Apparatus and methods for sniffing data in a cable head end

Abstract

Disclosed are methods and apparatus for selectively filtering data messages that are communicated between a head end complex and its associated cable modems. Filtering includes obtaining a copy of the message and sending the copied message to a memory device. The memory device is accessible, for example, via a user so that the filtered message may be analyzed. In a preferred embodiment, the memory device is a monitoring device in the form of a computer system (e.g., a router). Messages may be filtered to the memory or monitoring device based on any suitable filtering criteria that identifies specific message parameters. In a specific embodiment, filtering may be based on one or more message types. When filtering criteria specifies a particular message type, messages having such a specified type are filtered to the monitoring station. Additionally or alternatively, filtering may be based on one or more values of a particular field of the message. For instance, when filtering criteria is set to a particular field value, messages that contains that particular field value are copied and sent to the monitoring device. Filtering may also or alternatively be based on whether a message is associated with the downstream channel, the upstream channel, or a particular port number.