| 摘要 |
<p>A method and device for packet inspection whereby packets presented via an interleaved cell stream can be inspected 'on the fly' to identify, for example, the sequence of protocol encapsulations for each packet, as well as those portions of the packet which should be captured. The packet inspector is therefore capable of operating at high speeds. The packet inspector can also be used to inspect the payload portion of packets, if desired. A connection table look-up unit is used that accesses connection-based control data from a connection table for each cell input to the packet inspector. The look-up unit forwards the cell-specific control data to a data inspector via a forward control path, and the data inspector uses this control data when processing the associated cell. When processing of that cell is complete, the data inspector updates the associated control data to summarize its findings thus far, and then sends the updated control data back towards the look-up unit via a reverse control path for storage. When the next cell of the same packet is presented to the packet processor, the look-up unit retrieves and forwards the stored control data, which the data inspector uses to resumes the packet inspection process. A mechanism is also provided for replacing the control data for a cell propagating on the forward control path with updated control data that is propagating on the reverse control path.</p> |
