Abstract: Policy information is distributed to remote network devices by mapping high-level policy information into low-level configuration information and distributing the low-level configuration information to the remote network devices.

Abstract: A network route tracing system traces a path through a network and identifies network components and communications links affected by the path. According to one embodiment of the present invention, a route is traced between two hosts in a network. The network is represented as a logical tree having a plurality of nodes. Each one of the nodes corresponds to a component in the network and each non-root node has a parent node. Two nodes are identified in the logical tree. A first node corresponds to a first host and a second node corresponding to a second host. If one of the two nodes exists at a lower level of the logical tree, then a first path is traced from the first node at the lower level to the parent node at a higher level until the parent node is at a same level of the logical tree as the second node. The first path is further traced up the logical tree from the parent node and a second path is traced up the logical tree from the second node until the first path and the second path meet at a same node.

Abstract: A method and apparatus for configuring data plane behavior on network forwarding elements are described. In one embodiment, the method includes receiving, within a network element control plane, protocol configuration information extracted from a protocol application utilizing a network protocol application programming interface (API). Once the protocol configuration information is received, the protocol configuration information is processed using a control interface corresponding to the network protocol implemented by the protocol application. Once the protocol configuration information is processed, the control interface programs one or more data plane forwarding elements of the network element according to protocol configuration information. Accordingly, by providing similar control interfaces for multiple, network protocols, inter-operability between components from multiple vendors is enabled.

Abstract: Selecting a subset of a hierarchical data structure based on a correspondence of the subset with a target in a communication network, and sending the subset of the hierarchical data structure to the target.

Abstract: A method including matching a data transmission characteristic of a first application on a first network device and of a second application on a second network device, requesting a prioritized data transfer between the first and second applications from a policy manager application, determining whether to approve the requested prioritized data transfer based upon a set of policy rules, and transferring data between the first and second application with preferential treatment.

Abstract: A network route tracing system traces a path through a network and identifies network components and communications links affected by the path. According to one embodiment of the present invention, a route is traced between two hosts in a network. The network is represented as a logical tree having a plurality of nodes. Each one of the nodes corresponds to a component in the network and each non-root node has a parent node. Two nodes are identified in the logical tree. A first node corresponds to a first host and a second node corresponding to a second host. If one of the two nodes exists at a lower level of the logical tree, then a first path is traced from the first node at the lower level to the parent node at a higher level until the parent node is at a same level of the logical tree as the second node. The first path is further traced up the logical tree from the parent node and a second path is traced up the logical tree from the second node until the first path and the second path meet at a same node.

Abstract: A system and method for managing a network using a policy tree which includes a plurality of levels (e.g., two levels, five levels, etc.) is described. When the network receives a request to provide an action to a particular source, the network determines if the action is available as a function of at least one level of the plurality of levels. If the action is available, the network determines if the particular source is authorized to be provided with the action as a function of at least one rule of at least one further level of the plurality of levels. If the particular source is authorized, the network provides the action to the particular source.

Abstract: Method and apparatus for assigning policies which are rules that govern the use of or access to network services. Each rule defines conditions that when evaluated true trigger actions to allow or deny the service. Techniques are disclosed which provide for explicit, flexible, and centralized assignment of policy to targets which are specified network services. These techniques include explicitly associating a policy with a network resource or process, grouping policy related processes, grouping related targets, associating groups of targets with groups of policies, mapping a user name contained in a policy to an associated network address such as an Internet Protocol (IP) address, and providing dynamically mapped policy identified user and host names with associated network addresses, such as IP addresses, to client processes.

Abstract: A computer system with unattended on-demand availability includes power-saving features which place the system into a Standby mode whenever the system is idle or is not being used. Prior to entering Standby mode, the system sets a hardware timer which indicates when the next scheduled event in the system should be performed. When either the timer expires or another event occurs which requires system operation, the system resumes to the On power state without user intervention. In one embodiment, the system of the present invention allows applications to periodically save their operational states. By saving their operational states, applications are able to guard against power failures and crashes. If a power failure or crash occurs, the system consults restart policies and, if appropriate, automatically re-starts applications to their most recently saved operational states once power is re-stored.

Abstract: A method and apparatus for task scheduling across multiple execution sessions allows each scheduled task to be scheduled to occur at a specific time(s), to occur periodically, or to occur in response to certain system events. A task can be scheduled which requires execution of an application even if the application is not running at the scheduled time or event, and even if the system is in a low-power standby mode at the scheduled time or event. In one embodiment, the present invention keeps track of specific time events by setting a timer(s) which indicates the time which should elapse until a scheduled event is to occur. When a timer expires, the system determines which task is scheduled to occur at the time the timer expires and executes that task. In one embodiment, the present invention checks a scheduling database to determine which task is scheduled to occur when a timer expires.

Abstract: A computer system with unattended on-demand availability includes power-saving features which place the system into a Standby mode whenever the system is idle or is not being used. Prior to entering Standby mode, the system sets a hardware timer which indicates when the next scheduled event in the system should be performed. When either the timer expires or another event occurs which requires system operation, the system resumes to the On power state without user intervention. In one embodiment, the system of the present invention allows applications to periodically save their operational states. By saving their operational states, applications are able to guard against power failures and crashes. If a power failure or crash occurs, the system consults restart policies and, if appropriate, automatically re-starts applications to their most recently saved operational states once power is re-stored.

Abstract: A device driver in a computer system is dynamically loaded from a storage device to the computer system memory during run time to reduce the amount of memory required to store the device driver. During an initialization period, an initial copy of the device driver is loaded into the computer system memory from the storage device. After the initialization period, the device driver specifies, to the operating system, a minimum resident subset of the device driver of the initial copy which is to be retained in the computer system memory, thereby reducing the amount of computer system memory required to store the device driver. During run time of the device driver, a subsequent copy of the device driver is loaded from the storage device into the computer system memory. The computer system executes the device driver by using both the minimum resident subset of the device driver of the initial copy and a dynamically loaded subset of the device driver of the subsequent copy.