Abstract: Techniques for network packet flow analysis and control are described herein. One example method may include obtaining network topology information corresponding to a plurality of nodes of an access network, receiving communication monitoring messages from two or more of the plurality of nodes, wherein the communication monitoring messages include communication information corresponding to a plurality of communication layers, and determining information loss statistics associated with the plurality of nodes based on the communication monitoring messages and the network topology information.

Abstract: In general, techniques are described that may allow a network element to analyze the performance of a network without using external equipment external to the network. In one example, a method includes injecting a plurality of data units onto the network, forwarding the plurality of data units around the network loop, injecting at least one timing data unit on to the network, forwarding the at least one timing data unit around the network loop, and determining at least one latency statistic correlated to the at least one characteristic of the forwarded plurality of data units.

Abstract: Techniques for network packet flow management are described herein. For example, example methods may include receiving, at a first network device, a first flow identifier that identifies a first content of a first packet flow and a second flow identifier that identifies a second content of a second packet flow, wherein the first flow identifier and the second flow identifier are generated by a second network device. Such methods may also include receiving priority information indicating that the first content has a first priority and that the second content has a second priority that is lower than the first priority. Moreover, example methods may include transmitting the first packet flow and a modified second packet flow that includes the priority information to one or more other network devices.

Abstract: In general, techniques are described for monitoring downstream traffic in order to schedule delivery of upstream traffic in a computer network. The techniques may be implemented by an optical line terminal (OLT) comprising a control unit and an interface. The control unit determines an amount of upstream data that is waiting at one of a plurality of ONTs to be transmitted upstream to the OLT, and determines an amount of downstream data that is transmitted by the OLT to this ONT. The control unit increases the determined amount of upstream data based on the determined amount of downstream data transmitted by the OLT to the ONTs and, after increasing the determined amount of upstream data, generates an upstream grant map that grants time slots to the ONTs based on the determined amount of upstream data. The interface transmits the upstream grant map downstream to the ONTs.

Abstract: Techniques for dynamic backhaul bandwidth provisioning are described herein. For example, a method may include determining a potential subscriber user equipment load change, transmitting a backhaul bandwidth change request message based a potential subscriber UE load change, wherein the backhaul bandwidth change request message includes a requested backhaul bandwidth level, receiving a backhaul bandwidth change reply message in response to transmitting the backhaul bandwidth change request message, implementing a subscriber UE load change response corresponding to the potential subscriber UE load change based on receiving the backhaul bandwidth change reply message.

Abstract: In general, this disclosure describes network security techniques that may accommodate legitimate movement of a subscriber device while preventing MAC collisions that may result from configuration errors or MAC spoofing attempts. MAC spoofing may result in packets directed to one subscriber device being sent instead to another subscriber device. By modifying an access node or a Dynamic Host Configuration Protocol (DHCP) server to allow only authorized subscriber devices on the access network, layer two collisions (“MAC collisions”) may be prevented.

Abstract: Systems and methods for measuring frame loss in multipoint networks are provided. In one embodiment, a method for calculating frame loss comprises: performing a first continuity check message exchange between a first and a plurality of other devices, the first exchange comprises the first device collecting a first set of frame count data from each of the first and other devices, the first set of frame count data associated with a first instance of time by a first sequence identifier; performing a second continuity check message exchange between the first and plurality of other devices, the second exchange comprises the first device collecting a second set of frame count data from the first other devices, the second set of frame count data associated with a second instance of time by a second sequence identifier; and calculating a frame loss measurement by accounting for frame Ingress and frame Egress.

Abstract: In general, techniques are described for inline packet replication in network devices. A network device referred to as an optical line terminal (OLT) may implement the techniques. The OLT comprises a customer interface that supports different logical interfaces to which couple a plurality of optical network terminals (ONTs) and a network interface that receives a data unit. The OLT further comprises a conversion unit, such as a media access control (MAC) module, located in a data path of the optical line terminal that determines whether the received data unit is a candidate for replication. The conversion unit includes an inline packet processing module that performs replication to generate at least one copy of the data unit based on the determination that the received packet is a candidate for packet replication. The customer interface outputs the at least one copy of the data unit to the ONTs.

Abstract: In general, techniques are described that may allow a network element to autonomously validate a network or network segment. In one example, a method includes configuring a VLAN on a network having at least two network elements, configuring, via a first one of the at least two three network elements on the network, a network loop on the VLAN, generating, via the first one of the at least two network elements on the network, a plurality of data units and injecting the data units onto the network, forwarding, via each of the at least two network elements on the network, the data units around the network loop on the VLAN for a specified time at media speed, configuring one of the at least two network elements on the ring network to stop the network loop, and determining whether there are any network errors.

Abstract: In general, techniques are described for interworking between Ethernet organization, administration, and maintenance (OAM) frames and Asynchronous Transfer Mode (ATM) ATM OAM cells. For example, an access node in an Ethernet and ATM network may implement the techniques. The access node comprises an Ethernet interface that receives an Ethernet OAM Loopback frame from a device within an Ethernet network. The access node includes a control unit that constructs an ATM OAM End-to-End Loopback cell from the Ethernet OAM Loopback frame, and an ATM interface that transmits the ATM OAM End-to-End Loopback cell from the access node towards a virtual circuit connected to a subscriber device to verify connectivity from the originating device within the Ethernet network to the subscriber device within the ATM network.

Abstract: One or more devices of a network having asymmetric delay are configured to participate in time synchronization protocol sessions in which a client device synchronizes its local clock to a master device. In one example, a system includes an optical line terminal configured to receive a time synchronization protocol packet from a grandmaster clock and an optical network unit (ONU) configured to calculate a residence time of the time synchronization protocol packet, encode the residence time into the packet, and to forward the packet to a client device. Moreover, the system may participate in a plurality of time synchronization protocol sessions with a plurality of client devices, such that the client devices become synchronized in frequency and phase.

Abstract: An access network comprises a first network interface device coupled to a customer network and configured to provide an interface between the access network and the customer network. The access network also comprises a second network interface device coupled to a core network and configured to provide an interface between the access network and the core network. The first network device is configured to insert a Status Type Length Value (TLV) element into a Continuity Check Message (CCM) to form a modified CCM and to transmit the modified CCM to the second network interface device. The Status TLV element includes fields for at least one of a dying gasp indication from a customer premise equipment or performance monitoring data. The second network interface device is configured to store data from the Status TLV in a database entry associated with an identification number of the first network interface device.

Abstract: In general, techniques are described for protecting optical networks from consecutive identical digit (CID) errors. An optical network device comprising a control unit and an interface may implement the techniques described in this disclosure. The control unit determines whether a data packet will result in a CID error prior to encapsulating at least a portion of the data packet to form a passive optical network (PON) frame and then, in response to the determination that the data packet will result in the CID error, modifies the data packet to form a modified data packet so that the modified data packet will not result in the CID error. The control unit encapsulates the modified data packet to form a PON frame. The control unit applies a scrambling polynomial to the PON frame to form a scrambled PON frame. The interface transmits the scrambled PON frame.

Abstract: One or more devices of a network having asymmetric delay are configured to participate in time synchronization protocol sessions in which a client device synchronizes its local clock to a master device. In one example, a system includes an optical line terminal configured to receive a time synchronization protocol packet from a grandmaster clock and an optical network unit (ONU) configured to calculate a residence time of the time synchronization protocol packet, encode the residence time into the packet, and to forward the packet to a client device. Moreover, the system may participate in a plurality of time synchronization protocol sessions with a plurality of client devices, such that the client devices become synchronized in frequency and phase.

Abstract: Techniques are disclosed that relate to synchronizing a clock on a network interface device with a clock on an optical line terminal (OLT). In one example, the technique to synchronizing the clocks may include monitoring one or more instances when the network interface device transmits information to the OLT and determining when a frame should be received by the network interface device based on the monitored one or more instances when the network interface device transmits information the OLT.

Abstract: A demarcation point device positioned at a customer network to provide the customer network access to a service provider network. The demarcation point device comprises a control unit that transmits one or more service query data packets on the customer network to test at least one service within the customer network. The control unit receives one or more service reply data packets from the customer network in response to transmitting the service query data packets, and determines one or more service statistics based on one or more of the service query data packets and the service reply data packets.

Abstract: In general, techniques are described to detect potential issues with optical fibers. The techniques may be implemented using various optical network hardware. An example optical network unit (ONU) includes a network interface coupled to an optical fiber through which the ONU communicates with an optical line terminal (OLT). The ONU further includes a control unit that determines at least a first signal strength and a second signal strength of a signal received via the optical fiber, determines a rate of signal strength degradation based on the first signal strength and the second signal strength, compares the rate of signal strength degradation to a rate threshold so as to determine a potential issue with the optical fiber, and based on the comparison, causes the network interface to send a message to the OLT indicating a potential issue with the optical fiber to which the ONU connects to communicate with the OLT.

Abstract: Systems and methods for multicast admission control are provided. In one embodiment, a node comprises: a first interface configured to receive a multicast channel access request, from a subscriber interface, including an address for a channel; a memory including a subscriber profile and VLAN configuration data for the network; a processor that identifies a first VLAN corresponding to the address from the VLAN configuration data and determines whether the subscriber is authorized to receive the channel via the first VLAN based on access policy designated by the subscriber profile; wherein the processor further determines whether granting access to the channel violates admission control policy based on predefined bandwidth requirements and/or a stream count limit for the first VLAN; wherein when the subscriber interface is authorized to receive the channel and when granting access to the channel does not violate admission control policy, the processor routes the channel to the subscriber.

Abstract: Caching techniques are described. An example network device positioned between an optical line terminal (OLT) and a service provider device includes a hot cache, a wide cache controller, and a control unit. The control unit is configured to receive, from a first service delivery platform, a request for digital content, and determine whether the requested digital content is stored on the hot cache. The control unit is further configured to, when the requested digital content is not stored on the hot cache, determine, using the wide cache controller, whether the requested digital content is stored on a wide cache of a second service delivery platform, receive, from the second service delivery platform, the requested digital content, and responsive to the request received from the first delivery platform, send the received digital content to the first delivery platform.

Abstract: Techniques are described for maintaining the extinction ratio of an output optical signal over temperature and aging. In some examples, the techniques may determine the instantaneous slope efficiency of the laser outputting the optical signal, while the laser is outputting the optical signal. Based on the determined slope efficiency, the techniques may determine the needed drive current components (e.g., at least one of the bias current and the modulation current) that results in maintaining the extinction ratio to within a desired range.