Cisco Technology, Inc.

Jeremy Lawrence

Bruce Stuart Davie

David Anthony Hughes

Daniel C Tappan

Alex E Raj

Rodolphe Figaro

Peter Kline

A method and system to provide secure in-band management for a packet data network are disclosed. In a network device for configuring a virtual private network (VPN), management traffic is received over the VPN. The network device is managed using the management traffic received over the VPN. An in-band management system is created by configuring a virtual private network (VPN) for a network device and linking the VPN to a management device or a management function. By using the VPN to carry management traffic and to create the in-band management system, management of the network device can be made secure.

Method and system to provide secure in-band management for a packet data network

A method for operating a router which combines virtual channels is disclosed, where both forward and reverse directed resource management cells are used to control transmission rate of a source computer. The merging router receives forward directed resource management cells from a plurality of upstream routers, where each forward directed resource management cell represents a virtual channel. The router: (1) replies to each upstream router with a reverse directed resource management cell; and (2) forwards to a downstream router a combined forward directed resource management cell, the combined forward directed resource management cell combining a plurality of virtual channels established between the router and the plurality of upstream routers.

Virtual-channel merging

A data switching system is described to allow arbitrary types of connections to be established over arbitrary link types that include link types that do not inherently support virtual circuits. The data switching system includes a label switching system to establish virtual circuit connections over any link types. The data switching system also includes a connection routing and signaling controller, coupled to the label switching system to determine routes for connection over any link types.

Method and apparatus to allow connection establishment over diverse link types

The invention provides unique architectures and techniques for routing redundancy in a data switch configured to use label switching. Multiple label switch controllers (LSCs) each operate concurrently but independently of each other to provide routes through a data switching mechanism. Preferred embodiments provide a plurality of LSCs offering MPLS capabilities coupled to a single switch, such as an ATM switch. The similarly configured LSCs each can concurrently support a route for data (e.g., labeled ATM cells) within the data switching mechanism in parallel, thereby providing the ability to support redundant and multiple parallel data networks. The configuration is called a label switch router (LSR). A fully-meshed embodiment allows selected routes to share bandwidth on ports, while a fully parallel embodiment provides separate ports for selected routes. Since each LSC provides parallel routes with the other LSCs in an LSR, a communications between an LSR and a label edge router (LER) can use multipath routing to concurrently distribute data equally across the parallel routes for each destination. Alternatively, unipath routing techniques can select one route for use for each destination from the available routes concurrently offered by each LSC. In the event of a failure of one of the LSCs, multipath routing implementations can exclude transmission of data onto the failed network, while continuing to use the other parallel networks supported by non-failed LSCs in a concurrent manner. Alternatively, if a failure occurs with unipath routing, a new route offered by another LSC can be selected for data transfers. In either case, the LSC that fails does not need to provide state or connection information to the LSCs that operate subsequently to the failure, since they are already configured in parallel to support the same route. Upon an LSC failure, switch resources such as bandwidth that were used by the failed LSC are made available to the remaining non-failed LSCs. The design allows failures are handled gracefully without diminished network capacity or data loss resulting in a highly reliable routing capability provided within connection-based or circuit-switched networks.

Apparatus and methods providing redundant routing in a switched network device

A merging ATM switch forwards to a common downstream ATM switch ATM data cells that it receives from a plurality of upstream ATM switches. The merging ATM switch may have different upstream ATM switches employ different respective virtual-circuit identifiers for those commonly destined data cells, but it uses a common virtual-circuit identifier in forwarding them to the downstream switch. The upstream ATM switches intersperse among the data cells forward-directed resource-management cells bearing the virtual-channel identifiers that those upstream switches use on the commonly destined data cells. The merging ATM switch responds to such forward-directed resource-management cells by sending corresponding forward-directed resource-management cells to the downstream ATM switch and reverse-directed resource-management cells to the upstream ATM switches. The forward-directed resource-management cells sent to the downstream ATM switch bear the common virtual-circuit identifier, whereas the reverse-directed resource-management cells sent to the upstream ATM switches bear the respective virtual-circuit identifiers that those upstream ATM switches placed in the forward-directed resource-management cells. By so doing, the merging switch avoids the ambiguity that resource-management-cell forwarding other-wise entails.

An interface ( , or ) in a service-provider network's transit label-switching router (P ) employs resource-management messages to inform neighbor routers of the bandwidths that it can allocate to various routes that it supports. To allocate its available bandwidth, it employs a weight value set for the route by an ingress router (PE ) in a system to which the label-switching router belongs. The transit router treats the weight as a relative bandwidth: when the sum of the bandwidths requested for various routes exceeds the bandwidth available, the router sets the bandwidths for at least some routes in accordance with the ratio of a given route's weight to the sum of the weights assigned to all routes among which it divides available bandwidth in this manner. That is, it assigns at least some bandwidth to all such routes, regardless of how small the resultant bandwidth may be. In this way, the network can operate with virtually no packet loss and yet remain available to all of its customers.

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Newtown, Australia

Jeremy Lawrence