PA-assisted IP Reassembly Operation

The current version of PASS does not support IP reassembly, the IP fragments can be detected by PASS, forwarded to and reassembled at host. The reassembled IP packet may be forwarded back to PASS for continuous classification. The drawback of this approach is that the order of the incoming packets will not be maintained.

To provide better support for IP reassembly, the PA-assisted IP Reassembly operation is introduced and summarized below:

Note:
The minimum size packet wire rate throughput will not be guaranteed when this feature is enabled and there are active traffic flows.

The host IP reassembly module should interact with PASS and perform the full IP reassembly operation. The module user may choose to implement a simplified version of IP reassembly algorithm to save CPU cycle in controlled IP environment. A sample reassembly module is provided in the PA LLD release package, which demonstrates how to interact with the NetCP to perform the IP reassembly operation.

The sample code implements a simplified version of IP reassembly algorithm which supports non-overlapping segments only. The sample code performs the following tasks:


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