Abstract: A first Multi Protocol Label Switching (MPLS) Internet Protocol (IP) data network transmits data to a second MPLS IP network via a legacy network, which would not otherwise be able to handle the required user network interface (UNI) protocol by configuring the legacy network and its connection computing apparatus (CCA) so that they emulate an MPLS network. When a firt network element (NE) receives a connection (UNI) request from the MPLS network under a UNI protocol, the UNI request is passed to the CCA, which then sets the required connection across the legacy network via a second network element (NE) to an NE of the second network. Once the connection has been set, the CCA instructs the NE to send a return signal to the requesting network indicating that the connection has been successfully set. Data packets may then be transmitted across the network.

Abstract: A first Multi Protocol Label Switching (MPLS) Internet Protocol (IP) data network transmits data to a second MPLS IP network via a legacy network, which would not otherwise be able to handle the required user network interface (UNI) protocol by configuring the legacy network and its connection computing apparatus (CCA) so that they emulate an MPLS network. When a firt network element (NE) receives a connection (UNI) request from the MPLS network under a UNI protocol, the UNI request is passed to the CCA, which then sets the required connection across the legacy network via a second network element (NE) to an NE of the second network. Once the connection has been set, the CCA instructs the NE to send a return signal to the requesting network indicating that the connection has been successfully set. Data packets may then be transmitted across the network.

Abstract: A first Multi Protocol Label Switching (MPLS) Internet Protocol (IP) data network transmits data to a second MPLS IP network via a legacy network, which would not otherwise be able to handle the required user network interface (UNI) protocol by configuring the legacy network and its network management system (TNMS) so that they emulate an MPLS network. When a first network element (NE) receives a connection (UNI) request from the MPLS network under a UNI protocol, the UNI request is passed to the TNMS, which then sets the required connection across the legacy network via a second edge NE to an NE of the second network. Once the connection has been set, the TNMS instructs the edge NE to send a return signal to the requesting network indicating that the connection has been successfully set. Data packets may then be transmitted across the network.

Abstract: A first Multi Protocol Label Switching (MPLS) Internet Protocol (IP) data network transmits data to a second MPLS IP network via a legacy network, which would not otherwise be able to handle the required user network interface (UNI) protocol by configuring the legacy network and its network management system (TNMS) so that they emulate an MPLS network. When a first network element (NE) receives a connection (UNI) request from the MPLS network under a UNI protocol, the UNI request is passed to the TNMS, which then sets the required connection across the legacy network via a second edge NE to an NE of the second network. Once the connection has been set, the TNMS instructs the edge NE to send a return signal to the requesting network indicating that the connection has been successfully set. Data packets may then be transmitted across the network.

Abstract: A first multi protocol label switching (MPLS) enabled Internet Protocol (IP) data network is able to transmit data to a second MPLS enabled IP network via a legacy optical network, which would not otherwise be able to handle the user network interface (UNI) protocols required to be used within an MPLS network environment, by means of configuring the legacy optical network and its traditional network management system (TNMS) so that they simulate or emulate an MPLS enabled optical network. The simulation/emulation of an MPLS network is performed as follows: when a first legacy network element (NE) receives a connection request (a UNI request) from the MPLS network under a UNI protocol, the UNI request is passed to the TNMS, which then sets the required connection across the legacy network via a second edge NE to an NE of the second IP network.

Abstract: An optical transmitter system supplies a plurality of different wavelength optical radiation components to a transmission element which, in operation, is connected to the transmitter system for conveying the different wavelength radiation components to a respective receiver. The supply of the wavelength components is interrupted, preferably in response to a loss of the wavelength components at the respective receiver. A timer provides respective restart times which differ one to another for the wavelength radiation components. The supply of the wavelength components is restarted, following an interruption, at the respective restart times provided by the timer.

Abstract: An optical transmitter system supplies a plurality of different wavelength optical radiation components to a transmission element which, in operation, is connected to the transmitter system for conveying the different wavelength radiation components to a respective receiver. The supply of the wavelength components is interrupted, preferably in response to a loss of the wavelength components at the respective receiver. A timer provides respective restart times which differ one to another for the wavelength radiation components. The supply of the wavelength components is restarted, following an interruption, at the respective restart times provided by the timer.

Abstract: A communications network determines for itself its own network topology, that is, the identity and interconnection of nodes comprising the network. The network comprises a plurality of nodes each having at least one port. The ports are interconnected in accordance with the network topology in which communication traffic is conveyed over the network via the interconnected ports. Each port is arranged to transmit first information within the communication traffic including the identity of the port (Section trace identity) from which the communication traffic originates. Second information is transmitted between nodes identifying which first information identity relates to which node and which port. A processor is operative for determining for each node from the first and second information the identity of adjacent nodes and the identity of the ports to which its ports are connected.

Abstract: In a synchronous communications network such as SDH or SONET, traffic signals can be tagged to indicate that a fault condition has already been identified and reported. On examination of the alarm tag at subsequent stages, an alarm is suppressed if the tag indicates that the fault has already been reported.

Abstract: An optical transmitter system supplies a plurality of different wavelength optical radiation components to a transmission element which, in operation, is connected to the transmitter system for conveying the different wavelength radiation components to a respective receiver. The transmitter system detects a loss of a wavelength radiation component at the respective receiver. The supply of the wavelength component is interrupted in response to a detection of loss of the wavelength component at the receiver. A timing circuit provides respective restart times which differ one to another for the wavelength radiation components. The supply of the wavelength component is restarted, following an interruption, at the restart time provided by the timing circuit.

Abstract: A telecommunications interface network card, such as the type which is inserted into a suitable slot in a rack forming a network node, to provide an interface to the node for telecommunications traffic entering and leaving the node, typically carries a receptacle to receive a plugable module which contains a laser and receiver as optical interface, allowing one card to be used with a number of optical interfaces, to avoid the need for a range of cards to be produced, each dedicated to one particular type of traffic, for example, a particular distance and data rate. The invention provides a module which is compatible with existing optical modules, but which carries an electrical interface.

Abstract: Restoration of a failed link on a network is achieved by reserving a portion of the transmission bandwidth for at least some of the links connecting nodes of the network. The reserved portion of the transmission bandwidth is used for the transmission of traffic diverted from a failed link to provide a restoration path for that diverted traffic thereby enabling a protection path to be determined dynamically. The reserved portion is preferably configured in a block so that contiguous concatenated payloads can be transmitted across the protection bandwidth.

Abstract: An optical transmitter system for supplying a plurality of different wavelength optical radiation components (&lgr;1 to &lgr;n) to a transmission element (2), which, in operation, is connected to the transmitter system for conveying the different wavelength radiation components to a respective receiver (11), is disclosed. The transmitter system comprises means for detecting a loss of a wavelength radiation component at the respective receiver (11) and means (9) for interrupting the supply of the wavelength component in response to a detection of loss of the wavelength component at the receiver. The transmitter system is characterised by timing means (10) capable of providing respective restart times (t1 to tn) which differ one to another for the wavelength radiation components, and means (9) for restarting the supply of the wavelength component, following an interruption, at the restart time provided by the timing means.

Abstract: In a synchronous communications network such as SDH or SONET, traffic signals can be tagged to indicate that a fault condition has already been identified and reported. On examination of the alarm tag at subsequent stages, an alarm is suppressed if the tag indicates that the fault has already been reported.

Abstract: An Add-Drop Multiplexer (ADMUX) for use in a synchronous digital hierarchy telecommunication system is provided with a by-pass whereby, in use, it can be made to interface with a higher bit rate transmission system.

Abstract: A telecommunication switch protection arrangement has information sent in the form of an information frame through a switch. The information in the frame is reorganized in the switch between input and output and checked for parity by using a V4 byte in the frame before being sent from the switch.