WO2009125150A1

WO2009125150A1 - Method and device for communication taking account of a check of the validity of a bandwidth allocation request in a network architecture

Info

Publication number: WO2009125150A1
Application number: PCT/FR2009/050533
Authority: WO
Inventors: Joël PENHOAT; Tarek Tafasca; Olivier Galet
Original assignee: France Telecom2/4
Priority date: 2008-03-28
Filing date: 2009-03-30
Publication date: 2009-10-15

Abstract

The invention relates to a method of communicating between at least a first communication terminal (13) belonging to a first communication network (10) and at least a second communication terminal (14) belonging to a second communication network (11), said first (10) and second (11) networks being interlinked via an interface device (12). According to the invention, such a method comprises : a step (E1) of transmission by said first terminal (13) to said interface device (12), of a request asking for admission of a new datastream on said first and second communication networks (10, 11); a step (E2) of verification of the legitimacy of said request taking account of a bandwidth level required for the transmission of said new datastream and of a maximum bandwidth level underwritten for said first terminal (13) with an operator of said second network (11); if the legitimacy of said request asking for admission is verified, said interface device (12) executes an additional step (E3) of processing said admission request.

Description

Method and communication device for controlling the validity of a bandwidth allocation request in a network architecture

The present invention relates to communication between terminals belonging to different communication networks, for example between a terminal belonging to a private local mobile communication network and a terminal belonging to a broadband communication network administered by an operator.

More specifically, the invention relates to the control of the establishment of a new communication between such terminals, depending on the characteristics of a subscription subscribed for at least one of said terminals from an operator of a WAN communication network , for example of the GSM, GPRS or UMTS type.

The invention applies in particular, but not exclusively, to a network architecture of the UMA type (for "Unlicensed Mobile Access" in English, for "mobile open access" in French). Such an architecture makes it possible for a user to use his mobile phone on an IP local network (for "Internet Protocol" in English, or "Internet Protocol" in French), when he is at home, at the office or, more typically, when it is in an area covered by an access point of a private local mobile IP network, rather than using an operator's fixed or mobile pay network. Such an approach according to the UMA standard has the advantage of significantly reducing the communication costs, especially for a company in which the number of communications made by its employees is often important.

As a simple illustrative and non-limiting example, the implementation of a network architecture designed according to the UMA standard therefore makes it possible to extend the GSM / GPRS mobile services in wireless networks with no access rights (Wi-Fi ™ or

Bluetooth ™ in particular) by creating a communication tunnel, directly between a client communication terminal and the heart of the operator's network, in order to:

"to allow the user to use mobile voice and data services over private networks while keeping the same telephone number; "to support the transition from a private network to a GSM network and vice versa, without interruption;

"to be independent of the technology used for private networks, for example of the Wi-Fi ™ or Bluetooth ™ type, while also being transparent for existing equipment in private networks;

• provide security equivalent to GSM networks. In the context of a residential UMA network architecture (for example that deployed as part of the Unik offer - trademark of the operator Orange - trademark), when an outgoing call is generated by a first terminal of GSM / GPRS type communication on the Wi-fi (registered trademark) network, a decision is made in a relatively simple manner, according to criteria previously defined by the mobile operator.

If at the time of the call, the terminal is in the coverage area of its Wi-Fi gateway forming the single access point to the operator's network, then the Wi-fi communication is extended via the backbone of the network. the operator to the remote terminal to which the call is destined.

Otherwise, the outgoing call is automatically and seamlessly switched (commonly referred to as "handover" procedure) on the operator's GSM paying network. However, such decision-making proves incompatible with the implementation of an enterprise type UMA network architecture. Indeed, in such an architecture, the communication gateway serves as an interface between the private local mobile network (IP type, for example) of the company and the operator's communication network. The gateway must therefore simultaneously monitor and manage a plurality of access points to the mobile local area network, respectively distributed on the company's site, and must also manage a large number of communications of a large number of sites. mobile communication terminals associated with employees of the company.

However, it turns out that the maximum number of VoIP flows ("Voice over IP" in English, or "Voice over IP" in French) that can transmit a communication network at a given time, and more particularly in a UMA architecture , is an important parameter representative of the quality of service (QoS) level perceived by users. Indeed, when the number of VoIP flows transiting the network at a given time exceeds this maximum number of VoIP flows, the QoS offered to users is significantly degraded.

Also, a disadvantage of a UMA architecture comprising several mobile terminals (for example of the GSM, GPRS type) that can connect to several access points (AP) managed by a single communication gateway (called UMA gateway) for interfacing. the private local IP network of the enterprise with the core network of an operator, is mainly related to the difficulty of being able to guarantee and maintain a constant QoS with the users, in particular in case of a large influx of communications at a given moment or over a period of time.

Indeed, the large number of communications generated in the company on a daily basis, the maximum number of VoIP flows authorized by the operator will often be reached, resulting in a degradation of the quality of communications that will pass through the UMA communication gateway. To try to overcome this drawback, some technical approaches consist of evaluating the maximum number of VoIP streams that can transit at a given moment, on the WAN part (for "Wide Area Network" in English, or "broadband network" in French). the UMA architecture, that is to say the network core side of the operator only. Such an approach according to the prior art is however limited in that it provides a partial response to the aforementioned drawbacks.

Indeed, if it is now possible for an operator to determine the maximum number of VoIP flows that can pass on the WAN part of its network, or in a static way by recovering a preset value of maximum value value authorized VoIP flow, either dynamically, by means of a CAC type algorithm (for "CaIl Admission Control" in English, or "admission control of a communication" in French), for the purpose to evaluate the possibility of adding a new stream on this one, it is however impossible for him to be able to evaluate the impact of the addition of such a new flow, from end to end, on the part WAN, but especially on the WLAN part of a private mobile network. However, most often, the degradation of the QoS of communications in a corporate UMA architecture comes from an overload of the private mobile network of the latter. Moreover, in the UMA architectures, the dynamic computation of the number of VoIP streams does not exist, the WMM ™ standard (for "Wireless Multimedia" in English, or "wireless multimedia" in French) which aims to define criteria and methods to improve the quality of service rendered to users in wireless communication, specifying in paragraph 3.5.2 (Version 1.1 - Wi-Fi Alliance Technical Committee Quality of Service Task Group) that a method of determining the maximum value VoIP flow in a UMA architecture must be defined by each OEM.

This situation contributes to the difficulty encountered today by operators and equipment manufacturers in being able to offer companies high-performance and attractive telephony solutions based on a UMA-type architecture.

To remedy such a situation, the inventors have defined an entity, called "business zone" (for "area of activity") capable of adapting to the characteristics of the service to be transmitted. It includes converged terminals, networks and LAN access equipment of a company.

It incorporates a new concept of network convergence and a new end-to-end Quality of Service (QoS) protocol. This concept provides the Business Zone with methods of managing a service continuity of failover type of communication (commonly referred to as "handover procedure") allowing it to discover the topology of networks, the selection of the most suitable network the characteristics of the voice or data stream to be transmitted, the connection to the selected network.

The connection to the selected network requires the implementation of a security protocol and then a QoS protocol. When a terminal is connected to a first WiFi network (LAN type - for "Local Area Network"), it establishes an IPsec connection with an access gateway to a second communication network of an operator (WAN type - for "Wide Area Network"), before starting a calculation of the maximum number of VoIP (Voice over IP) streams that the Business Zone can transmit.

At the end of this calculation, an interface device between the first LAN type network and the second WAN type communication network is then able to authorize or refuse the admission of a new VoIP stream (or more generally from data to transmit between a first terminal belonging to the first network and a second terminal belonging to the second network.

The aforementioned technique, although perfectly adapted to the management and control of the QoS offered to the users of a UMA architecture, however, is not enough for operators and equipment manufacturers, to be able to offer companies high-performance and attractive telephony-based offers. a UMA-type architecture, the latter having to take into account at least some characteristics of a subscription subscribed by a person (physical or moral) to his operator to access the WAN network (GPRS or UMTS, for example). The present invention provides a solution that does not have the disadvantages mentioned above.

The invention aims to solve the aforementioned drawbacks by proposing a method making it possible on the one hand to control the legitimacy of the bandwidth request with respect to a subscription subscribed for a user terminal with a WAN network of an operator. and, on the other hand, who is able, when the legitimacy of the request is verified and validated, to calculate and control the maximum number of VoIP flows that can transit at a given time and / or over a given period, as well as on the LAN part, than on the WAN part (GSM / GPRS network of a mobile telephone operator) and therefore, end-to-end in a network architecture meeting the UMA standard.

It is particularly by means of the present invention to be able to control the admission or rejection of any new data flow representative of a new communication (VoIP stream in particular), with the objective of ensuring users a constant level of quality of service offered to them during their communications, through a UMA architecture, in particular implemented within a company, while ensuring in advance the legitimacy of such a request for admission of a new data stream.

For this purpose, the invention relates to a method of communication between at least one first communication terminal belonging to a first communication network and at least one second communication terminal belonging to a second communication network, said first and second networks being connected to each other. between them via an interface device. According to the invention, such a method comprises:

A step of transmission by said first terminal to said interface device of an admission request request for a new data stream on said first and second communication networks; A step of verifying the legitimacy of said request taking into account a level of bandwidth required for the transmission of said new data stream and a maximum level of bandwidth subscribed for said first terminal with an operator of said second network;

¹ if the legitimacy of said request for admission request is verified, said interface device performs an additional step of processing said admission request.

The communication method according to the invention therefore makes it possible to verify the legitimacy of any request for bandwidth allocation required for the transmission of a new data stream, end-to-end between said first and said second terminal, with due regard to account of bandwidth characteristics and bit rate specific to a subscription previously subscribed for the first terminal from an operator of said second network (WAN).

Thus, and advantageously, the request for bandwidth allocation required by said first terminal can be accepted because it is legitimate in view of the subscribed subscription for the first terminal to access the second communication network. In this case, the interface device, for example a LiveBox (trademark) of the operator Orange (registered trademark), will start the processing of the request for request of the said new data stream.

In the opposite case, the interface device will refuse the processing of said request.

Such a technical approach according to the invention, both new and inventive, offers the additional advantage of facilitating the control on the one hand of the service offer made available to users in UMA architecture by network operators and, d secondly, for the latter, to better adapt the remunerative scheme of their service offerings, taking into account the needs of users and the adequacy of these needs with the network subscription subscribed by them to said operators. In a preferred embodiment of the invention, said processing step takes into account the result of a dynamic calculation of a maximum data flow rate value that can pass between the first and second terminals, and in that said calculation takes into account observed flows in the first and second networks. The present invention therefore proposes a solution which advantageously makes it possible, in a network architecture of the UMA type, when a first terminal belonging to a first communication network, for example of the type of private mobile IP network WLAN, wishes to establish a new communication with a second terminal of a second communication network, for example broadband WAN type, end-to-end evaluate the availability of resources available on the first and on the second communication network.

Thus, depending on the result of this evaluation, if at least one of the two networks does not have the available resources, in particular bandwidth, to allow the flow of data (for example voice data) necessary to support the network. new communication, then it switches without interruption the latter on the mobile network of an operator.

In an advantageous embodiment of the invention, said verification step comprises the following substeps of:

"transmission by said interface device to a first message management entity belonging to said second network, of a message containing at least one bit rate information representative of a maximum bit rate requested by said first terminal for transmission of said new data stream; data;

"routing of said message from said first management entity to a decision entity of said second network;" comparison by said decision entity of said requested maximum rate with a maximum level of subscribed rate for said first terminal to access said second network;

sending a response message to said first terminal by said decision entity, via said first management entity, said message containing at least one value representative of an authorization or an admission refusal of said new flow; of data. Thus, the terminal transmitting the admission request request for a new data stream will receive from a decision entity belonging to the second communication network to which it can access via the interface device, information that its request will be accepted or refused. Indeed, the interface device is not able to determine the legitimacy of a request for admission of a new data stream. It has no information representative of the type of subscription subscribed for the first terminal to access the second communication network (WAN), including subscribed uplink and downlink. The information is transmitted by the decision-making entity to the transmitting terminal in the form of a SIP message that the interface device is not able to interpret.

The information transmitted by the decision-making entity to the transmitting terminal is in the form of a series of bytes of content representative of a confirmation or an infiltration of the legitimacy of the request for admission of a new stream of data.

The method according to the invention thus makes it possible to circumvent this incapacity of the interface device to be able to interpret the SIP-type messages transiting through it in the context of a SIP session (session of establishing a new communication between terminals). a UMA architecture) by proposing a query mechanism of a decision entity belonging to said second network, which therefore contains and knows all the information relating to a given terminal benefiting from a subscription with said second network.

Thus, when the first terminal establishes an outgoing call by requesting a request to establish a new data stream with a second remote terminal belonging to the second communication network, a message of the SIP type (for "Session Initiation Protocol" or ""Communication" session initialization protocol containing the codecs (codec-decoders) of said first terminal is transmitted to a first management entity belonging to the second network. This management entity, or P-CSCF (for "proxy-CSCF") then redirects this message to the PDP (for "Policy Decion Point" corresponding to said decision entity) that will compare the flow of the first terminal with the maximum flow authorized by the subscription of the first terminal. The P-CSCF then returns a response message to the first terminal which will store the information contained in this message in its code table.

The method according to the invention therefore advantageously makes it possible to dynamically interrogate a decision-making entity of said second network, in order to recover at the level of said first terminal information specific to the subscription subscribed for the first terminal and thus to check the legitimacy of its request for information. admission of a new data stream.

In one embodiment of the invention, said value is stored in the coder-decoder table of said first terminal. This value is in the form of a series of bytes.

Thus, and preferentially, said verification step comprises a step of obtaining by said interface device said value stored in said coder-decoder table of said first terminal, the execution of said processing step then being triggered or canceled. , respectively, according to the result of a step of requesting validation of said value by said interface device 12 from said decision entity 122.

The method according to the invention thus enables the interface device to authorize or refuse the admission of a new data stream required by the first terminal on the basis of information previously determined by a decision entity, in view of the characteristics of the subscription subscribed for the first terminal.

In an advantageous embodiment of the invention, at said substep of comparison, it is verified that said maximum bit rate required for the transmission of said new stream is less than or equal to a maximum level of debit subscribed on a rising communication channel and with a maximum level of debit subscribed on a downlink communication channel, between said second and said first terminal.

Indeed, to be able to establish a new data flow between the first terminal and the second terminal (called "uplink" stream), it will be necessary to open two communication channels between the latter, a first upstream channel in the first terminal direction to second terminal and, a second communication channel descending (return channel) in the second terminal direction to the first communication terminal (referred to as the "downlink" stream).

Thus, the method according to the invention makes it possible to verify the legitimacy of the request for admission of a new data stream transmitted by the first terminal to the interface device, with regard to a part of the maximum authorized bit rate on the channel. amount and, secondly, at the maximum flow rate allowed on the descending channel.

Advantageously, at said processing step, said interface device activates at least a first filter for controlling the maximum data flow rate that can pass on said uplink communication channel and at least a second filter for controlling the maximum bit rate of the data streams. data that can pass on said downlink communication channel, said first and second filters taking into account the maximum data rates subscribed for said first terminal to access said second network.

The invention thus allows a better control of the eligibility of a request for establishment of a new data stream by rejecting, after verifying the legitimacy of the request, any upstream flow that has a bitrate greater than a first debit threshold. maximum allowed on the upstream communication channel and any downstream stream which would have a bit rate greater than a second maximum allowed rate threshold on the downlink communication channel. The invention also relates to a communication system between at least one first communication terminal belonging to a first communication network and at least one second communication terminal belonging to a second communication network, said first and second networks being interconnected via An interface device According to the invention, such a communication system comprises:

means for transmission by said first terminal to said interface device of a request for admission of a new data stream to said first and second communication networks; means for verifying the legitimacy of said request taking into account a bandwidth level required for the transmission of said new data stream and a maximum level of bandwidth subscribed for said first terminal from an operator of said second network; Means for processing said admission request activated by said interface device if the legitimacy of said request for admission request is verified.

In a preferred embodiment of the invention, in such a system according to the invention, said first communication terminal complies with the standard defined by the UMA standard.

The invention thus makes it possible in a network architecture (for example an enterprise network architecture) compliant with the UMA standard, to ensure perfect control of the requests for admission of new data streams required by terminals of the LAN of a network. and to terminals belonging to a second WAN network, the LAN and WAN networks being interconnected by means of an interface device of the LiveBox (trademark) type of Orange (registered trademark), taking into account the the legitimacy of these requests, that is to say, by ensuring an adequacy between the bit rates necessary for the routing of such flows and the corresponding characteristics of the subscription subscribed for the terminals.

Such a system also allows and advantageously, a better control of the service offer of operators in UMA-type architectures and therefore probably the advent of a richer service offer to come by them.

The invention also relates to a computer program product downloadable from a communication network and / or stored on a computer-readable and / or executable information medium by a microprocessor, such a program comprising code instructions for execution. a communication method such as that described above.

The characteristics and technical advantages of the present invention will become more apparent from the following description, given by way of non-limiting indication, with reference to the appended drawings in which:

FIG. 1 is a schematic view of an architecture in which a system and a communication method according to the invention are implemented;

FIG. 2 is a flow chart of an embodiment of the communication method according to the invention.

The present invention proposes a solution which makes it possible, in a network architecture of the UMA type, when a first terminal belonging to a first network of communication, for example of the WLAN private mobile IP network type, wishes to establish a new communication with a second terminal of a second communication network, for example of the broadband WAN type, on the one hand to verify the legitimacy of any request for establishment of a new data stream with regard to a subscription previously subscribed to an operator for a terminal compliant with the UMA standard.

On the other hand, once the legitimacy of such a request has been verified, it is possible to evaluate end-to-end the availability of available resources on the first and the second communication network. Thus, depending on the result of this evaluation, if at least one of the two networks does not have the available resources, in particular bandwidth, to allow the flow of data (for example voice data) necessary to support the network. new communication, then it switches without interruption the latter on the mobile network of an operator.

FIG. 1 illustrates a network architecture of the UMA type in which the invention can be implemented. Such an architecture comprises a first part 10 corresponding to a first wireless local area communication network 10, called a WLAN network, for example of the private local mobile IP network type, and a second part 11, corresponding to the core part of the network, of the network. WAN of an operator. A hardware equipment 12 forming an interface device makes it possible to extend the communication services between the WLAN and the WAN network, particularly with regard to the communications established between a first radiocommunication terminal 13 of the WLAN network and a second terminal 14. remote communication, reached through at least one collection and / or routing equipment 18 and / or at least one secure gateway 110, WAN network. WLAN network 10 includes a plurality of points \ 5 _\ 15 ₂ 15 ₃ 15 ₄ connected to the access interface device 12 via a switch 16 of the Ethernet type, the set of points d access, including the interface device 12, defining a coverage zone 19 (called "business zone" according to the commonly adopted English terminology) for the mobile local IP network, within which the communication terminals 13 are recognized. .

The terminals 13 comply with the UMA standard (Technical Specification Group GSM / EDGE Radio Access Network; Generic Access to the A / Gb interface; Stage 2 - version 6 January 2006) and the "business zone" 19 complies with the WMM standard (WMM ™ - Version 1.1 - Wi-Fi Alliance Technical Committee Quality of Service Task Group).

The Business Zone 19 has a DHCP server located on the interface device 12. The interface device 12 performs NAT (1 to N) on its WAN interface.

The source IP address of an IPsec packet (secure) transmitted by a UMA terminal 13 to a secure gateway 110 of the WAN network 11 comes from the range of IP addresses administered by the DHCP server of the "Business Zone". 19. A communication virtual voice (CV) 17 is established on the WAN portion 11 of the UMA architecture, between the interface device 12 and a collection and routing equipment 18 of the WAN network 11, the latter forming multi-service point of presence (PoP) entry point, including Voice over IP.

The establishment of a secure connection between a terminal 13 and the secure gateway 110 requires (i) the detection of the presence of the NAT function on the interface device's WAN interface and (H) the authentication of the two ends. of the connection. The secure connection is established according to the IKEv2 protocol.

FIG. 1 describes a scenario for verifying the legitimacy of a request for admission of a new data stream (multimedia data, for example) between a first terminal 13 conforming to the UMA standard and belonging to a first LAN type network 10 and a second remote communication terminal 14 connected to a second communication network 11.

Thus, when the first terminal 13 establishes an outgoing call to the second terminal 14, via an interface device 12 connecting the networks 10 and 11 to form an architecture according to the UMA standard, a message

120 in accordance with the SIP protocol (for "Session Initiation Protocol"

"session establishment protocol" in French - see RFC No. 3261 of the IETF) is transmitted by the terminal 13 to a management entity P-CSCF (for "") forming an access gateway to the IMS part (for "IP Multimedia Subsystem" in English or "IP Multimedia Subsystem" in French) of said second network 11.

IMS offers independent access based on IP-compliant connectivity ("Internet Protocol") that allows the use of different types services by users using communication protocols of the Internet world, particularly with regard to the exchange of multimedia data streams.

In the architecture of FIG. 1, the IMS comprises the following entities: - the P-CSCF, for proxy-CSCF: establishes an IPsec ESP UDP-Encapsulated-Tunnel connection with the terminal 13. It performs a compression / decompression of SIP messages and detects emergency calls; the S-CSCF, for serving-CSCF: authenticates the terminal 13 and controls the legitimacy of a request for access to a service. He routes the request to the entity

SIP concerned and converts MSISDN URLs to SIP URIs; - riMS-MGW, for "IMS-Media Gateway" in English or "IMS gateway-

Media ": routes the call from terminal 13 to the circuit-mode network and performs PS / CS conversion (" Packet switched ")

Switch "(MGCF), for MGCF (Media Gateway Control Function): selects the IMS-MGW to route the call from the terminal 13 to the network 12, in circuit mode It converts SIP messages into ISUP / BICC communication establishment messages over a switched network (CS), the AS, for "Application Server" or "Application Server in French: provides the presence functions of terminals on the network 12, message exchange management, push-to-talk services between the network cells 12, the management of the conference services on the network 12, the management of the discussion groups, etc. the BGCF, for "Breakout Gateway Control Function" in English, or "control function interrupt gateway": selects the MGCF to handle the call from the terminal 13 to the network 12 and circuit mode. The IMS further comprises: a home subscriber server (HSS): it contains the private identity of the terminal 13 and an authentication method. It contains the public identities of the terminal 13 (SIP URI) and the services authorized for it on the network 12. It defines the S-CSCF to associate with the terminal 13 relative to the subscription subscribed for it with a network operator 12;

a decision-making entity, called "Policy Decision Point": which controls the legitimacy of a request for access to a network 12 from a terminal 13 belonging to the communication network 10 (enterprise LAN, for example) .

When the terminal 13 wishes to establish a new data stream with a terminal 14 connected to the second network 12, it sends a 120 SIP message containing all of its codec-decoders and therefore a message containing the bit rates required by this terminal 13 to transmit this new data stream to the remote terminal 14.

This SIP message is routed via the interface device 12 to the P-CSCF 121. It contains all the codec-decoders (or more commonly referred to as coded) of the transmitting terminal 13 and, consequently, the bit rates required by the terminal 13 for establishing the new data stream that it wishes to transmit to the second terminal 14.

When this SIP message is received by the P-CSCF 121, the latter extracts the bit rate requested by the terminal 13 and redirects this requested bit rate to the decision-making entity 122, called PDP, for "Policy Decision Point" in English, which in conjunction with the Home Subscriber Server (HSS), has all the characteristics of the subscribed network subscription for the first terminal 13.

On receipt of the bit rate requested by the terminal 13, the PDP compares it with the maximum upstream and downstream rates subscribed in the network subscription associated with the terminal 13.

A response is then transmitted by the PDP to the P-CSCF, which contains a first piece of information representing an accounting between the level of bit rate requested by the terminal 13 for the transmission to the terminal 14 of a new data stream and the maximum bit rate. authorized by his subscription subscribed with a network operator 11.

Similarly, the remote terminal 14 transmits almost simultaneously to the P-CSCF (whose role normally consists in initiating a communication session between terminals of the network 10 and network terminals 11) a SIP message, of the SIP message 183 type, containing a response from the remote terminal 14 to the P-CSCF informing the latter of the acceptance or refusal of the terminal 14 to establish a communication session with the transmitter terminal 13. This message contains the codings of the second terminal 14 and therefore the rates that it is able to process. These flows are also transmitted to the PDP by the P-CSCF, the

PDP verifying their compatibility with the bit rates necessary for the transmission of the new data stream whose establishment is requested by the transmitting terminal 13.

The PDP transmits back to the P-CSCF a response indicating the rate compatibility between the rate requested by the first terminal 13 transmitting the request for admission of the new data stream and the upstream and downstream flows that the second terminal 14 is able to treat, in view of these hardware characteristics and network subscription.

In return, the P-CSCSF transmits to the first terminal 13 a response which is also in the form of a message of the SIP message type 183 "session progress" containing a field filled of type "P-Media Authorization". This field contains information in the form of a series of bytes according to which the request for admission of the new data stream requested by the sending terminal 13 is legitimate, firstly in view of the subscription subscribed by the latter and, on the other hand, in view of the hardware / software capabilities and subscription characteristics of said second terminal 14.

On receipt of this message, the terminal 13 knows whether its request for admission of the new data stream that it wishes to transmit to the remote terminal 14 is legitimate in view of its network subscription and therefore, if it will be authorized by the device 12 interface to perform a resource reservation request, end-to-end in the UMA architecture, to establish the new data stream.

When the subscribed network subscription for the first terminal 13 is compatible with the request for admission of this new data stream, the SIP message 183 "session progress" received by the terminal contains in the "P-Media Authorization" field a piece of information. in this sense validating the legitimacy of the request for admission of the new data stream sent by the terminal 13. Also, when the terminal 13 then transmits to the interface device a resource reservation request (CAC request, for "CaIl Admission Control" in English), so as to ensure that the new data stream can be routed, end-to-end between the first terminal 13 connected to the first network 10 of the LAN type and the second terminal 14 connected to the second network of the WAN type.

Upon receipt of this resource reservation request, the interface device 12 will first request the terminal 13 to transmit the value of the "P-Media Authorization" field that the terminal 13 has stored in its code table and which contains a value established by the PDP 122 and the C-SCSF 121 of the second communication network 11 according to which the request for admission of the new data stream by the terminal 13 is legitimate or not, with regard to the network subscription which is associated with him.

However, the interface device has no ability to read and therefore interpret this "P-Media Authorization" field value. Also, and upon receiving the value of "P-Media Authorization" which transmitted the first terminal 13 to him at his request, the interface device 12 transmits to the PDP of the second network 12, a value validation request message. of "P-Media Authorization". In return, the PDP transmits to the interface device 12 a validation message indicating whether or not the request for admission of the new data stream transmitted by the first terminal 13 is legitimate or not.

If this request is legitimate with regard to the subscribed network subscription for this terminal 13, then the interface device 12 will continue the processing of the admission request of the new data stream and proceed to the next step of reservation of the data. resources necessary for routing the new stream between the terminal 13 and the terminal 14, end-to-end through the networks 10 and 11.

In the opposite case, the interface device will refuse the CAC request from the terminal 13 for the new data stream, which is not legitimate with respect to the network subscription of the terminal 13.

In summary, the major steps of the communication method between at least a first communication terminal 13 belonging to a first network 10 of communication and at least a second communication terminal 14 belonging to a second communication network 11, said first 10 and second 11 networks being interconnected via an interface device 12, can be summarized in the following way, in association with the FIG. 2: "transmission El by said first terminal 13 to said interface device 12 of an admission request request for a new data stream on said first and second communication networks (10, 11);

E2 verification of the legitimacy of said request taking into account a bandwidth level required for the transmission of said new data stream and a maximum level of bandwidth subscribed for said first terminal

13 to an operator of said second network 11;

"processing E3 of said admission request by the interface device 12 if the legitimacy of said request for admission request is validated beforehand.The processing step takes into account the result of a dynamic calculation E4 of a maximum data flow rate value that can pass between the first 13 and second 14 terminals, said calculation takes into account observed rates in the first 10 and second 11 networks.

The verification step E2 comprises the following substeps of: • transmission E20 by said interface device 12 to a first message management entity 121 belonging to said second network 11, of a message containing at least one bit rate information representative of a maximum rate requested by said first terminal 13 for the transmission of said new data stream; routing E21 of said message from said first management entity 121 to a decision entity 122 of said second network 11;

comparison E23 by said decision entity 122 of said requested maximum bit rate with a maximum level of debit subscribed for said first terminal 13 to access said second network 11; sending E24 of a response message to said first terminal 13 by said entity

122, through said first management entity 121, said message containing at least one value representative of an authorization or refusal of admission of said new data stream.

The verification step E2 also comprises a step E24 for obtaining, by said interface device 12, said binary value stored in said encoder-decoder table (coded) of said first terminal 13, the execution of said processing step E3. then being triggered or canceled, respectively, according to the result of a step E25 requesting validation of said value by said interface device 12 from said decision entity 122.

In the processing step E3_, said active interface device E5 at least a first filter for controlling the maximum flow rate of the data streams that can pass on said uplink communication channel and at least a second filter for controlling the maximum bit rate of the data streams. data stream that can pass on said downlink communication channel, said first and second filters taking into account the maximum data rates subscribed for said first terminal to access said second network.

Claims

claims

A method of communication between at least one first communication terminal (13) belonging to a first communication network (10) and at least one second communication terminal (14) belonging to a second communication network (1 1), said communication terminal first (10) and second (11) networks being interconnected via an interface device (12), characterized in that it comprises:

A step (EX) of transmission by said first terminal to said interface device, of an admission request request for a new data stream on said first and second communication networks; a step (E2) for checking the legitimacy of said request taking into account a bandwidth level required for the transmission of said new data stream and a maximum level of bandwidth subscribed for said first terminal with a operator of said second network;

if the legitimacy of said request for admission request is verified, said interface device executes an additional step (E3) of processing said admission request.

2. Method according to claim 1, characterized in that said processing step (E3_) takes into account the result of a dynamic calculation (E4) of a maximum data flow rate value that can pass between the first and second terminals. , and in that said calculation takes into account flow rates observed in the first and second networks.

3. Method according to any one of claims 1 and 2, characterized in that said verification step (E2) comprises the following substeps of:

"transmission (E20) by said interface device to a first message management entity belonging to said second network, of a message containing at least one bit rate information representative of a maximum bit rate requested by said first terminal for the transmission of said new data flow;

Routing (E21) of said message from said first management entity to a decision entity of said second network; • comparison (E22) by said decision entity of said requested maximum rate with a maximum level of subscribed flow for said first terminal to access said second network;

Sending (E23) a response message to said first terminal by said decision entity, via said first management entity, said message containing at least one value representative of an authorization or a refusal of admission of said new data stream.

4. Method according to claim 3, characterized in that said value is stored in a coder-decoder table of said first terminal.

5. Method according to claim 4, characterized in that said verification step (E2) comprises a step (E24) for obtaining by said interface device said value stored in said coder-decoder table of said first terminal. executing said processing step (E3_) then being triggered or canceled, respectively, according to the result of a request (E25) for validation of said value by said interface device (12) with said entity (122). ) decisional.

6. Method according to any one of claims 3 to 5, characterized in that said substep (E22) comparison, it is verified that said maximum rate required for the transmission of said new stream is less than or equal to a level flow rate subscribed on a rising communication channel and with a maximum level of flow subscribed on a downlink communication channel, between said second and said first terminal.

7. Method according to claim 6, characterized in that in said processing step (E3), said interface device (12) activates at least a first filter for controlling the maximum flow rate of the data streams that can pass on said channel. communication device and at least a second filter for controlling the maximum flow rate of the data streams that can pass on said downlink communication channel, said first and second filters taking into account the maximum data rates subscribed for said first terminal to access said second network.

8. A communication system between at least one first communication terminal (13) belonging to a first communication network (10) and at least one second communication terminal (14) belonging to a second network (11) of communication. communication, said first (10) and second (11) networks being interconnected via an interface device (12), characterized in that it comprises:

means for transmission by said first terminal to said interface device of an admission request request for a new data stream on said first and second communication networks;

Means for verifying the legitimacy of said request taking into account a bandwidth level required for the transmission of said new data stream and a maximum level of bandwidth subscribed for said first terminal with an operator of said second stream; network; means for processing said admission request activated by said interface device if the legitimacy of said request for admission request is verified.

9. Communication system according to claim 8, characterized in that said first (13) communication terminal complies with the standard defined by the UMA standard.

Computer program product downloadable from a communication network and / or stored on a computer-readable and / or executable information medium by a microprocessor, characterized in that it comprises code instructions for the execution of a communication method according to any one of claims 1 to 7.