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 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: 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: Apparatus and method for adapting a control plane of a communications network normally using a call session control function (CSCF) in communication with a resource access control function (RACF) by providing a priority service functional element (PS-FE) to handle call admission and priority services.

Abstract: In one embodiment, a method for setting up a flow-through mesh group (FTMG) for transmitting link-state packets (LSPs) in a network having a plurality of nodes interconnected by links. The FTMG is a combination of multiple spanning trees for the network through which LSPs are forwarded. FTMG set-up messages are received at ports of each node of the network from peer ports of linked nodes. FTMG set-up messages identify root nodes of the multiple spanning trees and the transmission modes of the peer ports. The FTMG set-up messages are used to determine (1) a root node for each spanning tree, (2) a root port on each node for each spanning tree, and (3) directionality of ports of the nodes. FTMG set-up messages are then used to determine the transmission mode of ports of the nodes and, subsequently, to update the spanning trees and transmission modes, as needed.

Abstract: In one embodiment, an automatically maintained, distributed source tree (DST) network has a plurality of fully connected internal nodes. One or more internal nodes may be connected to one or more external nodes. A first internal node synchronizes its link-state database with another internal node by sending and receiving respective Reduced Sequence Number Packet-Data-Units (PDUs) (RSNPs). An RSNP includes summary information for link-state packets (LSPs) (1) originated by the first internal node, (2) received by the first internal node from the other internal node, and (3) received from and/or originated by external nodes. If an internal link fails, then the corresponding end-nodes may recover and maintain automatic DST operation by entering either relay-mode or switch-mode operation. In relay-mode operation, an end-node tunnels packets to the other end-node via an intermediary node. In switch-mode operation, an intermediary node is selected to forward packets from one end-node to the other end-node.

Abstract: In one embodiment, a method for processing, at an enhanced Session Initiation Protocol (SIP) proxy (e-proxy), (1) a SIP INVITE message to a first user at an IPv4/IPv6 dual-stack (DS) host, connected to an IPv6 network, from a second user at an IPv4 host, connected to an IPv4 network. The e-proxy receives the SIP INVITE message from the IPv4 network. When the e-proxy determines that Dual Stack Transition Mechanism (DSTM) service is required, the e-proxy obtains a temporary IPv4 address for the DS host, finds a suitable tunnel end-point (TEP), and sends a corresponding, but modified, INVITE message to the DS host. The modified INVITE message body includes invocation of DSTM service, the temporary IPv4 address, the TEP's IPv6 address, and the IPv4 host's IPv4 address. The e-proxy sends a BIND message to the TEP to bind the DS host's IPv6 address to the temporary IPv4 address for proper tunneling.

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: In one embodiment, an automatically maintained, distributed source tree (DST) network has a plurality of fully connected internal nodes. One or more internal nodes may be connected to one or more external nodes. A first internal node synchronizes its link-state database with another internal node by sending and receiving respective Reduced Sequence Number Packet-Data-Units (PDUs) (RSNPs). An RSNP includes summary information for link-state packets (LSPs) (1) originated by the first internal node, (2) received by the first internal node from the other internal node, and (3) received from and/or originated by external nodes. If an internal link fails, then the corresponding end-nodes may recover and maintain automatic DST operation by entering either relay-mode or switch-mode operation. In relay-mode operation, an end-node tunnels packets to the other end-node via an intermediary node. In switch-mode operation, an intermediary node is selected to forward packets from one end-node to the other end-node.

Abstract: In one embodiment, a method for setting up a flow-through mesh group (FTMG) for transmitting link-state packets (LSPs) in a network having a plurality of nodes interconnected by links. The FTMG is a combination of multiple spanning trees for the network through which LSPs are forwarded. FTMG set-up messages are received at ports of each node of the network from peer ports of linked nodes. FTMG set-up messages identify root nodes of the multiple spanning trees and the transmission modes of the peer ports. The FTMG set-up messages are used to determine (1) a root node for each spanning tree, (2) a root port on each node for each spanning tree, and (3) directionality of ports of the nodes. FTMG set-up messages are then used to determine the transmission mode of ports of the nodes and, subsequently, to update the spanning trees and transmission modes, as needed.

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: 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: 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: 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 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: Apparatus and method for adapting a control plane of a communications network normally using a call session control function (CSCF) in communication with a resource access control function (RACF) by providing a priority service functional element (PS-FE) to handle call admission and priority services.

Abstract: An AAL2/SSCS packet voice system multiplexes various forms of voice-band traffic including voice packets, fax packets, and data packets into a virtual circuit (VC). This AAL2/SSCS packet voice system executes a dynamic call admission algorithm that takes into account call type in deciding whether to admit a new call to the VC. In particular, this approach takes into account different bandwidth needs for different call types. The AAL2/SSCS packet voice system also performs bit or block dropping on voice packets to mitigate the effects of traffic congestion. The bit or block dropping is done based on the packet queue fill value exceeding at least one queue threshold. Further, the AAL2/SSCS packet voice system also dynamically varies a queue threshold as a function of capacity.

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 switch fabric for routing data has a switching stage configured between an input stage and an output stage. The input stage forwards the received data to the switching stage, which routes the data to the output stage, which transmits the data towards destinations. In one aspect, at least one input port can be programmably configured to store data in two or more input routing queues that are associated with a single output port, and at least one output port can be programmably configured to receive data from two or more output routing queues that are associated with a single input port. In another aspect, the output stage transmits status information about the output stage to the input stage, which uses the status information to generate bids to request connections through the switching stage.

Abstract: A switch fabric for routing data has a switching stage configured between an input stage and an output stage. The input stage forwards the received data to the switching stage, which routes the data to the output stage, which transmits the data towards destinations. Each input device of the input stage transmits bids to the crossbar devices of the switching stage to request connections through the switching stage for routing the data to the output devices of the output stage. In one aspect, each crossbar device has (1) a bid arbitrator that determines whether to accept or reject each received bid, wherein, in response to a collision between multiple bids, the bid arbitrator accepts two or more of the colliding bids in a single time slot; and (2) memory for storing one or more accepted cells for the same output device, wherein the crossbar device can transmit grant signals for two or more accepted bids for the same output device in a single time slot.