摘要:
Systems and methods for estimating aggregate bandwidths of primary traffic flows are provided. Tighter upper bounds on aggregate bandwidths for arbitrary combinations of primary traffic flows may be computed. These tighter bounds are highly useful in configuring backup tunnels to protect a node in the event of failure in that the total backup bandwidth burden on individual links may be determined more accurately to permit optimal use of available backup bandwidth capacity.
摘要:
Systems and methods for estimating aggregate bandwidths of primary traffic flows are provided. Tighter upper bounds on aggregate bandwidths for arbitrary combinations of primary traffic flows may be computed. These tighter bounds are highly useful in configuring backup tunnels to protect a node in the event of failure in that the total backup bandwidth burden on individual links may be determined more accurately to permit optimal use of available backup bandwidth capacity.
摘要:
In one embodiment, a primary tunnel is established from a head-end node to a destination along a path including one or more protected network elements for which a fast reroute path is available to pass traffic around the one or more network elements in the event of their failure. A first path quality measures path quality prior to failure of the one or more protected network elements. A second path quality measures path quality subsequent to failure of the one or more protected network elements, while the fast reroute path is being used to pass traffic of the primary tunnel. A determination is made whether to reestablish the primary tunnel over a new path that does not include the one or more failed protected network elements, or to continue to utilize the path with the fast reroute path, in response to a difference between the first path quality and the second path quality.
摘要:
In one embodiment, an apparatus generally comprises one or more input interfaces for receiving a plurality of flows, a plurality of output interfaces, and a processor operable to identify large flows and select one of the output interfaces for each of the large flows to load-balance the large flows over the output interfaces. The apparatus further includes memory for storing a list of the large flows, a pinning mechanism for pinning the large flows to the selected interfaces, and a load-balance mechanism for selecting one of the output interfaces for each of the remaining flows. A method for local placement of large flows to assist in load-balancing is also disclosed.
摘要:
In one embodiment, an apparatus includes a processor for mapping packets associated with network flows to policy profiles independent of congestion level at the apparatus, and enforcing the policy profiles for the packets based on a congestion state. Packets associated with the same network flow are mapped to the same policy profile and at least some of the network flows are protected during network congestion. The apparatus further includes memory for storing the policy profiles. A method for protecting network flows during network congestion is also disclosed.
摘要:
In one embodiment, an intermediate node computes paths for a set of tunnels that do not include a particular link (e.g., and possibly a scaled-down bandwidth for each tunnel), considering all of the tunnels of the set. The intermediate node informs head-end nodes of the tunnels of the computed paths (e.g., and scaled bandwidth) and/or a time to reroute the tunnels.
摘要:
In one embodiment, head-end nodes receive a list of tunnels to be rerouted from a particular link of an intermediate node. If a head-end node is unable to reroute a tunnel for which it is the head-end node using conventional distributed routing, each head-end node executes the same algorithm to compute paths for all tunnels in the list (e.g., potentially applying bandwidth scaling).
摘要:
Systems and methods for two-rate scheduling over a class hierarchy wherein controlled rates are delivered in a smooth manner, even over short time intervals. A minimum rate scheduler and an excess rate scheduler are employed. The minimum rate scheduler and/or the excess rate scheduler, employ special binary search trees to make selections at each parent node in the class hierarchy.
摘要:
A virtual overlay backup network is established to provide Fast Reroute capability with guaranteed bandwidth protection to a network that employs end-to-end circuits such as label switched paths (LSPs). In some implementations, backup bandwidth is allocated from an available backup bandwidth pool, as defined herein, available on each link. Complete bandwidth protection may be provided rapidly upon detection of a failure while available backup bandwidth is shared between independent failures. In one embodiment, this is accomplished by provisioning backup tunnels to protect all links and nodes, wherein total available backup bandwidth on any link is not exceeded by the requirements of backup tunnels protecting any single node but backup tunnels protecting different nodes may share bandwidth.
摘要:
A technique dynamically determines whether to reestablish a Fast Rerouted primary tunnel based on path quality feedback of a utilized backup tunnel in a computer network. According to the novel technique, a head-end node establishes a primary tunnel to a destination, and a point of local repair (PLR) node along the primary tunnel establishes a backup tunnel around one or more protected network elements of the primary tunnel, e.g., for Fast Reroute protection. Once one of the protected network elements fail, the PLR node “Fast Reroutes,” i.e., diverts, the traffic received on the primary tunnel onto the backup tunnel, and sends notification of backup tunnel path quality (e.g., with one or more metrics) to the head-end node. The head-end node then analyzes the path quality metrics of the backup tunnel to determine whether to utilize the backup tunnel or reestablish a new primary tunnel.