Abstract: A cost effective congestion isolation for lossless Ethernet utilizing random selection is provided. Upon detecting congestion at one of its egress ports, a downstream device randomly selects a data packet received at one or more of its ingress ports for isolation in a congested priority queue at the ingress port. The downstream device sends a congestion isolation message, including a list of isolation hashes to an upstream device to identify data packets selected for isolation. Upon receipt, the upstream device identifies data packets selected for isolation and begins to queue such packets in a congested priority queue of the upstream device. When priority-based flow control is triggered, the upstream device ceases transmission of packets in the congested priority queue only, while allowing continued transmission of non-isolated data packets.

Abstract: A cost effective congestion isolation for lossless Ethernet utilizing random selection is provided. Upon detecting congestion at one of its egress ports, a downstream device randomly selects a data packet received at one or more of its ingress ports for isolation in a congested priority queue at the ingress port. The downstream device sends a congestion isolation message, including a list of isolation hashes to an upstream device to identify data packets selected for isolation. Upon receipt, the upstream device identifies data packets selected for isolation and begins to queue such packets in a congested priority queue of the upstream device. When priority-based flow control is triggered, the upstream device ceases transmission of packets in the congested priority queue only, while allowing continued transmission of non-isolated data packets.

Abstract: Some examples herein disclose identifying a service function chain based on a switch address from a packet. The examples disclose modifying the switch address to an address corresponding to a service function based on the identified service function chain. The examples also disclose forwarding the packet to the service function according to the modified switch address.

Abstract: Some examples herein disclose identifying a service function chain based on a switch address from a packet. The examples disclose modifying the switch address to an address corresponding to a service function based on the identified service function chain. The examples also disclose forwarding the packet to the service function according to the modified switch address.

Abstract: An optical communication device comprises an input/output configured to be coupled to an optical communications line, and a passive optical loopback module coupled to the input and configured to receive optical signals from the input/output, the loopback module being further configured to reflect incoming signals of a test wavelength to the input/output.

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 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: A metro area network is provided that includes edge and core multiplexors each having a plurality of line ports and one or more uplink ports, a transport network carrying multiplexed traffic between the edge and core multiplexors. In a hard cross connect implementation utilizing source port tagging, a cross-connect device coupled to the core multiplexors provisions or maps communications path between the core multiplexors thereby providing preselected connectivity/mapping of two or more line ports of any of the edge multiplexors. In a soft cross connect implementation utilizing destination port tagging, a cross-connect device includes additional cross-connect multiplexors and functionality to control the destination port tagging performed in the edge, core and cross connect multiplexors thereby provisioning or mapping the desired communications path(s) between various endpoints.

Abstract: An optical communication device comprises an input/output configured to be coupled to an optical communications line, and a passive optical loopback module coupled to the input and configured to receive optical signals from the input/output, the loopback module being further configured to reflect incoming signals of a test wavelength to the input/output.

Abstract: An optical communication device comprises an input/output configured to be coupled to an optical communications line, and a passive optical loopback module coupled to the input and configured to receive optical signals from the input/output, the loopback module being further configured to reflect incoming signals of a test wavelength to the input/output.

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: 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 metro area network is provided that includes edge and core multiplexors each having a plurality of line ports and one or more uplink ports, a transport network carrying multiplexed traffic between the edge and core multiplexors. In a hard cross connect implementation utilizing source port tagging, a cross-connect device coupled to the core multiplexors provisions or maps communications path between the core multiplexors thereby providing preselected connectivity/mapping of two or more line ports of any of the edge multiplexors. In a soft cross connect implementation utilizing destination port tagging, a cross-connect device includes additional cross-connect multiplexors and functionality to control the destination port tagging performed in the edge, core and cross connect multiplexors thereby provisioning or mapping the desired communications path(s) between various endpoints.

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: 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: 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: 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.