摘要:
Network processors commonly utilize DRAM chips for the storage of data. Each DRAM chip contains multiple banks for quick storage of data and access to that data. Latency in the transfer or the ‘write’ of data into memory can occur because of a phenomenon referred to as memory bank polarization. By a procedure called quadword rotation, this latency effect is effectively eliminated. Data frames received by the network processor are transferred to a receive queue (FIFO). The frames are divided into segments that are written into the memory of the DRAM in accordance with a formula that rotates the distribution of each segment into the memory banks of the DRAM.
摘要:
A system includes a data structure having a Direct Table (DT), Patricia-Trees, Pointers and high speed storage systems such as Contents Address Memory (CAM). The DT has a plurality of entries with each one coupled to a Patricia Tree having multiple nodes coupled to leaves. The number of Nodes, termed a threshold, that can be traversed to obtain information in the leaves is limited to a predetermined value. Once the threshold is reached a pointer indicates the address of the CAM and the address of the leaves is stored in the CAM. By using the structure and method the latency associated with tree search is significantly reduced.
摘要:
Packets or frames of data may be compressed, encrypted/decrypted, filtered, classified, searched or subjected to other deep-packet processing operations before being distributed through the internet. The microprocessor system and method of the present invention provide for the orderly processing of such data packets without disrupting or changing the sequence in which the data is intended to be transmitted to its destination. This is achieved by receiving frames into an input buffer for processing. Associated with this input buffer is a unit for determining the operation to be performed on each frame. An arbitrator assigns each frame to a processing core engine. An output buffer collects the processed frames, and a sequencer forwards the processed frames from the output buffer to their destination in the same order as received by the input/output buffer. Maintaining the sequence of data transmission is particularly useful in voice transmission, such as videos and movies.
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. A system for allowing peak bursts based on a system of credits and charges is taught along limits on such peak bursts. Also taught is a system for preventing a flow's disconnection and reconnection to the queues from allowing it to unfairly achieve an improved position.
摘要:
A system and method of altering frames being processed by a network processing unit. The system includes a set of defined alterations, with some of the alterations being fixed alterations which are advantageously handled by hardware to accomplish the fixed alterations rapidly and without executing a stored program and other alterations which include a variable portion, with these variable alterations being accomplished through the use of stored programs allowing the variables to be used to effect variable alterations to a frame. The present system accommodates a change in the duration of life of a frame or information unit and addition or deletion of bits and also allows for a new cyclic redundancy checking to be accomplished for a revised information unit. Advantageously, the frame alteration system is on the same substrate as the processors.
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.
摘要:
A Network Processor (NP) is formed from a plurality of operatively coupled chips. The NP includes a Network Processor Complex (NPC) Chip coupled to a Data Flow Chip and Data Store Memory coupled to the Data Flow Chip. An optional Scheduler Chip is coupled to the Data Flow Chip. The named components are replicated to create a symmetric ingress and egress structure.
摘要:
A system and method of transmitting multiple output messages from a single input message system where the system is keeping the messages in order by correlating the output messages with the input messages. For each output message, an indicator is associated with the output message indicating whether this output message is the last message being generated for the given input message. This allows multicasting to occur in a system where the output is matched to the input by allowing multiple output messages to be associated with a single input message.
摘要:
A method and system for efficiently implementing an error correction code scheme. In one embodiment of the present invention, a system comprises a processor configured to process frames of data. Each frame of data may be associated with a frame control block. The processor comprises a first queue configured to store one or more frame control blocks associated with one or more frames of data. The processor further comprises a second queue configured to store one or more frame control blocks not associated with a frame of data. The one or more frame control blocks associated with one or more frames of data in the first queue comprise a bit for storing a parity bit. The one or more frame control blocks in the second queue comprise a plurality of bits for storing a code of an error correction code scheme.
摘要:
A method for integrating Asynchronous Transfer Mode (ATM) and frame-based traffic flows within a telecommunications network is disclosed. The telecommunications network includes a network processor having upside processing means for delivering an incoming flow from the telecommunications network to a switch and downside processing means for delivering outgoing network traffic from the switch to the telecommunications network. The incoming flow is initially received at the upside processing means as a frame-based flow. The incoming flow may be characterized as belonging to a group having frame-based flows and ATM flows. In response to the receipt of the incoming flow, the incoming flow is determined if it is destined for a legacy, ATM-only device. The incoming flow is then processed according to the determined routing requirements and the incoming flow characterization before delivering the incoming flow to the switch.