Abstract:
There is disclosed a manner of managing the active topology, that is the scheme for forwarding data, in a computer network such as an Ethernet local area network. A root bridge is selected from a plurality of bridges in the network; the root bridge calculating at least one spanning tree from a topology database that has been populated by bridge neighbor information gleaned from link state advertising messages. The root bridge may also calculate an alternate topology for implementation in the event a failure condition that affects the primary spanning tree is detected. The root bridge then advertises the spanning tree and remotely configures the port states of the bridges in the spanning tree through tree advertising messages that the bridges are arranged to process and set their ports accordingly.
Abstract:
A system, method, and node for identifying non-Multiple Spanning Tree Protocol control planes. The method includes the steps of identifying a specific non-Multiple Spanning Tree Protocol control plane instance, associating a General Control Plane Identification, GCPID, with the specific control plane instance, wherein the GCPID binds a Virtual Local Area Identifier, VID, with the specific control plane, and advertising the GCPID to identify the specific control plane instance.
Abstract:
A system, method, and Ethernet bridge utilizing forced MAC learning to set up a path from an originating node, PON (23) to one or more terminating nodes, PTN (12) through intermediate bridge nodes (14, 21). In the point-to-point case, a Previous Hop Bridge (PHB) list defines the links in the path. Each link includes a destination address, source address, port number, and VID. A path learning frame (13, 19, 22) containing the list is sent in reverse order from the PTN through the intermediate bridge nodes to the PON. Each node in the path saves the received frame's header information as learned path information using standard MAC learning functionality, removes the node's own information from the list, and forwards the frame with the remainder of the list to the next node using the port specified by the port number for that link. When the frame arrives at the PON, all nodes have saved the learned path information.
Abstract:
Método de reserva de recursos para flujos de datos en una red de comunicaciones, que comprende: detectar una solicitud (151) de reserva de recursos para un flujo de datos nuevo que incluye una pluralidad de descriptores que especifican recursos solicitados; calcular un recuento de comprobación de admisión basándose en la pluralidad de descriptores del flujo de datos nuevo y recuentos de reserva que especifican los recursos acumulados de todos los flujos de datos admitidos, en los que cada recuento de reservas representa una función suma o una función producto, estando constituida la función suma por una suma de funciones que tienen como variables los descriptores de los flujos de datos admitidos y estando constituida la función producto por un producto de funciones que tienen como variables los descriptores de los flujos de datos admitidos; admitir el flujo de datos nuevo, si el recuento de comprobación de admisión es menor que un recuento de admisión máximo para la pluralidad de descriptores; y actualizar los recuentos de reservas basándose en los descriptores del flujo de datos nuevo, si se admite el flujo de datos nuevo.
Abstract:
A network node for reserving resources for data flows in a communication network. The node detects a request for resource reservation for a new data flow and computes an admission test count based on descriptors of the new data flow and reservation counts, which represent reservation functions of descriptors of previously admitted data flows and which specify resources of the admitted data flows. The new data flow is admitted if the admission test count is smaller than a maximum allowable count. The reservation counts are then updated based on the descriptors of the new data flow. A plurality of admission formulas may thus be used to maintain aggregated reservation counts for data flows, the number of counts being independent from the number of flows.
Abstract:
Methods, edge routers and an edge-router-refresh network signalling message used to update state information in edge routers. A data session is established on a path from a source towards a destination connected from the source via a plurality of Autonomous Systems (AS). The edge-router-refresh network signalling message is created by an edge router acting an an ingress edge router. The edge-router-refresh network signalling message comprises an identifier of the data session, an identifier of the edge router, which issued the edge-router-refresh message and an indication that the edge-router-refresh message is meant to be used by the edge routers present on the modified path. Optionally, the edge-router-refresh network signalling message further comprises a list of the plurality of AS traversed by the path before the modification.
Abstract:
A method is provided for use at a first node of a network. The first node (B) has an input path for receiving Ethernet frames destined for a second node of the network. The first node (B) also has a first output (working) path for forwarding the received Ethernet frames towards the second node. A failure along the first output (working) path is detected at the first node. Following such failure detection, the received Ethernet frames are caused, at the first node, to be re-routed along a second output (backup) path, different to the first output (working) path, towards the second node. The re-routing is performed by using (e.g. referring to and/or changing) respective indications (VLAN1) applied to the Ethernet frames to distinguish those Ethernet frames to be forwarded along the first output (working) path from those Ethernet frames to be forwarded along the second output (backup) path.