Abstract: In a system, the functionality is decentralized in a data transmission network so that the need of communications produced by and addressed to data terminals to pass by way of a single point in the data transmission network is diminished. A first data transmission installation is adapted to signal second data transmission installations, each of which is part of a ring-shaped data transmission topology, to be capable of building logical data transmission tunnels directed to the data terminals. Thereby, all the logical data transmission tunnels need not commence or, depending on the direction, terminate at the same point of a data transmission network. In addition, the data transmission installations present in a ring-shaped data transmission topology need not necessarily be taught routing information in order to enable each of these data transmission installations to send data transmission frames to be transmitted to another one of these data transmission installations.

Abstract: A method for optimizing entity-specific configuration systems for functional entities of a network element of a software-defined network is presented. The entity-specific configuration systems are based on a network element-specific configuration system related to the whole network element and including configuration entries for determining operations to be carried out by the network element. The method includes forming (401) relation data that indicates, for each of the functional entities, those of the configuration entries which are irrelevant to the functional entity under consideration so that operation of the functional entity is independent of these configuration entries. The relation data enables the entity-specific configuration systems to be constructed (402) so that the entity-specific configuration system of each functional entity is free from those configuration entries which, according to the relation data, are irrelevant to the functional entity under consideration.

Abstract: A device for controlling frequency synchronization includes a processor for controlling a phase-controlled clock signal to achieve phase-locking with a reference clock signal, and for controlling a frequency-controlled clock signal so as to achieve frequency-locking with the reference clock signal. The processor is also configured to monitor a deviation between the frequency and phase-controlled clock signals, detect a change of circumstances such as temperature changes causing frequency drifting of the frequency-controlled clock signal, and replace or correct the frequency-controlled clock signal with, or on the basis of, the phase-controlled clock signal when both the monitored deviation and the detected change of circumstances show correlation confirming frequency drift of the frequency-controlled clock signal.

Abstract: In a data communication system according to the invention the functionality of the gateway device is distributed in a data communication network thereby reducing the need to direct the data traffic from and to terminals (212, 213, 214) through a single point in the data communication network. A first data communication device (207) is arranged to make, through signalling, second data communication devices (204, 205, 206) capable of directing the data communications of the terminals to the starting points of the respective logical data communication tunnels (215, 216, 217). This way there is no need for all logical data communication tunnels to start from, or depending on the direction, to end at, the same point in the data communication network.

Abstract: A device for controlling a clock signal generator includes a processor (101) for forming at least two mutually different control quantities on the basis of reception moments of timing messages such as time stamps, where the reception moments are expressed as time values based on a first clock signal and the timing messages are transmitted in accordance with a second clock signal. The processor also calculates a weighted sum of the control quantities, and controls the clock signal generator with the weighted sum so as to synchronize the first clock signal and the second clock signal. The control quantities may represent, for example, a filtered value of observed phase-errors, a phase-error corresponding to a minimum observed transfer delay, and phase-errors corresponding to a given portion of the delay distribution. Using the weighted sum of the mutually different control quantities improves the utilization of the information content of the timing messages.

Abstract: A method for configuring a network element of a software-defined network “SDN” is presented. The network element maintains at least one look-up table defining actions to be executed in conjunction with managing a first data frame. The method comprises i) receiving (301) second data frames from a controller of the software-defined network, ii) reading (302), from the second data frames, a configuration program comprising one or more computer executable instructions defining at least one action to be executed in conjunction with managing the first data frame, and iii) associating (303) the configuration program to the at least one look-up table so that the configuration program is callable to be executed in conjunction with managing the first data frame with the aid of the at least one look-up table. The use of the configuration program instead of mere configuration parameters increases the freedom to implement different functionalities in the network element.

Abstract: An arrangement for adjusting a clock signal in a network element of a communications network includes a processor device arranged to produce a control variable containing information about synchronization messages received from at least two other network elements. A situation in which the reception from a sending network element of synchronization messages of a good enough quality ceases will not significantly disturb the clock signal to be adjusted because only part of the control variable used for the adjustment depends on synchronization messages sent by an individual network element. In a preferred arrangement, the reference value of the control variable is changed in response to a situation where the reception from a sending network element of synchronization messages of a good enough quality ceases. Thus it is possible to reduce the change of the difference between the control variable and its reference value which further reduces disturbances caused in the clock signal to be adjusted.

Abstract: A method for controlling advertising of routing data to neighbor routers is presented. A list of prefixes is maintained (301) and each prefix is associated (302) with an own indicator vector that contains a data item for each of the neighbor routers so that the data item indicates (304) whether the prefix concerned is to be advertised to the neighbor router concerned. For each neighbor router there is (303) a handling pointer pointing to the prefix that is relevant to the status of an advertising process related to this neighbor router, and the handling pointer is moved forward on the list of prefixes according as the prefixes are advertised to this neighbor router. As there is no need to maintain an own list of prefixes for each neighbor router separately, but only neighbor router-specific entries in the indicator vectors, savings can be achieved in the required memory space.

Abstract: A data transfer system comprises interconnected network devices organized to constitute a hierarchical logical arrangement having at least three levels of network hierarchy. A network device (102) receives from another network device (101) that is higher at the hierarchy a first data item such as an IP-prefix defining a first set of network addresses such as IP-addresses. The network device composes second data items so that each of the second data items defines one of mutually non-overlapping sub-sets of the first set. The network device transmits the second data items to network devices (104, 105) that are lower at the hierarchy in order to allocate one of the sub-sets to each of these network devices at the lower level of the hierarchy. This procedure can be repeated on all levels of the network hierarchy. Thus, the address configuration can propagate downwards through the hierarchical logical arrangement of the network devices.

Abstract: A device for controlling frequency synchronization includes a processor for controlling a frequency-controlled clock signal on the basis of received timing messages so as to achieve frequency-locking between the frequency-controlled clock signal and a reference clock signal. For the purpose of finding such timing messages which have experienced similar transfer delays and thus are suitable for the frequency control, the processor is configured to control a phase-controlled clock signal on the basis of the timing messages so as to achieve phase-locking between the phase-controlled clock signal and the reference clock signal, and to select the timing messages to be used for the frequency control on the basis of phase-error indicators related to the phase control. Thus, the phase-controlled clock signal is an auxiliary clock signal that is utilized for performing the frequency control.

Abstract: In a filter structure for suppressing a spurious signal, a conductor layer in a printed circuit board includes a pattern with interconnected pattern elements (106 to 114). A pattern element includes a low-impedance conductive region (119) the capacitance of which against a second conductor layer of the printed circuit board is dominant over the inductance. A pattern element includes at least two adjacent high-impedance conductor strips (115, 116) in a first direction, connected to a low-impedance conductive region, and at least two adjacent high-impedance conductor strips (117, 118) in a second direction, connected to the low-impedance conductive region. The inductance of each high-impedance conductor strips is dominant over the capacitance against the second conductor layer. The high-impedance conductor strips form together with the low-impedance conductive region a plurality of resonance points in the frequency range, thus achieving sufficient stop-band width.

Abstract: To transfer a communication session from a first data source to a second data source, the following operations are carried out when a radio terminal is handed over from a first base station to a second base station: the session settings and status information related to the communication session are transferred (503) to be used in conjunction with the second data source, a first portion of the payload data related to the communication session is sent (504) in accordance with the session settings from the first data source to the radio terminal via the second base station, and the next portion of the payload data which according to the status information still has to be sent to the radio terminal during the communication session is sent (506) in accordance with the session settings from the second data source to the radio terminal via the second base station.

Abstract: An arrangement for indicating correct installation of a plug-in unit (102) of a telecommunications device includes at least one distance indicator (106) located in the plug-in unit and adapted to produce an indication for correct installation of the plug-in unit in response to a situation where the distance of the distance indicator from a wall (107) of the frame of the telecommunications device is smaller than a predetermined threshold value. The distance indicator, which may be e.g. an electromechanical limit switch or capacitive distance sensor, is adapted to produce the indication for correct installation without a need for a galvanically conducted electric current between the distance indicator and the frame of the telecommunications device. There is thus no need to make any electric circuit arrangements in the frame of the telecommunications device for the indication of correct installation of a plug-in unit.

Abstract: The invention relates to a method and equipment for performing flow shaping that maintains service quality in packet-switched telecommunications. Using the method according to the invention, the speed properties (CIR, PIR, CBS) of an aggregate flow (A) can be monitored and limited in a situation, in which the aggregate flow contains delay-critical traffic (V1), the forwarding of packets representing which cannot be delayed. The invention is based on the fact that, when forwarding packets representing the aggregate flow, a variable is updated, the value of which expresses the earliest permitted moment, at which a packet, representing traffic (V2) other than the delay-critical traffic, can be forwarded. In that case, the transfer speed of the traffic (V2) other than delay-critical traffic adapts to the variations in the transfer speed of the delay-critical traffic, allowing the speed properties of the aggregate flow to be monitored and limited.

Abstract: A method and arrangement for transferring synchronizing information in a data transmission system includes modem connections. The arrangement includes a modulator (207) arranged to generate an analog signal (222) modulated by synchronizing information, the frequency spectrum of the signal being located in a frequency range that falls outside the data transmission bands of the modem line connected to the network element. The arrangement includes a switching circuit (208) arranged to connect the analog signal to a data transmission cable (206) that forms part of the modem line connected to a network element. The arrangement includes a second switching circuit (209) arranged to receive the analog signal from a data transmission cable that forms part of the modem line connected to the second network element. The arrangement also includes a regenerator (209-arranged to regenerate the synchronizing information from the analog signal.

Abstract: The invention relates to a method and equipment for performing flow shaping that maintains service quality in packet-switched telecommunications. Using the method according to the invention, the speed properties (OR, PIR, CBS) of an aggregate flow (A) can be monitored and limited in a situation, in which the aggregate flow contains delay-critical traffic (V1), the forwarding of packets representing which cannot be delayed. The invention is based on the fact that, when forwarding packets representing the aggregate flow, a variable is updated, the value of which expresses the earliest permitted moment, at which a packet, representing traffic (V2) other than the delay-critical traffic, can be forwarded. In that case, the transfer speed of the traffic (V2) other than delay-critical traffic adapts to the variations in the transfer speed of the delay-critical traffic, allowing the speed properties of the aggregate flow to be monitored and limited.

Abstract: The invention relates to transmitting digital information between the network elements of a frame switched data network. In the present invention, it has surprisingly been discovered that the padding bits of the data field of a minimum sized Ethernet frame can be used for transmitting digital information between the elements of a data network. In that case the frame data field (109) of a minimum sized Ethernet frame contains an information unit (DIU), the size of which in bytes is smaller than the minimum size of a frame data field, as well as other digital information (DI) that is written in an area (107) of the frame data field that corresponds to the padding bits. The invention makes it possible to also utilize the data transmission capacity needed for transmitting the padding bits.

Abstract: A system includes a communications device and power supply units detachably installable thereon. On an outer surface of the communications device there is an aperture arranged to enable the insertion of different power supply units in different sections of the volume inside the communications device. The volume is continuous so that instead of separate power supply units it is possible to insert, through the aperture, in the volume a physically larger power supply unit which, when installed in the volume, extends into more than one section of the volume. The communications device can be flexibly equipped e.g. with power supply units functioning as back-ups for each other, each taking up part of the volume, or with a single power supply unit, larger than the above-mentioned, taking up the volume. Therefore the volume inside the communications device can be utilized in connection with power supply units of various types.

Abstract: A method and apparatus for monitoring and limiting the transmission speed of a data traffic flow in a situation where the traffic flow also includes delay-critical traffic. With the sending of each protocol data unit it is determined whether the sending of the next protocol data unit should be delayed in order to meet a condition set on the transmission speed. It is also determined whether the transfer speed of delay-critical traffic meets a preset condition. If the transfer speed meets the condition, delay-critical protocol data units will not be delayed but if the condition is not met, delay-critical protocol data units will be delayed just like non-delay-critical protocol data units. Thus the transfer speed of non-delay-critical traffic adapts to variations in the transfer speed of delay-critical traffic and, furthermore, the transmission speed of the traffic flow can be monitored and limited.

Abstract: The invention relates to determining mutual differences of transmission delays experienced by protocol data units transmitted in a communications network. This invention is based on a surprising discovery that the time difference between the receiving moments of protocol data units the temporal receiving order of which deviates from their temporal transmitting order represents the smallest possible difference between the transmission delays experienced by these protocol data units. In a method according to the invention it is determined, based on an order indicator associated with a protocol data unit received at an earlier point of time and an order indicator associated with a protocol data unit received at a later point of time, whether the mutual order of the protocol data units changed during transmission.