Method for the automatic detection and documentation of the execution of a measurement with regard to a data communication connection

Abstract

The invention relates to a method, in particular for the automatic detection and documentation of the execution of a measurement with respect to a data communication link (100) between a first communication endpoint (30, 41) and a second communication endpoint (43, 50), wherein the data communication link (100) runs at least via a first network element (41) of a core network (40) configured for data transmission. A measuring device (20) is connected to the first network element (41). By means of the method, information supplied by the measuring device (20), in particular about the start of a measurement operation, the ongoing measurement operation, and the end of the measurement operation with respect to the data communication link (100), can be automatically detected by the first network element (41) and transferred to a network management system (70) for documentation purposes via a data communication network (60) separate from the core network (40).

Description

The invention relates to a method, in particular for automatic recognition and documentation of the performance of a measurement with respect to a data communication connection which runs between a first and a second communication terminal.It is known to measure transmission properties of a digital communication link between two subscriber terminals, which can be connected directly or in each case via a network termination unit to a telecommunications core network, by means of an externally connectable measuring device. Depending on the implementation, the measuring device can be connected, for example, to one of the network termination units. The core network can be, for example, an optical transport network according to the ITU-T G.709 standard. As long as a measuring device is connected, no control operation is possible via the communication link, so that an alerting as well as a performance data collection and their evaluation cannot take place reliably. Performance data relate to defined performance characteristics of the communication connection and are in particular required to determine a performance characteristic, also known as a key performance indicator (KPI), for the communication connection to be measured. In addition, to time the measurement phases, time stamps for the respective start and the respective end of a measurement must optionally be input repeatedly manually into a network management system.US 2015 / 0104167 A1 discloses a method for determining properties of an optical communication path between a first and a second optical network node. For this purpose, a time difference between respective first and second optical test signals which are transmitted at different wavelengths from the first optical network node is determined in the second optical network node. Further, in the second optical node, a chromatic dispersion parameter is obtained for each of the wavelengths in real time.US 2013 / 0195442 A1 discloses a transmission device and a method for measuring a transmission transit time in a transmission system in which a frame is transmitted between a first and a second transmission device. For this purpose, a runtime measurement is carried out a plurality of times, which determines a time duration between the transmission of a first frame from the first to the second transmission device and the reception of a second frame that was transmitted from the second to the first transmission device. A transmission transit time is then determined from the measurement results.From EP 3 179 676 B1 a delay measuring device of a communication system is known, which delay measuring device sends and receives successive frames with known frame lengths. The communication system includes a measurement object device that serves to measure a round trip time by the delay measurement device.US 2018 / 0175965 A1 describes a control method for a network, wherein the method is carried out by a processor of a network control device. According to the method, the time for creating an optical path that extends across multiple nodes of a network is measured. In addition, the optical path is set at a timing controlled based on the amount of the measured time.From US 2023 / 0300050 A1 a method for measuring a traffic volume time during a path switching is known, wherein the method is carried out by a first device. For this purpose, OAM (Operation Administration and Maintenance) frames are continuously transmitted from the first device to a second device and OAM frames are received from the second device. Based on the received OAM frames, a start and stop time for the traffic volume is determined.In US 2014 / 0314401 A1, a transmission system for selecting a path from a plurality of paths running between a first and a second transmission device is described, among other things. The first device is configured to transmit a frame to the second device via each of the paths. The second device is configured to measure, for each path, a delay time using a frame transmitted between the second and first devices. A path is selected based on the measured delay times.The object of the present invention is to provide a method with which measurement phases of a data communication link can be determined and documented more precisely and reliably.An advantageous aspect of the invention can be seen in the provision of a method, in particular for automatic recognition and documentation of the execution of a measurement with respect to a data communication connection existing between two communication terminals, wherein the data communication connection runs at least over a first network element of a core network designed for data transmission. A measuring device is connected to the first network element. By means of the method, information provided by the measuring device, in particular about the start of a measuring operation, the ongoing measuring operation and the end of the measuring operation, can be automatically recognized with respect to the data communication connection by the first network element and transferred to a network management system for documentation purposes via a data communication network separate from the core network.The above technical object is achieved by the features of claim 1.Accordingly, a method is provided, in particular for automatically detecting and documentation of the performance of a measurement with respect to a data communication connection existing between a first and a second communication terminal, wherein the data communication connection runs at least over a first network element of a core network configured for data transmission. The method has, for example, the following method steps: a) connecting a measuring device to the first network element; b) transmitting a first signal, which contains start information, which signals the start of a measuring operation, from the measuring device to the first network element; c) transmitting, after termination of the measuring operation, a second signal, which contains stop information, which signals the end of the measuring operation, from the measuring device to the first network element; d) after execution of step b) and before execution of step c), repeatedly transmitting a third signal, which contains measurement operation information, which signals a current measuring operation with respect to the data communication connection, from the measuring device to the first network element; e) detecting, by the first network element, the start information in the first signal, the stop information in the second signal, and the measurement operation information in each third signal, and transmitting the received start information, the received stop information, and each of the received measurement operation information from the first network element to a network management system (NMS) via a data communication network separate from the core network, wherein the core network and the data communication network separate from the core network support different communication protocols; and f) storing the information transmitted in step e) in the network management system to document the performance of a measurement relating to the data communication link.It should be noted that the first, second and each third signal preferably form a data frame comprising a plurality of bytes, wherein the data frame is implemented in particular according to a predetermined communication protocol, for example according to the ITU-T G.709 standard.It should also be noted that the measuring device can be directly connected to the first network element. In this case, the first network element can be considered a first communication terminal which is designed for the direct connection of at least one subscriber terminal. A subscriber terminal is, for example, a computer, a router or a switch or also the measuring device. Alternatively, the measuring device can also be indirectly connected to the first network element, for example via a customer-side network termination unit. In this case, the network terminating unit can be considered a first communication terminal.According to an advantageous embodiment, the core network can be a standardized optical transport network (OTN), in particular an optical transport network according to the ITU-T G.709 standard. In this case, the first network element is an OTN network element, which can be designed, for example, as an optical OTN terminal, as an OTN ADD / DROP multiplexer, as an OTN cross connector or as an OTN network termination. Such OTN network elements are known to the person skilled in the art.The communication between the measuring device and the first network element is preferably carried out via a standardized communication protocol, such as, for example, the Ethernet protocol according to an IEEE 802.3 standard, an OTN protocol according to the ITU-T G.709 standard or a fibre channel protocol stack (FC-P).In order to be able to reliably detect the operating state of the data communication link, in particular, the method may include the following further steps according to an advantageous development:generating, by the first network element, first status information signaling that the current operating state is a measurement operation; in response to the start information transmitted in step b);generating, by the first network element, second status information indicating that the measuring operation is ended and / or the data communication link is again in the normal communication operating state;transmitting the first and second status information from the first network element to the network management system via the data communication network separate from the core network; andstoring the first and second status information in the network management system for documenting the performance of a measurement with respect to the data communication connection.In order to be able to document the status of the data communication connection reliably, in particular, the first signal transmitted in step b), the second signal transmitted in step c), and each third signal transmitted in step d) can preferably each contain information for identifying the data communication connection, wherein the information for identifying the data communication connection is transmitted from the first network element to the network management system, and wherein the information for identifying the data communication connection is stored in the network management system for documenting the performance of a measurement with respect to the data communication connection.Optionally or additionally, at least the first signal transmitted in step b) can contain at least one piece of information relating to the measurement and / or at least one piece of information identifying the measuring device, wherein the at least one piece of information relating to the measurement and / or the at least one piece of information identifying the measuring device is transmitted from the first network element to the network management system, and wherein the at least one piece of information relating to the measurement and / or at least one piece of information identifying the measuring device is stored in the network management system for documentation of the performance of a measurement with respect to the data communication connection.According to an advantageous embodiment, the data communication connection can run at least in sections between the first network element and a second network element of the core network, wherein the method can have the following further steps:transmitting the information received in the first, second and every third signal from the first network element to the second network element via the core network and forwarding this information from the second network element to the network management system via the data communication network separate from the core network; andstoring the received information in the network management system for documenting the performance of a measurement with respect to the data communication connection.The second network element can likewise be an OTN network element which can be designed, for example, as an optical OTN terminal, as an OTN ADD / DROP multiplexer, OTN cross connector or as an OTN network termination. Such OTN network elements are known to the person skilled in the art.In order to enable decentralized documentation, the information contained in the first, second and each third signal can advantageously also be stored in the first and / or second network element.In order to increase the flexibility with respect to the measurement requirements, the method can have the following steps:transmitting, in step b), in the first signal at least one control command intended for the second communication terminal, the at least one control command including instructions for executing a predetermined action by the second communication terminal;transmitting the at least one control command from the first network element to the second communication terminal; anddepending on the at least one received control command, the second communication terminal performs the predetermined action, which can also be considered a communication remote station.It should be noted that the first and second communication terminals can each be designed to connect a subscriber terminal device, so that in normal operation two communication terminals can communicate with one another via the data communication link.According to an advantageous embodiment, the data communication connection can run at least in sections between the first network element and a second network element of the core network, wherein the second communication terminal is the second network element of the core network, and wherein the method comprises the following steps; transmitting the at least one control command from the first network element to the second network element acting as a second communication terminal; carrying out the predetermined action by the second network element as a function of the at least one received control command; transmitting the control command from the first and / or second network element to the network management system via the separate data communication network; and storing the control command transmitted from the first and / or second network element in the network management system for documentation of the performance of a measurement with respect to the data communication connection.According to an advantageous alternative embodiment, the data communication connection can run at least in sections between the first network element and a second network element of the core network, wherein the second communication terminal is directly connected to the second network element of the core network, wherein the at least one control command is transmitted from the first network element via the second network element to the second communication terminal, and wherein the method has the following steps; as a function of the at least one received control command, carrying out the predetermined action by the second communication terminal; transmitting the control command from the first and / or second network element to the network management system via the data communication network separate from the core network; and storing the control command transmitted from the first and / or second network element in the network management system for documenting the performance of a measurement with respect to the data communication connection.The second communication terminal can in this case be a subscriber-side network termination unit to which a subscriber terminal can be connected.The predetermined action can involve, for example, the formation of a test loop, in particular the formation of a software-based test loop in the second communication terminal, in order to transmit data transmitted from the measuring device via the data communication link back to the measuring device during a measuring operation.According to an advantageous development, the method can have the following steps:executing, by the measuring device, predetermined measurements regarding the data communication link between the first and second communication terminals; andproviding the measured values obtained by the predetermined measurements for further use.With the predetermined measurements, in particular transmission properties of the data communication link, such as the maximum data rate, the transmission duration and / or the number of lost or incorrectly transmitted data, can be determined.The present invention is explained in more detail below on the basis of exemplary embodiments in conjunction with the accompanying drawings. Shown therein are: FIG. 1 shows an exemplary communication system embodying the invention, in which the data communication link runs between two communication terminals, each designed as a network termination unit, FIG. 2 shows a further exemplary communication system embodying the invention, in which the data communication link runs between two OTN network elements each functioning as a communication terminal, FIG. 3 shows an exemplary communication system embodying the invention, in which the data communication link runs between two communication terminals, each designed as a network termination unit, which are connected to a common OTN network element, and FIG. 4 is a flow chart of an exemplary measurement operation.FIG. 1 shows an exemplary communication system 10 which comprises a core network 40, which in the present example is designed as an optical transport network (OTN) according to the ITU-T G.709 standard. The optical transport network 40 is a telecommunication network with which user data are transmitted by means of a transport service. It should be noted that a plurality of individual optical transport networks can also be connected to form a common core network. According to the ITU-T G.709 standard, user data are transmitted in data frames, the so-called optical transport units (OTU), specifically preferably with transmission rates of 2.66 Gbit / s, 10.7 / 11.1 Gbit / s, 112 Gbit / s or multiples of 112 Gbit / s. The optical multiplex technique used is in particular the density wavelength division multiplexing (DWDM).The optical transport network 40 has a plurality of optical network elements, also referred to below as OTN network elements, which can be connected to one another via optical glass fibre links. For the sake of clarity only four optical network elements 41-44 and the glass fibre paths 80-84 connecting them are shown. The OTN network elements 41- 44 of the optical transport network 40 are preferably designed as an OTN terminal, as an OTN ADD / DROP multiplexer, as an OTN cross connector or as an OTN network termination. Such OTN network elements are known to the person skilled in the art and are therefore not described in more detail here.To accommodate the high transmission rates mentioned above, each of the fiber optic links 80-84 preferably has two separate fibers to enable bidirectional data transmission. Each of the two optical fibers is used for a different transmission direction.The communication system 10 further comprises at least two communication terminals. In the exemplary embodiment, only the two communication terminals 30, 50 are shown. The communication terminals 30, 50 are designed, for example, as network termination units which are preferably implemented on the customer side and, in the case of operation illustrated in FIG. 1, function as end points or communication terminals of a schematically illustrated data communication connection 100. According to an exemplary implementation, the two communication terminals 30, 50 can each be designed as an optical network unit (OTN-NT of Optical Transport Network-Network Termination). If the two network termination units 30 and 50 are not implemented or are not used, then the two OTN network elements 41 and 43, as can be seen in FIG. 2, form the communication terminals of a data communication connection 101. It is also conceivable that in the exemplary embodiment according to FIG. 1 only one of the two network terminating devices 30 and 50 is implemented. In this case, either the OTN network element 41 and the network terminating device 50, or the network terminating unit 30 and the OTN network element 43 form the two communication terminals of the data communication link 100.As shown in FIG. 1, the communication terminal 30 is directly connected to the optical network element 41 of the optical transport network 40, for example, via an optical fiber 90. In order to be able to exchange data between the communication terminal 30 and the optical network element 41 in a predetermined manner, the communication terminal 30 and the optical network element 41 each have a communication interface 31 or 41.1, which implements a standardized communication protocol, for example the communication protocol according to the ITU-T G.709 standard.Similarly, the communication terminal 50 is directly connected to the optical network element 43 of the optical transport network 40, for example, via an optical fiber 91. In order to be able to exchange data between the communication terminal 50 and the optical network element 43 in a predetermined manner, the communication terminal 50 and the optical network element 43 each have a communication interface 51 and 43.1, respectively, which implement a standardized communication protocol, for example the communication protocol according to the ITU-T G.709 standard.Each of the communication terminals 30 and 50 designed as a network termination unit has a communication interface 32 and 52, respectively, to which a subscriber terminal device, such as a coupling element, a router, or a switch, or a server or a measuring device 20, is connected in each case. If a router / switch is used, at least one computer, for example, can be connected to the router / switch in a manner known per se. As shown in FIG. 1, a subscriber terminal 130 may be connected to the communication interface 52 of the network terminal 50.As FIG. 1 further shows, a measuring device 20 can be connected to the optical network element 41 via the network termination unit 30 functioning as a communication terminal for measurement purposes. For this purpose, the measuring device 20 can be connected directly to the communication interface 32 of the network termination unit 30 by means of a communication interface 21. As shown alternatively in FIG. 2, in the absence of the network termination unit 30, the measuring device 20 can also be connected directly to the communication interface 41.1 of the optical network element 41 functioning as a communication terminal by means of the communication interface 21.As FIG. 1 further shows by way of example, the optical network elements 41- 44 each have a communication interface 41.2, 42.1, 43.2 and 44.1, by means of which they are connected to a network management system (NMS) 70 via a separate data communication network 60 and can communicate according to a predetermined communication protocol. The network management system 70 and the communication interface 41.2, 42.1, 43.2 and 44.1 implement, for example, a standard communication protocol, such as, for example, an Ethernet protocol according to an IEEE 802.3 standard or the Internet protocol. The network management system 70 is designed to monitor and control the optical transport network 40, its optical network elements 41- 44 and, if appropriate, also the network termination units 30 and 50. Control or monitoring information determined for the network termination units 30 and 50 is transmitted from the network management system 70 via the data communication network 60 to the OTN network element 41 or 43 and from there via corresponding in-band channels, which are set up, for example, according to the communication protocol according to the ITU-T G.709 standard, to the network termination unit 30 or 50. The separate data communication network 60 is preferably an isolated firewall-secured network that supports communication between the network management system 70 and the optical network elements 41-44 using a preferably standardized communication protocol.FIG. 2 shows an exemplary communication system 10', which differs from the communication system 10 shown in FIG. 1 in that only the two network terminating devices 30 and 50 are not present. Accordingly, the reference numerals from FIG. 1 are adopted for the corresponding features in FIG. 2. The measuring device 20 is now connected directly to the communication interface 41.1 of the OTN network element 41. The two OTN network elements 41 and 43 in this case each form a communication terminal of the data communication link 101. The OTN network element 43 functioning as a communication terminal is in this case designed to be directly connected to a subscriber terminal 130'. For this purpose, the subscriber terminal 130' has a correspondingly designed communication interface 131', which preferably implements the communication protocol according to the ITU-T G.709 standard.FIG. 3 shows a further exemplary communication system 10", which differs from the communication system 10 shown in FIG. 1 in that not only the network termination unit 30, but also a further network termination unit 110 is connected directly to the OTN network element 41, for example via a glass fiber 92. For this purpose, the network terminating unit 110 has a communication interface 111 and the OTN network element 41 has a further communication interface 41.3, which implement, for example, the communication protocol according to the ITU-T G.709 standard. In this case, the two network termination units 30 and 110 each form a communication terminal of a data communication link 102 which is carried only via a single OTN network element, namely the OTN network element 41. The network terminating unit 110 preferably comprises a communication interface 112 for connecting a subscriber terminal, for example the terminal 130.The mode of operation of the communication system 10 shown by way of example in FIG. 1 is explained in more detail below.It should be noted here that, according to an exemplary implementation, the communication system is designed in particular to automatically identify the operating state of a data communication connection, i.e. to identify whether a data communication connection between a first and a second communication terminal, in the present example a data communication connection 100 schematically illustrated by a dashed line, between the communication terminal 30 and the communication terminal 50, is in the measurement mode or in the normal transmission mode. The current state is then signaled to the network management system 70 and documented there.It is initially assumed that the network operator of the optical transport network 40 has set up a permanent data communication connection 100 between the communication terminal 30 and the communication terminal 50 at customer request, for example, or has configured it in the network management system 70, for example, taking into account the unique address information of the two communication terminals 30 and 50. The data communication link 100 acting as an end-to-end link runs from the communication terminal 30 to the optical network element 41 and then via the optical network element 43 to the communication terminal 50, wherein, depending on the configuration and implementation, the data communication link 100 can be routed via at least one further, interposed optical network element of the optical transport network 40, for example via the optical network element 42. Depending on the implementation, the communication system 10 can be designed to detect the failure of optical network elements of the optical transport network 40 and to ensure that, in the event of a failure of, for example, the optical network element 42, the data communication link 100 established between the communication terminal 30 and the communication terminal 50, which is also carried by the two OTN network elements, is maintained, for example, while incorporating the optical network element 44.Furthermore, it is now assumed that the measuring device 20 is connected to the network termination unit 30 functioning as a communication terminal and is connected via this to the optical network element 41 in order to be able to carry out a measurement with respect to the data communication connection 100. As already explained above by way of example, the communication terminal 30 and the optical network element 41 each have a communication interface 31 or 41.1, which implement a standardized communication protocol, for example the communication protocol according to the ITU-T G.709 standard.According to an exemplary implementation, the measurement device 20 may be configured to generate predetermined binary pseudo random sequences, for example a pseudo random binary sequence (PRBS) known to the person skilled in the art. For example, a PRBS23 may be generated that is repeated every 8388607 bits.Now assume that the measuring device 20 generates a start signal which contains at least one piece of start information which signals the beginning of a measuring operation. The start signal can form, for example, a data frame with n bytes, where n is, for example, 64. The start information can be represented by a binary 1. In addition to the start information, the start signal can optionally contain at least one of the following information:information for uniquely identifying the data communication link 100,information about the first communication protocol which is used for communication between the measuring device 20 and the network termination unit 30,information about the communication protocol used for communication between the optical network elements 41 to 44 and the network management system 70,information about the communication protocol used for communication between the optical network elements of the optical transport network 40,a control command which contains an instruction to an remote station, in the present example to the network termination unit 50 functioning as a communication terminal station or remote station, for carrying out a predetermined action, at least one piece of information relating to the measurement and / or at least one piece of information characterizing the measuring device 20,a random number.The information regarding the measurement may include the minimum and / or maximum size of the data frame used, the core network 40 used, the data rate, the wavelength of light used to transmit data, and the like. The information identifying the measuring device 20 can contain the serial number and / or the measuring device type.According to the exemplary implementation, the start signal is transmitted in a binary pseudo random sequence via the network termination unit 30 functioning as a communication terminal to the optical network element 41. The optical network element 41 is designed to recognize the information contained in the start signal and, depending on the implementation, to store it in a local storage device and to forward it to the network management system 70 via the data communication network 60 for documentation purposes.Depending on the implementation, during a current measurement, for example after each transmission of a predetermined number of binary pseudo random sequences, a further signal is now repeatedly generated by the measuring device 20 and transmitted to the optical network element 41. Each further signal contains measurement operation information which signals a current measurement operation with respect to the data communication connection 100, that is to say indicates that the measuring device 20 is still in the measurement operation. Each further signal may form, for example, a data frame with n bytes, wherein n is, for example, 16. The measurement mode information can, for example, identify the random number transmitted in the first signal, which, depending on the implementation, can also identify the data communication connection 100. The optical network element 41 is designed to recognize the measurement operating information contained in each further signal and, depending on the implementation, to store it in a local storage device and to forward it to the network management system 70 via the data communication network 60 for documentation purposes.Assume that the measuring device 20 is designed to transmit, in the start signal, a control command determined for the remote station, here the network termination unit 50 functioning as a communication terminal station or remote station, to the optical network element 41. The control command includes an instruction to the network termination unit 50 to perform a certain action. The determined action may relate, for example, to the establishment of a test loop.In this case, the optical network element 41 may be configured to recognize the control command included in the start signal and transmit the control command to the network termination unit 50 in an optical transport unit (OTE), for example, via the optical transport network 40 and the optical network element 43. At least the network termination unit 50 acting as a communication terminal is designed to recognize and execute the control command contained in the received optical transport unit by the network termination unit 50 setting up a software-based test loop, for example, in order to transmit data coming from the communication terminal 30 or from the optical network element 41 back to the optical network element 41 or to the communication terminal 30. The network termination unit 50 may further be configured to generate action information describing the predetermined action performed by the network termination unit 50, and transmit the control command and / or the action information to the network management system 70 via the data communication network 60. The control command and / or the action information are then stored in the network management system 70 for further use, in particular for automatic documentation of the operating state of the data communication link 100.The measuring process with respect to the data communication link 100 is ended by the measuring device 20 generating a stop signal which contains at least one piece of stop information which signals the end of the measuring operation. The stop signal can form, for example, a data frame with n* bytes, where n is, for example, 64. The stop information may be represented by a binary 0. In addition to the stop information, the stop signal can contain at least one of the further information, which can also optionally be contained in the start signal. The stop signal is transmitted to the optical network element 41 via the communication terminal 30 in a binary pseudo random sequence according to the exemplary implementation. The optical network element 41 is designed to recognize the information contained in the stop signal and, depending on the implementation, to store it in a local storage device and to forward it to the network management system 70 via the data communication network 60.In order to be able to use the data communication connection 100 again normally for data transmission after the measurement process, the measuring device 20 is preferably designed to transmit a control command determined for the network terminating device 50 functioning as a communication terminal or remote station to the optical network element 41 in the stop signal. The control command includes an instruction to the network terminating device 50 to perform a particular action. The determined action can relate, for example, to the removal of a software-based test loop. In this case, the optical network element 41 can be configured to recognize the control command contained in the stop signal and to transmit the control command, for example, in an optical transport unit (OTE) via the optical transport network 40 and the OTN network element 43 to the network termination unit 50 functioning as the remote station. The network termination unit 50 is configured to recognize and execute the control command contained in the received optical transport unit by the network termination unit 50 removing the previously formed software-based test loop. The network terminating unit 50 may further be configured to generate action information describing the predetermined action performed by the network terminating unit 50, and transmit the control command and / or the action information to the network management system 70 via the OTN network element 43 and the data communication network 60. The control command and / or the action information are then stored in the network management system 70 for further use, in particular for automatic documentation of the operating state of the data communication link 100.For automatic documentation of the state of the data communication connection 100, the information contained in the start signal, in the stop signal and in each of the further signals is transmitted from the optical network element 41 to the network management system 70 via the data communication network 60 and stored there for documentation purposes with respect to the data communication connection 100.Depending on the implementation, the information contained in the start signal, in the stop signal and in each of the further signals can also be transmitted from the optical network element 41 to the remote station, here the optical network element 43, and can be further conducted from the optical network element via the data communication network 60 to the network management system 70 and stored there. Preferably, both the optical network element 41 and the optical network element 43 are designed to recognize the information contained in the start signal, in the stop signal and in each of the further signals and to store it at least until the measurement operation has been ended.At least the optical network element 41 is designed for this purpose,generating, in response to the start information contained in the start signal, a first status information item which signals that the current operating state of the data communication link 100 is a measurement operation,generating, in response to the stop information contained in the stop signal, a second status information signaling that the current operating state of the data communication link 100 is a normal communication operation, and transmitting the first and second status information to the network management system 70 via the data communication network 60, wherein the first and second status information are stored in the network management system 70 for further use, in particular for documentation purposes.If appropriate, the optical network element 41 is designed to transmit the first and second status information via the optical transport network 40 also to the optical network element 43. The first and second status information can optionally be stored in the optical network element 43 and transmitted to the network management system 70 via the data communication network 60.The binary pseudo random sequences generated and transmitted by the measuring device during a measuring operation, which are optionally transmitted from the remote station, here the network termination unit 50, back to the measuring device 20, can be used by the measuring device 20 to measure transmission properties of the data communication link 100. In this way, it is possible, for example, to detect an erroneous data transmission and the data rate that is not reached by a contracted data rate.The mode of operation explained above with regard to the communication system 10 shown in FIG. 1 essentially also applies to the communication system 10' shown in FIG. 2. The following differences exist with respect to the communication system 10:The data communication link 101 runs between the two OTN network elements 41 and 43 functioning as communication terminals.A start signal, repeatedly transmitted signals, which signal a current measurement mode, and a stop signal are transmitted from the measuring device 20 directly to the OTN network element 41. The measuring device 20 is preferably designed to transmit, in the start signal, a control command determined for the remote station, here the OTN network element 43 functioning as a communication terminal station or remote station, to the optical network element 41. The control command includes an instruction to the OTN network element 43 to perform a particular action. The determined action may relate, for example, to the establishment of a test loop. In this case, the optical network element 41 can be designed to recognize the control command contained in the start signal and to transmit the control command, for example in an optical transport unit (OTE), via the optical transport network 40 to the OTN network element 43 functioning as the remote station. The OTN network element 43 acting as a communication terminal is designed to recognize and execute the control command contained in the received optical transport unit by the OTN network element 43 setting up a software-based test loop, for example, in order to transmit the data coming from the optical network element 41 acting as a communication terminal back to the optical network element 41. The OTN network element 43 can furthermore be configured to generate action information describing the predetermined action carried out by the OTN network element 43 and to transmit the control command and / or the action information to the network management system 70 via the data communication network 60. The control command and / or the action information are then stored in the network management system 70 for further use, in particular for automatic documentation of the operating state of the data communication link 100.In order to be able to use the data communication connection 100 again normally for data transmission after the measurement process, the measuring device 20 is preferably designed to transmit a control command determined for the OTN network element 43 functioning as a communication end station or remote station to the optical network element 41 in the stop signal. The control command includes an instruction to the OTN network element 43 to perform a particular action. The determined action can relate, for example, to the removal of a software-based test loop. In this case, the optical network element 41 can be designed to recognize the control command contained in the stop signal and to transmit the control command, for example, in an optical transport unit (OTE) via the optical transport network 40 to the OTN network element 43 as the remote station. The OTN network element 43 is designed to recognize and execute the control command contained in the received optical transport unit by the OTN network element 43 removing the previously formed software-based test loop. The OTN network element 43 can furthermore be configured to generate action information describing the predetermined action carried out by the OTN network element 43 and to transmit the control command and / or the action information to the network management system 70 via the data communication network 60. The control command and / or the action information are then stored in the network management system 70 for further use, in particular for automatic documentation of the operating state of the data communication link 100.The mode of operation explained above with regard to the communication system 10 shown in FIG. 1 essentially also applies to the communication system 10'' shown in FIG. 3. The following differences exist with respect to the communication system 10:The data communication link 102 runs between the two network terminating units 30 and 110 which are directly connected to the OTN network element 41. Further OTN network elements are involved in this data communication connection.A start signal, repeatedly transmitted signals, which signal a current measurement operation, and a stop signal are transmitted from the measuring device 20, if present, via the network termination unit 30 to the OTN network element 41. The measuring device 20 is preferably designed to transmit, in the start signal, a control command determined for the remote station, here the network termination unit 110 functioning as a communication terminal station or remote station, to the optical network element 41. The control command includes an instruction to the network termination unit 110 to perform a certain action. The determined action can relate, for example, to the production of a test loop, in particular a software-based test loop. In this case, the optical network element 41 can be configured to recognize the control command contained in the start signal and to transmit the control command directly to the network termination unit 110 functioning as the remote station, for example in an optical transport unit (OTE). The network termination unit 110 functioning as a communication terminal is designed to recognize and execute the control command contained in the received optical transport unit by the network termination unit 110 setting up a software-based test loop, for example, in order to transmit data coming from the communication terminal 30 or from the optical network element 41 back to the optical network element 41 or to the communication terminal 30. The network terminating unit 110 may further be configured to generate action information describing the predetermined action performed by the network terminating unit 110 and transmit the control command and / or the action information to the network management system 70 via the OTN network element 41 and the data communication network 60. The control command and / or the action information are then stored in the network management system 70 for further use, in particular for automatic documentation of the operating state of the data communication link 100.In order to be able to use the data communication connection 120 again normally for data transmission after the measurement process, the measuring device 20 is preferably designed to transmit a control command determined for the network termination unit functioning as a communication terminal or remote station to the optical network element 41 in the stop signal. The control command includes an instruction to the network termination unit 110 to perform a certain action. The determined action can relate, for example, to the removal of a software-based test loop. In this case, the optical network element 41 can be configured to recognize the control command contained in the stop signal and to transmit the control command directly to the network termination unit 110 as the remote station, for example in an optical transport unit (OTE). The network terminating unit 110 is configured to recognize and execute the control command contained in the received optical transport unit by the network terminating unit 110 removing the previously formed software-based test loop. The network terminating unit 110 may further be configured to generate action information describing the predetermined action performed by the network terminating unit 110 and transmit the control command and / or the action information to the network management system 70 via the OTN network element 41 and the data communication network 60. The control command and / or the action information are then stored in the network management system 70 for further use, in particular for automatic documentation of the operating state of the data communication link 120.FIG. 4 shows the time sequence of an exemplary measuring operation with respect to the data communication link 100. The flow diagram schematically illustrates that the measuring device 20 first transmits a start signal, which is preferably contained in a first binary pseudo random sequence, then two binary pseudo random sequences followed by a signal for signaling a current measurement, and then once again two binary pseudo random sequences followed by a further signal for signaling a current measurement, and then once again two binary pseudo random sequences followed by a stop signal contained in a binary pseudo random sequence.

Claims

Method, in particular for automatic recognition and documentation of the performance of a measurement with respect to a data communication connection (100, 101, 102) existing between a first communication terminal (30, 41) and a second communication terminal (43, 50), wherein the data communication connection (100, 101, 102) runs at least over a first network element (41) of a core network (40) designed for data transmission, wherein the method has the following steps: a) connecting a measuring device (20) to the first network element (41); b) transmitting a first signal, which contains start information, which signals the start of a measurement operation, from the measuring device (20) to the first network element (41); c) after termination of the measurement operation of a second signal containing stop information indicating the termination of the measurement operation, transmitting from the measuring device (20) to the first network element (41); d) after execution of step b) and before execution of step c), repeatedly transmitting from the measuring device (20) to the first network element (41) a third signal containing measurement operation information indicating a current measurement operation with respect to the data communication link (100, 101, 102); e) detecting, by the first network element (41), the start information in the first signal, the stop information in the second signal and the measurement operation information in each third signal and transmitting the received start information, the received stop information and each of the received measurement operation information from the first network element (41) to a network management system (70) via a data communication network (60) separate from the core network (40), wherein the core network (40) and the data communication network (60) separate from the core network (40) support different communication protocols; and f) storing the information transmitted in step e) in the network management system (70) for documentation of the performance of a measurement relating to the data communication connection.Method according to claim 1, wherein the core network (40) is a standardized optical transport network, in particular an optical transport network according to the ITU-T G.709 standard.Method according to claim 1 or 2, wherein the method comprises the following steps: in response to the start information transmitted in step b), generating, by the first network element (41), a first status information, which signals that the current operating state is a measurement operation, in response to the stop information transmitted in step c), generating, by the first network element (41), a second status information, which signals that the measurement operation is ended and / or the data communication connection is again in the normal communication operating state, transmitting the first and second status information from the first network element (41) to the network management system (70) via the data communication network (60) separated from the core network (40); and storing the first and second status information in the network management system (70) for documentation of the performance of a measurement with respect to the data communication connection.Method according to one of the preceding claims, wherein the first signal transmitted in step b), the second signal transmitted in step c) and each third signal transmitted in step d) each contain information for identifying the data communication connection (100), wherein the information for identifying the data communication connection (100) is transmitted from the first network element (41) to the network management system (70), and wherein the information for identifying the data communication connection (100) is stored in the network management system (70) for documentation of the performance of a measurement with respect to the data communication connection (100).Method according to one of the preceding claims, wherein at least the first signal transmitted in step b) contains at least one piece of information relating to the measurement and / or at least one piece of information identifying the measuring device (20), wherein the at least one piece of information relating to the measurement and / or the at least one piece of information identifying the measuring device (20) is transmitted from the first network element (41) to the network management system (70), and wherein the at least one piece of information relating to the measurement and / or at least one piece of information identifying the measuring device (20) is stored in the network management system (70) for documenting the performance of a measurement with respect to the data communication connection (100).Method according to one of the preceding claims, wherein the data communication connection (100) runs at least in sections between the first network element (41) and a second network element (43) of the core network (40), and the method has the following steps: transmitting the information received in the first, second and in each third signal from the first network element (41) to the second network element (43) via the core network (40) and forwarding this information from the second network element (43) to the network management system (70) via the data communication network (60) separated from the core network (40); and storing the received information in the network management system (70) for documentation of the performance of a measurement with respect to the data communication connection.Method according to claim 6, wherein the information contained in the first, second and each third signal is stored in the first and / or second network element (41, 43).Method according to any of the preceding claims, wherein the method comprises the steps of: i) transmitting, in step b), in the first signal at least one control command intended for the second communication terminal (43, 50) of the data communication link (100, 101, 102), the at least one control command including instructions for executing a predetermined action by the second communication terminal (43, 50); transmitting the at least one control command from the first network element (41) to the second communication terminal (43, 50); and executing, in dependence on the at least one received control command, the predetermined action by the second communication terminal (43, 50)Method according to claim 8, wherein a test loop is established by the second communication terminal (43, 50) as a function of the at least one received control command.Method according to claim 8 or 9, wherein the data communication connection (100) runs at least in sections between the first network element (41) and a second network element (43) of the core network (40) and the second communication terminal (43, 50) is the second network element (43) of the core network (40), wherein the method comprises the following steps; transmitting the control command from the first and / or second network element (43) to the network management system (70) via the data communication network (60) separated from the core network (4); and storing the control command transmitted from the first and / or second network element (41, 43) in the network management system (70) for documentation of the performance of a measurement with respect to the data communication connection.Method according to claim 8 or 9, wherein the data communication connection (101) runs at least in sections between the first network element (41) and a second network element (43) of the core network (40) and the second communication terminal (43, 50) is directly connected to the second network element (43) of the core network (40, wherein the at least one control command is transmitted from the first network element (41) via the second network element (43) to the second communication terminal (50), wherein the method comprises the following steps; transmitting the control command from the first and / or second network element (43) to the network management system (70) via the data communication network (60) separated from the core network (40); and storing the control command transmitted by the first and / or second network element (41, 43) in the network management system (70) for documentation of the execution of a measurement with respect to the data communication connection (100).The method according to any of the preceding claims, wherein the method comprises the steps of: performing, by the measuring device (20), predetermined measurements relating to the data communication link (100, 101, 102) between the first and second communication terminals (30, 50); and providing the measurement values obtained by the predetermined measurements for further use.

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