Abstract: A method of determining the presence of a loopback in one or more networks comprises storing information related to a test instance; sending a loopback detection beacon (LPDB) containing information related to the test instance from a port on an originating device; monitoring the port for a predetermined time period to detect LPDBs arriving at the port during the predetermined time period; and determining whether a detected LPDB contains information corresponding to the stored information, to detect the presence of a loopback. The method may determine whether a detected loopback is a port loopback, a tunnel loopback or a service loopback. The stored information related to the test instance may be deleted if an LPDB arriving at the port and containing information corresponding to the stored information is not detected within the predetermined time period.

Abstract: A system for efficient routing of an OAM) frame in an Ethernet switch receives an OAM frame at a first port; building a first classification key dependent on an OAM frame header; classifies in a context of the first port to create a first classification; resolves action dependent on the first classification; modifies the first classification key to create a second classification key; classifies the frame in a context of the second port to create a second classification; sends the second classification key to an OAM engine coupled to the Ethernet switch for modification into a third classification key; receives the third classification key from the OAM engine; modifies the third classification key into a final classification key; modifies the header of the OAM frame with the final classification key; and sends the modified OAM frame to a switching fabric of the Ethernet switch.

Abstract: A method of discovering addressing information of one or more upstream devices to respond to specific messages by a second device on behalf of the one or more upstream devices in a network includes acquiring the addressing information in an upstream direction from one or more downstream devices to the one or more upstream devices. The method further includes acquiring the addressing information in a downstream direction from the one or more upstream devices to the one or more downstream devices. The method further includes responding to specific messages using the acquired addressing information about the one or more upstream devices.

Abstract: A method of simplifying the implementation of Synchronous Ethernet on an Ethernet device having a first port and a second port device using a predetermined protocol and signaling, comprises delivering a master clock from a Synchronous Ethernet system to the first port of the Ethernet device; transmitting the delivered master clock to the second port of the Ethernet device independently of the protocol and signaling of the Ethernet device; and transmitting the master clock from the second port of the Ethernet device to a downstream device that supports Synchronous Ethernet. In one implementation, the Ethernet device has a local clock, and the method synchronizes the local clock to the master clock. In another implementation, the Ethernet device does not have a local clock, and the master clock is transmitted from the second port of the Ethernet device to the downstream device without any synchronizing operation at the Ethernet device.

Abstract: A method is disclosed for the collection of performance metrics by establishing service operations administration and maintenance (OAM) sessions between an actuator and a plurality of reflectors in a communication network. Test packets from an actuator simultaneously reach a plurality of reflectors along a test path. Each single test packet results into a plurality of test results, one per reflector, with quasi-synchronous performance metrics to sectionalize a network and more efficiently isolate fault or performance problems without the need for additional test packets to isolate the issue. Another method is disclosed wherein an actuator generates and transmits a plurality of simultaneous test packets, one per NID device, resulting into a plurality of test results, one per reflector, with quasi-synchronous performance metrics to sectionalize a network and more efficiently isolate fault or performance problems without the need for additional test packets to isolate the issue.

Abstract: A method, a computer program product, and a carrier for indicating one-way latency in a data network (N) between a first node (A) and a second node (B), wherein the data network (N) lacks continuous clock synchronization, comprising: a pre-synchronization step, a measuring step, a post-synchronization step, an interpolation step, and generating a latency profile. The present invention also relates to a computer program product incorporating the method, a carrier comprising the computer program product, and a method for indicating server functionality based on the first aspect.

Abstract: A system is provided for multicasting an event notification from an event producer to multiple event listeners, where the event producer and event listeners exist within a computer operating system having a user space, a kernel space, a device space, and an event protocol handler located in the kernel space. The system generates an event indication from an event producer located in the user space, kernel space, or device space, and receiving the event indication in the event protocol handler and generating an event notification. The event producer and the event listeners interface with the event protocol handler to send the event indication and receive the event notification. The event listeners may be located in the user space, kernel space, or device space.

Abstract: A method of providing information regarding an Ethernet frame, within the Ethernet preamble of the Ethernet frame, comprises inserting into the Ethernet preamble an inter-line-card header that includes a start control character, a version number, a parity bit, a source port, a destination port, and a forwarding domain entry; and preserving said inter-line-card header, inside of said Ethernet preamble, in a Media Access Control (MAC) sub-layer in said Ethernet frame. The method may include a step of selecting the decoding format for the inter-line-card header corresponding to the version number and/or forwarding other Ethernet frames according to additional forwarding information provided by the forwarding domain entry. The inter-line-card header may be preserved in the MAC sub-layer by keeping the Ethernet preamble at the beginning of an Ethernet frame received over an Ethernet backplane, and passing the combined preamble and associated Ethernet frame to an inter-line-card header processing module.

Abstract: A method of discovering a device in a communication network having multiple interconnected nodes includes continuously monitoring, by a device to be discovered, any IP packets sent by a discoverer. The method further includes transmitting, by the discoverer, an IP packet destined for a downstream device and receiving, by the device to be discovered, the IP packet. The method further includes determining, by the device to be discovered, whether the IP packet is intended for the device to be discovered. If the IP packet is not intended for the device to be discovered, retransmitting, by the device to be discovered, the IP packet to the downstream device via an egress port of the device to be discovered.

Abstract: An enclosure with hybrid thermal management for a heat-generating electronic device comprises a passive heat sink for conducting heat away from the electronic device, a cold skin adapted to slide over the top of the passive heat sink and having a front wall forming a plurality of air intake ports, and a plurality of blowers mounted inside the cold skin for drawing air into the cold skin though the air intake ports and then directing the air through the passive heat sink. In one implementation, the passive heat exchanger includes multiple thermally conductive fins adjacent to the electronic device and extending rearwardly from the intake ports, the fins being spaced apart from each other for conducting heat away from the electronic device. The blowers preferably direct air rearwardly from the intake ports in the front wall into the spaces between the thermally conductive fins.

Abstract: A method of discovering a device to be discovered in a communication network having multiple interconnected nodes includes transmitting, by a discoverer, at least one beacon signal including an IP address to the network. The device to be discovered receives the at least one beacon signal. The device to be discovered configures the IP address located in the at least one beacon signal. Additionally, the device to be discovered transmits an advertisement to a server specified by the discoverer.

Abstract: A system for negotiating Ethernet link settings between interconnected nodes in a network having an Ethernet protocol stack that includes a PCS sub-layer with an auto-negotiation function. The system comprises connecting an intermediate device coupled between two network nodes via optical or copper interfaces, with the link settings between each node and the connected intermediate device being the same, thereby bypassing the auto-negotiation of the PCS sub-layer in the intermediate device. The intermediate device may transparently send negotiation messages from each node to the other during the link negotiation phase without interacting with those messages. Instead of the intermediate device, a single form pluggable (SFP) device may be connected between the two network nodes via optical or copper interfaces on the network side and via an SFP slot on the device side.

Abstract: A method for indicating one-way latency in a data network, with continuous clock synchronization, between first and second node having clocks that are not synchronized with each other includes a continuous synchronization session and a measurement session. The method repetitively sends predetermined synchronization messages from the first node to the second node and from the second node to the first node, calculates a round trip time for each message at the first node, updates a synchronization point if the calculated round trip time is smaller than a previously calculated round trip time, stores the updated synchronization points of a synchronization window, and calculates a virtual clock from the updated synchronization points of the synchronization window. The measurement session collects multiple measurements of one-way latency between the first and second nodes using the virtual clock, and generates a latency profile by interpolating the multiple measurements.

Abstract: A method of establishing a service operations administration and maintenance (OAM) session between an originator and a reflector in a communication network includes continuously monitoring, by the reflector, any test packets transmitted by the originator. The originator transmits to the reflector, at a time indicated by a first timestamp, a test packet. The reflector receives the test packet at a time indicated by a second timestamp and generates a unique flow identifier that identifies the reflector. The reflector transmits the test packet to the originator. The reflector assigns a sequence number to the test packet. The originator receives the test packet at a time indicated by a fourth timestamp. The reflector stores the unique flow identifier at least for the duration of the OAM session.

Abstract: In one embodiment, a connection is maintained between a pair of ethernet ports that have circuitry connected in series with the ports and receiving power-over-ethernet (PoE) from one of the ports, by providing a controllable bypass circuit coupled to the pair of ethernet ports in parallel with the circuitry receiving power-over-ethernet, sensing a preselected condition, and opening and closing the bypass circuit in response to the presence or absence of the preselected condition. Power sourcing equipment (PSE) may supply the one of the ports with power over ethernet, and the circuitry may transports data between the pair of ethernet ports. The circuitry may also supply the switch with a control signal in response to the detection of the preselected condition.

Abstract: A method of automatically detecting the service level agreement settings in an Ethernet virtual circuit (EVC) carrying user packets comprises generating synthetic packets different from the user packets, on a data path in the EVC at a level sufficiently high to saturate the EVC. This accelerates the detection of actual effective values for the Committed Information Rate (CIR) and the Excess Information Rate (EIR) by triggering traffic shaping devices in the data path to enforce the CIR and EIR settings configured for those devices. A plurality of traffic samples are collected from the data path during a sampling period that is long enough to allow the collection of at least two valid traffic samples, where a valid traffic sample is the amount of user packets measured between two consecutive losses of synthetic packets. The CIR and EIR values enforced by the traffic shaping devices are determined from the collected samples.

Abstract: A method of discovering and assigning an IP address to a device to be discovered in a communication network having multiple interconnected nodes includes continuously monitoring, by the device to be discovered, the network for address resolution protocol (ARP) requests. The discoverer node transmits a number of ARP request to the network. The device to be discovered receives the number of ARP requests. The device to be discovered determines whether the number of ARP requests are unanswered by other devices in the network. The device to be discovered answers to the number of ARP requests with an ARP reply to claim an IP address associated with the number of ARP requests. The discoverer node and the device to be discovered exchange a pair of User Datagram Protocol (UDP) packets to complete the detection process.

Abstract: A method is provided for efficiently scheduling timer events within an operating system by allocating a plurality of timers, each of which has an expiry time, to a set of available timer slots. The method defines a timer spread value that denotes the allowed variance of the expiry times of each of the timers, calculates a set of available timer slots for each of the timers based on the timer spread value, and adjusts the expiry times of the timers so as to insert and evenly spread the timers across the set of available timer slots. In one implementation, the set of available timer slots is located in a timer wheel existing within the operating system, and the timer wheel uses a plurality of timer vectors arranged into successively increasing levels, beginning with level zero.

Abstract: A method of discovering addressing information of one or more upstream devices to respond to specific messages by a second device on behalf of the one or more upstream devices in a network includes acquiring the addressing information in an upstream direction from one or more downstream devices to the one or more upstream devices. The method further includes acquiring the addressing information in a downstream direction from the one or more upstream devices to the one or more downstream devices. The method further includes responding to specific messages using the acquired addressing information about the one or more upstream devices.

Abstract: A method is disclosed for the collection of performance metrics by establishing service operations administration and maintenance (OAM) sessions between an actuator and a plurality of reflectors in a communication network. Test packets from an actuator simultaneously reach a plurality of reflectors along a test path. Each single test packet results into a plurality of test results, one per reflector, with quasi-synchronous performance metrics to sectionalize a network and more efficiently isolate fault or performance problems without the need for additional test packets to isolate the issue. Another method is disclosed wherein an actuator generates and transmits a plurality of simultaneous test packets, one per NID device, resulting into a plurality of test results, one per reflector, with quasi-synchronous performance metrics to sectionalize a network and more efficiently isolate fault or performance problems without the need for additional test packets to isolate the issue.