摘要 |
Methods and apparatus for wiretapping IP telephone calls are described. At the time an IP telephone registers its current IP address and telephone number with a soft switch responsible for routing calls to the IP telephony device a list of telephone numbers to be monitored is checked. If the number being registered is to be monitored, information identifying the edge router through which the IP telephony device connects to the IP network is obtained. The edge router is then sent a monitor message with the IP address corresponding to the telephone number to be monitored. IP packets including the specified IP address are then forwarded by the identified edge router to a monitoring station. Packet forwarding may involve packet duplication with the original packets being allowed to continue on to their original destination and the duplicated packets being forwarded or, alternatively, a simple packet redirection operation.
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