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 device including an ingress processor and egress processor which receives frames of data over the network on an input port, and transfers it to an appropriate output port. The received frame is processed by an ingress processor which prepares an intra-switch frame for delivery to an egress processor serving a relevant output port of the switch. The intra-switch frame includes a frame header having parameters which have been determined by the ingress processor, as well as data indicating an address for the egress processor for beginning processing of the frame. By identifying to the egress processor processing which has already taken place, the egress processor is relieved of any redundant processing of the frame. The egress processor provides a hardware frame classifier which decodes the information contained in the intra-frame header to derive parameters which have been previously computed as well as a starting address for the egress processor. By reducing the amount of redundant processing of the egress processor, total device throughput delay is reduced.
摘要:
A system and method of moving information units from a network processor toward a data transmission network in a prioritized sequence which accommodates several different levels of service. The present invention includes a method and system for scheduling the egress of processed information units (or frames) from a network processing unit according to stored priorities associated with the various sources of the information units. The priorities in the preferred embodiment include a low latency service, a minimum bandwidth, a weighted fair queueing and a system for preventing a user from continuing to exceed his service levels over an extended period. The present invention includes a plurality of calendars with different service rates to allow a user to select the service rate which he desires. If a customer has chosen a high bandwidth for service, the customer will be included in a calendar which is serviced more often than if the customer has chosen a lower bandwidth.
摘要:
A system and method uses grouped calendars, flow queues, pointers and stored rules to process information packets so that different flow control characteristics associated with the information units are maintained.
摘要:
An apparatus is disclosed for transporting control information in a communications system. The apparatus comprises a network processor, a control point processor operatively coupled to the network processor, and a guided frame generated by the control point processor. The guided frame comprises a first section in which frame control information is placed and is used by the network processor to update at least one control register within the network processor; a second section carrying correlators assigned by the control point processor to correlate guided frame responses with their requests; a third section carrying one or a sequence of guided commands; and an End delimiter guided command.
摘要:
A control sub system, a plurality of interface processors, a plurality of media interfaces a plurality of queues are operatively coupled and responsive to a control signal to move data from a memory to a selected one of the plurality of queues.
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 control point and a plurality of interface processors formed on a semiconductor substrate. The control point and interface processors together form a network processor capable of cooperating with other elements including an optional switching fabric device in executing instructions directing the flow of data in a network.
摘要:
A system and method of moving information units from an output flow control toward a data transmission network in a prioritized sequence which accommodates several different levels of service. The present invention includes a method and system for scheduling the egress of processed information units (or frames) from a network processing unit according to service based on a weighted fair queue where position in the queue is adjusted after each service based on a weight factor and the length of frame, a process which provides a method for and system of interaction between different calendar types is used to provide minimum bandwidth, best effort bandwidth, weighted fair queuing service, best effort peak bandwidth, and maximum burst size specifications. The present invention permits different combinations of service that can be used to create different QoS specifications. The “base” services which are offered to a customer in the example described in this patent application are minimum bandwidth, best effort, peak and maximum burst size (or MBS), which may be combined as desired. For example, a user could specify minimum bandwidth plus best effort additional bandwidth and the system would provide this capability by putting the flow queue in both the NLS and WFQ calendar. The system includes tests when a flow queue is in multiple calendars to determine when it must come out.
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 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 among a plurality of interface processors and a suite of peripheral elements formed on a semiconductor substrate. The interface processors and peripherals together form a network processor capable of cooperating with other elements including an optional switching fabric device in executing instructions directing the flow of data in a network.