Emulex Corporation

Emulex Design & Manufacturing Corporation

California Institute of Technology

Karl M Henson

David Brewer

Hossein Hashemi

David Bradley Baldwin

Bradley Eugene Roach

Raul Bersamin Oteyza

David Baldwin

Peter Mark Fiacco

Gregory John Scherer

Jean Xue

John Tang

A loop network hub including a hub port with a loop initialization insertion mechanism. The loop initialization insertion mechanism causes a hub port which detects a new node port connection to automatically begin generating loop initialization data. A hub port continues to generate loop initialization data until that hub port receives a loop initialization sequence. The loop initialization data propagates around the loop of the hub, halting ordinary processing. In this way, the entire loop is cleared. Upon receiving a loop initialization sequence, the hub port originating the loop initialization data inserts the new node port into the loop. At this point, loop initialization begins and each node port in the loop network obtains a unique loop network address.

Loop network hub using loop initialization insertion

A FIFO memory receives data transfer requests before data is stored in the FIFO memory. Multiple concurrent data transfers, delivered to the FIFO memory as interleaved multiple concurrent transactions, can be accommodated by the FIFO memory (i.e., multiplexing between different sources that transmit in distributed bursts). The transfer length requirements associated with the ongoing data transfers are tracked, along with the total available space in the FIFO memory. A programmable buffer zone also can be included in the FIFO memory for additional overflow protection and/or to enable dynamic sizing of FIFO depth.

Receiving data from interleaved multiple concurrent transactions in a FIFO memory having programmable buffer zones

A loop network hub port with an automatic bypass feature. The automatic bypass feature causes the hub port to enter a bypass mode upon detection of a specified loop failure initialization sequence from a node port attached to the hub port. The hub port does not propagate loop failure initialization data generated by the attached node port upon the failure of a data channel from the hub port to the node port. The hub port replaces loop failure initialization data received from the node port with buffer data and conceals the node port failure from the remainder of the loop. Upon detection of the loop failure initialization sequence received from the attached node port, the hub port enters a bypass mode and maintains that bypass mode until a recovery sequence is received from the node port. At that point, the hub port reinserts the node port into the loop.

Automatic isolation in loops

A system and method of sanitizing a data frame from a node in a network loop includes receiving the data frame from the node, and, when the data frame includes invalid data, replacing a first word of the invalid data with a frame termination primitive and subsequent words of the invalid data with buffer data.

Sanitizing fiber channel frames

A frame receive queue may perform disassembly and validation operations on frames received by a node in a Fiber Channel network. The frame receive queue may store information used for later processing of the frames, e.g., header data and the first eight payload words, in an on-chip memory for fast processor access. The payload data for the frames may be stored in a larger, external memory.

Queuing fibre channel receive frames

Sanitizing fibre channel frames

A method whereby a fair port in a Fibre Channel Arbitrated Loop behaves unfairly during portions of its loop tenancy and behaves fairly during other portions. In a preferred implementation, the fair port establishes a first loop circuit with an initial destination port during a loop tenancy. Before relinquishing control of the loop to an arbitrating port, the fair port&mdash;under the control of a transfer protocol&mdash;establishes one or more subsequent loop circuits with other destination ports. Loop circuits are established in sequence without the fair port relinquishing control of the loop and rearbitrating. This continues until (1) the fair port establishes a loop circuit with every destination port to which it desires to exchange information; (2) a fixed time period has lapsed; and/or (3) a predefined maximum number of loop circuits are established.

Variable access fairness in a fibre channel arbitrated loop

A scalable hub divided into a plurality of internal hubs. Each internal hub is connected to a subsequent internal hub in a loop topology. The connection point for each internal hub to the interhub loop is a port which either bypasses that internal hub, isolating the disconnected internal hub, or connects that internal hub to the interhub loop, such that data flows between that internal hub and the interhub loop. In addition the preferred embodiment provides graceful degradation when an internal hub connected to the interhub loop fails.

Scalable hub

A hub port in a hub of a loop network which detects and replaces invalid data and invalid control signals in the datastream of the loop. The hub port detects invalid data and invalid control signals or primitives received from an attached node port and substitutes buffer data or valid primitives. The hub port substitutes buffer data or primitives which have correct running disparity for the datastream at the point of substitution. In another implementation, an error detection device is included in a loop network and monitors the datastream of the loop network. The error detection device detects invalid data and invalid control signals or primitives received from an upstream node in the loop and substitutes buffer data or valid primitives. The error detection device substitutes buffer data or primitives which have correct running disparity for the datastream at the point of substitution.

Elimination of invalid data in loop network

A port for connecting a node to a network loop is disclosed. The port includes a detect element, a frame termination generator, a buffer data generator, a switching element, and a control element. The detect element monitors data from the node and sets an error flag when invalid data is received at the port. The frame termination generator generates frame termination primitives. The buffer data generator generates buffer data. The switching element has a control input, an output, and a plurality of data inputs. Each of an output of the node, the upstream node, the frame termination generator, and the buffer data generator is connected to a corresponding data input. The control element is connected to the detect element and the control input of the switching element. The control element selects, according to the error flag, one of the data inputs of the switching element. The selection connects to the output of the switching element to be output by the port to a downstream node. The control element terminates a current data frame by selecting the data input corresponding to the frame termination generator when the error flag indicates that the current data frame includes invalid data.

Methods and apparatus for implementing a technique for inserting and removing a node in a network loop. In a preferred implementation, a hub port includes a detect element which monitors data from the node and from an upstream node. The detect element sets a first flag when a primitive is received at the port, and sets a second flag when a primitive which is a frame termination primitive is received at the port. A frame termination generator generates frame termination primitives and a buffer data generator generates buffer data. A switching element has a control input, an output, and a plurality of data inputs. One data input is connected to each of an output of the node, the upstream node, the frame termination generator, and the buffer data generator. A control element is connected to the detect element and the control input of the switching element. The control element selects, according to the first flag and the second flag, one of the data inputs of the switching element to connect to the output of the switching element to be output by the port to a downstream node.

Node insertion and removal in a loop network

In a loop network system, a method and apparatus for automatic bypass of a node port associated with a hub port when the node port generates a number of errors beyond a threshold level. In one aspect, a programmable error control circuit provides this automatic bypass. The tolerance level is set through programmable parameters including a number of errors as well as a time interval to evaluate the number of errors detected. After a node port has been bypassed by the error control circuit, the error control circuit continues to monitor the error generation of the node port. When that error generation has reached an acceptable tolerance level, the error control circuit automatically reinserts the node port into the loop. The error control circuit provides statistical reporting on the number of errors as well as the number of bypasses generated at a particular hub port.

Growing community of inventors

Rancho Santa Margarita, CA, United States of America

Karl M Henson