Abstract: A method and an apparatus are provided, for monitoring OSNR system margin in optical networks, by relying on relationships that exists between the Optical Signal to Noise Ratio (OSNR) value and the Electrical Signal to Noise Ratio (ESNR) value.

Abstract: A method and system are provided for connecting at least three provider peer elements PEs located in two L2 network sites, via a provider network, wherein at least in one of the L2 sites and two of the provider peer elements PEs are connected to a customer equipment CE forming together a dual homing structure. The method and system are characterized in that they rely on the use of only a single PW in the provider network that extends between PEs of the two L2 network sites while ensuring traffic protection for the PW in the provider network, and ensuring that in case of a failure of one of the PEs or its connection to the customer equipment at one of the sites, the other L2 network site remains unaware of the failure, so that once established, traffic communication over the PW is maintained like no failure has happened.

Abstract: A dynamically self-configuring and re-configuring dual homing connection (DH) for loop-free data communication between a first communication network and a second communication network, the DH acquiring either a Symmetrical configuration or an Asymmetrical configuration.

Abstract: A method is provided for maintaining a synchronized local timer by using a periodic signal which comprises: providing a value of a clock cycle, and values for a first and second timer-parameters, wherein the first timer-parameter is less than the clock cycle value and the second timer-parameter is higher therefrom; providing values for a first (“a”) and second (“b”) arbitration parameters associated with the first and second timer-parameters respectively; upon receiving a periodic signal, adding to the local timer, at least once the first and/or the second timer-parameter, so that on average over one second, the first timer-parameter is added “a” times and the second timer-parameter is added “b” times, thereby ensuring that a value of the local timer essentially overlaps the period frequency of the periodic signal; upon receiving a subsequent periodic signal, setting the value of the local timer to a propagation delay of the periodic signal.

Abstract: A method is described for reducing interferences in communications exchanged along a plurality of communication channels operated by a first operator, caused by one or more alien communication channels operated by a second operator. The method comprises the steps of: (i) providing the second operator with information that relates to interferences experienced at the plurality of communication channels operated by a first operator, due to traffic conveyed along alien communication channels operated by the second operator; (ii) modifying the original signals conveyed by the second operator along the alien communication channels; (iii) sending the modified signals to the first operator; and (iv) applying the modified signals by the first operator to reduce interferences in communications exchanged along the plurality of communication channels and operated by the first operator.

Abstract: A method and device for managing E-tree services in an MPLS network having domains comprising network nodes and links, wherein the network is adapted to accommodate an E-tree structure formed by the network nodes for a specific E-tree service. The E-tree structure comprises a root point communicating with a number of leaf points, so that any network node of the E-tree structure is connected via its ports to links leading to a root point and/or a leaf point of said structure. The method comprises: marking ports of a specific node associated with links leading only to leaf points of the structure while marking differently ports of a specific node, associated with links leading to the root point; marking ports of a specific node connected to incoming or outgoing links of the same domain, and ensuring that traffic will not be returned thereby creating network loops.

Abstract: A method is provided for interconnecting base stations of a cellular network via a transport network which comprises a plurality of network elements (NEs), wherein at least two of the plurality of NEs are collocated with respective base stations. The method comprises the steps of: establishing in the TN at least one proximity group that comprises a plurality of geographically adjacent NEs; establishing a logical grid connectivity between NEs that are members of the same proximity group to enable direct communications there-between, thereby enabling establishment of communications paths between base stations collocated with the at least two of the plurality of NEs, wherein that path extends via the at least two respective NEs communicating directly there-between.

Abstract: A method and device are provided for affecting data conveyance within a cable comprising a plurality of copper wire lines. The method comprises: providing information about crosstalk interference experienced by the copper wire lines; for each copper wire line experiencing crosstalk interference (interfered line), identifying which other copper wire lines induce crosstalk interference to that interfered line; partitioning the copper wire lines into interference groups, where each interference group comprises at least one copper wire line, wherein at least one of the interference groups comprises at least three copper wire lines, and wherein in case that a given interference group comprises more than two copper wire lines, then each of the copper wire lines belonging to that interference group is subjected to interference induced by another copper wire line that belongs to that interference group; and based on the partitioning step, changing operational settings of at least one copper wire line.

Abstract: A method and a network node are provided, for distributing timing information in a packet-switched network. The method is characterized in that at least one network node used as a quasi slave node is located at a path extending between a master node and a slave node. The method comprising a step of calculating the timing at that network node, by passively processing packets belonging to a PTP-type packet stream being exchanged between the master node and the slave node and conveyed via that intermediate network node operating as a quasi slave.

Abstract: Method is provided for reducing adverse effects of a link failure in an optical network, wherein the optical network comprises at least one main link which comprises a first optical fiber amplifier (OFA), and along which communications traffic is currently being conveyed, and at least one protection link which comprises a second optical fiber amplifier (OFA) along which communications traffic is not currently being conveyed, wherein the at least one protection link is adapted to carry out communications traffic diverted from the at least one main link when a failure occurs at said at least one main link or at one or more nodes associated therewith, and wherein the method is further characterized in that when no communications traffic is being conveyed along the at least one protection link, one or more pumps of the second OFA is operating to provide an output having a pre-defined power level.

Abstract: A method is provided for managing congestion of traffic in a packet switch, which comprises the steps of: providing more than two different congestion levels at the switch for handling traffic associated with at least two different priorities, one being a low priority traffic and another being a high priority traffic; for each traffic flow having a specific destination and priority, determining a current congestion level that matches a congestion control level which is selected from among the more than two congestion control levels, and associating a different set of operations for handling each respective traffic flow, depending on its priority and its current congestion level, and for each traffic flow, performing operations that match the respective associated set of operations, and wherein a rate at which these operations are performed for each respective traffic flow increases when a higher congestion level occurs at that respective traffic flow.

Abstract: Technique for reducing start-up time of a computerized system comprising a computer application with a data base DB and one or more functional blocks with respective memories; the system comprises a communication network being managed by the computer application. The technique comprises providing each of said functional blocks with basic information about the communication network; updating the functional blocks about changes whenever take place in the network; updating objects in the base DB by the updated functional blocks; creating an image of at least one functional block of the blocks in a persistent memory, building a changes log and to in case of failure of the mentioned functional block, promptly restoring thereof by using the image in the persistent memory and the changes log.

Abstract: A method is disclosed for provisioning loop free H-VPLS traffic service in a multi-domain MPLS network having interconnected domains. The method comprises: provisioning pseudo wires (PWs) for MPTMP services in each domain of the MPLS network; defining multiple Split Horizon Groups (SHGs) in the network, wherein each SHG corresponds to a domain, for the H-VPLS service traffic and for each specific node of the MPLS network, automatically assigning indications to SHG and the pseudo wires connected to the specific node, wherein the same indication is assigned to all pseudo wires belonging to the same group (SHG-N), and wherein the step of assigning is characterized in that when traffic belonging to H-VPLS service crosses a border network node located between two interconnected domains, the SHG-N indication of PWs remains the same within a VPLS domain thereby preventing the service traffic from returning to the domain of origin.

Abstract: A method and module for affecting controlled switching of optical signals having different modes of propagation, wherein the module being provided with at least two multi-mode ports MMPs and a plurality of single-mode ports SMPs, the method comprises: inputting at least one multimode optical signal to an MMP of said MMPs; inputting the single mode optical signals to the SMPs; performing mode processing of one or more of the single mode and multi mode optical signals within the switching module, controllably and selectively switching different optical signals inputted to different ports of the module, preferably based on received feedback related to quality information, thereby allowing switching between single mode ports, between multi-mode ports, and between single mode and multi mode ports.

Abstract: A technique for power feeding of a common element of an access network from subscribers of the access network connected to the common element through subscriber lines being electric wires or optical fibers, the method comprises providing the subscribers with respective local power sources, and powering the common element from the one or more local power sources by selectively and/or dynamically combining power conducted there-from through the subscriber lines, thereby allowing at least partial operation of the common element.

Abstract: A method for selective admission of traffic packets to a telecommunication switch having a limited throughput T and a common input queue, wherein the traffic packets comprise packets pre-assigned to higher and lower classes; in case of congestion at the common input queue of the switch, the method performs selective admission of the packets to the switch according to classes pre-assigned to them and depending on dynamic, recently utilized throughput of the switch.

Abstract: A method is provided for synchronizing binary data transmitted in parallel via N channels. The method comprises performing at the receiver side, a data-clock-alignment for the data in the N channels by selecting an optimal reference channel to which no delay will be added, and adding an appropriate delay to each of the remaining channels, until their respective centers of valid data portions are aligned to each other, and associating clock edges with the centers of the valid data portions. The method is characterized in that the alignment is performed regardless to whether binary word alignment is simultaneously achieved or not, and wherein the optimal reference channel allows aligning the centers of valid data of all the channels while adding a minimal delay to a worst channel from among the remaining channels, wherein the worst channel carries valid data portions which are maximally shifted from those of the reference channel.

Abstract: A method and a Reconfigurable Optical Add Drop Multiplexer (ROADM) where blocking of a first optical signal carried over a specific optical channel in the ROADM is performed by compensating the first optical signal by a second optical signal created for that purpose.

Abstract: A method is provided for carrying out dispersion compensation in an optical mesh network supporting simultaneously traffic services being provided at two or three different bit rates including a basic bit rate being 10 Gbps and at least one higher bit rate selected from among 40 Gbps and 100 Gbps. The method comprises the following steps: providing in-line dispersion compensation for every span in the network so as to reach positive average residual dispersion RDS per span extending to less than about 3 km; providing start points of possible trails in the network with respective external, pre-compensation negative Dispersion Compensation modules (DCMs), and providing termination points of possible trails in the network with respective external post-compensation positive DCMs.

Abstract: A method is described to enable carrying out a fast reroute protection technique which provides both link and node protection without traffic duplication, without the need to distinguish between link and node failures, and without replicating traffic. The technique covers concurrent Working and backup logical path failures, and in particular LSP logical paths. The method is adapted to provide a “Dual Failure Protection” (DFP), and is expandable to various multi-failure scenarios.