A data communication network includes a plurality of primary virtual bridges, interconnected by primary virtual connections so as to transmit and receive data packets over the network to and from edge devices connected thereto One or more backup virtual bridges, each associated with at least one of the primary virtual bridges, are connected by at least one secondary virtual connection to at least another one of the primary virtual bridges, so that upon a failure of one of the primary virtual bridges with which it is associated, the backup virtual bridge transmits and receives the data packets over the network via the at least one secondary virtual connection in place of the at least one of the primary virtual bridges

Hierarchical virtual private LAN service protection scheme

A method for communication via a ring network that includes a plurality of nodes. The method includes receiving at a first node in the ring network a data packet transmitted over a virtual private LAN service (VPLS), the data packet including an identification of the VPLS. The first node reads the identification from the data packet. Responsively to reading the identification, the first node forwards the data packet to at least one second node in the ring network that is associated with the VPLS.

Virtual private LAN service over ring networks

A method for communication includes configuring a network node (30) having at least first and second line cards 32), the line cards having respective ports (36), to operate as a distributed media access control (MAC) bridge in a Layer 2 network. Each of the line cards has a respective forwarding database (FDB) (58). Upon receiving a data packet on a port of the network node from a MAC source address, the data packet is conveyed to at least the first line card for transmission to the MAC destination address. The MAC source address of the data packet is checked against the records in the FDB of the first line card. If the FDB does not contain a record of an association of the MAC source address with the port on which the data packet was received, the record is added to the FDB of the first line card, which sends a message to at least the second line card informing the second line card of the association.

Mac address learning in a distributed bridge

A cable modem termination system (CMTS) for receiving signals from, and transmitting signals toward, a High-Frequency Coax plant includes multiple normally-active CMTSs each configured to receive and transmit modem-compatible signals, multiple interface modules coupled to the normally-active CMTSs and configured to convey data toward the HFC from the normally-active CMTSs and from the HFC toward the normally-active CMTSs, and a spare CMTS configured to receive and transmit modem-compatible signals, where at least two interface modules are coupled to each other in a daisy-chain fashion to couple at least a first of the interface modules to the spare CMTS via at least a second of the interface modules to which the first interface module is daisy-chain coupled.

Radio-frequency communications redundancy

According to one embodiment of the invention a rugged Ethernet switch includes a housing and a passive cooling system associated with the housing and being devoid of fans as operable to cool the Ethernet switch. Ethernet switch also includes software operable to perform at least one of the functions selected from the group consisting of multiple spanning, rapid spanning, cluster management and IGMP snooping and querying. According to another embodiment, a rugged Ethernet switch includes a housing having a plurality of perforations formed therein for cooling the Ethernet switch. The switch also includes a passive cooling system be devoid of fans and that is operable to cool the Ethernet switch. A temperature sensor is operable to measure a temperature of the Ethernet switch is included as is an alarm software responsive to the temperature sensor and operable to initiate an alarm when a measured temperature of the Ethernet switch exceeds a particular limit.

Industrial ethernet switch

A method and system for configurable and scalable line interface card protection or redundance useful for a range of low speed digital to high speed digital and optical signal types such as STS-1, STS-3, VT1.5, DS-1/T1, DS-3/T3, ATM, ADSL, HDSL, OC-1, OC-3, OC-12, OC-48, OC-192, OC-768, STM-1, STM-4, STM-16, STM-64, E1, E3, J1, J2, and EtherNet and Token Ring LAN signals. A daisy-chain alternate signal path, signal selectors, and alternate front panel entry points are provided to a front-access telecommunications shelf system. Signal interface cards can be designated as primary cards to handle traffic under normal conditions, or as protection cards, without hardware constrained or slot-specific card requirements. Variations of 1:N protection, and multiple groups of 1:N configurations and partitions can be defined without changes to cabling or backplane design variations through setting of relays and signal selectors on each card. As such, any signal present on a cable connected to a primary card may be re-routed to any card designated as a protection card, by first routing the signal through a protection relay on the failed card to a cable to a neighboring card, through a data selector on the neighboring card onto the backplane, and to a selected protection card.

Timothy Albert Carey

Papers

Configurable scalable communications equipment protection method system