Abstract: A method and system for monitoring traffic and path information in a packet communication network operated according to an IP routing protocol is disclosed. The method and system enables a user, such as a network administrator, to explicitly identify a full set of paths (i.e., links and routers) that the traffic of a specific customer or set of customers, such as service providers hosted at a hosting site, is using when traversing the network. The system allows the dynamic monitoring of the set of active links carrying traffic belonging to the specific customer or set of customers, and the proportion of that traffic that is carried by each active link. This allows, among other things, the identification of network links that are critical for ensuring a high level of service to key customers.

Abstract: A method and system for extracting and building end-to-end route information in a multi-area Internet protocol (IP) autonomous system (AS) is disclosed. The method and system enable a user, such as a network administrator, to explicitly identify a full set of paths (links and routers) that a given IP packet would potentially traverse from its entry point in the source area of the AS where it originates until its exit point in its intended destination area.

Abstract: A method and system for extracting and building end-to-end route information in a two-level, multi-area Internet protocol (IP) autonomous system (AS) operated according to a simple link state routing protocol such as the Integrated System to Integrated System (IS-IS) protocol is disclosed. The method and system enables a user, such as a network administrator, to explicitly identify a full set of paths (links and routers) that a given IP packet would potentially traverse from its entry point in the area of the AS where it originates until its exit point in its intended destination or exit area.

Abstract: A method and system for extracting and building end-to-end route information in a multi-area Internet protocol (IP) autonomous system (AS) operated according to a link state routing protocol such as the Open Shortest Path First (OSPF) protocol is disclosed. The method and system enables a user, such as a network administrator, to explicitly identify a full set of paths (links and routers) that a given IP packet would potentially traverse from its entry point in the area of the AS where it originates until its exit point in its intended destination or exit area.

Abstract: A method, apparatus and system is provided by which two or more cooperating end-users of the Internet and/or other network can dynamically select and use a single Internet or other network service provider (ISP) from among a multitude of ISPs based on the application requirements. The service provider may be selected in a dynamic fashion. This overcomes the problem wherein traditionally most end-users, whether they are individuals or organizations, are connected to the Internet or other network through a single Internet and/or other network service provider. However, users generally may have more than a single connection to the Internet and/or other network. In such cases the routing of traffic over these multiple connections is handled by IP routers based on the routing information that they exchange with their peers. This information is relatively static in nature and is typically based on the state of links that interconnect the different routers.

Abstract: A method and apparatus are provided for scheduling the transmission of cells of a plurality of data streams in a communications network. An earliest deadline first (EDF) scheduler is provided for scheduling the transmission of cells of a plurality of data streams in a communications network to ensure that the connection or data stream with the earliest deadline is transmitted first. Each of the multiple data streams has a delay bound or deadline. Data of each data stream is enqueued to a corresponding data cell queue. A timing wheel time slot based on an identified target transmission time for each data cell queue is calculated utilizing an addition of a maximum delay value. A move forward timing mechanism includes a scan forward feature to identify a succession of virtual connection or data stream cell queues for transmission. A multiple tier cell scheduler is provided that includes at least two scheduling timing wheels.

Abstract: A method and apparatus are provided for resource allocation with guarantees. A resource allocator is coupled to a controller. The resource allocator allocates resources between a plurality of arrival processes. A dedicated resource pool and a shared resource pool are provided. When an arrival process is identified, the resource allocator obtains a predefined characterizing value for the identified arrival process. Responsive to the obtained predefined characterizing value, resource from one of the dedicated resource pool or the shared resource pool is allocated to the arrival process. The controller is utilized for tracking resource use and for providing the predefined characterizing value for each of the plurality of arrival processes. The dedicated resource pool has a predetermined capacity greater than or equal to the total of all the low threshold values for each of the arrival processes.

Abstract: The present invention addresses the issue of controlling delay variations (jitter) in packet-switched networks by enhancing the capabilities of existing scheduling policies. The idea is to use a few bits in the header of packets to send jitter control information to the downstream network elements, so that the delay variation caused by the upstream network element, is compensated for by the downstream network element. The key point to observe is that packets (or cells in ATM) may be small, and therefore, not contain many bits in the header that can be used for jitter control. We describe a unique scheme, that utilizes the bits that are available for jitter control in an efficient manner, allowing for the desired jitter to be obtained with as few bits as possible.

Abstract: A distance learning system consists of a plurality of multi-cast clients of various classes and priorities with one multi-cast client as a primary multi-cast client, a multi-cast server, arbitrator and a distance learning session coordinator. The primary multi-cast client provides the default or primary Audio-Visual Material (AVM) stream. The Multi-Cast Server (MCS) setups a multi-cast over a point to multi-point connection which connects all multi-cast clients that are to take part in a particular distance learning session, along with the Primary multi-cast client. Additionally, the primary multi-cast client is connected to the MCS via a point-to-point link. The multi-cast clients and the primary multi-cast client receive an AVM material stream from the multi-cast server via the point to multi-point connection. When a multi-cast client wishes to speak, a speaking request is sent to the arbitrator, the arbitrator determines whether to grant or deny the speaking request.

Abstract: A distance learning system consists of a plurality of multi-cast clients of various classes and priorities with one multi-cast client as a primary multi-cast client, a multi-cast server, arbitrator and a distance learning session coordinator. The primary multi-cast client provides the default or primary Audio-Visual Material (AVM) stream. The Multi-Cast Server (MCS) setups a multi-cast over a point to multi-point connection which connects all multi-cast clients that are to take part in a particular distance learning session, along with the Primary multi-cast client. Additionally, the primary multi-cast client is connected to the MCS via a point-to-point link. The multi-cast clients and the primary multi-cast client receive an AVM material stream from the multi-cast server via the point to multi-point connection. When a multi-cast client wishes to speak, a speaking request is sent to the arbitrator, the arbitrator determines whether to grant or deny the speaking request.

Abstract: A leaky bucket checker which combines synchronous updates with event driven asynchronous updates triggered by packet arrivals. A synchronous update is performed exactly as an event-driven update by assuming that a packet of length zero has arrived at the time of the update. These updates are performed in a round robin fashion on each connection. Therefore, assuming that one such update can be performed in each clock tick, the maximum bit representation of the last update time state variable can be limited to N bits for 2.sup.N total connections. Given the reduced processing and storage costs, a great number of network connections and leaky bucket checkers is possible.

Abstract: In a communication switch with input and output queueing, which handles different priority classes of traffic (e.g. video and audio applications with a high priority, and file transfers and e-mail as low priority traffic), the invention provides a timed shut-off mechanism at each input queue. This mechanism is activated when an input queue attempting to transmit low-priority traffic gets a backpressure signal. The mechanism interrupts further attempts to transmit low priority traffic for a predetermined period of T switching cell cycles. Hence, during the shut-off periods, the output queue is only used by the high priority traffic. Therefore, the performance of the high priority traffic is preserved.

Abstract: A non-quota access indicator is circulated among nodes in a multi-node quota based communication system with a shared resource, indicating maximum possible non-quota access to the shared resource to a given node receiving same. Upon arrival at a node, the indicator is saved and then updated to reflect the current status of that node as either starved or satisfied, the former being a condition of currently having quota remaining and a shared resource access requirement, and the latter being a condition of either currently having no remaining quota or having no current shared resource access requirement. After updating, the node immediately propagates the indicator to the next node in the system. When a node without quota requires access to the shared resource, it compares its requirement to the last stored indicator and accesses the shared resource if the stored indicator is equal to or greater than the access requirement.

Abstract: A polling procedure providing the capabilities to assign and dynamically modify a user's communication parameters (i.e., response allocation and polling rate) based on the user's bandwidth requirements. In addition, the polling procedure instructs the users to delay their responses as a function of round-trip propagation delay and remaining response allocation for previously polled users to ensure that poll responses from separate users do not overlap.

Abstract: Method and apparatus for managing internal-node communications in a packet switching network by calculating optimal routes for packets and addressing subnodes within packet nodes using a specific message format. Internal communication facilities called intranode links connect multiple subnodes within nodes. Each subnode contains a switching mechanism and routes packet to other nodes, subnodes, or user applications using a specific message format. The message format allows specific subnodes anywhere in the network to the addressed by any other subnode, making communications more efficient and simplifying the management of internode links.

Abstract: A non-quota access indicator is circulated among nodes in a multi-node quota based communication system with a shared resource, indicating maximum possible non-quota access to the shared resource to a given node receiving same. Upon arrival at a node, the indicator is saved and then updated to reflect the current status of that node as either starved or satisfied, the former being a condition of currently having quota remaining and a shared resource access requirement, and the latter being a condition of either currently having no remaining quota or having no current shared resource access requirement. After updating, the node immediately propagates the indicator to the next node in the system. When a node without quota requires access to the shared resource, it compares its requirement to the last stored indicator and accesses the shared resource if the stored indicator is equal to or greater than the access requirement.

Abstract: A counter for tracking current shared resource access quota requests of nodes in a multi-node system is circulated among the nodes. A quota for a given node is determined as a function of the counter, the needs of the given node and a variable indicative of total access quota for all nodes combined. The determined quota is then allocated to the given node, i.e., the node is allowed to access the shared resource in accordance with the determined quota.

Abstract: Method and apparatus for making limited internal-node communication facilities externally visible in a packet switching network. Internal-node communication facilities are called intranode links, can include any cable, channel, bus, etc. over which data passes, and are used to connect the multiple subnodes within a given node. Each subnode contains a switching mechanism and routes packets to other nodes, subnodes, or user applications. Each node provides network control functions such as topology, directory, path selection, and bandwidth management which can manage intranode links in the same manner that internode links are currently managed.

Abstract: A fast bandwidth reservation method and system used in packet-switched networks that reserve bandwidth for a data transfer over links in a path between a source node, at least one intermediate node, and a destination node with minimal latency where the source node desires to send data to the destination node along the specific path using at least a minimum bandwidth and up to a maximum bandwidth. The goal of the method and system is to reserve bandwidth for a data transfer in the minimal amount of time. No link on the path between the source node and destination node has more bandwidth allocated for the source node than the minimum allocated for the previous forward links on the path. Links on the path between the source node and destination node have their bandwidth allocation for the data transfer adjusted based on the final minimum bandwidth allocated for the data transfer.

Abstract: A congestion control system for packet communications networks in which access to the network is controlled to prevent such congestion. Packets within the prespecified statistical description of each packet source are marked as high priority ("green" packets) while packets exceeding the pre-specified characteristics are marked with a lower priority ("red" packets). The overall red packet rate is limited to prevent red packet saturation of the network. Packets are marked red for a continuous train of successive red packets. The introduction of red packets into the network is subjected to a degree of hysteresis to provide better interaction with higher layer error recovery protocols. The amount of hysteresis introduced into the red packet marking can be fixed or varied, depending on the statistics of the incoming data packets at the entry point to the network.