基于XMPP的TR069反向连接的私网穿越

Private Network Traversal Based on XMPP TR069 Reverse Connection

TR069的整体架构由客户终端设备和自动配置服务器ACS构成,其中CPE部署在私网环境下,ACS服务器则部署在公网环境下。当ACS服务器利用TR069对CPE进行远程管理时需要主动发起连接,由于网络地址转换会使得CPE的网际协议IP地址发生变化,从而在公网环境下的ACS无法直接访问CPE,这会给管理人员带来很大的麻烦。NAT会话穿越应用程序技术可以实现私网穿越从而解决这一问题,但是STUN技术的缺点是用户数据报协议不可靠且会重传丢包,还依赖上层路由的网络地址转换规则时间,因此设计并实现了一种基于可扩展通信和表示协议的TR069的反向连接的私网穿越方案。该方案采取简单的服务器/客户端架构,采用CPE和ACS作为XMPP客户端的方式,它的特点在于使用传输控制协议进行传输,由于TCP比UDP连接更可靠,效率更高,因此在私网穿越方案上,同样的条件下,使用XMPP技术的TR069的主动连接成功率比使用STUN技术要高,丢包率比STUN技术要低,ACS调用远程重启方法成功率比STUN技术要高,说明了在CPE与ACS的通信质量上,基于XMPP技术比基于STUN技术的TR069私网穿越方案更佳。

The appearance of CPE Wan Management Protocol(TR069)has brought great convenience to people,the overall architecture of TR069 is composed of Customer Premise Equipment(CPE)and Auto-Configuration Server(ACS),some CPES are deployed on a private network,while the ACS server is deployed on a public network.When the ACS server uses TR069 to remotely manage the CPE,it needs to initiate a connection,as the Internet Protocol(IP)address of the CPE changes due to network address translation,the ACS on a public network cannot access the CPE directly,which causes great trouble to the management personnel.Session Traversal Utilities for NAT(STUN)technology solves this problem by enabling private traversal.However,STUN technology has the disadvantages of unreliable User Datagram Protocol(UDP),the retransmission packet loss,and dependence on the Network Address Translation(NAT)rule time of upper-layer routes.Therefore,a reverse connection of TR069’s private network traversal scheme based on Extensible Communication and Presentation Protocol(XMPP)technology is designed and implemented.The scheme adopts a simple server/client architecture,using CPE and ACS as XMPP clients.It is characterized by using Transmission Control Protocol(TCP)for transmission,because TCP is more reliable and efficient than UDP.Therefore,in the private network traversal scheme,under the same conditions,TR069 using XMPP technology has a higher success rate of active connection,a lower packet loss rate,and a higher success rate of ACS calling remote restart method than STUN technology,indicating that in the communication quality between CPE and ACS,TR069 private network traversal scheme based on XMPP is better than that based on STUN.