Abstract: A method and system for an aggregated virtual local area network (VLAN) architecture in which several VLANs in a network share the same default router address and subnet mask, but remain isolated from one another's network traffic. Instead of the traditional method of assigning one subnet to a VLAN, each VLAN is assigned only a portion of a subnet's IP address space, and is further grouped into a super-VLAN uniquely associated with that subnet. Intra-VLAN traffic is forwarded only to host IP addresses assigned to that same VLAN according to a VLAN identifier carried in the data packet. Inter-VLAN traffic is processed by a virtual router interface which routes the data packet by applying the routing configuration for the subnet uniquely associated with the super-VLAN, according to a super-VLAN identifier carried in the data packet. The routing configuration used by the virtual router interface includes routing protocols, static routes, redundant router protocols and access-lists.

Abstract: A method and system is provided in which data packets from multiple customer VLANs are forwarded over a MAN using VLAN aggregation. A layer-2 switch located at the edge of the MAN connects the customer VLANs to the MAN. The edge switch aggregates multiple customer VLANs (the “sub-VLANs”) into one provider VLAN (the “super-VLAN”). When a packet is forwarded from the sub-VLAN to the super-VLAN and vice versa, the edge switch uses modified bridge forwarding rules to exchange the customer-configured VLAN-IDs with the provider-configured VLAN-IDs before transporting the packet over the MAN. The edge switch further uses modified bridge media access control (MAC) address learning rules to isolate one customer's traffic from another's (i.e. isolate one sub-VLAN's traffic from another sub-VLAN's traffic).

Abstract: A flexible, policy-based, mechanism for managing, monitoring, and prioritizing traffic within a network and allocating bandwidth to achieve true quality of service (QoS) is provided. According to one aspect of the present invention, a method is provided for managing bandwidth allocation in a network that employs a non-deterministic access protocol, such as an Ethernet network. A packet forwarding device receives information indicative of a set of traffic groups, such as: a MAC address, or IEEE 802.1p priority indicator or 802.1Q frame tag, if the QoS policy is based upon individual station applications; or a physical port if the QoS policy is based purely upon topology. The packet forwarding device additionally receives bandwidth parameters corresponding to the traffic groups.

Abstract: A method and apparatus is provided for automatic protection switching in a ring network by creating a protection domain having a control vlan and protected data vlans and designating a master node and transit nodes connected by a primary port and a secondary port. The master node blocks the secondary port for data vlan traffic until it detects a fault either by notice from a transit node or by polling. When a fault is detected, the master node unblocks the secondary port for data vlan traffic. When the fault is restored, the transit node temporarily blocks the restored port to data vlan traffic thereby preventing a loop. Each time the secondary port is blocked and unblocked, the forwarding databases on all the nodes are flushed.

Abstract: A flexible, policy-based, mechanism for managing, monitoring, and prioritizing traffic within a network and allocating bandwidth to achieve true quality of service (QoS) is provided. According to one aspect of the present invention, a method is provided for managing bandwidth allocation in a network that employs a non-deterministic access protocol, such as an Ethernet network. A packet forwarding device receives information indicative of a set of traffic groups, such as: a MAC address, or IEEE 802.1p priority indicator or 802.1Q frame tag, if the QoS policy is based upon individual station applications; or a physical port if the QoS policy is based purely upon topology. The packet forwarding device additionally receives bandwidth parameters corresponding to the traffic groups.

Abstract: A flexible, policy-based, mechanism for managing, monitoring, and prioritizing traffic within a network and allocating bandwidth to achieve true quality of service (QoS) is provided. According to one aspect of the present invention, a method is provided for managing bandwidth allocation in a network that employs a non-deterministic access protocol, such as an Ethernet network. A packet forwarding device receives information indicative of a set of traffic groups, such as: a MAC address, or IEEE 802.1p priority indicator or 802.1Q frame tag, if the QoS policy is based upon individual station applications; or a physical port if the QoS policy is based purely upon topology. The packet forwarding device additionally receives bandwidth parameters corresponding to the traffic groups.

Abstract: A method and system is provided for monitoring the health of processes running on a router. A behavior of a process is monitored and the process is killed if the behavior is abnormal. The behavior may be abnormal if the process is non-responsive, cannot start, or repeatedly crashes. The system may include a timer to measure a predetermined time interval for the process to perform a desired action, a counter to count a number of times the process fails to perform the desired action before the timer expires, and a controller to kill the process when the counter exceeds a maximum number of failures. Alternatively, the timer could measure an amount of uptime, the counter could count the number of times the process crashes, and the controller could kill the process when a crash rate calculated from the number of times the process crashes per the amount of uptime exceeds a maximum crash rate.

Abstract: A method and apparatus is provided to restore the configuration of a network device. A configuration manager in a network device saves a version of the configuration of the network device by storing the configuration data in an format that conforms to a standard markup language such as the extended markup language (XML). The format includes a sequence of corresponding tags and values that represent the content of the internal data structures in the memory of the router that comprise the saved version of the configuration. At the time of restoration, an parser is used to parse the values from the tags and the configuration manager restores the contents of the internal data structures in the memory of the router to the parsed values in accordance with the corresponding tags.

Abstract: A method and system is provided in which MAN traffic is segregated at a customer and a provider domain level. A switch at the edge of the MAN encapsulates a data packet in a new header, which is used to specify the customer domain tags. The data packet is encapsulated further in another new header, which is used to specify new VMAN tags. The nested encapsulation is repeated as necessary until the data packet is forwarded to a remote switch at the edge of the MAN in accordance with the VMAN configuration or the source and destination address in the original data packet. The remote switch strips the VMAN tags from the data packet, and forwards the stripped data packet to the receiving customer domain as specified in the customer domain tag.

Abstract: A method and system is provided in which MAN traffic is segregated at a customer and a provider domain level. A switch at the edge of the MAN encapsulates a data packet in a new header, which is used to specify the customer domain tags. The data packet is encapsulated further in another new header, which is used to specify new VMAN tags. The nested encapsulation is repeated as necessary until the data packet is forwarded to a remote switch at the edge of the MAN in accordance with the VMAN configuration or the source and destination address in the original data packet. The remote switch strips the VMAN tags from the data packet, and forwards the stripped data packet to the receiving customer domain as specified in the customer domain tag.

Abstract: A method and system is provided in which data packets from multiple customer VLANs are forwarded over a MAN using VLAN aggregation. A layer-2 switch located at the edge of the MAN connects the customer VLANs to the MAN. The edge switch aggregates multiple customer VLANs (the “sub-VLANs”) into one provider VLAN (the “super-VLAN”). When a packet is forwarded from the sub-VLAN to the super-VLAN and vice versa, the edge switch uses modified bridge forwarding rules to exchange the customer-configured VLAN-IDs with the provider-configured VLAN-IDs before transporting the packet over the MAN. The edge switch further uses modified bridge media access control (MAC) address learning rules to isolate one customer's traffic from another's (i.e. isolate one sub-VLAN's traffic from another sub-VLAN's traffic).

Abstract: In a data network, a source node transmits a data packet to a destination node across interconnected switches whereby a switch, upon receiving the data packet from the source node, queries other switches in the network for the appropriate switch and port on the switch out which to forward the data packet to the destination node. The appropriate switch responds to the query with its switch number and the port number of the port out which the data packet should be sent to reach the destination node. The querying switch caches the switch number and port number and prepends a destination tag to subsequent data packets it receives which are destined to the same destination node, thereby providing a distributed system among the switches in the network for maintaining detailed information regarding the appropriate switch and port out which to forward data packets received by a source node in the network.

Abstract: A flexible, policy-based, mechanism for managing, monitoring, and prioritizing traffic within a network and allocating bandwidth to achieve true quality of service (QoS) is provided. According to one aspect of the present invention, a method is provided for managing bandwidth allocation in a network that employs a non-deterministic access protocol, such as an Ethernet network. A packet forwarding device receives information indicative of a set of traffic groups, such as: a MAC address, or IEEE 802.1p priority indicator or 802.1Q frame tag, if the QoS policy is based upon individual station applications; or a physical port if the QoS policy is based purely upon topology. The packet forwarding device additionally receives bandwidth parameters corresponding to the traffic groups.

Abstract: A packet switching device having a central shared memory and a number of medium access controllers each coupled to a communications medium to exchange data packets therewith, and a controller coupled to each medium access controller via a data path to exchange data packets with the media access controller. The controller has a number of data path controllers each connected to each medium access controller via a separate and like portion of the data path to exchange a corresponding portion of the data packets with the medium access controller. The data path controllers each have a number of buffers each connected to one of the medium access controllers to which the data path controller is connected, to hold the portion of the data packets exchanged with the corresponding medium access controller.

Abstract: A network interconnect device and message exchange protocol for forwarding data among packet forwarding devices are provided. According to one aspect of the present invention, data is forwarded between a first and second packet forwarding device coupled to an interconnect device. The interconnect device receives a menu message from the first packet forwarding device that indicates one or more types of data that are awaiting transmission on the first packet forwarding device. Based upon the menu message, the interconnect device transmits an order message selecting a type of data of the one or more types of data awaiting transmission to the first packet forwarding device. The interconnect device receives a message from the first packet forwarding device containing data of the type selected by the order message. The interconnect device then forwards the data to the second packet forwarding device.

Abstract: In a segmentation and reassembly module in a local area network switch module, a method and apparatus for storing fixed length data cells received from an ATM network in a plurality of memory buffers during the reassembly of the data cells in to a variable length data packet to be transmitted on an attached local area network.