摘要:
A classification system includes a software managed tree testing bits from a key which labels an item. The bits are chosen by application of the Choice Bit Algorithm to the Rules in a Database of Rules. A controller including logic parses an unknown Key for bits to be tested in the decision nodes of a binary tree. Tests dictated by the tree are conducted in a predetermined way until all but one Rule from the database or all but a few Rules from the database are eliminated from consideration, whereupon the Key is fully tested by the one remaining Rule or in a lattice constructed of the remaining plurality of Rules, to determine an action to enforce on the item. Certain compare tests are used in the binary tree for the case that otherwise identical or similar rules are applied to integer ranges of key values which do not fall upon power of 2 boundaries. Furthermore, some very frequently occurring rules in such final tests might be designated as secondary rules, the remaining rules designated as primary rules, the entire decision tree recalculated using only primary rules, and the primary rules then connected to secondary rules only when logically necessary by means of a system of pointers making use of relative priorities of rules.
摘要:
Novel data structures, methods and apparatus for a Software Managed Tree (SMT) which provides a mechanism to create tree structures that follow a search mechanism defined by a control point processor. The search mechanism does not require storage on the previous pointer and uses only a forward pointer along with a next bit or group of bits to test thereby reducing storage space for nodes. The search mechanism processes multiple filter rules for an application without requiring multiple searches and also allows various filter rules to be chained. Two patterns of the same length are stored in each leaf to define a range compare. A compare at the end operation is either a compare under range or a compare under mask. In a compare under range, the input key is checked to determine if it is in the range defined by the two patterns. In a compare under mask, the bits in the input key are compared with the bits in a first leaf pattern under a mask specified in a second leaf pattern.
摘要:
The transport protocol for communicating between general purpose processors acting as contact points and network processors in a packet processing environment such as Ethernet is provided. In such an environment, there is at least one single control point processor (CP) and a plurality of network processors (NP), sometimes referred to as blades. A typical system could contain two to sixteen network processors, and each network processor connects to a plurality of devices which communicate with each other over a network transport, such as Ethernet. The CP typically controls the functionality and the functioning of the network processors to function in a way that connects one end user with another, whether or not the end user is on the same network processor or a different network processor. There are three types of communication provided; first, there is communication generally referred to as control services and normally there will be only one pico processor which operates as a GCH (guided cell handler) and only one that operates as a guided tree handler (GTH). A path is provided for the controls to the GCH and the GTH commands, and a separate path is provided for the data frames between the GDH's (general data handler) and the CP.
摘要:
A network processor useful in network switch apparatus and methods of operating such a processor in which data flow handling and flexibility is enhanced by the cooperation of an embedded processor complex with a suite of peripherals, all formed on a common semiconductor substrate. The interface processors provide data paths for inbound and outbound data flow and operate under the control of instructions stored in an instruction store formed on the semiconductor substrate, while storage of transiting data flow portions is provided by memory peripherals and interfaces to external memory elements.
摘要:
Methods systems and computer program products are provided for hashing address values that exhibit banding in a plurality of regions of an address space defined by at least two segments of the address values, by performing at least one of a translation and a rotation of the at least two segments to thereby map the at least two segments from the plurality of regions to one of the plurality of regions.
摘要:
A data processing system and method in a computer network are disclosed for improving performance of a link aggregation system included in the network. Parameters are established which are utilized to determine performance criteria of the link aggregation system. A performance of the link aggregation system is determined by determining the performance criteria. The performance of the link aggregation system changes in response to a flow traffic burden on the link aggregation system changing. The link aggregation system dynamically modifies the parameters in response to the changing performance of the link aggregation system. The link aggregation system is self-tuning and capable of automatically adjusting to a changing flow traffic burden on the link aggregation system.
摘要:
Novel data structures, methods and apparatus for finding a full match between a search pattern and a pattern stored in a leaf of the search tree. A key is input, a hash function is performed on the key, a direct table (DT) is accessed, and a tree is walked through pattern search control blocks (PSCBs) until reaching a leaf. The search mechanism uses a set of data structures that can be located in a few registers and regular memory, and then used to build a Patricia tree structure that can be manipulated by a relatively simple hardware macro. Both keys and corresponding information needed for retrieval are stored in the Patricia tree structure. The hash function provides an n->n mapping of the bits of the key to the bits of the hash key. The data structure that is used to store the hash key and the related information in the tree is called a leaf. Each leaf corresponds to a single key that matches exactly with the input key. The leaf contains the key as well as additional information. The length of the leaf is programmable, as is the length of the key. The leaf is stored in random access memory and is implemented as a single memory entry. If the key is located in the direct table then it is called a direct leaf.
摘要:
A network switch apparatus, components for such an apparatus, and methods of operating such an apparatus in which data flow handling and flexibility is enhanced by the cooperation of a plurality of memory elements and a plurality of interface processors formed on a semiconductor substrate. The memory elements and interface processors together form a network processor capable of cooperating with other elements in executing instructions directing the flow of data in a network. Access to the memory elements is controlled in a particular manner and under operative rules which provide controlled multiple accesses of the plurality of memory elements by the plurality of processors.
摘要:
Novel data structures, methods and apparatus for finding the longest prefix match search when searching tables with variable length patterns or prefixes. To find the exact match or the best matching prefix, patterns have to be compared a bit at a time until the exact or first: match is found. This requires “n” number of comparisons or memory accesses to identify the closest matching pattern. The trees are built in such a way that the matching result is guaranteed to be a best match, whether it is an exact match or a longest prefix match. Using the trail of all the birds and associated prefix lengths enables determination of the correct prefix result from the trail. By construction, the search tree provides the best matching prefix at or after the first compare during walking of the trail or tree.
摘要:
Novel data structures, methods and apparatus for finding the longest prefix match search when searching tables with variable length patterns or prefixes. To find the exact match or the best matching prefix, patterns have to be compared a bit at a time until the exact or first match is found. This requires “n” number of comparisons or memory accesses to identify the closest matching pattern. The trees are built in such a way that the matching result is guaranteed to be a best match, whether it is an exact match or a longest prefix match. Using the trail of all the birds and associated prefix lengths enables determination of the correct prefix result from the trail. By construction, the search tree provides the best matching prefix at or after the first compare during walking of the trail or tree.