Abstract: A system for controlling packet forwarding through a dual-homed connection between first and second network domains, the dual-homed connection including two peer nodes connected to the first and second network domains. A sub-ring network is instantiated in the first network domain, and includes at least two nodes connected in a linear topology between a pair of end-nodes. Each end-node corresponds with a respective one of the peer nodes. A virtual link through the second network domain for conveys traffic of the sub-ring network between the peer nodes, and closes the sub-ring network to define a ring topology. Each of the nodes of the sub-ring network is controlled to forward packets of the sub-ring network in accordance with a ring network routing scheme.

Abstract: Frame contained destination information may be used by a switch to identify an appropriate output port for a given frame without performing a table access operation. This reduces the processing requirements of the switch to enable the switch to handle frames more efficiently. The frame contained destination information may be contained in the frame's local destination MAC addresses (DA) such that a portion of the DA directly indicates, for each switch that handles the frame, an output port for that switch. Different portions of the DA may be used by different switches, depending on where they are in the network hierarchy. Large switches may also use sub-fields within their allocated portion in the DA to identify internal switching components. A location resolution server may be provided to store and distribute IP and MAC addresses and respond to local ARP requests on the local domain.

Abstract: A method is provided of planning routes and allocating route identifiers in a managed frame-forwarding network. The network comprises a plurality of nodes interconnected by links, with each node being arranged to forward data frames according to a combination of an identifier and a network address carried by a received data frame and forwarding instructions stored at the node. A first step of the method identifies a sub-set of nodes which are core nodes of the network. The remaining nodes are termed outlying nodes. A spanning tree is then built off each of the identified core nodes, with the spanning tree stopping one link short of any other core node. Each spanning tree defines a loop-free path between a core node at the root of the spanning tree and a set of outlying nodes. Connections are planned between roots of the spanning trees and a different identifier is allocated to each planned connection between a pair of spanning trees.

Abstract: A method is provided of planning routes and allocating route identifiers in a managed frame-forwarding network. The network comprises a plurality of nodes interconnected by links, with each node being arranged to forward data frames according to a combination of an identifier and a network address carried by a received data frame and forwarding instructions stored at the node. A first step of the method identifies a sub-set of nodes which are core nodes of the network. The remaining nodes are termed outlying nodes. A spanning tree is then built off each of the identified core nodes, with the spanning tree stopping one link short of any other core node. Each spanning tree defines a loop-free path between a core node at the root of the spanning tree and a set of outlying nodes. Connections are planned between roots of the spanning trees and a different identifier is allocated to each planned connection between a pair of spanning trees.

Abstract: Frame contained destination information may be used by a switch to identify an appropriate output port for a given frame without performing a table access operation. This reduces the processing requirements of the switch to enable the switch to handle frames more efficiently. The frame contained destination information may be contained in the frame's local destination MAC addresses (DA) such that a portion of the DA directly indicates, for each switch that handles the frame, an output port for that switch. Different portions of the DA may be used by different switches, depending on where they are in the network hierarchy. Large switches may also use sub-fields within their allocated portion in the DA to identify internal switching components. A location resolution server may be provided to store and distribute IP and MAC addresses and respond to local ARP requests on the local domain.

Abstract: A method is provided of planning routes and allocating route identifiers in a managed frame-forwarding network. The network comprises a plurality of nodes interconnected by links, with each node being arranged to forward data frames according to a combination of an identifier and a network address carried by a received data frame and forwarding instructions stored at the node. A first step of the method identifies a sub-set of nodes which are core nodes of the network. The remaining nodes are termed outlying nodes. A spanning tree is then built off each of the identified core nodes, with the spanning tree stopping one link short of any other core node. Each spanning tree defines a loop-free path between a core node at the root of the spanning tree and a set of outlying nodes. Connections are planned between roots of the spanning trees and a different identifier is allocated to each planned connection between a pair of spanning trees.

Abstract: An edge device is used to support a backbone provider bridging network to facilitate interconnection of a plurality of networks. The edge device is coupled between the backbone and a first one of the networks, and is operable to encapsulate data units received from the first network with a header, and to forward the encapsulated data unit to the backbone. The header is indicative of a tunnel that is used to support traffic from the first network to a second network over the backbone. The edge device also de-encapsulates data units received from the backbone that are destined for the first network.

Abstract: An Ethernet mapping enables high speed Ethernet data streams having a data rate of 10 Gb/s to be transported across a synchronous packet switched network fabric having a standard SONET OC-192 line rate of 9.953280 Gbaud. The 10 Gb/s Ethernet data stream is compressed by removing interframe gaps between successive MAC frames to produce a compressed data stream, which is then mapped to a synchronous container. The synchronous container is then launched across the synchronous packet switched network fabric at a standard SONET OC-192 line rate of 9.953280 Gbaud. The synchronous container is preferably provided as a stripped STS-192c frame having only A1 and A2 octets of the Transport Overhead (TOH).

Abstract: Frame contained destination information may be used by a switch to identify an appropriate output port for a given frame without performing a table access operation. This reduces the processing requirements of the switch to enable the switch to handle frames more efficiently. The frame contained destination information may be contained in the frame's local destination MAC addresses (DA) such that a portion of the DA directly indicates, for each switch that handles the frame, an output port for that switch. Different portions of the DA may be used by different switches, depending on where they are in the network hierarchy. Large switches may also use sub-fields within their allocated portion in the DA to identify internal switching components. A location resolution server may be provided to store and distribute IP and MAC addresses and respond to local ARP requests on the local domain.

Abstract: A method and apparatus for providing a Virtual Private Network (VPN) over a connectionless network connecting a plurality of Local Area Networks (LANs), such as an Ethernet network, is disclosed. The method and apparatus comprises associated each VPN with a unique identifier and each LAN of the VPN with a interface device connecting the LAN to the connectionless network, which may be for example, a Synchronous Optical Network (SONET). The interface device may service a plurality of LANs. Accordingly, each LAN is associated with a User-Network Interface that forms part of the interface device. Each data packet destined for a second LAN, such Ethernet frames, received by the interface device for a first LAN is encapsulated with, if known, a Media Access Control (MAC) address of the interface device connected to the second LAN, the VPN's unique identifier, and the port on the interface device connected to the second LAN.

Abstract: An Ethernet mapping enables high speed Ethernet data streams having a data rate of 10 Gb/s to be transported across a synchronous packet switched network fabric having a standard SONET OC-192 line rate of 9.953280 Gbaud. The 10 Gb/s Ethernet data stream is compressed by removing interframe gaps between successive MAC frames to produce a compressed data stream, which is then mapped to a synchronous container. The synchronous container is then launched across the synchronous packet switched network fabric at a standard SONET OC-192 line rate of 9.953280 Gbaud. The synchronous container is preferably provided as a stripped STS-192c frame having only A1 and A2 octets of the Transport Overhead (TOH).