Abstract: An adaptive weighted round robin scheduling apparatus and method schedules variable-length frame transmissions from a plurality of output queues having different transmission priorities by first allocating, for each queue, a number of bandwidth segments for a bandwidth cycle and a number of transmission opportunities for a round robin cycle, and then processing the queues consecutively in a round-robin fashion, beginning with a highest priority queue, until none of the queues has any bandwidth remaining. More specifically, during each iteration of a round robin cycle, a queue is permitted to transmit a frame if the queue has at least one remaining transmission opportunity, the queue has a frame ready for transmission, and the queue has at least one remaining bandwidth segment, and furthermore the number of transmission opportunities for the queue is decremented by at least one.

Abstract: A method of mirroring data to a mirrored to port in a plurality of switches. The method has the steps of determining if data was sent to all of said plurality of switches; determining if said data was sent to a mirrored to port (MTP); and resending said data to all of said plurality of switches if mirroring is enabled and said data was not sent to said MTP.

Abstract: A network switch for switching packets from a source to a destination includes a source port for receiving an incoming packet from a source, a destination port which contains a path to a destination for the packet, and a filter unit for constructing and applying a filter to selected fields of the incoming packet. The filter unit further includes filtering logic for selecting desired fields of the incoming packet and copying selected field information therefrom. The filtering logic also constructs a field value based upon the selected fields, and applies a plurality stored field masks on the field value. The switch additionally includes a rules table which contains a plurality of rules therein. The filtering logic is configured to perform lookups of the rules table in order to determine actions which must be taken based upon the result of a comparison between the field value and the stored filter masks and the rules table lookup.

Abstract: A method of handling packets includes inserting a stack-specific tag into a packet, then processing the packet in a stack of network switches in accordance with tag information in the stack-specific tag. The stack-specific tag is then removed from the packet.

Abstract: A network switch for switching packets from a source to a destination includes a source port for receiving an incoming packet from a source, a destination port which contains a path to a destination for the packet, and a filter unit for constructing and applying a filter to selected fields of the incoming packet. The filter unit further includes filtering logic for selecting desired fields of the incoming packet and copying selected field information therefrom. The filtering logic also constructs a field value based upon the selected fields, and applies a plurality stored field masks on the field value. The switch additionally includes a rules table which contains a plurality of rules therein. The filtering logic is configured to perform lookups of the rules table in order to determine actions which must be taken based upon the result of a comparison between the field value and the stored filter masks and the rules table lookup.

Abstract: A method of mirroring data to a mirrored to port in a plurality of switches. The method has the steps of determining if data was sent to all of said plurality of switches; determining if said data was sent to a mirrored to port (MTP); and resending said data to all of said plurality of switches if mirroring is enabled and said data was not sent to said MTP.

Abstract: Methods, systems, and devices are provided for managing flow of datagram traffic, generally across networks. According to some of these methods, a flow control mechanism is used to avoid over-subscription of some ports without pausing extended areas of a network. According to other methods, a congestion control mechanism is used to minimize datagram traffic between a port sending datagrams to an over-subscribed port and the over-subscribed port itself.

Abstract: A method of distributing data across a network having a plurality of equal-cost paths. Also, a device for distributing data over a network according to the method. The data, which is typically contained in data packets, may be distributed based on at least one attribute of each of the packets. The data may also be distributed according to a weighted distribution function that allows for unequal amounts of traffic to be distributed to each of the equal-cost paths.

Abstract: A method of handling packets includes inserting a stack-specific tag into a packet, then processing the packet in a stack of network switches in accordance with tag information in the stack-specific tag. The stack-specific tag is then removed from the packet.

Abstract: Aspects for processing data in a server may include receiving a packet and determining a function associated with the packet. A blade server handling the function associated with the packet may be determined and the packet may be steered to that blade server. At least one association may be generated or created between a particular characteristic of a packet and a particular function associated with that packet. At least one blade server may be assigned to handle the particular function associated with a packet. The particular characteristic of the packet may include, for example, a packet type, a field within the packet and/or a flag within a portion of the packet. Steered packets may be processed by one or more blade servers that may be adapted to handle the function associated with the packets. A switch blade may be utilized to control steering of the received packets.

Abstract: A method and a system for improving communication performance between nodes in a network is disclosed. In one embodiment, the system includes routers, switches, and a communication interface. The communication interface detects a communication flow between a source and a destination in response to a flow criteria. Upon detecting the communication flow, the communication interface issues a resolution request for identifying data path. After receipt of a response to the resolution request, multiple connections between switches are established in response to levels of quality of service (QoS).

Abstract: A technique for establishing a shortcut Virtual Channel Connection (VCC) in a Multi-Protocol Over ATM (MPOA) system detects a packet flow, and then determines whether to establish the shortcut VCC based upon an expected MPOA server response time. Specifically, an expected MPOA server response time is determined based upon an MPOA server response time history. The expected MPOA server response time is then compared to a predetermined MPOA server response time threshold to determine whether the expected MPOA server response time is within the predetermined MPOA server response time threshold. The shortcut VCC is established if the expected MPOA server response time is within the predetermined MPOA server response time threshold. Upon establishing the shortcut VCC, the MPOA server response time history is updated to reflect an actual MPOA server response time incurred when establishing the shortcut VCC.

Abstract: A method of forwarding data in a network switch fabric is disclosed. An incoming data packet is received at a first port of the fabric and a first packet portion, less than a full packet length, is read to determine particular packet information including an opcode value. The opcode value allows the fabric to determine the packet type, such a a whether the packet is a broadcast packet, a unicast packet, a multicast packet, etc. Based on the opcode value read, a particular forwarding table of a plurality forwarding tables is read and an egress port bitmap is determined based on entries read from the particular forwarding table. The incoming data packet is then forwarded based on the egress port bitmap. In addition, the architecture of the switch fabric is also disclosed.

Abstract: A network device for network communications is disclosed. The device includes at least one data port interface, the at least one data port interface supporting at least one data port transmitting and receiving data and a CPU interface, the CPU interface configured to communicate with a CPU. The network device also includes a memory communicating with the at least one data port interface, a memory management unit, the memory management unit including a memory interface for communicating data from the at least one data port interface and the memory and a communication channel, the communication channel for communicating data and messaging information between the at least one data port interface, the CPU interface, the memory, and the memory management unit.

Abstract: A network switch for network communications is disclosed. The switch includes a first data port interface, supporting at least one data port transmitting and receiving data at a first data rate and a second data port interface, supporting at least one data port transmitting and receiving data at a second data rate. A memory management unit for communicating data from at least one of the first data port interface and the second data port interface and a memory is also included. The switch uses a communication channel for communicating data and messaging information between the first data port interface, the second data port interface, and the memory management unit. The switch also has a plurality of lookup tables, including an address resolution lookup table, a VLAN table and module port table.

Abstract: An adaptive weighted round robin scheduling apparatus and method schedules variable-length frame transmissions from a plurality of output queues having different transmission priorities by first allocating, for each queue, a number of bandwidth segments for a bandwidth cycle and a number of transmission opportunities for a round robin cycle, and then processing the queues consecutively in a round-robin fashion, beginning with a highest priority queue, until none of the queues has any bandwidth remaining. More specifically, during each iteration of a round robin cycle, a queue is permitted to transmit a frame if the queue has at least one remaining transmission opportunity, the queue has a frame ready for transmission, and the queue has at least one remaining bandwidth segment, and furthermore the number of transmission opportunities for the queue is decremented by at least one.

Abstract: A method of forwarding data in a network switch fabric is disclosed. An incoming data packet is received at a first port of the fabric and a first packet portion, less than a full packet length, is read to determine particular packet information, the particular packet information including a source address and a destination address. An egress port bitmap is determined based on a lookup in a forwarding table and it is determined if the destination address belongs to a trunk group of trunked ports. The incoming data packet is forwarded based on the egress port bitmap, when the destination address does not belong to the trunk group. When the destination address does belong to the trunk group, a particular trunked port of the trunk group is determined and the incoming data packet is forwarded thereto.

Abstract: A method of forwarding data in a network switch fabric is disclosed. An incoming data packet is received at a first port of the fabric and a first packet portion, less than a full packet length, is read to determine particular packet information including an opcode value. The opcode value allows the fabric to determine the packet type, sucha a whether the packet is a broadcast packet, a unicast packet, a multicast packet, etc. Based on the opcode value read, a particular forwarding table of a plurality forwarding tables is read and an egress port bitmap is determined based on entries read from the particular forwarding table. The incoming data packet is then forwarded based on the egress port bitmap. In addition, the architecture of the switch fabric is also disclosed.

Abstract: A method of forwarding data in a network switch fabric is disclosed. An incoming data packet is received at a first port of the fabric and a first packet portion, less than a full packet length, is read to determine particular packet information, the particular packet information including a source address and a destination address. An egress port bitmap is determined based on a lookup in a forwarding table and it is determined if the destination address belongs to a trunk group of trunked ports. The incoming data packet is forwarded based on the egress port bitmap, when the destination address does not belong to the trunk group. When the destination address does belong to the trunk group, a particular trunked port of the trunk group is determined and the incoming data packet is forwarded thereto.

Abstract: A method for establishing a virtual channel between network devices is disclosed. In the case of a local network device establishing a virtual channel with a remote network device, a virtual channel request message is sent from the local network device to the remote network device. A virtual channel acknowledgement message and a remote capability list are received and a virtual channel resume message and a local capability list are sent. The virtual channel is then enabled. In the case of a remote network device establishing a virtual channel with a local network device, a virtual channel request message is received from a local network device by a remote network device. A virtual channel acknowledgement message and a remote capability list are sent and a virtual channel resume message and a local capability list are received. The virtual channel is then enabled.