FR2876524A1 - METHOD AND DEVICE FOR TRANSFERRING INFORMATION FLOWS IN A LABEL SWITCHED TELECOMMUNICATION NETWORK - Google Patents

Abstract

The invention relates to a method for transferring information flows in a label permutation telecommunications network, the information flow being transmitted by a client device and being composed of packets comprising data and a header consisting of fields, characterized in that the method comprises the steps of: - reading the content of a predetermined field of a header of a packet, - determining a service associated with the client and traffic engineering parameters representative of a quality of service to be applied to the information flow and associated with the service determined from the content of the predetermined field read, - selection of at least one tunnel of the label permutation telecommunications network in accordance with the parameters of read traffic engineering, transfer of packets from the information flow in a selected tunnel. The invention also relates to the associated device.

Description

The present invention relates to a method and a transfer device

  an information flow in a telecommunication network with MPLS label switching, acronym for Multi Protocol Label Switching.

  More specifically, the present invention relates to a distributed method for transferring information flows in a telecommunication network with label switching according to a quality of service determined according to the service to which the client sending the stream is subscribed.

  The MPLS standard, published under the auspices of the Internet Engineering Task Force (IETF), is a label switching technique for creating a connection-oriented network from a datagram-based network such as IP network. Detailed MPLS documentation can be found at www.ietf.org.

  Shown schematically in FIG. 1 an MPLS network 150, comprising a plurality of routers called LSR (Label Switching Routers) such as 100a, 100b, 110a, 110b, 110c and 120 interconnected by IP links. When an IP packet arrives on an input peripheral router 100a or 100b, called LER or Label Edge Router, the latter assigns a label according to its IP header and concatenates it to said packet. The router that receives the tagged packet replaces the (incoming) tag with an outgoing tag based on its routing table and the process repeats from router to router to outbound router 120 (also referred to as Egress LSR) which delete the tag before sending the packet. Alternatively, tag deletion may already be performed by the penultimate router since the output router 120 does not use the incoming tag. An LSR router uses the incoming packet label (incoming label) to determine the outbound port and the outgoing packet label (outbound label). The path traversed by a packet through the network of the input router 100a to the output router 120 is called a Label Switched Path (LSP). According to the example of FIG. 1 in which a path is represented by arrows 105a, 105b and 105c, LSR routers 110a, 110c traversed by the path and separate input peripheral routers 100a and output 120 are called transit routers. On the other hand, the so-called Forward Equivalence Class (FEC) is the set of IP packets that are transmitted along the same path.

  MPLS enables IP packets to follow a pre-established LSP path that is generally not the optimal IP path in terms of number of hops or path metrics. The technique of determining the path or paths to take is called traffic engineering or MPLS-TE (for MPLS Traffic Engineering). The determination of the path takes into account constraints on the available resources (constraint based routing), in particular in bandwidth on the different links of the network. Unlike conventional hop-by-hop routing, the determination of an LSP is performed in an explicit routed mode (explicitly routed LSP or ER-LSP) in which certain or all the nodes of the path from the input router to the output router. When all the nodes of the path are fixed, we speak of explicit routing in the strict sense. A path determined in an explicit mode is still called an MPLS tunnel.

  The choice of one or more MPLS tunnels can be done centrally or distributed. According to the distributed Constraint based Routing method, each router is informed about the topology of the network and the constraints affecting the different links of the network. To do this, each router determines and transmits to its neighbors a message indicating its immediate links and the constraints (or attributes) associated with them. These messages are then propagated from node to node by extended IGP messages, according to a flooding mechanism until all the routers are informed. Thus, each router has its own database (known as TED for Traffic Engineering Database) giving it the topology of the network and its constraints.

  The determination of the label switching path is then performed by the input peripheral router also taking into account other constraints set by the network operator (for example to avoid such or such node or to avoid the links of such or such type). The input peripheral router then determines, for example by means of the Dijkstra algorithm, the shortest path satisfying all the constraints (Constraint Shortest Path First or CSPF), those affecting the links such as those fixed by the 'operator. This shortest path is then signaled to the routers of the LSP path by means of the signaling protocols known as RSVP-TE abbreviations (Resource reSerVation Protocol for Traffic Engineering) or CR-LDP (Constrained Route Label Distribution Protocol). A description of the RSVP-TE protocol can be found in the document by D. Adwuche et al. titled RSVP-TE: Extensions to RSVP for LSP tunnels available under the aforementioned IETF website.

  These MPLS signaling protocols allow the distribution of tags along the path and the reservation of resources.

  For example, if the RSVP signaling protocol is used, the input router 100a transmits a Path message in an IP packet to the output router 120. This message specifies the list of nodes 110a, 110c through which the LSP must pass. At each node the Path message sets the path and makes a state reservation. When the Path message reaches the output router 120, an acknowledgment message Resv is returned by the same path to the input router 100a.

  At each node, the MPLS routing table is updated and the resource reservation is performed. For example, if the resource is a bandwidth and you want to reserve is 10 Mbits for the path, the bandwidth respectively assigned to each link are decremented by the reserved value of 1 OMbits during the retro propagation of the message. acknowledgment / reservation. It should be noted that the resource in question (eg bandwidth) is a logical resource on the IP link and not a physical resource. When the acknowledgment message is received by the input router, the tunnel is established.

  As indicated above, the determination of the LSP paths can be done centrally. In this case, a server is aware of the topology of the network and takes into account the constraints on the links and constraints set by the network operator to determine tunnels between the input routers and the output routers. The input peripheral routers are then notified by the server of the tunnel or tunnels for which they are the input node. The tunnels are then established as indicated above.

  The IETF Recommendation RFC 2475 An Architecture for Differentiated Services provides a method in which priorities are allocated based on IP information flow classes in the MPLS 150 network. These classes are defined from the IP packet DSCP fields. transferred in the IP network. DSCP stands for DiffServ Code Point. This method ensures that the priority information flows will be treated preferentially to the lower priority information flows but it does not guarantee any quality of service, for example in terms of bandwidth reservation, for information flows that pass through a network. IP or MPLS telecommunication.

  The IETF Recommendation RFC 3270, MPLS support for differentiated services, provides a method in which priorities are assigned to both MPLS data frames and IP packets without taking into account the constraints of each class for their routing. This method is thus based on an aggregated routing of the different classes of services in each LSP router of the MPLS network and does not guarantee a quality of service for each class of service and each flow of information.

  The IETF Recommendation RFC 3564, Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering, proposes a method in which the routing of information flows is done by considering the constraints associated with each class of service and thus allows to guarantee a certain quality of service in the MPLS network.

  These techniques do not propose a distributed method for transferring information flows in a telecommunication network with label switching according to a quality of service determined according to the service to which the client sending the stream is subscribed.

  The object of the invention is to solve the disadvantages of the prior art by proposing a method and a device which allow the transfer of information flows in a telecommunication network with label switching with a quality of service determined according to the service to which the client sending the stream is subscribed. The invention also aims to make the determination of the service to which the customer is subscribed fast and to accelerate the transfer of information flows in the telecommunications network to permutation of labels.

  For this purpose, according to a first aspect, the invention proposes a method for transferring information flows in a telecommunication network with tag swapping, the information flow being transmitted by a client device and being composed of packets comprising data and a header consisting of fields, characterized in that the method comprises the steps of: - reading the contents of a predetermined field of a header of a packet, - determining a service associated with the client and traffic engineering parameters representative of a quality of service to be applied to the flow of information and associated with the service determined from the content of the predetermined read field, - selection of at least one tunnel of the telecommunication network to tag swapping according to read traffic engineering parameters, - forwarding information stream packets to a selected tunnel.

  Correlatively, the invention relates to a device for transferring information flows in a telecommunication network with tag swapping, the information flow being transmitted by a client device and being composed of packets comprising data and a header. consisting of fields, characterized in that the device comprises: - means for reading the contents of a predetermined field of a header of a packet, - means for determining a service associated with the customer and parameters traffic engineering representative of a quality of service to be applied to the information flow and associated with the service determined from the content of the predetermined read field, - means for selecting at least one tunnel of the permutation telecommunications network label according to the read traffic engineering parameters, - means for transferring the information flow packets in a selected tunnel.

  Thus, the transfer of information flows in the telecommunication network with label switching is performed according to a quality of service. In addition, by determining the service and the associated traffic engineering parameters, it is possible to apply different qualities of services to the information flows. In addition, by having a predetermined field of a header of a packet that determines the service to which a customer is subscribed, the determination of the service to which a customer is subscribed is simple and fast and does not require the use of centralized systems.

  According to another aspect of the invention, the content of the predetermined read field is modified.

  According to another aspect of the invention, the information flow is transmitted to an input peripheral router of the telecommunication network with label swapping and the method is executed by the peripheral input router of the permutation network. tags.

  According to another aspect of the invention, there is determined an output peripheral router of the telecommunication network with label swapping which is associated with the identifier of the recipient of the information flow and the tunnels existing between the peripheral router of input and output peripheral router determined.

  According to another aspect of the invention, the selection of at least one tunnel is carried out among the tunnels of the telecommunications network which have the same input peripheral router, the same output peripheral router as that associated with the address of destination included in the header of the received packet and which have at least traffic engineering parameters.

  Thus, the information flows are processed according to a precise quality of service.

  According to another aspect of the invention, if no tunnel of the telecommunications network complies with the traffic engineering parameters read, a tunnel is created in the telecommunication network.

  The invention also relates to a method for transferring an information flow by a client device to a telecommunication network with tag swapping, the information flow being composed of packets comprising data and a header consisting of fields, characterized in that the method comprises the steps performed by the client device of: reading at least one code stored by the client device and representative of a service associated with the client, inserting the code read in a predetermined field of the header of at least one packet of the information flow, - transfer of the information flow to the telecommunication network with label switching.

  Correlatively, the invention relates to a device for transferring an information flow to a telecommunication network with tag swapping, the information flow being composed of packets comprising data and a header consisting of fields, characterized in that the transfer device comprises: means for reading at least one code stored by the transfer device and representative of a service associated with the transfer device; means for inserting the code read in a field; predetermined one of the header of at least one packet of the information flow; - means for transferring the information flow to the telecommunication network with tag swapping.

  Thus, by inserting a code representative of a service to which the customer has subscribed to the service provider in a predetermined field of the header of at least one packet of the information flow, it facilitates the identification of the service the customer is subscribed.

  In another aspect of the invention, the packets conform to an IP protocol and the predetermined field is a service type representative field to be applied to the packets of the information stream.

  Thus, by diverting the use of a field from an IP packet header, it is possible to inform the telecommunication network of the quality of service, such as for example a bandwidth guarantee, which must be provided during the transfer of the information flow in the telecommunication network.

  The invention also relates to computer programs stored on an information medium, said programs comprising instructions for implementing the previously described methods, when they are loaded and executed by a computer system.

  The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in connection with the attached drawings, among which: FIG. . 1 represents a telecommunication system using the MPLS protocol in which the present invention is implemented; FIG. 2 shows a functional representation of the input peripheral router according to the present invention; FIG. 3 represents the algorithm executed by the input peripheral router according to the present invention; FIG. 4 shows a table of correspondence between the different values of a predetermined field of a packet received from a client by an input peripheral router and a subscription to an information flow transfer service according to a quality of service according to the present invention; FIG. 5 shows a table of correspondence between the different subscriptions to information flow transfer services according to a guaranteed quality of service according to the present invention and traffic engineering parameters; FIG. 6 is a block diagram of a communication device of a client 180; FIG. 7 shows the algorithm executed at a client level when subscribing to a service offered by an access provider according to the present invention; FIG. 8 shows the algorithm executed at a client during the transfer of packets to an input peripheral router according to the present invention.

  Fig. 1 represents a telecommunication system using the MPLS protocol in which the present invention is implemented.

  The MPLS network 150 is accessible to client devices 180, hereinafter referred to as clients, for transmitting and / or receiving information. According to the example of FIG. 1, only two clients 180a and 180b are connected to the MPLS network 150. Of course, a larger number of clients 180 accesses the MPLS network 150.

  The clients 180 are connected to the MPLS network 150 via a conventional Internet type network (not shown in FIG. 1.

  To access the information flow transfer service in a guaranteed quality of service, a customer, for example the customer 180a, must subscribe to a service provider 170 such a service. The service provider 170 is, for example and without limitation, a service provider 170 offering the client 180a the possibility of accessing the Internet network with a guarantee of bandwidth and / or establishing between at least two clients of the sessions. conferences in which a certain quality of service is guaranteed. The service provider 170 offers the customer 180a different services that have a respective quality of service. These services are, for example, voice over IP or IP telephony services. When a client 180a selects a service from the services offered, the service provider 170 transfers to the client 180a a predetermined code associated with the selected service. This predetermined code is preferably a byte.

  When the client 180a subscribes to such services wishes to transfer an information flow, it generates a datagram or packet compliant with the IP protocol. According to the invention, the client 180a inserts into a predetermined field of the packet header the predetermined code that it has received from the service provider 170. Preferentially, the client 180a inserts the predetermined code into the service type field or Type of service as described in IETF RFC 791.

  The packet or packets transmitted also include an identifier of the client 180a and the identifier of the requested service or an identifier of the correspondent with whom the client 180a wishes the service to be established, or even a password.

  The input peripheral router 100a reads a predetermined field of at least one received packet, determines from the content of the read field the service to which the client 180a is subscribed, determines the traffic engineering parameters corresponding to the service determined for the provision of the resources of the MPLS network 150. The engineering parameters are for example and in a nonlimiting manner, the bit rate allocated for a service, the processing time and the class of traffic engineering service, the type of protection guarantee for the service or the fact that the service is uni or bidirectional.

  In an alternative embodiment, the input peripheral router 100a communicates to the service provider 170 whose identifier is included in the request of the client 180a, the client identifier 180a and the identifier of the requested service. The service provider 170, according to the customer's subscription 180a, confirms or not access to such a service.

  The input peripheral router 100a is able to allocate, according to the determined traffic engineering parameters and according to the recipient of the information flow, a tunnel in the MPLS network 150 for transferring the information flow in the network. MPLS network 150. The allocated tunnel is an existing tunnel or a tunnel created for the information flow.

  Fig. 2 shows a functional representation of the input peripheral router according to the present invention.

  An input peripheral router 100 comprises according to the invention a client interface module 101. The client interface module 101 ensures the sending of packets to the client 180a and / or the reception of the packets sent by the client 180a when the latter wishes to access the information flow transfer service according to a guaranteed quality of service.

  The client interface module is able to read a predetermined field of at least one received packet. This field is preferably the service type field conforming to the IP protocol. The packet further comprises an identifier of the requested service, the client IP address 180a, the source port number, the destination IP address with which the client 180a wishes the information flow transfer service to be of a quality. guaranteed service is established, the destination port number and a protocol identifier used.

  The client interface module 101 is able to transfer the content of the service type field to the admission control module 102 of the input peripheral router 100.

  The admission control module 102 is able, from the content of the service type field, to determine the service to which the client 180a is subscribed and to determine the traffic engineering parameters corresponding to the service determined for the provision of the service. The admission control module 102 interrogates the database 105 and obtains, using the contents of the service type field as a key, the service to which the client 180a is subscribed and the parameters of the service. corresponding traffic engineering. Preferably, the admission control module 102 determines the service to which the client 180a is subscribed and the traffic engineering parameters corresponding to the service by performing a single query of the database 105.

  The admission control module 102 is able to verify whether the client 180a is accredited to access the service corresponding to the content of the service type field. For this, the admission control module 102 checks whether the IP address of the client 180a is stored in the database 105 and is associated with the requested service.

  The database 105 includes a table of correspondence between the different values of the service type field and the different service subscriptions offered by the access provider 170. The database 105 also includes a correspondence table between the various subscriptions to the service providers. services provided by the access provider 170 and the traffic engineering parameters associated with these services in the MPLS network 150. The database 105 furthermore comprises the IP addresses of the clients 180 subscribing respectively to the different services according to the present invention. . The database 105 is updated by the access provider 170 each time it creates a new service or a service is used by a new client 180 attached to the input device 100a.

  When the traffic engineering parameters have been obtained, the admission control module 102 is able to control the tunnel agent 107 of the input peripheral router 100, the establishment of a connection that is able to support the client requested service 180. The tunnel agent 107 selects an existing tunnel between the input and output peripheral routers or creates, based on the processing rules including the traffic engineering parameters related to the requested service, a new connection between the input and output edge routers.

  The tunnel agent 107 dialogs with the output peripheral router 120 to which is attached the destination IP address with which the client 180 wishes that the information flow transfer service with a guaranteed quality of service is established.

  The output peripheral router 120 is determined, for example, from the destination IP address with which the client 180 wishes the information flow transfer service with a guaranteed quality of service to be established. The tunnel agent 107 transfers to the peripheral output router 120 the identifier of the tunnel used for the service in the peripheral router input to output peripheral router direction. Through the admission control module 102 and the signaling module 104, the tunneling agent 107 receives the identifier of the tunnel used for the service in the peripheral router output direction to the input peripheral router when the service is bidirectional.

  The tunnel agent 107 determines the shortest path satisfying all the constraints. This shortest path is then signaled to the routers of the LSP path using signaling protocols known as RSVP-TE or CR-LDP abbreviations.

  The input peripheral router also includes a database of client sessions 106. The client session database 106, accessible by the admission control module 102, stores information related to each of the information flows. which pass through the input peripheral router 100. For each of the information flows, the traffic engineering parameters associated with the session are stored in the database of client sessions 106. The database of sessions of clients 106 is updated by the admission control module 102 when an information flow transfer is established or stopped.

  Fig. 3 represents the algorithm executed by the input peripheral router according to the present invention.

  In step E300, a packet issued by a client 180a is received by the client interface 101 of the input peripheral router 100a. This packet conforms to the IP protocol as described in RFC 791 with the only difference that the service type field includes a predetermined code allocated by the access provider 170 of the client 180a and representative of the service that the client 180a has subscribed to. It should be noted that the packet or packets received also include the identifier of the client 180a and the identifier of the recipient 180b of the information stream.

  In the next step E301, the client interface 101 reads the different fields of the header of at least one received packet. The client interface 101 reads the content of the type of service field of the packets received.

  In the next step E302, the client interface 101 transfers the content of the service type field to the admission control module 102 of the input peripheral router 100 which determines the service corresponding to the content of the service type field. For this, the admission control module 102 interrogates the database 105 and obtains, using the content of the service type field as a key, the service to which the client 180a is subscribed and the corresponding traffic engineering parameters. .

  The database 105 includes a table of correspondence between the different values of the service type field and the different service subscriptions offered by the access provider 170. An example of such a table is shown in FIG. 4.

  Fig. 4 shows a table of correspondence between the different values of a predetermined field of a packet received from a client by an input peripheral router and a subscription to an information flow transfer service according to a guaranteed quality of service. according to the present invention.

  The table of FIG. 4 consists of two columns denoted 400 and 401 and seven lines marked 410 to 416.

  Column 400 includes the different values in Hexadecimal that may be included in the service type field.

  Column 401 includes the different services that the access provider 170 provides to its customers.

  Line 410 includes the service associated with the value 07 in Hexadecimal included in the service type field. This service is a service called Platinum by the service provider 160 and authorizes with a predetermined quality of service, the establishment of video and voice session by the client 180a when the latter subscribes to this service.

  Line 411 includes the service associated with the value 06 in Hexadecimal included in the service type field. This service is a service called Platinum by the service provider 160 and authorizes with a predetermined quality of service, the establishment of voice sessions by the client 180a when the latter is subscribed to this service.

  Line 412 includes the service associated with the value 05 in Hexadecimal included in the service type field. This service is a service called Gold by the service provider 160 and authorizes with a predetermined quality of service, the establishment of video and voice sessions by the client 180a when the latter is subscribed to this service.

  Line 413 includes the service associated with the value 04 in Hexadecimal included in the service type field. This service is a service called Gold by the service provider 160 and authorizes, with a predetermined quality of service, the establishment of voice sessions by the client 180a when the latter subscribes to this service.

  Line 414 includes the service associated with the value 03 in Hexadecimal included in the service type field. This service is a service called Money by the service provider 160 and authorizes with a predetermined quality of service, the establishment of video and voice sessions by the client 180a when the latter is subscribed to this service.

  Line 415 includes the service associated with the value 04 in Hexadecimal included in the service type field. This service is a service called Money by the service provider 160 and authorizes with a predetermined quality of service, the establishment of voice session by the client 180a when the latter subscribes to this service.

  Line 416 includes the service associated with the value 00 in Hexadecimal included in the service type field. This service is a service called best effort or best effort by the service provider 160 and authorizes with unsecured quality of service, the establishment of sessions by the client 180a when it is subscribed to this service.

  The database 105 also includes a correspondence table between the different service subscriptions offered by the access provider 170 and the resource reservation parameters in the MPLS network 150 associated with these services.

  Fig. 5 represents a table of correspondence between the different subscriptions to QoS services according to the present invention and traffic engineering parameters.

  The table of FIG. 5 consists of six columns denoted 500 and 505 and seven lines denoted 510 to 516.

  Column 500 includes the different services that the access provider 170 offers to its customers.

  Columns 501 to 505 include the traffic engineering parameters associated with the services in column 500. Specifically, column 501 includes the allowed rates for the different services in column 500, column 502 includes the allowed Diffserv classes for different services. in column 500, column 503 includes the allocated protection (in the maximum cut-off time of a call) for the different services in column 500, column 504 includes the maximum allowed packet processing times for the different services of the column 500 and column 505 includes the feature that the information flow transfer is uni or bidirectional for the different services in column 500.

  Thus, when the admission control module 102 interrogates the database 105 by using the value 07 in Hexadecimal as a key, the admission control module receives in response the following information: the service subscribed by the client 180a is a Platinum service for voice and video.

  In the next step E303, the admission control module 102 polls the database 105 using the Platinum service for voice and video and obtains in response the associated traffic engineering parameters. The associated traffic engineering parameters are 1 Mbps bandwidth, EF Diffserv class, 50ms protection, 100ms maximum delay, and bidirectional link.

  It should be noted here that steps E302 and E303 can be executed simultaneously. In this case, the tables of Figs. 4 and 5 are grouped into a single table.

  The traffic engineering parameters obtained, the algorithm proceeds to the next step E304 which consists of transferring them to the tunnel agent module 107.

  The next step E305 consists of searching whether a tunnel of the MPLS network 150 is able to support the requested service. For this purpose, the tunnel agent module 107 consults a tunnel table comprising, among other things, the source and the destination of each tunnel as well as the available bandwidth of each tunnel, the processing delay, the traffic engineering service class, protection, the fact that the service is uni or bidirectional. It should be noted here that the MPLS network tunnels 150 can be centrally created or by each input peripheral router 100 of the MPLS network 150. These tunnels can be created from the average traffic forecasts and traffic statistics. These tunnels or at least some of these tunnels can also be dynamically created according to the specific needs of the clients 180 of the MPLS network 150.

  In the next step E306, the tunnel agent module 107 checks whether there exists a tunnel adapted to the needs of the requested service. For this, the tunnel agent module 107 checks whether there exists in the tunnel table at least one tunnel having the same input peripheral router, the same peripheral router that is associated with the destination address included in the tunnel. header of the received packet, having at least bandwidth associated with the service, a processing delay at least less than or equal to the delay associated with the service, a traffic engineering service class at least equal to the service class associated with the service , a protection at least greater than the protection associated with the service and which is capable of ensuring the transfer of information flows in a uni or bidirectional manner in accordance with the service.

  If so, tunnel agent module 107 proceeds to step E310 which will be described later. If not, the algorithm proceeds to step E307.

  The next step E307 is to search for a new tunnel in the MPLS network 150. For this, it is determined the greatest bandwidth available in the MPLS network 150 between the input peripheral router 100 and the peripheral output router 120 at which is connected the correspondent of the client 180 who issued the request. For example, it may be determined that the path between the input peripheral router 100 and the peripheral output router 120 marked by the arrows 105a, 106 and 107 of FIG. 1 is the path that has the largest bandwidth. It is then checked whether this bandwidth is greater than the bandwidth required for the requested service.

  Once this is done, the algorithm proceeds to the next step E308. Step E309 is to determine if a new tunnel can be created in the MPLS network 150. It is verified that the largest bandwidth available in the MPLS network 150 between the input peripheral router 100 and the peripheral output router 120 is greater than the bandwidth required for the requested service. If so, a new tunnel is created by the input peripheral router 100 and the algorithm proceeds to step E310. If not, the algorithm goes to step E309 which consists in authorizing the transfer of the information flow in the MPLS network without any guarantee of quality of service. This operation performed, the present algorithm ends and waits for a new request from a client 180 in step E300.

  If the test of step E306 or step E308 is positive, the algorithm proceeds to step E310. At this step, the client session database 106 is updated by inserting therein the new information flow.

  In the next step E311, the information flow is transferred to the selected tunnel or created. It should be noted here that, in a preferred embodiment, the content of the service type field of each packet of the transferred information stream is modified by the input or output peripheral router, for example by putting it at a minimum. value equal to 00 in Hexadecimal.

  The next step E312 is a waiting loop of the end of the newly established session. When the session is interrupted, the algorithm proceeds to the next step E313 and updates the client session database 106 by deleting therein the information flow. The client session database 106 is updated, the present algorithm is terminated and waits for a new request from a client 100 in step E300.

  Fig. 6 shows a block diagram of a communication device of a client 180.

  The communication device of the client 180 is adapted to establish communication sessions with an access provider 170 and to allow the client 180 to subscribe to one or more services offered by the access provider 170.

  The communication device of the client 180 is able to store a predetermined code transmitted by the access provider 170 and insert it in a predetermined field of IP packets that it transfers to the input peripheral router 180 to which it is connected.

  The communication device of the client 180 is for example a microcomputer. It can also be a telephone handset.

  The client communication device 180 comprises a communication bus 601 to which are connected a central unit 600, a read-only memory 602, a random access memory 603, a screen 604, a keyboard 614, a hard disk 608, a disk reader / recorder compact or CD 609, a network interface 612.

  The hard disk 608 stores the programs implementing the invention, as well as the data processed according to the invention. These programs can also be read via the compact disc or received via the network interface 612, or stored in read-only memory 602. The hard disk 608 stores a predetermined value transmitted by the access provider 170 according to the present invention. .

  More generally, the programs according to the present invention are stored in storage means. This storage means is readable by a computer or a microprocessor 600. This storage means is integrated or not to the device, and can be removable.

  When the communication device is powered up, the programs according to the present invention are transferred into the random access memory 603 which then contains the executable code of the invention as well as the variables necessary for the implementation of the invention.

  The network interface 612 makes it possible, for example, to access the Internet and to exchange data between the access provider 170 and / or correspondents via an input peripheral router 100. The network interface 612 is adapted to insert a predetermined code transmitted by the access provider 170 in a predetermined field of the IP packets that are transmitted to the input peripheral router 180 to which it is connected.

  The communication device comprises a screen 104 and a keyboard 114 serving as a human-machine interface that allow the selection of one or more services offered by the access provider 170.

  Fig. 7 shows the algorithm executed at a client when subscribing to a service offered by an access provider according to the present invention.

  In step E700, the communication device of the client 180 connects to the access provider 170 and selects in step E701 a service from the proposed services. These services are for example and without limitation, such as those described with reference to FIGS. 4 and 5. The service provider 170 transfers to the client 180 a code for the selected service. This code consists of a byte whose different values are represented in FIG. 4.

  In step E702, the client communication device 180 receives the code and stores it in step E703.

  Fig. 8 shows the algorithm executed at a client during the transfer of packets to an input peripheral router according to the present invention.

  In step E800, when the client 180 wishes an information flow transfer to be performed in accordance with a service to which it previously subscribed according to the algorithm of FIG. 7, the communication device of the client 180 reads in memory the code that the access provider 170 transmitted to him when subscribing to the service.

  In the next step E801 the service code is inserted in the service type field of the IP packet as compliant with RFC 791.

  Once the packet is formed, it is transferred to step E802 to the input peripheral router to which client 180 is attached.

  Of course, the present invention is not limited to the embodiments described herein, but encompasses, on the contrary, any variant within the scope of those skilled in the art.

Claims (1)

19 CLAIMS   A method of transferring information flows in a tag swap telecommunication network, the information flow being transmitted by a client device and being composed of packets comprising data and a header consisting of fields, characterized in that the method comprises the steps of: - reading the contents of a predetermined field of a header of a packet, - determining a service associated with the client and representative traffic engineering parameters of a quality of service to be applied to the flow of information and associated with the service determined from the content of the predetermined read field, selection of at least one tunnel of the telecommunication network with label switching according to the traffic engineering parameters read - forwarding packets from the information flow in a selected tunnel.   2) Method according to claim 1, characterized in that the method further comprises a step of modifying the content of the predetermined field read.   3) Method according to claim 1 or 2, characterized in that the packets are in accordance with an IP protocol and the predetermined field is a field representative of the type of service to be applied on the packets of the information stream.   4) Method according to any one of claims 1 to 3, characterized in that the information flow is transmitted to an input peripheral router of the telecommunication network with label switching and that the method is executed by the input peripheral router of the network with label switching.   5) Method according to any one of claims 1 to 4, characterized in that the method further comprises the steps of determining an output peripheral router of the telecommunication network label permutation which is associated with the identifier of the receiver of the information flow and tunnels defining existing between the input peripheral router and the determined output peripheral router.   6) Method according to claim 5, characterized in that the selection of at least one tunnel is carried out among the tunnels of the telecommunications network which have the same input peripheral router, the same output peripheral router as that associated with the destination address included in the header of the received packet and which have at least traffic engineering parameters.   7) Method according to any one of claims 1 to 6, characterized in that if no tunnel of the telecommunications network does not comply with the traffic engineering parameters read, the method further comprises a step of creating a tunnel in the telecommunication network.   8) A method of transferring an information flow by a client device to a telecommunication network with tag swapping, the information flow being composed of packets comprising data and a header consisting of fields, characterized in that the method comprises the steps performed by the client device of: reading at least one code stored by the client device and representative of a service associated with the client, inserting the code read in a predetermined field of the header at least one packet of the information flow, - transfer of the information flow to the telecommunication network with label switching.   9) A method according to claim 8, characterized in that the packets conform to an IP protocol and the predetermined field is a service type representative field to be applied to the packets of the information stream.   An information flow transfer device in a tag swap telecommunication network, the information flow being transmitted by a client device and consisting of packets comprising data and a field header, characterized in that the device comprises: means for reading the contents of a predetermined field of a header of a packet; means for determining a service associated with the customer and parameters for traffic engineering; representative of a quality of service to be applied to the flow of information and associated with the service determined from the content of the predetermined field read, - means for selecting at least one tunnel of the telecommunications network with label switching according to traffic engineering parameters read, - means for transferring the information flow packets in a selected tunnel.   11) Device for transferring an information flow to a telecommunication network with label switching, the information flow consisting of packets comprising data and a header consisting of fields, characterized in that the device transfer comprises: - means for reading at least one code stored by the transfer device and representative of a service associated with the transfer device, - means for inserting the code read in a predetermined field of the at least one packet of the information flow; means for transferring the information flow to the telecommunication network with tag swapping.   12) computer program stored on an information carrier, said program comprising instructions for implementing the method according to any one of claims 1 to 7 when it is loaded and executed by a computer system.   13) computer program stored on an information carrier, said program comprising instructions for carrying out the method according to claim 8 or 9, when loaded and executed by a computer system.