Method for managing a test of the quality of a telephone communication link

Abstract

The invention relates to a method for managing a test (TST) of the quality of a telephone communication link (L) between a terminal (TER) and a test server (SRV), wherein the telephone communication link (L) may be open or closed, the test (TST) being carried out when the link (L) is open, characterised in that, when carrying out the test (TST) of the quality of the link (L), the link (L) is kept open regardless of whether an instruction (RAC) is received to close the link (L) by the terminal (TER) for a given duration that is at least equal to the duration required to complete the test (TST) carried out by the test server (SRV).

Description

[0001] Description

[0002] Title: Method for managing a test of the quality of a telephone communication link

[0003] Technical field

[0004] The technical field is that of fixed telephony and in particular IP telephony, that is to say fixed telephone connections made using the IP protocol (acronym for Internet Protocol).

[0005] More specifically, the invention relates to a method for managing a test of the quality of a telephone communication link. Most often, the method according to the invention will be a method for managing a test of the quality of an IP telephone communication link.

[0006] Landline telephone connections are now generally made using telephony platforms that use the IP protocol to transmit voice signals between telephone sets. This is called IP telephony, or also Voice over IP. The term VoIP telephony (acronym for Voice over IP) is also used. Older landline telephone protocols, such as PSTN (acronym for Public Switched Telephone Network) or ISDN (acronym for Integrated Services Digital Network), are being phased out.

[0007] In telephony, the telephone which is at the end point of the telephone communication link and which will allow users to communicate with each other is generally called a terminal.

[0008] Telephone sets that allow IP telephony communication are dedicated devices called IP phones. These IP phones can establish IP communication sessions with other IP phones by requesting IP telephony platforms. Once the session is established between two IP phones, a communication channel is established and the voice is transmitted between the two IP phones via the IP protocol. Sometimes, the landline phone does not connect directly to the IP network, but is present in a local network and connects to a home gateway that will establish the IP telephone communication. We generally speak of an IP terminal to cover the two distinct cases of a phone that can directly use the IP protocol and a home gateway that serves as a relay for a phone present in its local network.The connection between the home gateway, which serves as an IP terminal, and the landline telephone is generally made using a DECT connection (acronym for Digital Enhanced Cordless Telecommunications).

[0009] IP telephony communication is generally established using the Session Initiation Protocol (SIP), which is a general-purpose protocol for establishing communication sessions. Previous versions of IP telephony used the ad hoc H.323 protocol. IP telephony platforms also serve as gateways to allow IP phones and IP terminals to access terminals belonging to other telephony networks, in particular traditional fixed-line telephone networks or mobile telephone networks.

[0010] State of the art

[0011] One of the needs of telephone service operators is to be able to test the quality of telephone lines, and in particular the part of the telephone lines that is located between customers' homes and the first equipment of the telephone network. Indeed, these parts of the telephone lines are partly located on private land and are not easily accessible to telephone service employees. The inspection of these parts of the lines requires making an appointment. A customer who notices poor quality of his telephone connection will therefore contact his telephone operator who will schedule an intervention with a technician who will carry out tests of the telephone connection and will have to travel, which entails a significant cost as well as delays before receiving the test results. There is therefore a need to be able to remotely test the quality of such a line.In the case of older landline telephone networks, such as the PSTN, there is a well-known technique for remote testing of telephone lines. This remote testing technique relies on the propagation properties of electrical waves in a copper medium, which is the most widely used medium in the PSTN network. By exploiting in particular the well-known echo phenomenon of electrical waves in this type of medium, it is thus possible for a telephone operator to remotely test a telephone line in the PSTN network. When a customer complains about the quality of their telephone line, a technician from the operator will be able to carry out a remote test to measure this quality and detect potential problems.

[0012] For IP telephony services, such physical properties of the telephone line cannot be used to perform a remote test. However, the French patent published under number 3,063,407 on August 31, 2018 and issued on September 10, 2021 presents a method for remote testing of such a communication link and an associated test server. The test server, present in the IP telephony network, sends a request to an IP terminal whose communication link is to be tested. The test server sends, after establishing the communication, data packets to the terminal, which then allows it to calculate test results and give an indication as to the quality of the IP telephony communication link.Performing the test by the server implies that the IP terminal must accept the establishment of the connection, which implies the insertion by the test server of a specific parameter in the request sent by the server to the IP terminal. The test calculation can use the G.107 standard which is part of the ITU-T recommendations, i.e. the recommendations for the telecommunications sector of the International Telecommunications Union.

[0013] However, since such a test is triggered by a test server in the network, the method described above implies that a customer must contact the after-sales service of his telephone operator to trigger a test when he notices a malfunction of his line. If the method introduces a possibility of remote testing, it does not allow a customer to diagnose the state of his IP telephony line without intervention of the after-sales service of his telephone operator. Such an intervention implies a delay before obtaining a response regarding the state of his line for the customer of the IP telephony service and a significant cost for the IP telephony service operator in order to respond to the requests of its customers. This disadvantage due to carrying out a test at the initiative of a server present in the network also exists in conventional telephony.

[0014] On the other hand, performing the test according to the G.107 standard implies that the test server must have a certain amount of time with the link open to the terminal to perform quality tests. However, a user interacting with the IP terminal could cut the open link with the server before the test is completed, for example by hanging up an IP phone or a DECT phone linked to the home gateway that serves as the IP terminal. This disadvantage due to the time taken to perform a test also exists in traditional telephony. In this case, if the user hangs up the terminal, he can cut the open link with the server before the test is completed.

[0015] The invention improves the situation.

[0016] Statement of the invention

[0017] According to a first functional aspect, the invention relates to a method for managing a test of the quality of a telephone communication link between a terminal and a test server, the telephone communication link being able to be open or closed, the test being carried out by the test server when the link is open, characterized in that the opening of the telephone communication link is preceded by a request to open the link from the terminal and in that, during the performance of the test of the quality of the link, said link is kept open independently of the reception of an instruction to close the link by the terminal for a given duration.

[0018] Thanks to the invention, the test management method ensures that the test is carried out completely by the test server. A test here is a complete interaction session between the server and the terminal, which comprises several steps, and which makes it possible to obtain a whole set of information regarding the quality of the telephone communication link. The complete execution of such a test therefore extends over a certain period of time. Completion of the test requires the server to carry out calculations for a certain time. Keeping the communication link open for a given period of time ensures that the test is carried out by the test server. The given duration is at least equal to the duration required to complete the test.

[0019] This advantage is particularly important to implement when the test is carried out at the initiative of the terminal. Indeed, the test can then be carried out by making a call to a dedicated number operated by the test server. It is therefore important in this case to ensure that the terminal does not hang up before the tests are completed. The invention makes it possible to ensure that, even if a user hangs up before the tests are complete, the terminal will keep the connection open to ensure the completion of the test steps.

[0020] Since the connection opening is preceded by a connection opening request from the terminal, it is possible to carry out communication connection quality tests at the initiative of the telephony service customers. The test server can have a dedicated telephone number that will be called by a terminal at the initiative of a user, who will simply dial the number. This action will trigger the opening of the communication connection between the terminal and the test server following a request issued by the terminal. The opening of the connection will allow the server to start the test. The advantage of this mode is that the test is carried out at the initiative of the customers, which avoids customers having to contact the telephone service operator's after-sales service. The test is carried out remotely and at the initiative of the customers, which minimizes the need to involve the telephone operator's after-sales service.

[0021] According to a first particular embodiment of the invention, if an instruction to close the link is received during the given duration, the execution of said instruction is postponed by another given duration.

[0022] With this implementation, the connection closure instruction is delayed for a given period of time but will be executed later. When the closure instruction is a hang-up operation performed by a terminal user, the advantage of this mode is that the test will be completed, but the instruction will also be executed, even if it is delayed. As long as the necessary delay is limited, it is possible that the user will not notice the delay in the execution of the closure instruction.

[0023] In another possible embodiment of the invention, the execution of the instruction is canceled. This mode has the advantage of simplifying the processing of closing instructions received by the terminal.

[0024] According to a second particular embodiment of the invention, which may be implemented alternatively or cumulatively with the previous embodiment, the link is an open IP telephone communication link between the terminal and the test server, said link comprising a signaling channel allowing the test server to obtain information relating to the signaling and the performance, by the test server, of the test of the quality of the link depends on the information obtained relating to the signaling.

[0025] An IP telephone communication link generally comprises two channels, a channel for exchanging information relating to signaling, and therefore to establishing communication, and a multimedia data transmission channel which in particular allows the voice signal to be exchanged between the two IP stations. It is this channel which allows users to speak to each other, their speech being transformed into IP data packets, and exchanged in both directions in the data transmission channel present in the open telephone communication link. Thanks to this mode of implementation, the test steps carried out are divided into two categories: on the one hand, tests relating to signaling, and on the other hand tests relating to the transmission of data packets.Since speech signals are transmitted via data packets, testing the quality of an IP telephone communication link relies primarily on data transmission tests. However, signaling tests are also useful. One of the advantages of this method is that it allows you to perform a quality test based on the signaling information obtained. For example, the signaling information allows you to identify the IP terminal that initiated the test. The test server can then differentiate the tests based on the terminal that initiated the connection used for the test. A telecommunications operator may, for example, refuse to perform tests from terminals that are not part of its customers. Or, an operator may perform more or less detailed tests depending on the subscription of the customer owning the terminal that initiated the test.

[0026] According to a third particular embodiment of the invention, which may be implemented alternatively or cumulatively with the previous embodiments, the opening of the connection is preceded by a request to open the connection from the terminal.

[0027] Thanks to this embodiment of the invention, it is possible to carry out quality tests of the communication link at the initiative of the customers of the telephone service. The test server can have a dedicated telephone number which will be called by a terminal at the initiative of a user, who will simply dial the number. This action will trigger the opening of the communication link between the terminal and the test server following a request issued by the terminal. The opening of the link will allow the server to start the test. The advantage of this mode is that the test is carried out at the initiative of the customers, which avoids the customers having to contact the after-sales service of the telephone service operator. The test is carried out remotely and at the initiative of the customers, which minimizes the need to involve the after-sales service of the telephone operator.

[0028] This mode can be implemented when terminal users call a dedicated number operated by the test server; in this case, the terminal is the originator of the opening of the communication link, which triggers the execution of the test by the server.

[0029] In one variant, the telephone communication link is opened by the terminal without user intervention. The terminal is programmed to open the link to the test server without human intervention. The advantage of this mode is that it can perform preventive tests, and therefore anticipate potential problems by detecting degradations in the quality of the link that would not necessarily have been detected by a user. In this variant, if the link is an IP telephone communication link, the IP terminal can be either an IP telephone or a home gateway.

[0030] According to a fourth particular embodiment of the invention, which may be implemented alternatively or cumulatively with one of the preceding embodiments, the connection is an IP telephone communication connection and the opening of the connection is preceded by an opening request from a telephone separate from the terminal.

[0031] Thanks to this embodiment, the invention adapts to the case, present in IP telephony, where the IP terminal is a home gateway to which terminals such as DECT telephones are attached. In this case, the user of the DECT telephone, distinct from the IP terminal, will call a number dedicated to the test server, and therefore create a request to open the telephone communication link. This request will then come from the IP terminal (the home gateway) to the test IP server. The DECT telephone, which does not have an IP interface, is still at the origin of the request to open the telephone communication link.

[0032] According to a fifth particular embodiment of the invention, which may be implemented cumulatively with one of the two preceding modes, the communication link being an open IP telephone communication link between the terminal and the test server, said link comprises a multimedia data transmission channel and the terminal transmits data packets in said data transmission channel independently of instructions received through an interface of the terminal.

[0033] In the case of IP telephony, for a test of the quality of the IP telephone communication link to take place, it is necessary for data packets to be exchanged on the open multimedia data transmission channel. The calculations necessary for carrying out the test are in fact applied to all the packets transmitted through the communication link during the duration of the test. However, if the IP terminal is at the origin of the opening of the link, including without user intervention, it is necessary for the IP terminal to transmit data packets in the data transmission channel even without user action at the terminal interfaces or, more clearly, without the user speaking into the telephone. This embodiment therefore makes it possible to ensure that the test will take place under good conditions even in the absence of user intervention.

[0034] According to a sixth particular embodiment of the invention, which may be implemented alternatively or cumulatively with the preceding embodiments, the management method comprises the reception by the terminal, during the given duration, of a message from the test server intended to be restored by the terminal.

[0035] With this embodiment, the server sends a message which may be, for example, a voice message. This message will be played back by the terminal, for example directly on the telephone speaker if the terminal is itself a telephone or, in the case of an IP telephony connection where the IP terminal is a home gateway, the message will be played back by the IP terminal to a DECT telephone which will then play back the voice message on its own speaker. The playback may also take the form of playback on a screen. The advantage of this embodiment is that it plays back a message for the entire duration of the test and therefore encourages the user to stay online, which avoids the user having to hang up.

[0036] According to a seventh particular embodiment of the invention, which may be implemented cumulatively with the previous embodiment, the message received by the terminal includes information relating to the test carried out by the test server.

[0037] With this embodiment, which complements the previous embodiment, the message received by the terminal includes information on the results of the various stages of the test carried out by the test server. The advantage of this mode is to immediately provide information to the user who has called a number dedicated to the test server and who has therefore triggered the quality test of his communication link. Here again, an advantage is to limit the need for users to contact after-sales service since they have a self-service test service, which will carry out the stages of the test and provide them with the results via the message sent by the test server and returned by the terminal.

[0038] According to a first material aspect, the invention relates to an entity for managing a test of the quality of a telephone communication link between a terminal and a test server, the telephone communication link being able to be open or closed, the test being carried out by the test server when the link is open, characterized in that the opening of the telephone communication link is preceded by a request to open the link from the terminal and in that said management entity comprises a processor configured to ensure that, during the performance of the test of the quality of the link, said link is kept open by said management entity, independently of the reception of an instruction to close the link by the terminal, for a given duration.

[0039] According to another material aspect, the invention relates to a terminal comprising a management entity according to the preceding aspect.

[0040] Thanks to this hardware aspect, it is possible to have terminals that will collaborate with a test server in order to ensure that, once a quality test of the telephone communication link is started, it will not be interrupted, including in the presence of actions by the user of the terminal, such as a hang-up action. The invention therefore makes it possible to have a system for testing the quality of a telephone communication link accessible in self-service for a user and which remains robust in the face of user actions. In general, such a terminal is a telephone. As already explained, in the case of IP telephony, such an IP terminal can be, among others, an IP telephone or a home gateway. It can also be a computer, fixed or portable, having the capacity to carry out IP telephony communications and attached to an IP telephone network.

[0041] According to another material aspect, the invention relates to a computer program capable of being implemented by a terminal according to the preceding aspect, the program comprising code instructions which, when executed by a processor, carry out the management method according to the invention.

[0042] The computer programs in question can be written in any programming language. For example, they can be compiled or interpreted languages, or they can use a mixed mode of operation using compilation to bytecode, which will then be interpreted by a virtual machine. The programs can run on hardware architectures, or in virtual machines, or in related technologies such as container systems.

[0043] According to another material aspect, the invention relates to a data carrier on which a computer program according to the preceding aspect is recorded.

[0044] The data carriers may be any entity or device capable of storing the programs. For example, the carriers may comprise a storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording means such as a hard disk. On the other hand, the carriers may be transmissible media such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means. The programs according to the invention may in particular be downloaded from a network such as the Internet. Alternatively, the information carrier may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

[0045] Brief description of the figures

[0046] The invention will be better understood on reading the following description, given by way of example, and made with reference to the appended drawings in which:

[0047] [Fig 1] represents an example of steps implemented within the framework of an embodiment of the invention.

[0048] [Fig 2] represents an example of implementation of the invention by an IP terminal and a test server, the IP terminal being a home gateway separate from a telephone.

[0049] [Fig 3] represents an example of implementation of the invention by an IP telephone and a test server.

[0050] Detailed description

[0051] Figure 1 represents an example of steps implemented within the framework of an embodiment of the invention.

[0052] The two vertical lines represent the evolution of a TER terminal on the one hand and of a SRV test server on the other hand during the implementation of a management method according to the invention. Conventionally, the evolution of time is represented by the passage from top to bottom along the two vertical lines.

[0053] In our detailed description example, we are considering IP telephony. The test is a quality test of an IP telephone communication link, and the TER terminal is an IP TER terminal.

[0054] In the embodiment presented here, the IP TER terminal comprises a management entity 100 according to the invention, which implements the test management method. In other modes, the management entity 100 may belong to the test server SRV or belong to service platforms, not shown in the figures, which implement the IP telephony network between the IP TER terminal and the test server SRV. However, the embodiment in which the management entity 100 is included in the IP TER terminal is the preferred mode because the management entity 100 is responsible for canceling the effect of actions intended for the IP TER terminal and a situation of the management entity 100 in the IP TER terminal is most suitable for this.

[0055] The management entity 100 comprises a processor and possibly one or more memories (not shown in the figures) which allow it to execute programs. The presence of processors and memories in telephone terminals, or in home gateways which serve as IP TER terminals is common nowadays. The processor of the management entity 100 will have to have access to the network interfaces of the IP TER terminal in order to be able to intercept the instructions for closing the link L during the execution of the test. The processor program will also have to be able to detect that the link L must remain open. One way of doing this may be to associate telephone numbers dedicated to the quality tests, numbers which will be stored in a memory of the management entity 100.The program implementing the method according to the invention having access to the network interfaces of the IP terminal TER will then detect a call to one of these numbers dedicated to quality tests and will then begin to execute the method. Another way of proceeding may be, for the test server SRV, to send, at the start of a quality test of the link L, a specific message to the management entity 100 asking it to implement the method according to the invention and to keep the link L open for a duration at least equal to the duration necessary for the execution of the test TST.

[0056] The TER IP terminal can take several forms.

[0057] The IP TER terminal can, for example, be a home gateway that provides access to the Internet network in a home or small business premises. Such a home gateway will create a local network and will have the ability to connect a TEL telephone to its local network, for example, using the DECT protocol. On the other hand, the home gateway will be connected to an IP telephony network as an IP TER terminal and will be able to establish IP telephone communication links for the benefit of the TEL telephone. This situation is represented in Figure 2, which will be detailed later. The IP TER terminal can also be a telephone capable of connecting directly to the IP telephony network. This situation is represented in Figure 3, which will be detailed later.

[0058] The TER IP terminal can also be a computer, fixed or portable, with the capacity to carry out IP telephony communications and attached to an IP telephone network.

[0059] The SRV test server, for its part, generally has the hardware architecture of a conventional computer and includes in particular a processor, a RAM (Read Access Memory) type memory and a read-only memory such as a Flash, ROM (Read Only Memory) type memory, or others, not shown in the figure, as well as input-output devices such as keyboards and / or screens (not shown in the figure). The management entity can be a hardware server or be deployed on a cloud computing architecture (from the English cloud computing). The management entity has communication links (not shown in Figure 1) which allow it to communicate with other entities to exchange data or instructions.

[0060] The SRV test server must be able to connect to IP telephone communication links in order to carry out quality tests of such a link. The SRV test server must therefore be connected by a communication link (not shown) to the IP telephony network and must be able to interact with it, for example by having one or more dedicated telephone numbers on the IP telephone network and by being able to pass instructions relating to the establishment of IP telephone communication links. The SRV test server therefore has communication possibilities according to the SIP or H.323 protocols or others according to the IP telephony protocols present in the IP telephony network for which the SRV test server will carry out tests.

[0061] The method is implemented while an IP telephone communication link L is open between the IP terminal TER and the test server SRV. Such a link L can be opened following several events. In a simplest embodiment, a telephone number is dedicated to the test server SRV and a user of the IP terminal TER will dial this number in order to open the IP telephone communication link L. In another embodiment, the IP terminal TER will be able to initiate the opening of the link L without any user initiative. In this mode, the IP terminal TER has programming capabilities that allow it to trigger an IP telephone call and therefore the opening of an IP telephone communication link L with the server SRV, either at planned times or in response to instructions not coming from a user but from other machines.The embodiment in which the IP terminal TER triggers calls to the test server SRV in a planned manner makes it possible to implement preventive maintenance of the quality of the IP telephone communication link L, by carrying out tests at regular intervals. In another embodiment, it is the test server SRV which will trigger a call to the IP terminal TER which will open the IP telephone communication link L.

[0062] The IP telephone communication link L comprises in several embodiments a CS signaling channel and a CD multimedia data transmission channel. The CS signaling channel is used to transfer information and instructions relating to telephone signaling and for example to the establishment of IP telephone communications, the transfer of these communications, the closure of communications or any other signaling operation. The CD multimedia data transmission channel is used to transmit multimedia data in the form of data packets. In particular, the voice signal between the two ends of the IP telephone communication link L is transmitted in both directions in the form of data packets encoding the voice signal transmitted at the two ends of the link L.The protocol for exchanging such multimedia data packets is the RTP protocol (acronym for Real-time Transport Protocol). Its concepts are well known to those skilled in the art in the field of IP telephony and are not detailed further. Once the IP telephone communication link L is open between the IP terminal TER and the test server SRV, the latter will carry out a TST test of the quality of the link L. Such a TST test is a succession of steps that will make it possible to obtain a whole set of results qualifying the quality of the link L with the IP terminal TER.

[0063] The execution of the entire TST test by the SRV test server takes a significant amount of time before the results of the TST test steps performed by the SRV test server are obtained. This time occupies a period represented in Figure 1 by a thicker line placed on the line representing the actions of the SRV test server and the TER IP terminal. Some of the TST test steps will be executed almost instantly by the SRV test server, which is represented in Figure 1 by a looping arrow, arriving a little below their starting point, representing that the end of this TST test step occurs very soon after its start. Other TST test steps will, on the contrary, take a significant amount of time to be executed, which is represented by an arrow whose arrival point is significantly later than the starting point.These different steps of the TST test are in all cases labeled TST in Figure 1, the differentiation of the different steps of the TST test having no influence on the implementation of the management method according to the invention. In all cases, it is the execution of all the steps of the TST test by the test server SRV which takes a significant amount of time.

[0064] The stages of the TST test can be of several types.

[0065] The TST test can first concern IP telephone signaling. In this case, the server retrieves data transmitted through the CS channel of the IP telephone communication link L established between the IP TER terminal and the SRV server. To perform a TST test relating to signaling, the SRV server must have the means to interpret the signaling messages which will generally use the SIP protocol and possibly protocols dedicated to IP telephony such as H.323. The TST test server will thus obtain a set of information relating to signaling, transmitted by the CS signaling channel. For example, in the case where the link L is opened at the initiative of the IP TER terminal using the SIP protocol, the SRV test server will be able to access the P-Asserted-Identity field \s SIP-Invite message.This field allows the SRV test server to obtain information about the IP TER terminal, in particular its telephone number and the telephony platform used by the IP TER terminal to place its call. The SRV test server can thus deduce from which telephony network the IP TER terminal placed its call, as well as the operator of the telephony service used by the IP TER terminal and possibly other commercial information.

[0066] Another example of a signaling-related TST test is to access the SDP (Session Description Protocol) field in the SIP-Invite message sent by an IP TER terminal. This field allows the SRV test server to know the capabilities of the network used to establish the IP telephone communication link L between the SRV test server and the IP TER terminal. The TST test server can thus deduce the codecs (programs or hardware used to encode audio or video signals, acronym for codecs-decoders) that are used by the IP TER terminal or imposed by the underlying network to transmit multimedia data in the CD channel of the link L.

[0067] Another example of a signaling-related TST test is to extract the user-agent field from SIP messages exchanged between the IP terminal TER and the test server SRV. The test server SRV can then deduce the model of the terminal TER located at the end of the IP telephone communication link L.

[0068] The TST test steps can then concern the quality of the IP telephone communication link L with regard to the transmission of multimedia data. To establish these TST test steps, data must be transmitted in the multimedia data transmission channel CD of the IP telephone communication link L. This data must in particular be transmitted from the IP TER terminal to the SRV test server. In the case where the IP TER terminal is the one who initiates the opening of the link L following a user action, i.e. when the user has used the IP TER terminal to call the dedicated number of the SRV test server, the analog audio signal recorded by the microphone of the TEL telephone or the IP TER terminal will be encoded into data packets using a given codec, then the packets will be sent to the SRV test server using the RTP protocol.The SRV test server will then perform a test of the quality of the L link based on the received data packets. The SRV test server must therefore have the means to interpret the received data packets according to the RTP protocol.

[0069] The steps of the TST test relating to data transmission in the CD channel will rely on the transmission of a certain number of data packets and consist of calculations carried out on the received packets. By nature, these steps of the TST test must therefore take a certain amount of time in order to be carried out on a sufficient quantity of received data packets so that the results obtained are significant. As an indication, the time required to carry out the steps of the TST test varies from a few seconds to a few tens of seconds. During this time, the IP telephone communication link L between the IP terminal TER and the test server SRV must not be interrupted.

[0070] The steps of the TST test relating to data transmission will, for example, consist of calculating the ratio between the number of packets received by the SRV test server and the number of packets sent by the TER IP terminal. Calculating the number of lost packets is also an interesting result of the TST test.

[0071] Another example of a TST test related to data transmission in the CD channel is to calculate jitter. Jitter is the variation of latency over time. A packet sent by the IP terminal TER will take a certain amount of time to be transmitted to the test server SRV. This transmission delay is the latency. As transmission progresses, the latency can decrease (packets take less time to be transmitted) or increase. Jitter measures this variation in latency and is defined, for example, in the IETF (Internet Engineering Task Force) RFC 3393. Several methods for calculating jitter can be applied and give different TST test results and are not detailed further.

[0072] Another example of TST testing related to data transmission is to perform the calculations defined in the G.107 standard, which is part of the ITU-T recommendations, i.e. the recommendations for the telecommunications sector of the International Telecommunications Union.

[0073] In some embodiments, the performance of the TST test relating to data transmission by the SRV test server depends on the information obtained during the TST test relating to signaling. For example, the telecommunications operator that deploys the SRV test server may want to reserve its use only for its customers and will therefore use the result of a step of the TST test identifying the IP TER terminal that calls the SRV test server and will continue the TST test only if the IP TER terminal belongs to the operator's customers. The steps of the TST test finally performed may also depend on the subscription to which the IP TER terminal subscribes and will be, for example, more detailed for a business customer than for a private individual. Or, the SRV test server will be able to modify the TST test performed according to the codecs used by the IP TER terminal, which is revealed by a step of the initial TST test relating to signaling.Or, the steps of the TST test carried out will be selected according to the model of the IP TER terminal.

[0074] In all the embodiments of the management method according to the invention, the communication link L is kept open for the duration necessary for the completion of the TST test and this independently of the reception by the IP terminal TER of a RAC instruction to close the link L. Such a RAC instruction will in the most frequent case be a hang-up operation initiated by the user of the IP terminal, as shown in FIG. 1. Throughout the execution of the steps of the TST test, the management entity 100 ensures that such RAC instructions are ignored by the IP terminal TER. In this way, the IP telephone communication link L is kept open and the execution of the TST test by the test server SRV can continue. When the management entity 100 belongs to the IP terminal TER, keeping the link L open even in the presence of RAC instructions received by the IP terminal TER is made easier.The management entity 100 will in fact be able to more easily intercept the RAC instructions received by the IP terminal TER by being included in the IP terminal TER. In certain embodiments, the time required for the completion of the TST test by the test server SRV is known in advance to the management entity 100 which implements the management method. In other embodiments, the test server SRV sends a message to the management entity 100 when all the steps of the TST test have been carried out. In this way, the management entity 100 is informed that it no longer has to implement the management method and ensure that the link L remains open even in the presence of RAC instructions.

[0075] In some embodiments of the invention, when a RAC instruction to close the link L is received by the IP terminal TER during the given duration, the execution of said RAC instruction is postponed for another given duration. In this way, the RAC instruction will be finally executed by the IP terminal TER but outside the period during which the IP telephone communication link L must be kept open for the execution of the TST test.

[0076] In other embodiments of the invention, when a RAC instruction to close the link L is received by the IP terminal TER during the given duration, the execution of said RAC instruction is canceled. The management entity 100 ensures that the RAC instruction is not received by the IP terminal TER.

[0077] In some embodiments, the request to open the IP telephone communication link L comes from an IP interface of the IP terminal TER. For example, in a simple mode, a user of the IP terminal TER triggers a telephone call to a dedicated number of the SRV test server, which sends a request to open the communication link L between the IP terminal TER and the SRV test server. In this mode, the SRV test server is self-service and will perform a TST test of the link L when it is called by the IP terminal TER. The management method according to the invention will then make it possible to ensure that the link L remains open and therefore that the SRV test server has the necessary time to perform the TST test even in the presence of RAC instructions to close the link L. These RAC instructions are typically hang-up operations on the part of the user.In other examples, the IP TER terminal issues the request to open the L link without user intervention. The opening of the L link and the performance of the TST test is then programmed and triggered by the IP TER terminal.

[0078] In some embodiments, the request to open the L link comes from a TEL telephone separate from the TER IP terminal. These are the modes in which the TER IP terminal is not a telephone but for example a home gateway to which one or more telephones are connected in its local network. The user will then use the TEL telephone to call the dedicated number of the SRV test server; the request to open the L link therefore comes from the TEL telephone, separate from the TER IP terminal.

[0079] In some embodiments, the IP terminal TER transmits data packets in the multimedia data transmission channel CD independently of instructions received through an interface of the IP terminal. These modes can be useful when the IP terminal TER is the one initiating the opening of the link L independently of a user action. Indeed, even in the absence of instructions received, such as sending signals from the microphones, the IP terminal TER will transmit data packets to ensure that the test server SRV can carry out the TST test of the quality of the IP telephone communication link L. The management entity 100 which is responsible for carrying out the management method and therefore intercepting the RAC instructions for closing the link will also ensure the transmission of these packets for the duration necessary for the TST test.

[0080] In embodiments of the invention, the management method comprises the reception by the IP TER terminal, during the given duration, of a message from the SRV test server intended to be played back by the IP TER terminal. This message will be for example a voice message, produced by a speech synthesis component, or pre-recorded, which will be played back by the loudspeaker of the IP TER terminal, when the IP TER terminal is a telephone, or sent by the IP TER terminal to a TEL telephone which will broadcast it on its loudspeaker. The message can also comprise elements which can be played back on a screen of the IP TER terminal or the TEL telephone. One of the advantages of this mode appears when the opening of the link L has been carried out at the request of a user of the IP TER terminal who has dialed the dedicated telephone number of the SRV test server.The message from the SRV test server and returned by the TER IP terminal will allow information to be communicated to the user relating to the progress of the TST test steps executed by the SRV test server. The message can also give instructions to the user to help carry out the TST test.

[0081] For example, the message may ask the user to press one or more keys on the IP terminal TER or the telephone TEL. In this way, the SRV test server will be able to perform TST test steps related to the correct operation of DTMF (Dual-Tone Mu / ti-Frequency) along the IP telephone communication link L.

[0082] In some embodiments, the message may ask the user to speak a particular sentence. A speech recognition system present in the SRV test server will then allow it to perform a TST test based on the quality of the received speech signal which can be compared to the requested message.

[0083] An advantage of the SRV test server sending a message is to encourage the user who initiated the TST test by calling the dedicated number of the SRV test server to keep the link L open for the time necessary to perform the TST test, in other words to encourage him not to hang up RAC. In this way, all the steps of the TST test can be carried out by the SRV test server even when it is a question of testing the quality of the link L with an IP TER terminal which does not have the management entity 100. Even in the absence of a management entity 100 intercepting the RAC instructions for closing the link L, this embodiment will make it possible to avoid the production of such RAC instructions. This embodiment therefore makes it possible to provide a self-service SRV test server which can be called by all types of IP TER terminals and will carry out all the TST tests.The message sent by the SRV test server keeps the user who called the SRV test server on the line for the necessary time. In embodiments, the message sent during the duration of the TST test steps includes information relating to the TST test performed by the SRV test server. This information may be, for example, indications of the start and end of the performance of the TST test steps as each of them is performed. This information may also include the results of the TST test, including an overall indication of the quality of the IP telephone communication link L between the IP terminal TER and the SRV test server.

[0084] Figure 2 shows the situation when the IP TER terminal is not an IP telephone. The IP TER terminal is, for example, a home gateway and creates a DECT local area network to which a TEL telephone is connected. The IP telephone communication link L is then opened within an IP network between the IP TER terminal and the SRV test server. The communication link L comprises a CS channel dedicated to the transmission of signaling information and a CD channel dedicated to the transmission of multimedia data, including the voice signal between the IP TER terminal and the SRV test server. In this situation, a RAC instruction to close the link L can be received by the IP TER terminal in several situations, and in particular when the user of the TEL telephone performs a RAC hang-up action on the TEL telephone. Such a RAC action is transmitted via the DECT link to the IP TER terminal.The presence of the management entity 100 implementing the management method ensures that the RAC closure instruction will not be implemented during the time necessary to carry out the TST test.

[0085] Figure 3 shows the situation when the IP TER terminal is an IP telephone. The IP TER terminal is a telephone capable of directly implementing the necessary IP telephony protocols. The IP telephone communication link L is open between the IP TER terminal and the SRV test server, possibly through several IPI, IP2 networks connected by one or more routers. The link L comprises a CS channel dedicated to the transmission of signaling information and a CD channel dedicated to the transmission of multimedia data. The management entity 100 present in the IP TER terminal ensures that the link L remains open even in the presence of a RAC instruction to close the link L, in this case a hang-up instruction by the user of the IP TER terminal.

Claims

Claims 1. Method for managing a test (TST) of the quality of a telephone communication link (L) between a terminal (TER) and a test server (SRV), the telephone communication link (L) being able to be opened or closed, the test (TST) being carried out by the test server (SRV) when the link (L) is open, characterized in that the opening of the link (L) is preceded by a request to open the link (L) from the terminal (TER) and in that, during the performance of the test (TST) of the quality of the link (L), said link (L) is kept open independently of the reception of an instruction (RAC) to close the link (L) by the terminal (TER) for a given duration 2. Method for managing a test (TST) according to claim 1 characterized in that, if an instruction (RAC) to close the link (L) is received during the given duration, the execution of said instruction (RAC) is postponed by another given duration.

3. Method for managing a test (TST) according to one of claims 1 or 2, characterized in that, the link (L) being an open IP telephone communication link between the terminal (TER) and the test server (SRV), said link (L) comprises a signaling channel (CS) allowing the test server (SRV) to obtain information relating to the signaling and in that the performance, by the test server (SRV), of the test (TST) of the quality of the link (L) depends on the information obtained relating to the signaling 4. Method for managing a test (TST) according to one of claims 1 to 3, characterized in that the link (L) is an IP telephone communication link and in that the request to open the link (L) from the terminal (TER) is preceded by an opening request from a telephone (TEL) separate from the terminal (TER) 5. Method for managing a test (TST) according to claim 4, characterized in that, the link (L) being an open IP telephone communication link between the terminal (TER) and the test server (SRV), said link comprises a multimedia data transmission channel (CD) and in that the terminal (TER) transmits data packets in the channel (CD) independently of instructions received through a terminal interface (TER) 6. Method for managing a test (TST) according to one of claims 1 to 5, characterized in that it comprises the reception by the terminal (TER), during the given duration, of a message from the test server (SRV) intended to be restored by the terminal (TER).

7. Method for managing a test (TST) according to claim 6 characterized in that the message received by the terminal (TER) includes information relating to the test (TST) carried out by the test server (SRV) 8. Management entity (100) for a test (TST) of the quality of a telephone communication link (L) between a terminal (TER) and a test server (SRV), the telephone communication link (L) being able to be opened or closed, the test (TST) being carried out by the test server (SRV) when the link (L) is open, characterized in that the opening of the telephone communication link (L) is preceded by a request to open the link (L) from the terminal (TER) and in that said management entity comprises a processor configured to ensure that, during the performance of the test (TST) of the quality of the link (L), said link (L) is kept open by said management entity (100), independently of the reception of an instruction (RAC) to close the link (L) by the terminal (TER), for a given duration 9. Terminal (TER) comprising a management entity (100) according to claim 8 10. Computer program capable of being implemented by a terminal (TER) according to claim 9, the program comprising code instructions which, when executed by a processor, carry out the management method according to claim 1 11. Data carrier on which a computer program according to claim 10 is recorded.

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