or virtual cluster switch system in data communication network. It puts forward a new TCP high availability scheme, which only makes a small amount of modification of the TCP/IP protocol stack and upper layer TCP applications. The master synchronizes TCP connection in- formation to slave only when the TCP connection was established or closed, the TCP/IP protocol stack in slave card or device uses the received TCP synchronization information to create or close the TCP socket and store the TCP connection information into TCP control block （TCPCB）, then inform the TCP socket information to upper layer TCP applications to handle. When master crashes for some reason, the slave will change to master immediately, the synchronized TCP connection on the new master initializes its TCP control block information, such as send packet sequence number and receive packet sequence number, when receives the first TCP packet of the TCP socket. After that the TCP connection has been switched successfully, the upper layer TCP applications then send or receive packet as a normal TCP connection. The scheme described above has been used in practice on high-end Ethemet switch and router de- veloped by the author＇s team, the test results and practical application show that the TCP high availability scheme consumed a small a- mount of communication bandwidth to synchronize the TCP connection information from master to slave and achieved microsecond level switchover of TCP connection when master card or device going down.

关 键 词：嵌入式网络设备 TCP 高可用 TCP IP栈 TCP应用 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]