摘要:
There is disclosed a method and apparatus for facilitating a network, such as an Ethernet LAN, for efficient forwarding of data traffic by collecting neighbor information, generating and distributing link state advertisements, populating a topology database for the network, and calculating trees for each bridge serving as a root bridge. In a preferred embodiment the method and system also prepare one or more backup topologies, and store them for use if they are needed due to a failure condition detected in the network. In a particularly preferred embodiment, probabilities are assigned to various potential failure conditions, and the probability values are used to decide which backup topologies to calculate, store, or use.
摘要:
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.
摘要:
The invention relates to failure handling in a tree sructure network (NW1) that has edge nodes (EN1 . . . EN4) and switching nodes (SW1 . . . SW4) interconnected by lines (L1). VLANs (VLAN1-VLAN3) are established such that at least one thereof provides connectivity in case of any single failure in the network. The VLANs can be established by using spanning trees (ST1,ST2,ST3). Among the edge nodes, emitters (EN3) broadcast alive messages (A1,A2,A3) regularly on the VLANs and notifiers (EN2) note the alive messages. A missing alive message indicates a failure (CD1) on one VLAN (VLAN2) and the notifier (EN2) broadcasts corresponding failure messages (F1,F2,F3) on the VLANs. When all the alive messages (A1,A2,A3) appear again the notifier (EN2) broadcasts corresponding repair messages (R1,R2,R3). If the notifiers don't note a failure the nodes (EN1,EN4) with no special role performs a similar function as the notifier (EN2) somewhat slower. The failure handling is fast, robust, uses few messages, increases only slightly the traffic load in the network (NW1) and is compliant with present standards.
摘要:
In the area of network provisioning, there is a problem of selecting a suitable traffic-provisioning model for large networks due to the high management complexity of the resource-efficient trunk model and the poor bandwidth efficiency of the easy-to-configure hose model. The invention is based on the idea of partitioning at least part of the network into multi-node clusters, and defining traffic limitations on at least two levels, including the intra-cluster level and the inter-cluster level, where the traffic limitations include one or more node-to-cluster traffic limitations for inter-cluster traffic. Subsequently, cluster-based provisioning of the network is performed based on the traffic limitations. The novel node-to-cluster limitations proposed by the invention are preferably applied in a cluster-based trunk or hose model on the inter-cluster level. In other words, for the description of the inter-cluster traffic (traffic between the clusters) cluster-based trunk or hose models can be used, preferably depending on the available information about the traffic. The cluster-based provisioning makes it possible to find a trade-off between management complexity and overprovisioning.
摘要:
A method and arrangement for failure handling in a tree-structured communications network having interconnected edge nodes and switching nodes. VLANs may be established by using spanning trees to provide connectivity in case of a failure in the network. Emitters in the edge nodes periodically broadcast alive messages on the VLANs, and notifiers note the alive messages. A missing alive message indicates a failure on one of the VLANs, and the notifier broadcasts corresponding failure messages on the VLANs. When the alive messages are restored, the notifier broadcasts corresponding repair messages. If a notifier fails to note a failure, one of the edge nodes performs a similar function although somewhat slower.
摘要:
A method and arrangement for failure handling in a tree-structured communications network having interconnected edge nodes and switching nodes. VLANs may be established by using spanning trees to provide connectivity in case of a failure in the network. Emitters in the edge nodes periodically broadcast alive messages on the VLANs, and notifiers note the alive messages. A missing alive message indicates a failure on one of the VLANs, and the notifier broadcasts corresponding failure messages on the VLANs. When the alive messages are restored, the notifier broadcasts corresponding repair messages. If a notifier fails to note a failure, one of the edge nodes performs a similar function although somewhat slower.
摘要:
A method and arrangement for failure handling in a tree-structured communications network having interconnected edge nodes and switching nodes. VLANs may be established by using spanning trees to provide connectivity in case of a failure in the network. Emitters in the edge nodes periodically broadcast alive messages on the VLANs, and notifiers note the alive messages. A missing alive message indicates a failure on one of the VLANs, and the notifier broadcasts corresponding failure messages on the VLANs. When the alive messages are restored, the notifier broadcasts corresponding repair messages. If a notifier fails to note a failure, one of the edge nodes performs a similar function although somewhat slower.
摘要:
In the area of network provisioning, there is a problem of selecting a suitable traffic-provisioning model for large networks due to the high management complexity of the resource-efficient trunk model and the poor bandwidth efficiency of the easy-to-configure hose model. The invention is based on the idea of partitioning at least part of the network into multi-node clusters, and defining traffic limitations on at least two levels, including the intra-cluster level and the inter-cluster level, where the traffic limitations include one or more node-to-cluster traffic limitations for inter-cluster traffic. Subsequently, cluster-based provisioning of the network is performed based on the traffic limitations. The novel node-to-cluster limitations proposed by the invention are preferably applied in a cluster-based trunk or hose model on the inter-cluster level. In other words, for the description of the inter-cluster traffic (traffic between the clusters) cluster-based trunk or hose models can be used, preferably depending on the available information about the traffic. The cluster-based provisioning makes it possible to find a trade-off between management complexity and overprovisioning.
摘要:
The present invention relates to a method and an arrangement for controlling the user plane of a UMTS Terrestrial Radio Access Network, UTRAN, comprising a first edge node connected via a Transport Network Layer to a second edge node, by using Transport Network Layer, TNL, signalling. A radio link is set up by using the Node B Application Part between the first and second edge nodes of the UTRAN, RSVP-TE based TNL signalling messages are transmitted between said first and second edge nodes for each TNL flow, and each TNL flow is identified by using RSVP-TE messages, wherein the object SESSION and SENDER_TEMPLATE comprises an IP based 5-tuple flow information, which is adapted to be used as a TNL flow identity.
摘要:
A call admission control system and method for Internet Protocol (IP) Differentiated Services (DiffServ) network having at least one node for interpreting signaling messages and controlling traffic load in the network. The method consists of an initialization (601) and a real-time phase (602). In initialization phase (601), coefficients of the approximating hyperplanes are computed (61) and stored (62). This phase is repeated when the descriptor of a traffic class changes (63), which usually happens when nodes are configured or reconfigured. A traffic mix is admissible (67), if for each real-time traffic class both the stability (65) and the delay (66) constraints are fulfilled. Stability is tested by evaluating the number of lost packets and comparing it to the tolerated packet loss ratio for each class in that queue. Delay constraint is tested by checking if the traffic mix is below at least one of the approximating hyperplanes in the space of number of sessions for each class.