Patent application number | Description | Published |
20080219172 | Forwarding Plane Data Communications Channel for Ethernet Transport Networks - Described is a process and system for providing an extensible forwarding plane data communications channel adapted to selectively support operations, administration and maintenance (OAM) activity within one or more different domains of an Ethernet transport network. The data communication channel is established using Ethernet protocol data units forwarded within the forwarding plane, between network elements. The Ethernet protocol data units can be Ethernet OAM frames modified to include an OpCode indicative of a maintenance communication channel. The OAM frames are generated at a selected one of the network elements (source), forwarded along the same network path as the Ethernet frames, and terminate at another network element (destination) associated with a maintenance level identified within the OAM frame. The source and destination network elements can reside on a domain boundary using the Ethernet OAM frames flowing therebetween to relay maintenance communications channel messages. | 09-11-2008 |
20080259784 | Failure notification in a network having serially connected nodes - Multicast capabilities of a link state protocol controlled network are used to accelerate the flooding advertisement of topology change notifications within portions of the network. This flooding mechanism may be particularly efficient in a network with a large number of two-connected nodes such as a ring network architecture. A control plane specific multicast group address is used when flooding topology change notifications, and a process such as reverse path forwarding check is used as an additional control on forwarding of the notification to prevent looping of control plane packets. Two-connected nodes insert a forwarding entry into their FIB to enable frames containing the control message to be forwarded via the data plane on to the downstream node so that propagation of the control message along a chain of two-connected nodes may occur at data plane speeds. | 10-23-2008 |
20080279196 | Differential Forwarding in Address-Based Carrier Networks - The invention relates to enabling differential forwarding in address-based carrier networks such as Ethernet networks. There is described a method of and connection controller for establishing connections ( | 11-13-2008 |
20080310417 | DIFFERENTIAL FORWARDING IN ADDRESS-BASED CARRIER NETWORKS - The invention relates to enabling differential forwarding in address-based carrier networks such as Ethernet networks. There is described a method of and connection controller for establishing connections ( | 12-18-2008 |
20090041023 | Method and Apparatus for Interworking VPLS and Ethernet Networks - To allow seamless interworking between an 802.1ah service instance (ISID) and a VPLS service instance, the AGI value used to signal the setup of the pseudowire portion of the VPLS may carry the ISID value of an associated 802.1ah service instance. This allows the service instance to be identified end-to-end across the Ethernet and VPLS networks using the same value without modifying how the MPLS network operates. The VPLS network will use AGI/AII signaling to set up pseudowires on the MPLS network, but instead of using an AGI value assigned by the MPLS network, the AGI value that is assigned will be taken from the ISID value of the Ethernet frame or from ISIDs registered by the Ethernet network. The AGI message may be given a new type value indicating that the AGI message carries a value that corresponds to the ISID value on an attached Ethernet network. Alternatively, an existing AGI message type may be used to carry the ISID value, and a second type field may be used to indicate that the AGI contains an ISID value. | 02-12-2009 |
20090059799 | SCALING OAM FOR POINT-TO-POINT TRUNKING - A shared (proxy) OAM session is performed in a packet-based network on behalf of a plurality of connections. First and second connections are each routed between respective nodes of the network for carrying data traffic. The second connection shares a portion of the routing of the first connection. The shared OAM session is performed along a path which is co-routed with at least part of the shared portion of the routing of the first connection and the second connection. Failure notification signalling is propagated to an endpoint node of each of the first and second connections when the shared OAM session indicates a failure has occurred. The use of a shared OAM session reduces processing at nodes and reduces OAM traffic. Each connection can be a trunk, such as a PBT/PBB-TE trunk, or a service carried within a trunk. | 03-05-2009 |
20090073998 | Interworking Point to Point Protocol for Digital Subscriber Line Access w/Ethernet Connections in the Aggregation Network - Methods and apparatus for enabling the establishment of a Point to Point Protocol (PPP) session to a broadband network gateway through an access node of a packet-switched wireline aggregation network and methods and apparatus for enabling Ethernet frame data to be transported through an access node of packet-switched wireline aggregation network between a remote gateway a broadband network gateway are provided. In one aspect conventional PPP over Ethernet (PPPoE) BNG discovery using broadcast PADI messages is replaced by configured unicast PADI messages to specified BNGs over Ethernet Connections. In other aspects Ethernet data is transported through the access node by swapping the upstream source MAC address with the MAC address of the access node to shield the provider network from customer MAC addresses, and swapping the downstream destination MAC address to the MAC address of the remote gateway by looking up the MAC address of the remote gateway in a mapping of PPPoE Session ID to MAC address of the remote gateway. | 03-19-2009 |
20090161669 | Evolution of Ethernet Networks - An Ethernet network comprises nodes which support a plurality of different forwarding modes. A range of VLAN Identifiers (VIDs) are allocated to each of the forwarding modes. Connections are configured between a source node and a destination node of the network using different forwarding modes. Packets carrying data traffic are sent to the destination node by selectively setting a VID in a packet to a first value, to transfer a packet via a first connection and a first forwarding mode, and a second value to transfer a packet via the second connection and the second forwarding mode. Packets received from both of the connections and sent on to an end-user. VLAN Identifiers can be allocated to different releases of functionality at nodes (e.g. software releases) such that packets are forwarded via a set of nodes supporting a first release, or via a set of nodes supporting a second release. It is possible to provide a controlled and disruption-free network evolution. | 06-25-2009 |
20090168666 | Implementation of VPNs over a link state protocol controlled Ethernet network - Nodes on a link state protocol controlled Ethernet network implement a link state routing protocol such as IS-IS. Nodes assign an IP address or I-SID value per VRF and then advertise the IP addresses or I-SID values in IS-IS LSAs. When a packet is to be forwarded on the VPN, the ingress node identifies the VRF for the packet and performs an IP lookup in customer address space in the VRF to determine the next hop and the IP address or I-SID value of the VRF on the egress node. The ingress node prepends an I-SID or IP header to identify the VRFs and then creates a MAC header to allow the packet to be forwarded to the egress node on the link state protocol controlled Ethernet network. When the packet is received at the egress node, the MAC header is stripped from the packet and the appended I-SID or IP header is used to identify the egress VRF. A customer address space IP lookup is then performed in the identified VRF on the egress node using the information in the client IP header to determine how to forward the packet. Customer reachability information within a VPN may be exchanged between VRFs using iBGP, or directly by using link state protocol LSAs tagged with the relevant I-SID. | 07-02-2009 |
20090168768 | Tie-Breaking in Shortest Path Determination - A consistent tie-breaking decision between equal-cost shortest (lowest cost) paths is achieved by comparing an ordered set of node identifiers for each of a plurality of end-to-end paths. Alternatively, the same results can be achieved, on-the-fly, as a shortest path tree is constructed, by making a selection of an equal-cost path using the node identifiers of the diverging branches of the tree. Both variants allow a consistent selection to be made of equal-cost paths, regardless of where in the network the shortest paths are calculated. This ensures that traffic flow between any two nodes, in both the forward and reverse directions, will always follow the same path through the network. | 07-02-2009 |
20090168780 | MPLS P node replacement using a link state protocol controlled ethernet network - When a MPLS Virtual Forwarding Entity (VFE) on a Link State Protocol Controlled Ethernet Network learns a forwarding equivalency class (FEC) to label binding from an attached MPLS-LER, it will determine an associated MAC address for the FEC, and advertise the FEC/label binding along with the MAC address. Nodes in the Ethernet network will install shortest path forwarding state for the MAC to the MPLS-VFE advertising the FEC/label binding. Each MPLS-VFEs on the Ethernet network that receive the advertisement will update its database and generate a label that is distributed to attached MPLS LERs using LDP. When the MPLS-LER needs to transmit traffic to the FEC, it will use the label provided by the MPLS-VFE. The MPLS-VFE maintains a mapping between the label and the MAC address so that it may use the MAC address to forward the packet across the Ethernet network. | 07-02-2009 |
20090180400 | BREAK BEFORE MAKE FORWARDING INFORMATION BASE (FIB) POPULATION FOR MULTICAST - A method of installing forwarding state in a link state protocol controlled network node having a topology database representing a known topology of the network, and at least two ports for communication with corresponding peers of the network node. A unicast path is computed from the node to a second node in the network, using the topology database, and unicast forwarding state associated with the computed unicast path installed in a filtering database (FDB) of the node. Multicast forwarding state is removed for multicast trees originating at the second node if an unsafe condition is detected. Subsequently, a “safe” indication signal is advertised to each of the peers of the network node. The “safe” indication signal comprises a digest of the topology database. A multicast path is then computed from the network node to at least one destination node of a multicast tree originating at the second node. Finally, multicast forwarding state associated with the computed multicast path is installed in the filtering database (FDB) of the network node, when predetermined safe condition is satisfied. | 07-16-2009 |
20090201937 | RESILIENT PROVIDER LINK STATE BRIDGING (PLSB) VIRTUAL PRIVATE LAN SERVICE (VPLS) INTERWORKING - A method of peer interfacing a Link-State controlled network domain with an Ethernet Bridging controlled network domain. A pair of peer attachment points are provided between the Link-State controlled network domain and the Ethernet Bridging domain. The peer attachment points are respective endpoints of a set of one or more LAN segments defined within the Ethernet Bridging domain. The set of LAN segments are represented as a virtual node in the Link-State controlled network domain. The virtual node is represented in the Link-State controlled network domain as connected to each of the peer attachment points via a respective virtual link. The virtual links are configured such that frames to or from an address in the Link-State controlled network domain are forwarded over a tree passing through only one of the peer attachments points. | 08-13-2009 |
20090279536 | IP forwarding across a link state protocol controlled ethernet network - Nodes on an Ethernet network run a link state protocol on the control plane and install shortest path forwarding state into their FIBs to allow packets to follow shortest paths through the network without requiring MAC header replacement at each hop through the network. When a node learns an IP address, it will insert the IP address into its link state advertisement to advertise reachability of the IP address to the other nodes on the network. Each node will add this IP address to its link state database. If a packet arrives at an ingress node, the ingress node will read the IP address, determine which node on the link state protocol controlled Ethernet network is aware of the IP address, and construct a MAC header to forward the packet to the correct node. The DA/VID of the MAC header is the nodal MAC of the node that advertised the IP address. Unicast and multicast IP forwarding may be implemented. | 11-12-2009 |
20100080238 | Extended Private LAN - A virtual private network is provided across a Provider Link State Bridging (PLSB) network between a first node connected to a private LAN and a second node connected to a roaming device. The roaming device is authenticated. A successful authentication results in a Service Identifier for the VPN being sent to the second node. Connectivity between members of the VPN service instance is maintained as part of the PLSB Link State process for forwarding table maintenance, rather than by any form of explicit signalling. A single Customer Virtual Bridge/Virtual Switch Instance can be located at the first node to provide point-to-point connectivity to each roaming device. A virtual Residential Gateway function can be combined with the Customer Virtual Bridge/Virtual Switch Instance. | 04-01-2010 |
20100103813 | PROVISIONED PROVIDER LINK STATE BRIDGING (PLSB) WITH ROUTED BACK-UP - A method of managing traffic flow in a packet network. A working sub-network is provided, which comprises one or more provisioned static working paths between at least one source node and one or more destination nodes in the network, and the working sub-network with a service instance. A backup sub-network is provided, which comprises one or more dynamic protection paths between the at least one source node and the one or more destination nodes, and the backup sub-network associated with the service instance. During a normal operation of the network, forwarding subscriber traffic associated with the service instance through the network using the working sub-network. Following detection of a network failure affecting the service instance, the subscriber traffic associated with the service instance is switched for forwarding through the network using the backup sub-network. | 04-29-2010 |
20100103846 | PROVIDER LINK STATE BRIDGING (PLSB) COMPUTATION METHOD - A method of multicast route computation in a link state protocol controlled network. A spanning tree is computed from a first node to every other node in the network using a known spanning tree protocol. The network is then divided into two or more partitions, each partition encompassing an immediate neighbour node of the first node and any nodes of the network subtending the neighbour node on the spanning tree. Two or more of the partitions are merged when a predetermined criterion is satisfied. Nodes within all of the partitions except a largest one of the partitions are then identified, and each identified node examined to identify node pairs for which a respective shortest path traverses the first node. | 04-29-2010 |
20100157844 | RESILIENT ATTACHMENT TO PROVIDER LINK STATE BRIDGING (PLSB) NETWORKS - A method system for interfacing a client system in a first network domain with a Provider Link State Bridging (PLSB) network domain. At least two Backbone Edge Bridges (BEBs) of the PLSB domain | 06-24-2010 |
20100169471 | Verification of Configuration Information in BGP VPNs - Described are mechanisms for verifying configuration information in 2547 BGP VPNs. An originating PE generates a first knowledge digest encoding first configuration information associated with a current set of information advertised for a VRF. The originating PE also generates a second knowledge digest encoding second configuration information associated with cumulative information advertised for the VRF. The originating PE is capable of receiving a message from a user PE, the message including a third knowledge digest encoding third configuration information related to the user VRF. The originating PE is capable of comparing the first knowledge digest to the third knowledge digest and producing a first indication if the third configuration information encoded in the third knowledge digest is not a subset of the first configuration information encoded in the first knowledge digest. | 07-01-2010 |
20100189015 | Planning Routes and Allocating Identifiers to Routes in a Managed Frame-Forwarding Network - A method is provided of planning routes and allocating route identifiers in a managed frame-forwarding network. The network comprises a plurality of nodes interconnected by links, with each node being arranged to forward data frames according to a combination of an identifier and a network address carried by a received data frame and forwarding instructions stored at the node. A first step of the method identifies a sub-set of nodes which are core nodes of the network. The remaining nodes are termed outlying nodes. A spanning tree is then built off each of the identified core nodes, with the spanning tree stopping one link short of any other core node. Each spanning tree defines a loop-free path between a core node at the root of the spanning tree and a set of outlying nodes. Connections are planned between roots of the spanning trees and a different identifier is allocated to each planned connection between a pair of spanning trees. | 07-29-2010 |
20100238813 | Q-in-Q Ethernet rings - A resilient virtual Ethernet ring has nodes interconnected by working and protection paths. Each node has a set of VLAN IDs (VIDs) for tagging traffic entering the ring by identifying the ingress node and whether the traffic is on the working or protection path. MAC addresses are learned in one direction around the ring. A port aliasing module records in a forwarding table a port direction opposite to a learned port direction. Each node can also cross-connect working and protection paths. If a span fails, the two nodes immediately on either side of the failure are cross-connected to fold the ring working-path traffic is cross-connected onto the protection path at the first of the two nodes and is then cross-connected back onto the working path at the second of the two nodes so that traffic always ingresses and egresses the ring from the working path. | 09-23-2010 |
20100271936 | Pre-Computing Alternate Forwarding State in a Routed Ethernet Mesh Network - A set of critical nodes or links is identified on the network and alternate forwarding state is pre-computed and disseminated within a node such that, upon failure of one of the critical nodes/links, a minimal trigger will cause the alternate forwarding state to be used to forward traffic on the routed Ethernet mesh network. In one embodiment rather than storing full tables of alternate forwarding state, only the changes to the forwarding state required by an identified failure is stored by the network nodes. Upon occurrence of a failure on the network, the identified failure is used to select the alternate forwarding state. | 10-28-2010 |
20100272110 | Virtual Links in a Routed Ethernet Mesh Network - Virtual links may be used to divert traffic within an Ethernet network without affecting overall traffic patterns on the Ethernet network. In one embodiment, the virtual link may be established on the network via a routing system in use on the network. Nodes on a defined path for the virtual link will install forwarding state for the virtual link so that traffic may follow the defined path through the network. The logical view of the virtual link, from a routing perspective however, has the same cost as the shortest path between the endpoints of the virtual link and, accordingly, does not affect other traffic patterns on the network. Once established, the end nodes on the virtual path will have two equal cost paths through the network—one following the shortest path tree and one along the path for the virtual link. The end nodes may use a tie breaking process in an Equal Cost Multi Path (ECMP) selection process to preferentially select the virtual link over the shortest path. | 10-28-2010 |
20100274924 | Method and Apparatus for Accommodating Duplicate MAC Addresses - Each access node is associated with one or more IP subnets with a preferred default subnet. Each subnet is instantiated as a unique virtual Ethernet broadcast domain. As client nodes register on the communication network, they will dynamically try to obtain an IP address for use on the communication network. As part of this process, the MAC address of the client node will be checked to ensure that it is not a duplicate of another MAC address associated with another client node that has already been assigned an IP address from the default subnet. When duplicate MAC addresses are detected, the device with the duplicate MAC address will be assigned an IP address from a different subnet so that more than one client device with the same MAC address are not associated with the same subnet. In one embodiment, a DHCP server may implement the process of checking for duplicate MAC addresses. In an Ethernet context, different IP subnet prefixes may be mapped to different S-VID values so that the different subnets are implemented as different VLANs within the Ethernet network. | 10-28-2010 |
20100284309 | Method and Apparatus for Multicast Implementation In a Routed Ethernet Mesh Network - Interest in multicast group membership may be advertised via a routing system on an Ethernet network along with an indication of an algorithm to be used by the nodes on the network to calculate the distribution tree or trees for the multicast. Each node, upon receipt of the advertisement, will determine the algorithm that is to be used to produce the multicast tree and will use the algorithm to calculate whether it is on a path between nodes advertising common interest in the multicast. Example algorithms may include shortest path algorithms and spanning tree algorithms. This allows multicast membership to be managed via the routing control plane, while enabling spanning tree processes to be used to forward multicast traffic. Since spanning tree is able to install multicast state per service rather than per source per service, this reduces the amount of forwarding state required to implement multicasts on the routed Ethernet mesh network. | 11-11-2010 |
20100322263 | Method and Apparatus for Implementing Control of Multiple Physically Dual Homed Devices - A ring control protocol is used to establish a separate control plane for a plurality of physically dual homed devices to enable collections of dual homed devices to be represented by a single pair of addresses into the attached routed Ethernet network. The gateway devices analyze the passing ring control packets to create direct mappings for data packets to the routed Ethernet network. Thus, although the dual homed devices are treated as a ring from a control perspective, the data path is implemented to be direct so that data packets continue to flow directly from the dual homed devices to each of the attached gateway devices. In one embodiment, each of the gateway devices implements a virtual switch and advertises the MAC address of the virtual switch into the routed Ethernet network rather than the MAC addresses of each of the attached Ethernet Switch Units. | 12-23-2010 |
20110032936 | MULTICAST IMPLEMENTATION IN A LINK STATE PROTOCOL CONTROLLED ETHERNET NETWORK - Forwarding state may be installed for sparse multicast trees in a link state protocol controlled Ethernet network by enabling intermediate nodes to install state for one or more physical multicast trees, each of which may have multiple logical multicast trees mapped to it. By mapping multiple logical multicasts to a particular physical multicast, and installing state for the physical multicast, fewer FIB entries are required to implement the multiple multicasts to reduce the amount of forwarding state in forwarding tables at the intermediate nodes. Mapping may be performed by destination nodes before advertising membership in the physical multicast, or may be performed by the intermediate nodes before installing state when a destination node advertises membership in a logical multicast. Intermediate nodes will install state for the physical multicast tree if they are on a shortest path between a source and at least one destination of one of the logical multicasts that has been mapped to the physical multicast. | 02-10-2011 |
20110058483 | Forwarding Plane Data Communications Channel for Ethernet Transport Networks - Described is a process and system for providing an extensible forwarding plane data communications channel adapted to selectively support operations, administration and maintenance (OAM) activity within one or more different domains of an Ethernet transport network. The data communication channel is established using Ethernet protocol data units forwarded within the forwarding plane, between network elements. The Ethernet protocol data units can be Ethernet OAM frames modified to include an OpCode indicative of a maintenance communication channel. The OAM frames are generated at a selected one of the network elements (source), forwarded along the same network path as the Ethernet frames, and terminate at another network element (destination) associated with a maintenance level identified within the OAM frame. The source and destination network elements can reside on a domain boundary using the Ethernet OAM frames flowing therebetween to relay maintenance communications channel messages. | 03-10-2011 |
20110060844 | Method and Apparatus for Selecting Between Multiple Equal Cost Paths - Each equal cost path is assigned a path ID created by concatenating an ordered set of link IDs which form the path through the network. The link IDs are created from the node IDs on either set of the link. The link IDs are sorted from lowest to highest when creating the path ID to facilitate ranking of the paths. The low and high ranked paths are selected from this ranked list as the first set of diverse paths through the network. Each of the link IDs on each of the paths is then renamed, for example by inverting either all of the high node IDs or low node IDs. After re-naming the links, new path IDs are created by concatenating an ordered set of renamed link IDs. The paths are then re-ranked and the low and high re-ranked paths are selected from this re-ranked list as the second set of diverse paths through the network. Selective naming of node IDs and use of different inversion functions can be exploited to further optimize distribution of traffic on the network. | 03-10-2011 |
20110080836 | Method and Apparatus for Providing Bypass Connectivity Between Routers - Forwarding Adjacencies (FAs) can be set up between IP/MPLS routers without requiring a Routing Adjacency (RA) to be brought up for every FA. This enables increased bypass connectivity to be established between end-point routers in the IP/MPLS network without attendant additional processing associated with having dedicated RA for each FA. Where it is possible to modify the end-point routers, the physical ports may be configured to support stand-alone FAs. A configured FA at a physical port is then associated with an IP address of a remote end-point router and a connection within the bypass technology. OAM is used to verify connectivity and configuration across the FA. Alternatively, an emulated Ethernet LAN segment may be used for IP traffic to enable full mesh connectivity to be provided by the bypass technology while requiring only one or a small number of RAs to be implemented at each end-point router. | 04-07-2011 |
20110103263 | Implementation of VPNs over a Link State Protocol Controlled Ethernet Network - Nodes on a link state protocol controlled Ethernet network implement a link state routing protocol such as IS-IS. Nodes assign an IP address or I-SID value per VRF and then advertise the IP addresses or I-SID values in IS-IS LSAs. When a packet is to be forwarded on the VPN, the ingress node identifies the VRF for the packet and performs an IP lookup in customer address space in the VRF to determine the next hop and the IP address or I-SID value of the VRF on the egress node. The ingress node prepends an I-SID or IP header to identify the VRFs and then creates a MAC header to allow the packet to be forwarded to the egress node on the link state protocol controlled Ethernet network. When the packet is received at the egress node, the MAC header is stripped from the packet and the appended I-SID or IP header is used to identify the egress VRF. A customer address space IP lookup is then performed in the identified VRF on the egress node using the information in the client IP header to determine how to forward the packet. Customer reachability information within a VPN may be exchanged between VRFs using iBGP, or directly by using link state protocol LSAs tagged with the relevant I-SID. | 05-05-2011 |
20110128857 | TIE-BREAKING IN SHORTEST PATH DETERMINATION - A consistent tie-breaking decision between equal-cost shortest (lowest cost) paths is achieved by comparing an ordered set of node identifiers for each of a plurality of end-to-end paths. Alternatively, the same results can be achieved, on-the-fly, as a shortest path tree is constructed, by making a selection of an equal-cost path using the node identifiers of the diverging branches of the tree. Both variants allow a consistent selection to be made of equal-cost paths, regardless of where in the network the shortest paths are calculated. This ensures that traffic flow between any two nodes, in both the forward and reverse directions, will always follow the same path through the network. | 06-02-2011 |
20110167155 | BREAK BEFORE MAKE FORWARDING INFORMATION BASE (FIB) POPULATION FOR MULTICAST - A method of installing forwarding state in a link state protocol controlled network node having a topology database representing a known topology of the network, and at least two ports for communication with corresponding peers of the network node. A unicast path is computed from the node to a second node in the network, using the topology database, and unicast forwarding state associated with the computed unicast path installed in a filtering database (FDB) of the node. Multicast forwarding state is removed for multicast trees originating at the second node if an unsafe condition is detected. Subsequently, a “safe” indication signal is advertised to each of the peers of the network node. The “safe” indication signal comprises a digest of the topology database. A multicast path is then computed from the network node to at least one destination node of a multicast tree originating at the second node. Finally, multicast forwarding state associated with the computed multicast path is installed in the filtering database (FDB) of the network node, when predetermined safe condition is satisfied. | 07-07-2011 |
20110292836 | EVOLUTION OF ETHERNET NETWORKS - An Ethernet network comprises nodes which support a plurality of different forwarding modes. A range of VLAN Identifiers (VIDs) are allocated to each of the forwarding modes. Connections are configured between a source node and a destination node of the network using different forwarding modes. Packets carrying data traffic are sent to the destination node by selectively setting a VID in a packet to a first value, to transfer a packet via a first connection and a first forwarding mode, and a second value to transfer a packet via the second connection and the second forwarding mode. Packets received from both of the connections and sent on to an end user. VLAN Identifiers can be allocated to different releases of functionality at nodes (e.g. software releases) such that packets are forwarded via a set of nodes supporting a first release, or via a set of nodes supporting a second release. | 12-01-2011 |
20110292838 | PROVIDER LINK STATE BRIDGING (PLSB) COMPUTATION METHOD - A method of multicast route computation in a link state protocol controlled network. A spanning tree is computed from a first node to every other node in the network using a known spanning tree protocol. The network is then divided into two or more partitions, each partition encompassing an immediate neighbour node of the first node and any nodes of the network subtending the neighbour node on the spanning tree. Two or more of the partitions are merged when a predetermined criterion is satisfied. Nodes within all of the partitions except a largest one of the partitions are then identified, and each identified node examined to identify node pairs for which a respective shortest path traverses the first node. | 12-01-2011 |
20110317678 | Extended Private LAN - A virtual private network is provided across a Provider Link State Bridging (PLSB) network between a first node connected to a private LAN and a second node connected to a roaming device. The roaming device is authenticated. A successful authentication results in a Service Identifier for the VPN being sent to the second node. Connectivity between members of the VPN service instance is maintained as part of the PLSB Link State process for forwarding table maintenance, rather than by any form of explicit signalling. A single Customer Virtual Bridge/Virtual Switch Instance can be located at the first node to provide point-to-point connectivity to each roaming device. A virtual Residential Gateway function can be combined with the Customer Virtual Bridge/Virtual Switch Instance. | 12-29-2011 |
20120134357 | MULTICAST IMPLEMENTATION IN A LINK STATE PROTOCOL CONTROLLED ETHERNET NETWORK - Forwarding state is installed for sparse multicast trees in a link state protocol controlled Ethernet network by enabling intermediate nodes to install state for one or more physical multicast trees, each of which may have multiple logical multicast trees mapped to it. By mapping multiple logical multicasts to a particular physical multicast, and installing state for the physical multicast, fewer FIB entries are required to implement the multiple multicasts. Mapping may be performed by destination nodes before advertising membership in the physical multicast, or may be performed by the intermediate nodes before installing state when a destination node advertises membership in a logical multicast. Intermediate nodes will install state for the physical multicast tree if they are on a shortest path between a source and at least one destination of one of the logical multicasts that has been mapped to the physical multicast. | 05-31-2012 |
20120207171 | Method and Apparatus for Interworking VPLS and Ethernet Networks - To allow seamless interworking between an 802.1ah service instance (ISID) and a VPLS service instance, the AGI value used to signal the setup of the pseudowire portion of the VPLS may carry the ISID value of an associated 802.1ah service instance. This allows the service instance to be identified end-to-end across the Ethernet and VPLS networks using the same value without modifying how the MPLS network operates. The VPLS network will use AGI/AII signaling to set up pseudowires on the MPLS network, but instead of using an AGI value assigned by the MPLS network, the AGI value that is assigned will be taken from the ISID value of the Ethernet frame or from ISIDs registered by the Ethernet network. | 08-16-2012 |
20120230183 | METHOD AND APPARATUS FOR IMPLEMENTING CONTROL OF MULTIPLE PHYSICALLY DUAL HOMED DEVICES - A ring control protocol is used to establish a separate control plane for a plurality of physically dual homed devices to enable collections of dual homed devices to be represented by a single pair of addresses into the attached routed Ethernet network. The gateway devices analyze the passing ring control packets to create direct mappings for data packets to the routed Ethernet network. Thus, although the dual homed devices are treated as a ring from a control perspective, the data path is implemented to be direct so that data packets continue to flow directly from the dual homed devices to each of the attached gateway devices. In one embodiment, each of the gateway devices implements a virtual switch and advertises the MAC address of the virtual switch into the routed Ethernet network rather than the MAC addresses of each of the attached Ethernet Switch Units. | 09-13-2012 |
20120257514 | Failure Notification in a Network Having Serially Connected Nodes - Multicast capabilities of a link state protocol controlled network are used to accelerate the flooding advertisement of topology change notifications within portions of the network. This flooding mechanism may be particularly efficient in a network with a large number of two-connected nodes such as a ring network architecture. A control plane specific multicast group address is used when flooding topology change notifications, and a process such as reverse path forwarding check is used as an additional control on forwarding of the notification to prevent looping of control plane packets. Two-connected nodes insert a forwarding entry into their FIB to enable frames containing the control message to be forwarded via the data plane on to the downstream node so that propagation of the control message along a chain of two-connected nodes may occur at data plane speeds. | 10-11-2012 |
20120263075 | Method and Apparatus for Exchanging Routing Information and the Establishment of Connectivity Across Multiple Network Areas - Routes may be installed across multiple link state protocol controlled Ethernet network areas by causing ABBs to leak I-SID information advertised by BEBs in a L1 network area into an L2 network area. ABBs will only leak I-SIDs for BEBs where it is the closest ABB for that BEB. Where another ABB on the L2 network also leaks the same I-SID into the L2 network area from another L1 network area, the I-SID is of multi-area interest. ABBs will advertise I-SIDs that are common to the L1 and L2 networks back into their respective L1 network. Within each L1 and L2 network area, forwarding state will be installed between network elements advertising common interest in an ISID, so that multi-area paths may be created to span the L1/L2/L1 network areas. The L1/L2/L1 network structure may recurse an arbitrary number of times. | 10-18-2012 |
20120307832 | METHOD AND APPARATUS FOR SELECTING BETWEEN MULTIPLE EQUAL COST PATHS - Each equal cost path is assigned a path ID created by concatenating an ordered set of link IDs which form the path through the network. The link IDs are created from the node IDs on either set of the link. The link IDs are sorted from lowest to highest to facilitate ranking of the paths. The low and high ranked paths are selected from this ranked list as the first set of diverse paths through the network. Each of the link IDs on each of the paths is then renamed, for example by inverting either all of the high node IDs or low node IDs. After re-naming the links, new path IDs are created by concatenating an ordered set of renamed link IDs. The paths are then re-ranked and the low and high re-ranked paths are selected from this re-ranked list as the second set of diverse paths. | 12-06-2012 |
20120331123 | Verification of Configuration Information in BGP VPNs - Described are mechanisms for verifying configuration information in 2547 BGP VPNs. An originating PE generates a first knowledge digest encoding first configuration information associated with a current set of information advertised for a VRF. The originating PE also generates a second knowledge digest encoding second configuration information associated with cumulative information advertised for the VRF. The originating PE is capable of receiving a message from a user PE, the message including a third knowledge digest encoding third configuration information related to the user VRF. The originating PE is capable of comparing the first knowledge digest to the third knowledge digest and producing a first indication if the third configuration information encoded in the third knowledge digest is not a subset of the first configuration information encoded in the first knowledge digest. | 12-27-2012 |
20130013810 | METHOD AND APPARATUS FOR ACCOMMODATING DUPLICATE MAC ADDRESSES - Each access node is associated with one or more IP subnets with a preferred default subnet. Each subnet is instantiated as a unique virtual Ethernet broadcast domain. As client nodes register on the communication network, they will dynamically try to obtain an IP address for use on the communication network. As part of this process, the MAC address of the client node will be checked to ensure that it is not a duplicate of another MAC address associated with another client node that has already been assigned an IP address from the default subnet. When duplicate MAC addresses are detected, the device with the duplicate MAC address will be assigned an IP address from a different subnet so that more than one client device with the same MAC address are not associated with the same subnet. | 01-10-2013 |
20130064074 | BREAK BEFORE MAKE FORWARDING INFORMATION BASE (FIB) POPULATION FOR MULTICAST - A method of installing forwarding state in a link state protocol controlled network node having a topology database representing a known topology of the network, and at least two ports for communication with corresponding peers of the network node. A unicast path is computed from the node to a second node in the network, using the topology database, and unicast forwarding state associated with the computed unicast path installed in a filtering database (FDB) of the node. Multicast forwarding state is removed for multicast trees originating at the second node if an unsafe condition is detected. Subsequently, a “safe” indication signal is advertised to each of the peers of the network node. The “safe” indication signal comprises a digest of the topology database. A multicast path is then computed from the network node to at least one destination node of a multicast tree originating at the second node. Finally, multicast forwarding state associated with the computed multicast path is installed in the filtering database (FDB) of the network node, when predetermined safe condition is satisfied. | 03-14-2013 |
20130070586 | Scaling OAM for Point-to-Point Trunking - A shared (proxy) OAM session is performed in a packet-based network on behalf of a plurality of connections. First and second connections are each routed between respective nodes of the network for carrying data traffic. The second connection shares a portion of the routing of the first connection. The shared OAM session is performed along a path which is co-routed with at least part of the shared portion of the routing of the first connection and the second connection. Failure notification signalling is propagated to an endpoint node of each of the first and second connections when the shared OAM session indicates a failure has occurred. The use of a shared OAM session reduces processing at nodes and reduces OAM traffic. Each connection can be a trunk, such as a PBT/PBB-TE trunk, or a service carried within a trunk. | 03-21-2013 |
20130100801 | PROVIDER BACKBONE BRIDGING - PROVIDER BACKBONE TRANSPORT INTERNETWORKING - An Ethernet virtual switched sub-network (VSS) is implemented as a virtual hub and spoke architecture overlaid on hub and spoke connectivity built of a combination of Provider Backbone Transport (spokes) and a provider backbone bridged sub-network (hub). Multiple VSS instances are multiplexed over top of the PBT/PBB infrastructure. A loop free resilient Ethernet carrier network is provided by interconnecting Provider Edge nodes through access sub-networks to Provider Tandems to form Provider Backbone Transports spokes with a distributed switch architecture of the Provider Backbone Bridged hub sub-network. Provider Backbone transport protection groups may be formed from the Provider Edge to diversely homed Provider Tandems by defining working and protection trunks through the access sub-network. The Provider Backbone Transport trunks are Media Access Control (MAC) addressable by the associated Provider Edge address or by a unique address associated with the protection group in the Provider Backbone Bridged network domain. | 04-25-2013 |
20130148660 | MULTICAST IMPLEMENTATION IN A LINK STATE PROTOCOL CONTROLLED ETHERNET NETWORK - Forwarding state is installed for sparse multicast trees in a link state protocol controlled Ethernet network by enabling intermediate nodes to install state for one or more physical multicast trees, each of which may have multiple logical multicast trees mapped to it. By mapping multiple logical multicasts to a particular physical multicast, and installing state for the physical multicast, fewer FIB entries are required to implement the multiple multicasts. Mapping may be performed by destination nodes before advertising membership in the physical multicast, or may be performed by the intermediate nodes before installing state when a destination node advertises membership in a logical multicast. Intermediate nodes will install state for the physical multicast tree if they are on a shortest path between a source and at least one destination of one of the logical multicasts that has been mapped to the physical multicast. | 06-13-2013 |
20130176906 | TRAFFIC ENGINEERING IN FRAME-BASED CARRIER NETWORKS - The invention relates to enabling traffic engineering in frame-based networks such as Ethernet networks. There is described a method of and connection controller for establishing connections ( | 07-11-2013 |
20130215749 | RESILIENT ATTACHMENT TO PROVIDER LINK STATE BRIDGING (PLSB) NETWORKS - A system for interfacing a client system in a first network domain with a Provider Link State Bridging (PLSB) domain includes at least two Backbone Edge Bridges (BEBs) of the PLSB domain. Each BEB is an end-point of a connection in the first network domain to the client system and an end-point of at least a unicast path in the PLSB domain. An inter-node trunk is provided in the PLSB domain for interconnecting the BEBs. A phantom node is defined in the PLSB domain and is notionally located on the inter-node trunk. Each of the BEBs is configured such that: an ingress packet received from the client system via the connection in the first network domain is forwarded through a path notionally rooted at the phantom node; and an egress packet destined for the client system is forwarded to the client system through the connection in the first network domain. | 08-22-2013 |
20140092748 | RESILIENT PROVIDER LINK STATE BRIDGING (PLSB) VIRTUAL PRIVATE LAN SERVICE (VPLS) INTERWORKING - A method of peer interfacing a Link-State controlled network domain with an Ethernet Bridging controlled network domain. A pair of peer attachment points are provided between the Link-State controlled network domain and the Ethernet Bridging domain. The peer attachment points are respective endpoints of a set of one or more LAN segments defined within the Ethernet Bridging domain. The set of LAN segments are represented as a virtual node in the Link-State controlled network domain. The virtual node is represented in the Link-State controlled network domain as connected to each of the peer attachment points via a respective virtual link. The virtual links are configured such that frames to or from an address in the Link-State controlled network domain are forwarded over a tree passing through only one of the peer attachments points. | 04-03-2014 |
20140105071 | PROVIDER LINK STATE BRIDGING (PLSB) COMPUTATION METHOD - A method of multicast route computation in a link state protocol controlled network. A spanning tree is computed from a first node to every other node in the network using a known spanning tree protocol. The network is then divided into two or more partitions, each partition encompassing an immediate neighbour node of the first node and any nodes of the network subtending the neighbour node on the spanning tree. Two or more of the partitions are merged when a predetermined criterion is satisfied. Nodes within all of the partitions except a largest one of the partitions are then identified, and each identified node examined to identify node pairs for which a respective shortest path traverses the first node. | 04-17-2014 |
20140126420 | BREAK BEFORE MAKE FORWARDING INFORMATION BASE (FIB) POPULATION FOR MULTICAST - A method of installing forwarding state in a link state protocol controlled network node having a topology database representing a known topology of the network, and at least two ports for communication with corresponding peers of the network node. A unicast path is computed from the node to a second node in the network, using the topology database, and unicast forwarding state associated with the computed unicast path installed in a filtering database (FDB) of the node. Multicast forwarding state is removed for multicast trees originating at the second node if an unsafe condition is detected. Subsequently, a “safe” indication signal is advertised to each of the peers of the network node. The “safe” indication signal comprises a digest of the topology database. A multicast path is then computed from the network node to at least one destination node of a multicast tree originating at the second node. Finally, multicast forwarding state associated with the computed multicast path is installed in the filtering database (FDB) of the network node, when predetermined safe condition is satisfied. | 05-08-2014 |
20140129722 | PSUEDO WIRE MERGE FOR IPTV - A pseudo-wire merge is disclosed. Communicating with a first communication server enables registration of a first endpoint with the first communication server thereby enabling the first endpoint to establish a communication session under control of the first communication server with a second endpoint coupled to the communication network. Communicating with a second communication server enables registration of the first endpoint with the second communication server while the first endpoint is registered with the first communication server thereby enabling the first endpoint to establish a communication session over the communication network selectively either under the control of the second communication server or under the control of the first communication server. | 05-08-2014 |
20140140347 | TIE-BREAKING IN SHORTEST PATH DETERMINATION - A consistent tie-breaking decision between equal-cost shortest (lowest cost) paths is achieved by comparing an ordered set of node identifiers for each of a plurality of end-to-end paths. Alternatively, the same results can be achieved, on-the-fly, as a shortest path tree is constructed, by making a selection of an equal-cost path using the node identifiers of the diverging branches of the tree. Both variants allow a consistent selection to be made of equal-cost paths, regardless of where in the network the shortest paths are calculated. This ensures that traffic flow between any two nodes, in both the forward and reverse directions, will always follow the same path through the network. | 05-22-2014 |
20140146701 | EVOLUTION OF ETHERNET NETWORKS - An Ethernet network comprises nodes which support a plurality of different forwarding modes. A range of VLAN Identifiers (VIDs) are allocated to each of the forwarding modes. Connections are configured between a source node and a destination node of the network using different forwarding modes. Packets carrying data traffic are sent to the destination node by selectively setting a VID in a packet to a first value, to transfer a packet via a first connection and a first forwarding mode, and a second value to transfer a packet via the second connection and the second forwarding mode. Packets received from both of the connections and sent on to an end user. VLAN Identifiers can be allocated to different releases of functionality at nodes (e.g. software releases) such that packets are forwarded via a set of nodes supporting a first release, or via a set of nodes supporting a second release. | 05-29-2014 |
20140153382 | METHOD AND APPARATUS FOR IMPLEMENTING CONTROL OF MULTIPLE PHYSICALLY DUAL HOMED DEVICES - A ring control protocol is used to establish a separate control plane for a plurality of physically dual homed devices to enable collections of dual homed devices to be represented by a single pair of addresses into the attached routed Ethernet network. The gateway devices analyze the passing ring control packets to create direct mappings for data packets to the routed Ethernet network. Thus, although the dual homed devices are treated as a ring from a control perspective, the data path is implemented to be direct so that data packets continue to flow directly from the dual homed devices to each of the attached gateway devices. In one embodiment, each of the gateway devices implements a virtual switch and advertises the MAC address of the virtual switch into the routed Ethernet network rather than the MAC addresses of each of the attached Ethernet Switch Units. | 06-05-2014 |
20140177433 | RESILIENT ATTACHMENT TO PROVIDER LINK STATE BRIDGING (PLSB) NETWORKS - A system for interfacing a client system in a first network domain with a Provider Link State Bridging (PLSB) domain includes at least two Backbone Edge Bridges (BEBs) of the PLSB domain. Each BEB is an end-point of a connection in the first network domain to the client system and an end-point of at least a unicast path in the PLSB domain. An inter-node trunk is provided in the PLSB domain for interconnecting the BEBs. A phantom node is defined in the PLSB domain and is notionally located on the inter-node trunk. Each of the BEBs is configured such that: an ingress packet received from the client system via the connection in the first network domain is forwarded through a path notionally rooted at the phantom node; and an egress packet destined for the client system is forwarded to the client system through the connection in the first network domain. | 06-26-2014 |
20140269433 | Failure Notification in a Network having Serially Connected Nodes - Multicast capabilities of a link state protocol controlled network are used to accelerate the flooding advertisement of topology change notifications within portions of the network. This flooding mechanism may be particularly efficient in a network with a large number of two-connected nodes such as a ring network architecture. A control plane specific multicast group address is used when flooding topology change notifications, and a process such as reverse path forwarding check is used as an additional control on forwarding of the notification to prevent looping of control plane packets. Two-connected nodes insert a forwarding entry into their FIB to enable frames containing the control message to be forwarded via the data plane on to the downstream node so that propagation of the control message along a chain of two-connected nodes may occur at data plane speeds. | 09-18-2014 |
20140286334 | METHOD AND APPARATUS FOR SELECTING BETWEEN MULTIPLE EQUAL COST PATHS - Each equal cost path is assigned a path ID created by concatenating an ordered set of link IDs which form the path through the network. The link IDs are created from the node IDs on either set of the link. The link IDs are sorted from lowest to highest to facilitate ranking of the paths. The low and high ranked paths are selected from this ranked list as the first set of diverse paths through the network. Each of the link IDs on each of the paths is then renamed, for example by inverting either all of the high node IDs or low node IDs. After re-naming the links, new path IDs are created by concatenating an ordered set of renamed link IDs. The paths are then re-ranked and the low and high re-ranked paths are selected from this re-ranked list as the second set of diverse paths. | 09-25-2014 |
20140301244 | Method and Apparatus for Exchanging Routing Information and the Establishment of Connectivity Across Multiple Network Areas - Routes may be installed across multiple link state protocol controlled Ethernet network areas by causing ABBs to leak I-SID information advertised by BEBs in a L1 network area into an L2 network area. ABBs will only leak I-SIDs for BEBs where it is the closest ABB for that BEB. Where another ABB on the L2 network also leaks the same I-SID into the L2 network area from another L1 network area, the I-SID is of multi-area interest. ABBs will advertise I-SIDs that are common to the L1 and L2 networks back into their respective L1 network. Within each L1 and L2 network area, forwarding state will be installed between network elements advertising common interest in an ISID, so that multi-area paths may be created to span the L1/L2/L1 network areas. The L1/L2/L1 network structure may recurse an arbitrary number of times. | 10-09-2014 |