Abstract: A method, a system, and a network entity for performing the switch-over of a protected Label Switched Path (LSP) in (less than) 50 ms. A goal of the preferable arrangement is to move the tasks related to the switch-over away from the CPU to hardware (HW). The ASIC applies a communication protocol to signal a need for a switch-over between two (or several) units without CPU's participation. A unit, for example Sink of protected domain, which has detected a fault, sends a so-called protection message to a protection pair unit of the unit. The protection pair unit interprets the protection message and actives the connection on the protecting unit.

Abstract: Each received piece of configuration data is added at a next currently free location in a volatile buffer. The contents of the volatile buffer are compressed after adding each received piece of configuration data. The compression result is stored in a non-volatile flash memory. If the compression result was shorter than a limit, it is allowed to be overwritten in the flash memory by a next compression result. If the compression result was longer than the limit, it is stored in the flash memory and the next compression result is directed to a different location in the flash memory.

Abstract: The invention relates to a method and an arrangement for regenerating a timing signal in digital data communication where two network elements operate in a master/slave loop timing mode. In a solution according to the invention two different frequency difference indicators are formed. Values or changes of the values of both of them in relation to time indicate a frequency difference between a reference timing signal present in a master device and a regenerated timing signal present in a slave device. One frequency difference indicator is formed on the basis of reception taking place in the master device, and the other one on the basis of reception taking place in the slave device. The frequency of the regenerated timing signal is adjusted utilizing information contained by both frequency difference indicators. The probability of incorrect frequency adjustment measures can be thereby reduced.

Abstract: A physical data transmission port in a network element of a data network, suited for realizing for instance both an electric packet switched Ethernet connection and an electric time slot switched E1/T1 connection. It has surprisingly been found out that the electric connector (101) and connected circuits provided in the network element can be arranged to support more than one wiring standard. For example the generally used RJ connector can be arranged to support both the RJ45 wiring standard and the RJ48c wiring standard, in which case, with the electric connector (101), there can be realized a physical data transmission port that is suited for realizing both an 10/100 Ethernet connection and an E1/T1 connection.

Abstract: Determining mutual differences of transmission delays experienced by protocol data units transmitted in a communications network 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 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 later, whether the mutual order of the protocol data units changed during transmission. If the mutual order has changed, the time difference between the receiving moments of the protocol data units is calculated, which time difference represents the smallest possible difference between the transmission delays experienced by these protocol data units.

Abstract: A method and system for adjusting a clock signal in a network element of a data network adjusts the clock signal based on difference values formed by received synchronizing messages. Each difference value is a difference of a reception and transmission values of a received synchronizing message. The reception value depends on a cumulated number of periods of the clock signal at a moment of arrival of the synchronizing message. The transmission value depends on a position of the synchronizing message in a chronological transmission order of synchronizing messages. When adjusting, an adjusting effect of the difference values belonging to a lower part of a margin of fluctuation of the difference values is weighted more heavily than that of an upper part. Thus, for clock signal adjustment, that share of information represented by the received synchronizing messages that has the least interference is used, irrespective of the data network load.

Abstract: A method and arrangement for adjusting the degree of filling of a jitter buffer in a network element receiving digital data. To the jitter buffer, there is connected a read-out unit for reading digital data from the jitter buffer. In the method, there is composed a time reserve indicator for the received protocol unit, the time reserve indicator being essentially the difference of an order indicator connected to the protocol unit and an order indicator connected to the operational cycle of the read-out unit. The time reserve indicator of the protocol unit indicates whether the protocol unit was received in good time, in order to ensure that the digital data is in the jitter buffer when the digital data is in turn to be read out. The degree of filling of a jitter buffer is adjusted on the basis of time reserve indicators composed for the received protocol units.

Abstract: The invention relates to determining a quantity to be measured from a communication system, such as a transmission delay or the phase difference of clock times. Measurement messages are transmitted (501, 502) between the two areas of the communication system in both transmission directions. Values of the time difference are calculated (503) for the measurement messages transmitted in at least one of the transmission directions, each of which values is the difference between the instant of reception measured at the reception and the instant of transmission measured at the transmission of the measurement message. The values of the time difference are used to calculate (504) an estimate of the distribution of the time difference, on the basis of which an estimate of the minimum value of the time difference is calculated (504).

Abstract: A method and equipment for obtaining routing data for a data transfer packet is presented. The data transfer packet is associated with information indicating a quality-of-service class of the data transfer packet and is related to protocol data associated with a data transfer protocol being used. The method using the protocol data as an input quantity for reading basic data and a reduction rule that are compatible with a routing table and the protocol data, using the information indicating the quality-of-service class as an input quantity of the reduction rule for obtaining auxiliary routing data, and obtaining the routing data on the basis of the basic data and the auxiliary routing data. The reduction rule connects auxiliary data to each quality-of-service class in such a way that each auxiliary data is associated with at least two different quality-of-service classes in order to reduce the amount of required storage capacity.

Abstract: The invention relates to a method and equipment for performing aggregate-portion-specific flow shaping in packet-switched telecommunications, in such a way that the traffic flows (V1-VL) arriving in the system can be arbitrarily bundled into shaping groups and the speed properties (CIR, PIR, CBS) of an aggregate portion formed of packets representing the arbitrary shaping group (k) can be monitored and limited (aggregate-portion-specific shaping group).

Abstract: The invention relates to a method and apparatus for scheduling transmission-link capacity between packet switched telecommunications flows (L1, L2), in such a way that it is possible to ensure the scheduling of packets representing delay-critical traffic to the transmission link (S) before packets representing non-delay-critical traffic and, in addition, to achieve the desired division of the capacity of the transmission link (S) between different traffic groups. The invention is based on performing the selection in the scheduling in stages, as follows: 1) the packets with the highest priority among the packets being offered are sought and 2) from the sub-group obtained, a final selection is performed using a weighting-factor based scheduling method, in such a way that the same weighting-factor based scheduling process is used to handle the sub-groups representing different priority levels in the consecutive selection situations.

Abstract: In a processing management or control messages in a packet or cell switched data network, a protocol packet (131) is provided with a selection identifier that indicates the sub-system (145) of the receiving network element (102), which sub-system operates the management and/or control session connected to said protocol packet. Now that sub-system (144) of the receiving network element that receives said protocol packet (131), is capable of conducting the information contained in said protocol packet to the appropriate sub-system (145) of the receiving network element (102) on the basis of said selection identifier.

Abstract: The invention relates to producing data traffic where the time intervals between successive data frames follow a predetermined probability distribution. In the present invention, it is surprisingly discovered that a time interval of a desired length between successive data frames can be produced by setting a certain bit quantity of digital stuffing data, defined on the basis of the target length of the time interval target, in a buffer memory (101), where successive data frames are waiting to be transmitted. The digital stuffing data is set in the buffer memory (101), so that the stuffing data is, in the read-out order, located between successive data frames.

Abstract: The invention relates to a method and apparatus for scheduling transmission-link capacity between packet-switched telecommunications flows, in such a way that it is possible to guarantee that packets representing delay-critical traffic will be scheduled to the transmission link (S0) before packets representing non-delay-critical traffic and, in addition, that it is possible to limit the joint transmission speed of specific service-quality classes of an individual customer flow. The invention is based on the service-quality classes being separated into two different categories: a service-quality-class based scheduling branch (C) and a customer-flow based scheduling branch (F).

Abstract: The invention relates to a method and equipment for controlling the congestion management and transmission-link-capacity scheduling in packet-switched telecommunications, in such a way that 1) it is possible to define what share of the capacity of the transmission link will be reserved for traffic representing a specific service level class, and 2) it is possible to define the weighting coefficient that the portion of the traffic exceeding the reservation of each service level class will use to compete for the portion of the capacity of the transmission link that is not reserved, or that is reserved but is not being used momentarily by traffic entitled to the reservation, and 3) it is possible to use overbooking, in such a way that the reduction in service quality due to overbooking affects only the service level class in which overbooking is used, and 4) it is possible to prevent an increase in delays detrimental to traffic-flow control even in a congestion situation arising from overbooking.

Abstract: The present invention concerns adjustment of tap coefficients of a Tomlinson-Harashima precoder in a digital communications path during a data transmission state. According to the invention, the tap coefficients of the Tomlinson-Harashima precoder are adjusted based on content values of a delay line of the Tomlinson-Harashima precoder and on an error variable associated with a receive. Synchronization between the error value and the content values of the delay line is performed according to line frame synchronization information.

Abstract: The invention relates to a method and apparatus for scheduling transmission link bandwidth between packet-switched data flows so that a desired CoS (Class of Service) is provided with an ability to utilize the instantaneously available bandwidth of a data transmission network while simultaneously offering a guaranteed minimum data rate (Guaranteed Data Rate and Best Effort) without compromising the operation of such classes that have no guaranteed lower bound of data rate, but instead, have the service implemented by the utilization of the instantaneously available bandwidth (Best Effort). The invention is based utilizing in the scheduler control, not only the information indicating the class of service, but also the information indicating the subgroup inside a class of service (e.g., drop precedence). The information indicating the subgroup is conventionally utilized only for congestion control purposes.

Abstract: The invention relates to a method for implementing adaptive Tomlinson-Harashima precoding using a digital data communications link. According to the method, the outgoing bit stream is coded into symbols, channel distortion is corrected by precoding (TML) the symbols, the precoded symbols are sent over a data communications channel (2, CHN), in which case the symbols, which have passed through the channel (2, CHN) and signal processing means for the receiver are reconstructed to form a bit stream. According to the invention, updated precoder coefficient parameter values are formed with the aid of an error variable (e), which is dependent on the symbol decisions (S?) of the receiver, the output signal of a decision-feedback equalizer, and a signal (Q) that is formed from the received signal by compensating the effect of the precoder transfer function of the received signal with an inverse precoder transfer functions.

Abstract: The invention relates to a method and an arrangement for transferring timing messages in a digital data transfer system. In a solution according to the invention a timing message is transferred (101, 102, 103) within control data carried in a protocol data unit. The timing message is dependent on a transmission moment of the protocol data unit from a network element of the digital data transfer system. The control data is either a synchronization status message (Ethernet-SSM) carried in an Ethernet-frame, an overhead (OH) of a Synchronous Optical Network-frame (SONET), or an overhead (OH) of a Synchronous Digital Hierarchy-frame (SDH). Therefore, the number of such protocol data units that are dedicated only for timing purposes can be reduced.

Abstract: The invention relates to a method and apparatus for improving the quality of receiver synchronization on QAM- or CAP-modulated modem connections having an adaptive linear equalizer. The invention is based on the finding that in a QAM- or CAP-modulated data transmission system where the symbol rate and the average carrier frequency are in fixed relationship with each other, the vector formed by the In-phase and the Quadrature component of the detector input signal rotates with the timing phase shift of the receiver. The quality of receiver synchronization is improved by utilizing information extracted from the vector rotation.