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 technique for controlling power of a network node in an optical mesh network, comprising: determining a number of optical paths ingressing or expected to ingress the node, determining capacity or expected capacity of each of the paths; calculating for each of the paths a virtual input power Pvirtual, based on estimation of relative capacity of a specific path with respect to total capacity of all the paths; applying to the network node a power control mechanism, while utilizing a corresponding virtual input power Pvirtual as input power of any of the paths.

Abstract: A technique for monitoring at least a network portion of an optical communication network, by monitoring changes of a decision threshold used for discriminating a digital optical signal being propagated via the network portion.

Abstract: Creating an Ethernet network, within an existing MPLS network, for one or more specified traffic services by selecting in the MPLS network one or more bidirectional non-disjoint LSPs between dual-enabled nodes, presenting these LSPs as Ethernet-enabled links, deploying over them an Ethernet protocol and forwarding there-along dedicated Ethernet over MPLS packets according to Ethernet forwarding rules regardless any MPLS labels except for a predetermined dedicated LSP label.

Abstract: A method for allocating faults in a passive optical network (PON) by placing a number of passive unique optical correlators in a number of respective diagnostic points of the PON, each of the passive unique optical correlators being responsive to an optical diagnostic signal by returning a predetermined unique matching signal; by further transmitting the diagnostic optical signal in the PON towards the diagnostic points to receive upstream response signals from the correlators. Upon detecting presence or absence, in the received response signals, of a predetermined unique matching signal expected from a specific optical correlator, judging about a fault in proximity of the respective specific diagnostic point.

Abstract: A method and apparatus are described for providing communication services to a mobile platform while moving, wherein the mobile platform communicates along two current communication links extending between the mobile platform and two network gateways. The method comprises: setting an H-VPLS service to enable provisioning of L2 services to the moving platform via at least one of the two current communication links; enabling the moving platform to exchange communications along one or both communication links; replacing one of the two current communication links while the mobile platform is moving, with another communication link extending towards a third network gateway, by using Pseudo Wire Redundancy (PWR) to re-route traffic from the communication link being replaced to the other communication link, thereby allowing the moving platform to continue provisioning the L2 services while communicating with two network gateways, being the third network gateway and one of the former two network gateways.

Abstract: A method of managing a communication network, using a multi-layer management system having at least two management layers each comprising one or more elements, which elements serving as managing entities and/or managed objects. The method comprises performing a network operation simulation at a selected management level of the system, by one or more selected managing entities, while, at the time of the simulation, comprises interrupting management communication between the one or more selected managing entities and elements in an underlying management layer.

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 technique for protecting traffic in a Layer 2 (L2) communication network between a first and a second local nodes (CE1, CE2) interconnected via a redundant dual homed structure, the technique comprises a) distributing the traffic in the dual homed structure in a fault-free state, to form two traffic flows between the CE1 and CE2; b) providing Layer 2 (L2) fault indications for the dual homed structure, in the form of operation and maintenance (OAM) tools, c) in a faulty state of the dual homed structure, forwarding traffic packets at the provider edges of the structure, based only on conventional physical fault indications and L2 fault indications, by locally making forwarding decisions for selecting an active communication line via the redundant dual homed structure.

Abstract: A dual homing technique for ensuring loop free transmission of traffic between telecommunication networks such as VPLS by utilizing a loop protocol in the dual homed connection. The technique also provides selective handling of VPLS data streams protected and non-protected by the dual homing loop protocol.

Abstract: Technique for handling traffic between a specific common source node and a network element NE being part of a dual homing configuration, via a main path and an auxiliary path in the configuration, the technique comprises redirection of the traffic from one of said paths to another while the path from which the traffic has been redirected remains active, while relearn of MAC addresses which is required due to the redirection is performed without executing a MAC addresses flush operation.

Abstract: For determining OSNRreal of a real optical signal carried in an optical network link, the following has been proposed: tapping a portion of the real optical signal, altering the tapped signal portion by adding to it in-band artificial noise signal, thus obtaining a combined signal, scattering the combined signal by stimulated Brillouin or Raman scattering (SBS or SRS) in an optical element, extracting a signal back reflected by SBS/SRS from the optical element, determining OSNRcomb of the back reflected signal and deriving the OSNRreal from the OSNRcomb knowing absolute and/or relative power of the added artificial noise.

Abstract: A technique enabling an access node to undertake more responsibility and render multicast streaming more effective by utilizing streaming service control messages SSCP which contain important information such as Quality of Experience or Quality of Service. The access node itself or in cooperation with a processing/monitoring entity may be enabled to analyze QOE data in SSCP report messages from different access network receivers, to identify specific receivers which encounter problems and to indicate the problems to the provider of the network.

Abstract: A reconfigurable wavelength selective dispersion compensation device RWSDCD for selective compensation of dispersion in optical channels having different wavelengths. The RWSDCD comprises a controllable wavelength selective unit WSU having a plurality of local, wavelength related input/output (I/O) ports. The RWDSD also comprises a dispersion compensation cascade comprising at least one chain of successively connected dispersion compensation units DCUs, wherein one or more of the DCUs in the chain are respectively connectable to one or more of the local I/O ports. The RWSDCD outputs one or more of the incoming optical channels upon selectively compensating chromatic dispersion in them, by controllably passing these channels via one or more DCUs of the dispersion compensation cascade.

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 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 reconfigurable optical switching device comprising a Tunable Filters Array (TFA) unit incorporating tunable optical filters, wherein the arrangement is such that one and the same TFA unit is utilized both for performing a drop function of the device in a colorless and reconfigurable manner, and a through function of the device in a reconfigurable manner.

Abstract: Technique for fast rerouting (FRR) of traffic in a communication network, from a working path comprising a link with its downstream node, to one or more backup paths concurrently providing link protection and node protection to the link and the downstream node; the method comprises enabling the downstream node to block forwarding of traffic, if received at the downstream node along the backup path(s), towards a more-down-stream node in the working path in case the more-down-stream node participates in providing node protection against a failure of the downstream node, the technique thereby prevents traffic duplication at the more-down-stream node and does not require distinguishing a link failure from a node failure.

Abstract: A technique for performing a flushing process at a port of a network switch, where the flushing process comprises a flooding operation and an operation of relearning MAC addresses. In the method, these two operations are made independent, and the operation of relearning MAC addresses is started before termination of the flooding operation. An operation of forwarding packets to the relearned MAC addresses can be started before termination of the flooding operation.

Abstract: A technique for forwarding downstream packets in a GPON comprising an OLT unit having a physical PON port connected to N Optical Network Termination (ONT) units by optical fibers. The physical PON port accommodates N individual virtual GEM ports terminated with the N ONT units (ONTs) which form N:1 service. The technique comprises assigning in the physical port of the OLT unit a virtual GEM port being a shared broadcast GEM port terminated with all the N ONTs of the N:1 service. Those downstream packets applied to the physical PON port, which would otherwise be flooded—such as broadcast packets or packets having unknown destination address—will now be forwarded only via the shared broadcast GEM port.