WO2014001706A1 - Method for securing flows of different service classes, device and program - Google Patents

Description

 Method for securing different class of service streams, device and program

The invention relates to a method and a device for securing flow of different classes of services.

 The field of application of the invention relates to flows carried from a first telecommunications network, which may be in particular a network of a telecommunications operator, to a second network, for example a private network of a customer of the operator.

 Different types of data flows (voice, data, etc.) generally correspond to different classes of service. According to the current techniques for securing flows, it is considered that all the data flows corresponding to different types of service classes, linked to a logical connection access (VCS), connecting the first network to an access equipment to the service (EAS) linking to the client network, takes the same physical path in the first network. In this context, a service access equipment (EAS) typically adds path continuity check (DCAM) frames or messages to a data stream corresponding to a given service class from the set of flows using the same path. logical access (EVC), in order to enable it to detect a flow cut and thus a possible failure on the corresponding physical path, and to trigger backup mechanisms accordingly.

 Therefore, according to the technique described above, the fault detection is performed on the non-reception of continuity check messages (DC OAM) sent with a data flow corresponding to a single class of service, among the set of different service class streams transmitted via the logical access considered (EVC).

 However, in reality, flows related to different service classes can take different physical paths in the first network, in particular to improve the transit time of the data.

Thus, if a path relating to a class of service not carrying continuity control messages fails, the supervision mechanisms and therefore the backup will not be triggered. Therefore, in this case, the class of service data whose physical path is in fault will continue to be sent and will therefore be lost.

 The invention thus aims to secure the transmission of data streams of different classes of service, which can be carried by different physical paths.

 For this purpose, according to a first aspect, the subject of the invention is a method for securing the transmission of a plurality of respectively associated data streams of the different classes of service, said streams being transmitted via at least one virtual connection through a first telecommunication network having at least two distinct physical paths to at least one access equipment to at least one second client network, characterized in that it comprises the following steps:

 sending path continuity check messages in each of said data streams;

 monitoring continuity control messages received by said access equipment via said virtual connection;

 - in case of detection of the absence of continuity check message received for a given data stream, creation of at least one of the flow cutoff representative of the detected absence of continuity check message for the data flow considered.

 Thanks to the sending of the continuity check messages for each flow, we manage to test a break of each flow, even when the flows take different physical paths, contrary to the state of the art where only one flow could have path continuity control messages.

 According to one embodiment of the invention, in which the service access equipment comprises, in addition to the (or) virtual connection (s) to the first network:

at least one connection interface element with at least one second network for transmitting the flows between the virtual connection and the first network and the second network, each of the plurality of different service class streams taking a single physical path from the plurality of different physical paths in the first network;

 at least one switching member for the flows between the virtual connection (s) to the first network and the connection interface element;

 the aforementioned step of creating flow cut information is followed by a step of sending the flow cutoff information to at least one member of the service access equipment, among the aforementioned organs.

 According to one embodiment of the invention, the at least one flow cutoff information comprises a closing command of the connection interface member to the connection interface member, so that following this command this connecting interface member transmits no more flows between the service access equipment and the second network.

 According to one embodiment of the invention, the at least one flow cutoff information comprises a determined cut-off warning message of the flow associated with the undetected continuity check message to the connection interface member, for that the connection interface member transmits this determined cutoff warning message to the second network.

 According to one embodiment of the invention, the at least one flow cutoff information comprises a switching command determined at the switching element, so that at least the flow associated with the undetected continuity check message is transmitted. between at least one other virtual connection to the first network and the connection interface member.

 According to one embodiment of the invention, each service access equipment comprises a sending device for sending, for example periodically or successively, in each transmitted stream going to the first network in each virtual connection to the first network, the (or the) continuity check message (s) associated with this flow.

According to one embodiment of the invention, the flow cutoff information triggers the transmission, by another virtual connection to the first network, at least the stream associated with the undetected path continuity check message (s).

 According to one embodiment of the invention, the determined data flow cut-off information for which the absence of continuity check messages has been detected, triggers the transmission, by another virtual connection to the first network and by a other service access equipment, at least the stream corresponding to the undetected path continuity check messages.

 According to one embodiment of the invention, the respectively associated data flows of the different service classes take different physical paths in the first network.

 In practice, the method for securing the transmission of data streams, according to the invention, as succinctly described above, is implemented in the form of one or more computer programs forming a software package whose execution by a processor of a network equipment, such as equipment access to the service defined above, causes the implementation of the steps of the method according to the invention. Therefore, the present invention also relates to such a computer program, which program can use any programming language and be in the form of source code, object code, or intermediate code between source code and object code. The invention is therefore also directed to a computer-readable information recording medium on which a computer program according to the invention is recorded. Such a recording medium may be constituted by any entity or device capable of storing such a program. For example, such a medium may comprise storage means, such as a ROM (read only memory), or a removable recording means such as a USB key or a magnetic recording means, such as than a hard drive.

According to a second aspect, the subject of the invention is a device for transmitting streams of different classes of service, for the implementation of a method of securing the transmission of the plurality of data streams such that described above, this device comprising at least one service access equipment, which comprises at least one virtual connection to a first network for the transmission of flows between the virtual connection to the first network and the second client network. According to the invention, the device is remarkable in that the equipment for accessing the service comprises:

 detection means able to monitor the continuity check messages received with each data stream, via said virtual connection,

 means for creating, in the event of detection of the absence of a continuity check message received for a given data stream, at least one flow cut information representative of the detected absence of a continuity check message; for the given data stream.

 According to a particular embodiment, the access equipment of the transmission device according to the invention further comprises:

 at least one connection interface element to said at least one second network for transmission of flows between said virtual connection and the second network;

 at least one flow switch member between said virtual connection and the connection interface element;

 control control means able to trigger, in the absence of continuity check messages detected by the detection means, sending at least one flow cutoff information to at least one member among a connection interface member and a flow switching member.

According to a third aspect of the invention, there is provided a method for securing different service class streams, in which a plurality of different class of service streams is transmitted, via a first telecommunication network comprising a multiplicity of physical paths. different, to at least one service access equipment, which comprises at least one virtual connection to the first network and at least one connection interface member to at least one second user network for the transmission of flows between the connection virtual to the first network and the second network of the user, each of the plurality of different service class streams borrowing in the first network a single physical path from the plurality of different physical paths, the service access equipment including at least one flow switching member between at least one virtual connection to the first network and the connection interface member, and a device for detecting the reception of a path continuity check message by each virtual connection to the first network.

 According to the invention defined according to this third aspect, the continuity control message is sent in each transmitted stream of different service classes, the detection device being provided in the service access equipment for detecting the presence of the message. continuity check in each stream received on each virtual connection to the first network,

 the service access equipment comprising a control device which triggers, in the event of a continuity check message not detected by the detection device, sending at least one of the components of at least one information item to determined cut-off of the flow associated with the undetected continuity check message.

 According to one embodiment of the invention, the control device triggers, in the event of a continuity check message not detected by the detection device, sending, as determined cut-off information, the flow associated with the continuity check message. not detected, a closing command of the connection interface member to the connection interface member, so that following this command this connection interface member does not transmit more flow between the equipment access to the service and the second user network.

According to one embodiment of the invention, the control device triggers, in the event of a continuity check message not detected by the detection device, sending, as determined cut-off information, the flow associated with the continuity check message. undetected, a determined flow failure warning message associated with the undetected continuity check message to the connection interface member for the connection interface member to transmit this warning message of determined cutoff at the second network. According to one embodiment of the invention, the control device triggers, in the event of a continuity check message not detected by the detection device, sending, as determined cut-off information, the flow associated with the continuity check message. not detected, from a switch command determined at the switch member, so that at least the flow associated with the undetected continuity check message is transmitted between at least one other virtual connection to the first network and the connection interface.

 According to one embodiment of the invention, the sending of the determined breaking information of the flow associated with the undetected continuity check message triggers by the control device, the transmission, by another virtual connection to the first network, at least the stream associated with the undetected path continuity check message.

 According to one embodiment of the invention, the sending of the determined cut-off information of the flow associated with the undetected continuity check message triggers by the control device, the transmission, by another virtual connection to the first network and by another service access equipment, at least the stream associated with the undetected path continuity check message.

According to the aspect of the invention set out above, the invention also relates to a device for transmitting streams of different classes of service, this device comprising at least one service access equipment, which comprises at least one virtual connection. a first network and at least one connection interface member to at least a second user network for the transmission of the streams between the virtual connection to the first network and the second user network, the access equipment to the service comprising at least one flow switch between the at least one virtual connection to the first network and the connection interface member, and a device for detecting the reception of a path continuity check message by each virtual connection to the first network. According to the invention, the service access equipment comprises a sending device for sending, in each sent stream going to the first network in each virtual connection to the first network, the messages of path continuity control associated with this stream, the detection device being provided in the service access equipment for detecting by the detection device the presence of continuity check messages in each stream received on each virtual connection to the first. network. Moreover, the service access equipment comprising a sending control device, in case of a continuity check message not detected by the detection device, to at least one of the aforementioned members, at least one information determined cutoff of the flow associated with the undetected continuity check message (s). The invention will be better understood on reading the description which will follow, given solely by way of nonlimiting example, with reference to the appended drawings, in which:

 - Figure 1 shows schematically the operation of a flow transmission device according to the state of the art;

 - Figure 2 shows schematically the operation of the device according to Figure 1 of the state of the art in case of failure;

 - Figure 3 schematically shows a flow transmission device operating according to the method according to the invention, in a first embodiment;

 - Figure 4 shows schematically the device according to the first embodiment of Figure 3 in case of failure;

 - Figure 5 schematically shows the device according to the first embodiment of Figure 3 after the failure;

 - Figure 6 schematically shows a flow transmission device operating according to the method according to the invention, in a second embodiment;

 - Figure 7 schematically shows a flow transmission device according to the invention operating according to the method according to the invention, in a third embodiment;

- Figure 8 shows schematically the device according to the third embodiment of Figure 7 in case of failure; - Figure 9 schematically shows the device according to the third embodiment of Figure 7 following a failure; and

 FIG. 10 represents, by way of example, a block diagram of a service access equipment according to the invention.

 The terms used are defined as follows.

 EAS: service access equipment. It is an equipment, for example an operator, to be located at a customer or user. This is the first piece of equipment encountered by the streams when they leave the second UT network of the user or the client to go to the first telecommunication network RI, which may be the network of an operator.

 EVC: Logical connection access or virtual connection between the EAS equipment and the first IN network. EVC is an abbreviation of "Ethernet Virtual Connection" ', that is virtual channel. This EVC access is positioned at the user. This EVC access is mounted between the EAS equipment and the first equipment El of the first network RI. The EVC access may contain multiple COS streams of different service classes, which then have different priorities in the IN network.

COS: class of service corresponding to a type of flow. Flows are referred to as Service Class COS Flows. There are several COS 1, COS2 streams of different service classes. For example, there may be a control stream, a voice stream, a data stream, a video stream, which are as many different classes of service. There are, for example, as COS classes of different services, so-called "best efforts" data, which have a most basic priority level and which are, for example, e-mail or Internet browsing data. . Another class of services is for example critical data. Another class of services is, for example, real-time data, such as, for example, videoconferencing data or video. Another class of services is, for example, telephony data over IP. These COS flows are flows sent by the user's UT network to the first network RI or sent from the first network RI to the second network UT of the user. Each COS class of service stream is marked at the entrance of the first network RI and is then treated both with regard to its priority but also its routing according to this marking. The COS streams of different classes of service can follow different physical paths C1, C2 in the first network RI.

 IAS: Connection interface member or service access interface. This connection interface member IAS serves for the transmission of flows between the EAS equipment and the UT network of the user. This IAS interface member therefore materializes the limit of responsibility between the second network UT client and the first network RI. The network RI comprises several second nodes El, N defining several different physical paths C1, C2, C10, C20. The second user UT network comprises a plurality of second nodes or N2 elements, at least one of which is connected to the interface IAS element or to the IAS interface members.

 OAM-CC: continuity check message. OAM is an abbreviation for "Operation, Administration and Maintenance". These OAM-CC messages are frames that are not part of the streams sent by the customer's UT network equipment positioned behind the EAS. These messages are added by the EAS on a stream of a given COS and follow the physical path taken by this stream in the first network RI. The OAM-CC path continuity check messages are periodically sent, for example, to each of the different service class data streams.

 The operation of the mechanisms existing in the state of the art is explained below with reference to FIGS. 1 and 2.

In Figure 1, there is for example a first COS 1 stream having a different class of service than a second COS2 stream. It is assumed that the two streams COS 1 and COS 2 take different physical paths C1, C2 in the first network R1. The OAM-CC message is sent only for the COS 1 stream. The two COS 1 and COS 2 streams are for example sent by a second device EAS2 via the access EVC2 of the latter to the first network RI, then this first network. IR at a first access or EVCl virtual connection of a first EAS equipment 1 connected to the second UT network of the user by the IAS interface member. FIG. 2 represents the operation of the mechanism existing in the state of the art in the event of a failure P on the physical path C2 of the second stream COS2 in the first network RI. For example, this failure P is a cut of the second path C2. This break can not be detected by the equipment EAS1, since it only checks the good transmission of the first stream COS l. The second stream COS2 is therefore always transmitted on the same physical path C2 and is therefore lost, whereas the first stream COS 1 and the messages OAM-CC continue to be correctly received by the equipment EAS 1.

 The current G.8031 / Y.1342 (06/2011) standard of the International Telecommunication Union has as its perimeter a backup mechanism (in English: back-up) carried by the same access EAS equipment with sending secure OAM-CC frames based on the Ethernet connection identifier or the VLAN (Virtual Local Area Network) and thus secures the EVC access. It therefore does not differentiate security by class of services. Likewise, the standard deals only with the case where the emergency link is carried by the same EAS equipment which then carries all the security mechanisms; it therefore does not respond to the rescue problem on redundant EVC access carried by other EAS equipment than the nominal EAS equipment.

 Figures 3 to 9 show various embodiments of the method according to the invention, Figure 10 showing an embodiment of the device for the implementation of this method.

In FIGS. 3 to 10, a plurality of COS I, COS2 streams of different classes of services are transmitted via the first telecommunications network RI comprising a multiplicity of different physical paths C1, C2 to at least one EAS service access equipment. 1. The EAS 1 access access equipment comprises at least one EVC1 logical connection or virtual connection access to the first IN network and at least one IAS interface member for connection to the at least one second user UT network for the transmission of the COS I, COS2 flows between the access connection EVC1 to the network RI and the second network UT of users. Each COS 1, COS 2 stream among the plurality of different class of service streams borrows in the first network RI a single physical path C1, C2 from the multiplicity of different physical paths. This means that the first class of service stream COS 1 borrows in the first network RI a single physical path C1, while the second class service stream COS2 different from the service class of the first stream Fl borrows in the first network RI only one second physical path C2. It is assumed that the first physical path C1 borrowed by the stream COS 1 is different from the second physical path C2 borrowed by the second stream COS2.

 EAS 1 access equipment comprises at least one device

Switching control COS 1, COS2 flow between the at least one logical connection EVC1 access to the first network RI and the connection interface member IAS. EAS access equipment 1 also comprises a device or DET means for detecting the receipt of a physical path continuity OAM-CC message by each access EVC1 connection to the first network RI.

 According to one embodiment of the invention, each transmitted COS 1, COS 2 and different service classes are sent the respective OAM-CC 1, OAM-CC 2 message for checking the continuity of the respective physical path C1, C2, the device Detection DET being provided in the EAS 1 access equipment for detecting by the detection DET device the presence of the physical path continuity check OAM-CC 1, OAM-CC2 message respectively in each COS 1 stream, COS2 received on each access EVC1 of connection to the first network RI. In case of detection of the absence of a continuity check message received for a given data stream, creation of at least one information (FER and / or MES and / or CCO) of flow cutoff representative of the detected absence. continuity check message for the given data stream.

In the embodiment of FIG. 10, the service access equipment EAS1 comprises a control device CTRL which triggers, in the event of a message

OAM-CC continuity check not detected by DET detection device, sending at least one of the IAS devices, COMM, at least one determined cut-off information of the flow associated with the OAM-CC undetected continuity check message.

 For example, in the embodiment of FIG. 5, the control device CTRL triggers, in the case of a continuity check message OAM-CC 1 which is not detected by the detection device DET in the stream COS 1, the sending as determined cut-off information of the flow associated with the undetected continuity check OAM-CC 1 message, of a closing command FER of the IAS interface member for connection to the connection interface member IAS, so that following this FER closing command, this connection interface member IAS no longer transmits flows between the EAS service access equipment 1 and the second user UT network.

 According to one embodiment, each EAS service access equipment comprises a device or sending means for sending, in each COS 1 stream, transmitted COS2 going to the first network RI in each connection EVC access to the first network RI. , the respective OAM-CC1, OAM-CC2 message of continuity of path control associated with this stream.

 For example, in FIGS. 3 to 9, it is assumed that a second service access equipment EAS2 sends, by its second access EVC2 of logical connection or virtual connection to the first network RI, the first stream COS 1 and the second stream COS 2 class of service different from the service class of the first stream Fl, and that in this case this second service access EAS2 equipment sends in the first stream COS 1 a first path continuity check message OAM-CC 1 and sends in the second stream COS2 the second OAM-CC2 continuity check message.

In the absence of P failures and P cuts on the first and second different paths C1 and C2 respectively borrowed by the first and second streams COS 1 and COS 2, the first and second streams COS 1 and COS 2 arrive via the EVCl access of logical connection to the first access service EAS equipment l associated with this first access EVCl. In this case, the detection DET detects that the first OAM-CC 1 continuity check message is present in the first received COS stream l and the second OAM-CC2 continuity check message is present in the second COS2 stream. These first and second streams COS 1 and COS 2 are then routed by the equipment EAS1 to the connection interface member IAS associated with this first equipment EAS1 to be transmitted to the user's UT network.

 In the embodiment shown in FIGS. 3 to 6, there is provided a second EAS20 equipment for access to the emergency service associated with the second EAS2 service access equipment, referred to as nominal, as well as a second logical connection access port EVC20. backup or EVC20 emergency logical connection to the first network RI, associated with the second access EVC2 logical connection, said nominal, to the first network RI. Similarly, in the embodiment represented in FIGS. 3 to 6, there is provided a first EAS 10 emergency service access equipment associated with the first EAS 1 service access equipment, said to be nominal, as well as a first EVC10 access of backup logical connection to the second network R2, associated with the first access EVC1 logical connection, said nominal, to the second network R2. The logical connection or backup virtual connection ECV10 is provided to connect the COS 1 and COS 2 streams between the first network RI and EAS 10 emergency access equipment in the event of a breakdown or a break P from the first nominal logical connection access EVC1 to the first network RI. Similarly, the emergency ECV20 logic connection access is provided to connect the COS2 and COS l streams between the second network R2 and EAS20 emergency service access equipment in the event of a breakdown or a break P second nominal logical connection access EVC2 to the first network RI.

 In the embodiment shown in FIGS. 3 to 6, the first EAS 10 emergency service access equipment is different from the first nominal service access EAS equipment. Likewise, in the embodiments shown in FIGS. 3 to 6, the second EAS20 equipment for access to the emergency service is different from the second nominal EAS2 service access equipment.

In the embodiment of FIGS. 7 to 9, the first nominal logical connection access EVC1 and the first emergency EVC10 logical connection access. associated with this first access EVC1 are provided between the first network RI and the same access equipment EAS 1. Similarly, in the embodiment of Figures 7 to 9, the second nominal logical connection access EVC2 and the second EVC20 logical connection access of the associated second EVC2 access are provided between the second network R2 and the same EAS2 service access equipment.

 In a general manner, in the event of a breakdown or a cut-off (cases not shown in the figures) on the first nominal EVC1 logical connection access or on the second nominal EVC2 logical connection access, the COS 1 and COS 2 flows pass through the EVC10 and EVC20 backup logical connection access. In this case, the first and second streams COS 1 and COS 2 can respectively borrow the physical paths C1 and C2 in the first network R1 or other backup physical paths C10 and C20, different from the paths C1 and C2. In the figures, the paths actually taken by the streams COS 1 and COS 2 are represented in a continuous line, whereas the paths not actually taken by the streams COS 1 and COS 2 are represented in broken line.

 Of course, the mechanism is implemented on both ends of the user's connectivity, that is to say not only on the EAS equipment 1 leading through the IAS interface to the user's second UT network, but also at the second EAS2 and EAS20 equipment, leading through another connection interface member not also shown to a network of the user.

In the first embodiment of FIGS. 3 to 5, it is assumed in FIG. 4 that a failure or a cutoff P occurs on the first path C1 borrowed by the first stream COS 1. In this case, the first EAS 1 service access equipment and its detection DET device no longer receive the OAM-CC1 path continuity check message in the first COS I stream, since it no longer receives this first stream COS l because of this break or failure P. Following the non-receipt of this message OAM-CC1 related to the first stream COS l, the information is propagated to the second UT network of the user by closing the IAS body service access interface of the first service access EAS equipment 1. In general, the IAS access interface member may be a physical input port or a user network interface (which is the translation of the English term UNI, which is the abbreviation for User Network Interface). The second UT network of the user detects, by appropriate means, that the IAS interface member connecting to the first service access EAS equipment 1 is closed, which triggers in the second UT network of the user the activation, by appropriate means, of its own protection mechanisms to pass the COS 1 and COS 2 streams on other service access equipment, such as for example the first EAS 10 access equipment to the emergency service as shown in FIG. 5. In the embodiment represented in FIG. 5, the activation of the protection mechanisms of the user's UT network triggers the passage of all the COS 1 and COS 2 flows through the network. EVC10 access of backup logical connection to the first network RI by the access equipment EAS 10 emergency service having another interface member IAS 10 connection to the second network UT of the user, and the other side by the second EAS20 emergency equipment and the second emergency access EVC20.

 In another embodiment, at least the COS flow 1 associated with the OAM-CC1 continuity check message not detected by the first EAS equipment 1 passes through the emergency access ports EVC10 and EVC20 and by the access equipment. EAS 10 and EAS20 rescue service.

In the second embodiment shown in FIG. 6, the control device CTRL triggers, in the event of an OAM-CC1 continuity check message not detected by the detection DET device in the first received COS stream, sending, as a determined cut-off information of the flow associated with the undetected continuity check message OAM-CC1, of a MES message for a determined cut-off warning of the COS flow 1 associated with the OAM-CC1 continuity check message not detected at the connecting interface member IAS, so that this connection IAS interface member transmits this determined cutoff warning MES message to the user's second UT network. Thus, in FIG. 6, assuming, as in FIGS. 4 and 5, a cutoff or failure P on the first path C1 borrowed by the first flow COS 1, the information is propagated to the user's UT network by sending the MES message to the second UT network of the user. The mechanism in charge of the protection of the links in the second UT network of the user will therefore automatically propagate by appropriate means the fault MES information of the first stream F1. The UT network of the user can for example then activate, by appropriate means, its own protection mechanisms to pass the traffic of the at least COS 1 flow associated with the OAM-CC1 continuity check message not detected on other equipment EAS such as, for example, the first EAS 10 emergency equipment.

 For example, in FIG. 6, only this stream COS 1 associated with the OAM-CC1 continuity check message not detected by the detection DET device is transmitted from the first network RI to the first emergency access EVC10 and the first EAS equipment 10. and on the other side on the second emergency access EVC20 and on the second emergency equipment EAS20, the other COS2 stream (s) continuing to be routed through the first access EVC20 and the first EAS equipment 1 and on the other side the second EVC2 access and the second EAS2 equipment.

 In the embodiment represented in FIGS. 7 to 9, the control device CTRL triggers, in the event of an OAM-CC1 continuity check message not detected by the detection DET device in the COS stream 1 received, the sending, as determined cut-off information of the flow associated with the undetected continuity check message OAM-CC1, of a determined switching CCO command to the switching COMM element, so that at least the COS flow 1 associated with the OAM-CC1 message undetected continuity control is transmitted between at least the other EVC10 logical connection access to the first network RI and the connection interface member IAS.

For example, in FIG. 7, a failure or cutoff P occurs on the first path C1 borrowed by the first stream COS 1, as indicated previously for FIG. 4. In this case, the control device CTRL sends the command CCO of commutation. to the switching COMM member, which then passes the first stream Fl, whose OAM-CC1 continuity check message was not detected by the detecting device DET of the first equipment EAS 1, the EVC10 logical connection access of the first equipment EAS 1 to the first network RI.

 In the embodiment shown in FIG. 9, all the streams COS 1 and COS 2 which passed through the first access EVC1 before the failure or cutoff P are routed, following this switching command CCO, by the other access EVC10. of the first EAS equipment 1 to the first network RI and the paths C10 and C20 and the control device CTRL cut the entire access EVCl by a cutoff command COUP.

 In a general manner with FIGS. 5, 6 and 9, the control device CTRL triggers, in case of OAM-CC1 continuity check message not detected by the detection DET device in the received stream COS 1, the passage, by the emergency access access EVC10 and / or EVC20 and / or by the EAS 10 and / or EAS20 emergency access access equipment and by the corresponding emergency physical path C10, of at least the COS I stream associated with the OAM-CCl path continuity check message not detected, initially going through EVCl access.

 In one embodiment, the control device CTRL triggers, in the event of an OAM-CCl continuity check message not detected by the detection DET device in the received COS stream, the passage through the emergency access EVC10 and / or EVC20 and / or EAS 10 and / or EAS20 emergency service access equipment and the corresponding physical spare paths C10 and C20 of several COS streams COS1 initially passing through the EVCl port ( for example, by also cutting this EVCl access by the cutoff command COUP), at least the COS stream associated with the OAM-CCl path continuity control message not detected.

In another embodiment, the control device CTRL triggers, in the event of an OAM-CC1 continuity check message not detected by the detection DET device in the received COS stream, the passage through the emergency access EVC10. and / or EVC20 and / or by EAS 10 and / or EAS20 backup service access equipment and by the corresponding backup physical paths C10 and C20, of all COS I, COS2 flows initially passing through the access EVCl (for example by also cutting this EVCl access by the cut OFF command ), of which at least the COS flow 1 associated with the OAM-CC1 continuity check message is not detected.

 Thus, the invention provides, in response to the non-detection of an OAM-CC continuity check message by the DET device for detecting EASl service access equipment, either sending to the UT network of the user of the information FER or MES of cut of the flow COS 1 associated with the message OAM-CC1 not detected, is the reassembly of this information CCO of cut of the flow COS 1 associated with the message OAM-CC1 not detected towards the equipment EAS l access to the service.

 These two mechanisms do not prevail actions that will be performed by the second UT network of the user following receipt of this information FER or MES.

 The invention thus enables the user to refine the processing of its different types of flows and thus to better parameterize its engineering of its network UT according to its needs as well as to better ensure the maintenance of its requirements, especially in time. transit, by being warned of an IRON or MES interrupt information or by having an automatic action of its EAS equipment l in case of CCO cutoff information. The quality of the service is improved.

 In one embodiment, the EAS access equipment 1 comprises a single virtual connection EVC1 to the first network RI and / or the access equipment EAS 1 comprises a single virtual connection EVC10 to the first network RI and / or the EAS2 access equipment comprises a single EVC2 virtual connection to the first network RI and / or EAS20 access equipment comprises a single EVC20 virtual connection to the first network RI.

Claims

A method of securing the transmission of a plurality of data streams (COS1, COS2) respectively associated different classes of service, said flows being transmitted via a virtual connection (EVC1) through a first network (RI) telecommunication system having at least two distinct physical paths (C1, C2) to at least one access equipment (EAS1) to at least one second client network (UT), characterized in that it comprises the following steps:  sending path continuity check messages (OAM-CC) in each of said data streams;  monitoring of the continuity check messages (OAM-CC 1, OAM-CC2) received by said access equipment (EAS1) via said virtual connection (EVC1);  - in case of detection of the absence of a continuity check message received for a given data stream, creating at least one information (FER, MES, CCO) flow cutoff representative of the detected absence of message of continuity check for the given data stream. 2. Method according to claim 1, characterized in that said step of creating a flow interruption information (FER, MES, CCO) is followed by a step of sending said flow cutoff information to a destination. at least one member of said service access equipment (EAS1), among the following organs:  at least one interface element (IAS) for connection to said at least one second network (UT) for the transmission of said streams (COS1, COS2) between said virtual connection (EVC1) and the second network (UT); - At least one member (COMM) switching flows (COS1, COS2) between said virtual connection (EVC1) and the interface member (IAS) connection. 3. Method according to claim 2, characterized in that the at least one flux cutoff information comprises a control (FER) closing the interface member (IAS) for connection to the interface member (IAS ) of connection, so that following this command this connecting interface member (IAS) no longer transmits flow between the equipment access to the service (EAS 1) and the second network (UT). 4. Method according to claim 2 or 3, characterized in that the at least one flow cutoff information comprises a message (MES) for a determined cut-off warning of the flow associated with the message (OAM-CC1, OAM-CC2) of continuity check not detected at the interface interface member (IAS), so that the connection interface element (IAS) transmits this determined cut-off warning message (MES) to the second network (UT). 5. Method according to any one of claims 2 to 4, characterized in that the at least one flow cutoff information comprises a switching command (CCO) determined at the switching member (COMM), so that minus the flow associated with the undetected continuity check message (OAM-CC1, OAM-CC2) is transmitted between at least one other virtual connection (EVC10) to the first network (RI) and the interface element (IAS) of connection. Method according to any one of the preceding claims, characterized in that each service access equipment (EAS) comprises a sending device for sending, in each transmitted stream going to the first network in each virtual connection (EVC ) to the first network (RI), path continuity control messages (OAM-CC1, OAM-CC2) associated with this stream. 7. Method according to any one of the preceding claims, characterized in that the flow-cutting information triggers the transmission, by another virtual connection (EVC10, EVC20) to the first network (RI), from minus the data flow (COS1) for which the absence of path continuity check messages (OAM-CC1, OAM-CC2) has been detected. 8. A method according to any one of the preceding claims, characterized in that the determined breaking information of the flow corresponding to the non-detection of continuity check messages (OAM-CC1, OAM-CC2) triggers the transmission, by a another virtual connection (EVC10, EVC20) to the first network (RI) and by another service access equipment (EAS 10), at least the stream (COS1) corresponding to the path continuity control messages (OAM- CC 1, OAM-CC2) undetected. 9. Method according to any one of the preceding claims, characterized in that said data streams (COS1, COS2), respectively associated with different classes of service, take different physical paths (C1, C2) in the first network ( RI). 10. Device for transmitting data streams of different classes of service, for implementing a method of securing the transmission of the plurality of data streams according to any one of the preceding claims, the device comprising at least a service access equipment (EAS1), which comprises at least one virtual connection (EVC1) to a first network (RI) for the transmission of the streams (COS1, COS2) between the virtual connection (EVC1) and the first network (RI) ) and the second client network (UT),  characterized in that said service access equipment (EAS) comprises: - detection means (DET) capable of monitoring the messages (OAM- DC 1, OAM-CC2) received with each data stream, via said virtual connection (EVC1), means for creating, in the event of detection of the absence of a continuity check message received for a given data stream, at least one information (FER, MES, CCO) of flow cutoff representative of the absence detected continuity check message for the given data stream. Apparatus according to claim 10, wherein said service access equipment (EAS 1) further comprises:  at least one interface member (IAS) for connection to said at least one second network (UT) for the transmission of said streams (COS 1, COS 2) between said virtual connection (EVC 1) and the second network (UT);  at least one flow switching element (COS) (COS 1, COS 2) between said virtual connection (EVC 1) and the connection interface element (IAS);  control control means (CTRL) able to trigger, in the absence of continuity check messages detected by said detecting means (DET), sending at least one information of flow cutoff at destination at least one of an interface member (IAS) for connection and a flow switching member (COMM). A computer program comprising program instructions for implementing a method of securing the transmission of a plurality of data streams, according to any one of claims 1 to 9, when the program is executed by a processor.