Abstract: The invention pertains to methods and apparatus for determining when and how to perform communications network congestion control tactics with respect to packet-based networks that are used to interconnect other networks, particularly time division multiplexed (TDM) networks. The congestion control mechanisms include rerouting and call gapping in the TDM networks to reduce congestion at ports of the packet-based network.

Abstract: A protected communication network utilizes a link-based recovery strategy that supports independent recovery paths for individual demands, where each link includes one or more lines and each line can support one or more demands. Failure of one or more—or even all—of the lines/ports of a link will typically result in the independent rerouting of the affected demands along one or more link-detour paths. The flexibility afforded by recovery at the granularity of a demand supports the computation of more-optimal link-detour paths and a corresponding increase in sharing of network resources between disjoint failures. The network also addresses the restricted case where all demands on a line/port are recovered along the same link-detour path.

Abstract: A protected communication network utilizes a link-based recovery strategy that incorporates loop-avoidance mechanisms to eliminate redundant traversal of links in recovery paths, thereby improving network efficiency. The loop-avoidance mechanisms can include calculation of recovery paths taking into account protected segments that include shared risk link groups. In one two-phase loop-avoidance mechanism, a full link-detour path is calculated for a primary-path link by generating a minimum cost path between the upstream and downstream terminating nodes for the link. Next, the full link-detour path is shortened by removing redundant links that are shared by the full link-detour path and the original primary path. Calculation of link-detours and elimination of loops is supported in some embodiments by the distribution of link-state parameters via extensions to the link-state-advertisement (LSA) protocol.

Abstract: A protected communication network utilizes a link-based recovery strategy that includes methods for calculating and distributing link-protection parameters and calculating primary and link-detour paths based on these parameters. These link-protection parameters support the computation of more-optimal link-detour paths and a corresponding increase in sharing of network resources between disjoint failures. A joint-optimization mechanism can be employed that considers both the cost of link-detour paths as well as the cost of links in candidate primary paths in the selection of a primary path for a demand. Information for the joint optimization is preferably distributed using link-state advertisements.

Abstract: An architecture for quality-of-service (QoS) management creates a logical circuit-switched network within a packet network to support QoS-sensitive demands levied on the network. This QoS-managed network can serve to interwork, e.g., a PSTN with VoIP networks. The architecture can include a connection resource manager (CRM), which oversees bandwidth availability and demand admission/rejection on dynamically provisioned virtual trunk groups (VTGs) within the packet network, and a transport bandwidth controller (TBC). The VTGs serve to transport QoS-sensitive demands across the packet network. The TBC serves the CRM by providing an interface to routers and/or OAM systems of the packet network to size VTGs to meet QoS requirements. Media switches located at the packet network borders serve to mux/demux the demands into/from VTGs. CRMs and TBCs can be implemented as centralized, distributed, or hierarchical, and flat and aggregated variants of the architecture are supported.

Abstract: The invention pertains to methods and apparatus for determining when and how to perform communications network congestion control tactics, such as reconfiguring pipeline bandwidths, with respect to packet-based networks.

Abstract: The location of a mobile wireless communication unit in the service area of a CDMA communications system is predicted utilizing two likelihood functions that define maximum likelihood estimators of the mobile unit's location, based on attribute measurements, such as but not limited to pilot signal strength, being made at the location of the mobile unit and reported back to a base station. One of the likelihood functions comprises a frequentist likelihood function and the other comprises a Bayesian-modified likelihood function. The likelihood functions are based on the assumption that there is an RF model which provides the probability a mobile unit is able to detect one or more attributes associated with an arbitrary base station, given it is located at an arbitrary location within the service area. Each of the likelihoods are also incorporated into a sequential Bayesian procedure which outputs a posterior distribution indicative of the location of the mobile unit.

Abstract: Congestion across links in a network, such as the Internet, is reduced by diverting traffic from the congested link to alternative, shortest paths by adjusting splitting factors associated with the congested and alternative links. The alternative shortest paths comprise equal cost paths. Alternatively, adjustments occur after the creation of additional equal cost paths/shortest paths if none are initially available within the network. Unique programs control the adjustment of the splitting factors and the creation of the additional shortest paths. The programs make use of both existing, real networks and constructed, virtual networks in conjunction with novel traffic flow relationships to divert traffic from a congested link without causing further congestion within the network. Another unique program deletes shortest paths once used to accept traffic diverted from a congested link when traffic in the network decreases.

Abstract: A method for determining a restoration path for a new service in a mesh network involves selecting between candidate restoration paths corresponding to a primary path for the new service based on the shared-risk link groups (SRLGs) associated with links in the primary path. The method includes, for each of a plurality of candidate restoration paths associated with the primary path, (1) determining whether the primary path requires any additional restoration bandwidth to be reserved on any link of the restoration path based on whether, for each link of the restoration path, the primary path is SRLG-disjoint from each other primary path that is protected by that link, (2) generating a path cost for the restoration path, where the path cost is a function of whether any additional restoration bandwidth is required; and (3) selecting the restoration path for the new service based on the path cost.

Abstract: A method for determining primary and restoration paths for a new service in a mesh network involves (1) for each of a plurality of candidate primary/restoration path pairs for the new service, generating a path cost for each candidate pair, where the path cost for each restoration path is a function of the sum of the cost of links within the restoration path, and (2) selecting the primary and restoration paths for the new service from the plurality of candidate path pairs based on the path cost. If no sharing is possible, for low utilization links, the cost of links is a function of the administrative weight of the link, whereas for high utilization links, the link cost is a function of the inverse of the available capacity on the link. If sharing is possible, the cost is a function of the inverse of a sharing degree for the link.

Abstract: An extension to a connection setup protocol for establishment of a restoration path for a service in a mesh network involves, at a transit node along the restoration path, the steps of (1) receiving a service data structure having an identification of each link and transit node in a primary path for the service, and (2) determining whether to reserve additional protection bandwidth on an outgoing link incident to the transit node using the service data structure, wherein the outgoing link is part of the restoration path. In one or more embodiments, the service data structure includes identification of the service, identification of the outgoing link, and bandwidth of the service. In some cases, the extension involves reserving the additional protection bandwidth on the outgoing link, if the transit node determines that the protection bandwidth is required, based upon knowledge of the protection bandwidth already reserved on the outgoing link.

Abstract: A shared mesh data network (SMDN) for path-based recovery at the packet level. In one implementation, a first link in the network is part of two or more different protection paths, where each protection path corresponds to a different primary path. A network manager determines how much protection bandwidth to reserve on the first link for the two or more protection paths in such a way that the protection bandwidth reserved on the first link is shared between the protection paths of the two or more primary paths. As such, the amount of protection bandwidth reserved on the first link can be less than the sum of the bandwidths of the two or more primary paths. The SMDN provides efficient sharing of protection capacity. Implementations of the SMDN are appropriate to multiprotocol label-switched (MPLS) optical networks.

Abstract: A method for representing, in a network data structure, a minimum amount of protection bandwidth required to be reserved on each link in a mesh network, to restore service upon failure of another node or link in the network. The method includes (1) receiving a request for a new service in the network, wherein the new service is represented by a service data structure having an identification of each link and transit node in a primary path for the new service, (2) determining, using the network and service data structures, whether the new service requires additional protection bandwidth to be reserved on any link in the network, and (3) updating the network data structure if any additional protection bandwidth is determined to be needed. In one implementation the network and service data structures are vectors and the steps of determining and updating involve vector operations between these structures.

Abstract: The invention pertains to methods and apparatus for determining when and how to perform communication network congestion control tactics, such as call blocking, with respect to packet-based networks.

Abstract: The invention pertains to methods and apparatus for determining when and how to perform communications network congestion control tactics with respect to packet-based networks such as data compression.

Abstract: In a packet-based data network, packets are duplicated and a sequence number is inserted into each duplicate packet, where the duplicate packets are transmitted along two different paths from a source node to a destination node in the network. Depending on the implementation, the source node inserts different types of sequence numbers into the duplicate packets, and the destination node processes those sequence numbers accordingly to determine whether to accept or reject each received packet. In certain implementations, the number of sequence bits allocated to each packet is smaller than the size of the effective sequence number for the packet as interpreted by the destination node.

Abstract: A packet switch is configured for determining an equivalent bandwidth for use in GCAC. The equivalent bandwidth definition of the invention is derived by multiplying some known connection parameter such as, for example, a selected bandwidth value by a multiplier preferably computed and stored in look-up tables according to the invention. The appropriate multiplier for a given connection request associated with a call may then be found by accessing sets of the look-up tables based on one or more connection and/or network parameters. For each link in a path considered during GCAC, the product of the multiplication of the selected bandwidth value and the multiplier is then compared to the available bandwidth, AvCR, of the path links to determine if the path satisfies the connection request.

Abstract: The specification relates to a device and method utilized for packaging voice data (and other delay critical ‘connection’ or ‘flow’ type application data) for point-to-point transport from one Packet Circuit Gateway (PCG) to a second PCG over Label Switching Routers (LSRs) within an Internet Protocol (IP) network; the beneficial aspects of the packaging format being: (i) a reduced overhead requirement when compared to conventional IP telephony due to inclusion of a switching label in lieu of an appended IP header, thereby increasing network bandwidth efficiency, and (ii) the increased transport speed associated with layer two label switching when compared to layer three forwarding.

Abstract: The method estimates a capacity requirement as a function of a cell loss ratio (CLR) requirement, estimates a capacity requirement as a function of the a cell delay variation (CDV) requirement, and sets the capacity requirement based on these independent estimates. The capacity requirement is then used to determine connection admission control in the network.

Abstract: Apparatus and a method are disclosed for providing a priority queuing arrangement in the transmit direction in Inter-Working Units (IWUs) that permits Frame Relay data packets or ATM cells from channels that have contracted for a particular level of bandwidth service to be provided that service, even during heavy traffic periods when there is contention for resources in the IWU.