关键词: 非对称数字用户线路（ADSL）, 数字用户线接入复用器（DSLAM）, 异步传输模式（ATM）, 监听

Abstract: Traditional interception is hard to be implemented in Asymmetric Digital Subscriber Line（ADSL） because of its end-to-end architecture.Analyzing the encapsulating methods ADSL carrying network traffic and user authentication，the gateway based on Digital Subscribe Loop Access Multiplexer（DSLAM） technology is designed.This paper describes the picking-up of IP packages and the mapping of ATM channels in detail and the user’s network traffic is online intercepted.

Key words: Asymmetric Digital Subscriber Line（ADSL）, Digital Subscribe Loop Access Multiplexer（DSLAM）, Asynchronous Transfer Mode（ATM）, interception