Abstract: A simple and effective all-optical system, producing a multilevel coded optical signal based on the M-ASK technology and by the minimized equipment. The novel all-optical modulation technique for optical M-ASK generation is based on nonlinear interaction between optical signals, say between N 2-ASK modulated pump signals having extinction ratio ER1 and a single 2-ASK modulated optical probe signal having extinction ratio ER2. According to the invention, a 4-ASK optical signal can be obtained using just a single binary modulated pump optical signal and a single binary modulated probe optical signal.

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: A method is described for providing an MPLS tunnel adapted for sharing bandwidth (BW) in an MPLS network. The method comprises establishing the MPLS tunnel as a working MPLS tunnel (ST) to be shared by a plurality of pseudo wires (PWs) passing at least partially along the path of the tunnel ST, wherein a predetermined bandwidth of the bandwidth allocated for the ST is adapted to be shared by the plurality of PWs, of which at least one PW has a different source point and/or a different destination termination point at the ST path, from at least one other of the plurality of PWs.

Abstract: Technology for detecting an optical data signal carried in a combined optical signal that comprises a carrier optical signal modulated by the optical data signal and also comprises ASE noise. The proposed optical data detector/receiver is provided with an SHG device adapted to generate a second harmonic optical signal of the carrier optical signal modulated by the data signal. In the signal, generated by the SHG, the ASE noise will be essentially reduced.

Abstract: A technique for testing peer nodes in a multicast domain (such as an access network) interconnected with an Ethernet network via an Intermediate Bridge (IB), especially helpful when an individual MAC address of a destination peer node is unknown. The technique comprises a) issuing a Connectivity Fault Management (CFM) message from the Ethernet network, and introducing into the CFM message alternative destination data being different than the individual MAC address of the destination peer node; b) utilizing the alternative destination data, at the IB, for determining topological position or address of the destination peer node, and c) forwarding contents of the CFM message only to the destination peer node.

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 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 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: A system for serving N optical communication lines by a redundant set of modules in an optical network; where the set of modules comprises N>1 main modules and one backup module, N optical splitters, 2N fiber connections and a control means. In the system, each of the N optical splitters is connected to two different modules of the set by two respective fiber connections out of the 2N connections, while each of the N optical splitters is also coupled to one of the N optical communication lines. The arrangement is such that the control means selectively activates/inactivates any of the fiber connections for respectively enabling/blocking transfer of data there-along; the control means thus ensures that each specific line of the N optical communication lines is always served by either one or another of two different modules.

Abstract: Technique is proposed for managing total power consumption in an access network comprising two or more interface modules serving a plurality of subscriber lines, the technique comprises performing a study of real power consumption of the subscriber lines in the access network on a line-to-line basis, correlating results of the study with inventory information concerning allocation of the subscriber lines to the interface modules and power consumption ensured by said modules to the lines and, based on the correlation, assessing optimality of allocation of the subscriber lines to the interface modules.

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.

Abstract: A method for estimating a bandwidth limiting penalty of a chain of bandpass optical filters in an optical telecommunication system. The method is advantageous for systems carrying an optical signal at a bit rate of about 10 Gb/s, wherein average bandwidth of the filters in the chain is of the same order of magnitude as bandwidth of the optical signal. The method comprises selecting a worst case filter, checking the system by testing and/or simulating it as being provided with the selected worst case filter instead of the chain of filters, and then judging about the bandwidth limiting penalty of the chain of filters based on results of the checking.

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 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 Home Gateway (HGW) interconnects a Home Network (HN) and an External Network (EN), and is adapted to communicate with the HN and EN at a Network layer. HGW is provided with a Service Application Programming Interface Layer (SAPI Layer) capable of performing, at an Application layer, mediator functions for supporting communication and services between the HN and EN. Devices of the HN are able to communicate with devices of EN via the HGW, and to actualize services via the HGW.

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 10G bps 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 provided for routing optical data, which method comprises transmitting optical addressing data to a first network element having routing capabilities, assigning an appropriate optical link connecting the first network element with a second network element where the assignment is based on the optical addressing data, and transmitting the optical data via the assigned optical link.

Abstract: A method and system are provided for improving bandwidth efficiency in an optical network by dynamically utilizing unused bandwidth located around preliminarily allocated optical channels. The method comprising monitoring actual bandwidth of the preliminarily allocated optical channels incoming to a node of the optical network, reporting the monitoring results to the controller of that node and further to a network controller, receiving at that node recommendations generated by the network controller, adjusting bandwidth of one or more of the allocated optical channels thereby releasing spare bandwidth for inserting one or more additional optical channels thereat.

Abstract: A technique of finding connectivity solutions for network elements to be switched into a path selected in a network managed by a network management system (NMS), wherein each network element comprises input ports and output ports, each of the ports enabling a plurality of connection points, the technique including providing, at the level of NMS, a connectivity table (CT) comprising data on possible internal connections between connection points of any input port and any output port of any of the network elements managed by the NMS. The technique enables, whenever a particular network element is selected with its input port and its output port to be used in the path, obtaining a connectivity solution for the particular network element at the level of NMS.

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.