Patent ID: 7870278
Filing Date: 2011-01-11
Classification: H04L,Y10S

Abstract:
1. A wire-speed forwarding platform for supporting multifield classification of a packet fragmented into a plurality of fragments, the platform comprising: media interface for receiving a fragment of the fragmented packet at the forwarding platform; a network processor device for preprocessing the received fragment by querying a data structure in the forwarding platform, the data structure comprising one or more flags for determining whether the received fragment is to be classified in the forwarding platform, one queried flag indicating presence of any re-defined transfer control protocol (TCP) rules to apply, and performing multifield classification of the received fragment in the forwarding platform if said one queried flag indicates no TCP rules to apply; or, either redirecting or discarding the received fragment from the forwarding platform if it is determined that the received fragment is not to be classified at the forwarding platform; and said network processor for deriving a key from one or more fields of the received fragment; and performing multifield classification of the received fragment by matching the key to a rule out of a plurality of rules, the rule comprising a plurality of fields including at least a first field comprising a first fragmented flag (FRAG) for specifying if this rule should match fragmented frames, non-fragmented frames, or both; and a second field comprising a not subsequent fragment flag (NO SUBS) in the rule key specifying whether this rule should match only non-fragmented frames including a first fragment of a fragmented frame, or is to be matched only to subsequent fragments of a fragmented frame, whereby said first and second fields specify whether the received fragment's fragmentation characteristics are to be applied when performing the multifield classification.