WO2013140097A1 - Selection of a network entity for the provision of a digital content - Google Patents

Description

 Selecting a network entity for the provision of digital content

The present invention relates to the downloading of digital content by means of a content delivery network, and in particular the selection of at least one content server for use when a content to be downloaded is stored in a plurality of content servers. of such a network.

 The supply of digital content, for example in the form of files, web application elements (pages, javascript code), video streaming, radio or internet TV, to a user connected to the Internet requires determining the "best" network entity (s) capable of providing this content.

 In the case where such network entities are content servers, this generally requires to know or determine the closest available servers to this user (close to the network sense as geographical sense) capable of providing the content.

 Servers that contain a copy of the content to download, called

"Caches" are conventionally hosted by Content Delivery Networks (CDNs), whose providers position themselves as intermediaries between the internet access provider and the content provider (for example Dailymotion), or by user terminals acting as "caches" of a peer-to-peer network.

 A good interconnection between the different networks implemented, be it content delivery networks or ISP networks, is therefore crucial. In order to guarantee the speed of interconnection and the quality of user experience, it is particularly necessary to determine the geographical location of the terminal requiring the content and the access provider providing the connectivity to this entity.

 Some current solutions are based on the grouping of IP prefixes into named groups. Thus, solutions using the ALTO protocol use grouping of PID-based group prefixes, whereas solutions using the BGP protocol use group-based group-based prefix grouping (AS number, community ID field value). a region or type of access), which requires the communication of very large and confidential information to the service applications.

In addition, the current interconnection solutions between content delivery networks have the following drawbacks: - They are complex and involve numerous interactions between the different network entities involved (terminal, server caches CDN, domain name servers (DNS), etc.);

 - These multiple round trips introduce a delay in the access to the content, and thus affect the experience of the customer who suffers a delay before viewing and thus hinders the rendering of the service;

 Access to rich content increases the number of interactions (the current mechanism does not scale). The present invention aims to overcome these disadvantages, by proposing a method of selecting one or more network entity (s) to be used, when downloading digital content, which is simple and offers a better customer experience in limiting redirection messages between different entities of the download system.

Thus, according to a first aspect of the invention, there is provided a method for selecting at least one network entity to be used, to provide digital content to a user equipment, among a plurality of network entities capable of providing at least a part of the digital content, characterized in that the method comprises, after receiving a request to obtain at least one digital content by a content request routing entity, for each of the network entities able to provide at least part of the digital content:

 send an information request on the IP address of this network entity to an address storage server; and

 receiving a response message from the address storage server, the response message containing an information data field comprising information data relating to said network entity;

 the at least one network entity to be used being selected using the information data relating to the network entities.

 The selection of a network entity for providing the digital content can thus be performed more quickly, with a reduced number of signaling messages.

 According to an advantageous embodiment, this selection method also comprises:

send an information request on the IP address of the user equipment to the address storage server; and receiving a response message sent by the address storage server, the response message containing an information data field comprising information data relating to said user equipment,

 the at least one network entity to be used being further selected by means of the user equipment (UE) information data.

 It is thus possible to obtain all the information necessary for the selection of the network entity to be used in the same way, from the address storage server, whether the information concerning the network entities able to provide the content or those concerning the user equipment.

 In a particularly advantageous embodiment, the address storage server is a domain name server and, for each of the network entities able to provide at least part of the digital content, the address information request. The IP of the network entity is a reverse DNS query and the information data field is inserted into a PTR field associated with the network entity and stored in the domain name server.

 It is thus possible to implement the invention by means of already existing features offered by the DNS servers but usually used in other contexts completely different from that of the present invention.

 According to one characteristic of the invention, the information data relating to each network entity able to provide at least a part of the digital content comprises geographical location data of this network entity, the network entity to be used being selected. according to the geographic location data of the network entities able to provide at least a portion of the digital content and geographic location data of the user equipment. This makes it possible to make the selection taking into account geographical criteria, for example the geographical proximity of the user equipment with one of the network entities.

According to another characteristic of the invention, the information data relating to each network entity able to provide at least a part of the digital content comprise data characterizing the administrative domain of the network of this network entity, the network entity. to be selected based on the data characterizing the administrative domains of the network of network entities able to provide at least a portion of the digital content and data characterizing the administrative domain of the network of the user equipment. This makes it possible to make the selection by taking into account computer proximity criteria, for example the membership of the user equipment in the same network as one of the network entities. According to another characteristic of the invention, the information data relating to each network entity able to provide at least a part of the digital content comprises state information of this network entity, the network entity to be used being selected according to the status information data of the network entities capable of providing at least a portion of the digital content. This makes it possible to make the selection taking into account the status of the network entities, for example their possible saturation.

 According to another aspect of the invention, there is provided a method of downloading digital content by a user equipment comprising the steps of: sending a request to obtain the digital content to a content request routing entity;

 receive at least one signaling message designating at least one network entity to be used to obtain at least a portion of the digital content, this at least one network entity to be used being selected, from among a plurality of network entities capable of providing the digital content, using network entity information data obtained from an address storage server;

 send at least one request for downloading the digital content to the at least one network entity to be used; and

 receive at least a portion of the digital content of the at least one network entity to be used.

 Digital content can thus be provided more quickly to the user equipment the applicant, with a reduced number of signaling messages.

 According to another aspect of the invention, there is provided a selection entity of at least one network entity to be used for providing at least one digital content to a user equipment, this selection entity comprising a processing module able to select the at least one network entity to be used, among a plurality of network entities capable of providing at least a portion of the digital content, by implementing the above selection method.

 In an advantageous embodiment, this selection entity corresponds to a content request routing entity comprising communication means capable of receiving a request for obtaining a digital content transmitted by the user equipment, which allows a directive routing from the entry point of the network to which this routing entity belongs

According to another aspect of the invention, there is provided an address storage server, able to interact with a selection entity to implement the method for selecting at least one network entity to be used, for providing digital content to a user equipment, as described above, the address storage server comprising:

 a storage unit configured to store, for each network entity of a plurality of network entities capable of providing at least a portion of the digital content, the IP address of said network entity associated with relative information data. to this network entity;

 a communication unit capable of receiving at least one information request on the IP address of one of these network entities able to supply at least a portion of the digital content and configured to transmit at least one response message comprising the data information relating to this network entity capable of providing at least a portion of the digital content.

 According to an advantageous embodiment, the storage unit is further configured to store the IP address of the user equipment associated with information data relating to said network entity, and the communication unit is furthermore adapted to receive an information request on the IP address of this user equipment and configured to send a response message comprising the information data relating to this user equipment.

 According to an advantageous characteristic, the communication unit is furthermore able to receive a first request for updating information relating to one of the network entities or to the user equipment, to relay part of this first update request. to a third party server and receive, from the third party server, a second update request, consolidated from the first update request by said third party server.

 In a particular embodiment, this address storage server is a domain name server, the information request on the IP address is an inverted DNS request and the information data field is inserted into a field. PTR associated with the network entity and stored in the domain name server.

According to another aspect of the invention, there is provided a user equipment comprising communication means able to receive digital content from at least one network entity, the communication means being configured to send a request for obtaining digital content to a content request routing entity and send a request to download at least a portion of the digital content to a network entity to be used to obtain at least a portion of the digital content, upon receipt of a message from signaling designating that entity to be used, the entity to be used selected from among a plurality of network entities capable of providing at least a portion of the digital content, using network entity information data obtained from an address storage entity by means of information requests on the IP addresses of the network entities.

 The invention also relates to a computer program comprising instructions for executing the steps of the selection method above, when this program is executed by a processing module of a selection entity. The invention is also directed to a computer program comprising instructions for executing the steps of the downloading method above, when this program is executed by a processing module of a user equipment.

 These programs can use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other form desirable shape.

 The invention also relates to a computer readable information medium, and comprising instructions of the computer programs as mentioned above. The information carrier may be any entity or device capable of storing the program. For example, the medium may comprise storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a diskette or a hard disk. On the other hand, the information medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio or by other means. The program according to the invention can be downloaded in particular on an Internet type network. Alternatively, the information carrier may be an integrated circuit in which the program is incorporated, the circuit being ad

Other features and advantages will appear on reading the description and the figures in which:

 FIG. 1 illustrates a digital content downloading system according to the principle of the present invention;

FIGS. 2A to 2C illustrate a method of selecting a network entity to be used, when downloading digital content by a user equipment, according to the principle of the present invention; FIGS. 3A and 3B illustrate an embodiment of the present invention relating more particularly to the selection of content servers by means of a domain name server;

 FIGS. 4A and 4B illustrate another embodiment of the present invention in which the user equipment UE is in a mobility situation;

 Figs. 5A and 5B illustrate another embodiment of the present invention involving downloading of content through network entities belonging to a peer-to-peer network; and

 FIGS. 6A and 6B describe processes for updating the state information concerning either a network entity capable of supplying all or part of a digital content, or the user equipment requiring this digital content, according to two modes of embodiment of the invention.

Referring first to Figure 1, which illustrates a digital content downloading system according to the present invention.

 Here, the term "digital content" means a digital data file corresponding to all or part of a multimedia content that can be a data file, a movie, a piece of music, an image, a WEB page, a javascript file. etc.

 This downloading system includes a user equipment

UE, a CRE content request routing entity, a SEL selection entity, an IAS address storage server, and a plurality of CS1, CS2 network entities capable of providing at least a portion, if not all, of digital content to download.

 A user wishing to obtain a digital content C1 thus uses UE user equipment (which may be a terminal such as a computer, fixed or portable, or even a smartphone, as non-limiting examples) to address the entity CRE content request routing. This user equipment UE thus has communication means configured to send requests to this CRE routing entity, and able to receive response messages from this CRE routing entity, as well as the digital content C1 downloaded from the entity (s) (s) network CS1, CS2.

The system further includes a CRE content request routing entity, which may typically be an ISP's internet portal, a P2P tracker, a CCN or ICN router, or a network CDN controller. content delivery. This CRE routing entity is able to receive requests issued by the user equipment UE and to send back response messages designating the network entity (s) to be used to download the digital content Cl.

 The CRE routing entity is connected to the IAS address storage server on which the IP addresses of the network entities CS1, CS2 are stored, each IP address of one of these network entities being respectively associated with information data concerning this network entity. This IAS address storage server is advantageously implemented in the form of a domain name server (DNS), the primary function of which is to establish a correspondence between names of domain names. domain and IP addresses. In practice, upon receipt of a request comprising a specific domain name, such a DNS server returns to the sender of the request one or more IP addresses associated with that specific domain name.

 The digital content C1, meanwhile, is provided by the network entities CS1, CS2, which are capable of providing at least a part, or all, of this digital content C1 to download. These network entities in particular have storage means capable of storing, temporarily, for long periods or permanently, digital contents as well as communication means capable of receiving a request for downloading content and sending, in return , the digital content, or part of it, desired.

 These network entities CS1, CS2 can be data servers, for example belonging to the same network of CDN content provider or to the same network of access provider, or belonging to different networks. These data servers can store all or part of digital contents to download, or contain a copy of them in which case they are so-called "cache" servers. They can also be peer entities of a Peer-to-Peer network, also acting as "caches", as will be seen later.

 In order to simply illustrate the invention, the system of FIG. 1 comprises only two network entities CS1 and CS2, but the invention naturally applies to any number N of network entities able to supply all or part of this digital content C1, since N is an integer greater than or equal to 2, these network entities being able to belong to the same content delivery network, to different distinct content delivery networks, or even to different networks of networks. different nature.

The present invention thus aims to select at least one network entity to be used for downloading the digital content C1 as required by the user of the the UE equipment, among all network entities CS1, CS2 able to provide all or part of this digital content Cl.

 To do this, one (or more) network entity to be used is selected by a selection entity SEL by means of information data relating to the network entities obtained from the IAS address storage server.

 FIG. 1 illustrates a particular embodiment where this selection entity SEL corresponds to the content request routing entity CRE, used by the user equipment UE to request the digital content, which advantageously allows directive routing from the entry point of the network to which this CRE routing entity belongs. Alternatively, this selection entity SEL can be a computer entity, for example a selection server, distinct from this routing entity.

 Thus, following the reception by the routing entity CRE of a request to obtain the digital content C1 emitted by the UE UE (designated by Req (Cl)), the selection entity SEL obtains from the server IAS storage, UE and network entity information capable of providing all or part of this digital content Cl, ie to the CS1 and CS2 entities, so that the entity (s) to be used can be selected to provide this content to the UE equipment.

 In particular, the selection entity SEL obtains this information by sending to the IAS address storage server one or more information request (designated by Rev_IAS) on the IP addresses of the user equipment UE and entities CS1, CS2, so that the latter transmits in return one or more response message (designated (s) by Resp_IAS) comprising information data relating to UE UE and CS1 and CS2 entities.

 For each of the entities UE, CS1 and CS2, this information data, stored in the IAS address storage server, can be:

 - data on the geographical location of this entity;

 data characterizing the administrative domain of the addressing plan of this entity;

 - state data of this entity.

With such information data, the selection entity SEL is then able to select the network entity (s) for the most efficient download of the digital content C1 by the UE. FIG. 1 thus illustrates an example where the network entity CS1 is selected to obtain all the digital content C1, in which case the UE is redirected to this network entity CS1, by means of a Redir (CS1) signaling message sent back by the CRE routing entity, and sends it a download Req '(Cl) request, to which this CSl network entity responds by transmitting the desired digital content C1.

 Thus, in the case where geographic location data of each of the content servers is provided by the IAS address storage server, the selection entity SEL can select the network entity to be used based on this data of the server. geographical location and geographical location data of the user UE UE, by comparing these data with each other.

 In particular, the selection entity SEL can determine the network entity CSi which is the closest geographically to the user equipment UE and select it.

 In order to compare this information with each other, the information about the network entities CSi and the information about the user equipment UE may be formatted in the same way, using the same units and the same write convention.

 Alternatively, in the case where data characterizing the network administrative domain of each of the network entities are received, the selection entity SEL can select the network entity to be used based on these data characterizing the network and data administrative domain. characterizing the network administrative domain of the UE, always comparing these data with each other. In particular, the selection entity SEL can determine the network entity CS1 or CS2 which administratively belongs to the same network domain as the user equipment UE and select it.

Thus, if the data characterizing the network administrative domain of the first network entity CS1 indicate that it belongs to a first network administrative domain (for example, its IP address ends with foo.isp.com) while the data characterizing the network administrative domain of the second network entity CS2 indicates that it belongs to a second network administrative domain (for example, its IP address ends in bar.isp.com), and if the data characterizing the network administrative domain UE indicate that this UE also belongs to the second network administrative domain (ie its IP address ends with bar.isp.com), then the selection entity SEL selects the second network entity CS2 to provide the content.

 In another embodiment, in the case where status data of each of the network entities are received (i.e. data indicating the state of operation and availability and / or the specific characteristics of the network entity), the selection entity SEL can select the network entity to be used, among the entities CS1 and CS2, according to these state data.

 Thus, if the state data for the first network entity indicates that it is saturated while the state data for the second network entity CS2 indicates that the second network entity is available, the selection entity SEL can select the network entity CS2 for providing the digital content C1 to the user equipment UE.

 These different selection criteria can be combined, for example by prioritizing a first selection criterion with respect to another, in order to make a multi-criteria selection of the network entity to be used.

 Thus, if the IAS address storage server provides geographic location data of the network entities CS1, CS2 and state data of these same entities CS1, CS2, the selection can consist in first selecting the one or more entity (s) available, then the nearest network entity geographically among these available entities.

 The various information data items mentioned above are thus stored, in association with an identifier (ie the IP address) of the network entity CSi on which they bear, in the IAS storage server so that the latter can recover, when the SEL selection entity so requires, and provide them by inserting them into a Resp_IAS response message.

 This can be done by sending this data to the address storage server

IAS during an initialization procedure, then updating this information, either at regular intervals, or at each event involving one of the network entities CS1, CS2, or at each change of state (especially for the modifications of the availability status of one of these entities).

 The update can be done directly by the network entity affected by a change of situation, by means of an update request transmitted from this network entity to the IAS address storage server.

In one embodiment, the IAS address storage server is a Domain Name Server (DNS). In such a case, to obtain the information stored in the DNS server, it is particularly advantageous to use the reverse DNS query mechanism ("reverse DNS").

 This mechanism is based on the association of information (usually a domain name), recorded in a PTR field (for "Pointer Record" in English), with one or more IP addresses. Thus, when a DNS server receives an inverted DNS request containing an IP address, this DNS server returns to the sender a response message containing the information stored in the PTR field.

 In order to memorize the information relating to the UE and the network entities CS1, CS2 in the DNS server, it is possible, in particular, to use the DNS entry called "PTR" (for "Pointer Record"), which is a field in which a domain name registration can be associated with an IP address, which makes it possible to perform the inverse function of the address entry (or "A record") of a DNS server usually used to obtain the address IP from a domain name.

 Thus, for the CSi entity, the IP address of this entity CSi is stored in the DNS server in association with information relating to this server CSi as defined above.

 The selection entity SEL can then send to this DNS server an inverted DNS request containing the IP address of the entity CSi, which returns a response containing the information relating to this entity CSi, as associated with its address. IP in the DNS server, thanks to this DNS inversion mechanism.

 It is thus possible to insert, in the data field "PTR" stored for a given network entity CSi, an information field relating to this network entity CSi, this information field containing one or more of the information previously described.

 This information field thus advantageously comprises one and / or the other of the following fields:

 A geographical field, designated by "Geo", gathering the geographical or administrative location information concerning the network entity CSi;

 A status field, designated by "Status", gathering the information concerning the operating state of this network entity CSi.

 The "Geo" field can include:

o an identifier field, comprising data identifying the internet access provider (ie the AS number for "Autonomous System") o an administrative region field, comprising data identifying the administrative region to which the network entity CSi belongs, based for example on the ISO 3166-1 standard (for a country code) and its administrative subdivisions 3166-2

The "Status" field may notably consist of a register of n states expressing the operating state, or the trend of the operating state, of a network entity, each bit of this register characterizing successively one of the following elements ( a bit at zero signifying the non-functioning of the element and a bit at a signifying the proper functioning of the element):

 o Power supply ("1" for an entity with sufficient energy, "0" otherwise)

 o Processor ("1" for an unsaturated processor, "0" otherwise)

 o Network ("1" for good network connectivity, "0" otherwise) o Storage ("1" to indicate storage capacities, "0" otherwise) o Client ("1" for a client entity, "0" " if not)

 o Server ("1" for a server entity, "0" otherwise)

 o Mobility ("1" for a moving entity, "0" otherwise)

 o Standby ("1" for an entity in standby mode, "0" otherwise)

For example, as a "status" field:

 o 11101001 indicates a customer in perfect working order;

 o 11100101 indicates a server in perfect working order;

 o 10100101 indicates a saturated server.

To illustrate an example of an information field comprising both a geographical field and a status field, the PTR field associated with the IPv4 address 92.142.202.252 of a network entity CSi of an operator whose name is domain is "isp.fr" can take the following form:

3215.FR.223.11101000.092142202252.

With the meaning of the following fields:

• Geographical field "Geo" filled in with the following data o 3215 is the ASN number of the access network operator's RBCI network or the administrative code name of the operator;

 o FR is the ISO 3166-1 administrative code of the country where the home gateway is located, here France;

 o 223 is the root of the postal code or ISO 3166-2 administrative code indicating an administrative area;

 "Status" status field populated with the following data:

 o 11110100 means a customer in service, with the following values:

^■ First bit at "1" indicates that the CSi entity is energized;

^■ Second bit at "1" indicates that the processor of the CSi entity is running;

^■ Third bit at "1" indicates that the CSi entity is reachable by the network;

^■ Fourth bit at "1" indicates that the CSi entity has storage capabilities;

^■ Fifth bit at "0" indicates that the CSi entity is not a client-type entity;

^■ Sixth bit at "1" indicates that the CSi entity is a server-type entity;

^■ Seventh bit at "0" indicates that the CSi entity is fixed; and

^■ Eighth bit at "0" indicates that the CSi entity is not in sleep mode. In addition to the "Geo" and "Status" fields, the information field may also include a monitoring information field, called a "monitoring" field, which may contain arbitrary information data (eg the number of sessions in progress on a server), CCN routing (eg the hash key of a content or family of content available or searched by the equipment) and a field value, which is transmitted to a third party entity, so that it updates, in return, the state field of the network entity CSi.

This field value makes it possible to delegate to a third party server the updating of the state information of the network entity CSi or of a UE. It also makes it possible to inform this third server of a change of state of the network entity (eg mobility of the network entity, overloading of the "cache" at this entity, etc.). The third-party server can to be informed of these changes, in real time, in order to take them into account in a first case.

 In another context, the third party server can also modify the state information without taking into account this "monitoring" field. For example, when this third party server is a CDN controller, it can update the status information of a "cache" type network entity to "saturated" to indicate that it wishes to stop this "cache" feature. within two hours to save energy.

 The level of semantic precision of the information field returned by the IAS address storage server to the SEL selection entity varies depending on the level of trust, as well as any trade agreements, between those two entities.

 By way of example, the following four different decreasing information field levels of information can be envisaged for a unique identifier 092142202252 corresponding to the IP address 252.202.142.92:

Level 1 - information field = "3215.FR.223.111010.092142202252.isp.fr"

Level 2 - information field = "3215.FR.223.092142202252.isp.fr"

Level 3 - information field = "FR.092142202252.isp.fr"

Level 4 - information field = "092142202252.isp.fr"

 Level 1 is a level of trust that can be used when the IAS storage server and the SEL selection entity are on the same network.

 Level 2, less accurate, can be used when the IAS storage server is queried by a SEL selection entity belonging to a network operator partner.

 Levels 3 and 4, even less precise, can be used when the IAS storage server and the selection entity belong to different networks that do not have a privileged relationship of partnership.

 In order to determine which level of semantic precision to use, the IAS address storage server may include a database associating a confidence level as a function of ranges of IP addresses or administrative domain, as well as a filter applied on the information field based on the IP address of the SEL selection entity that issued the request to obtain information.

Thus, if the IP address of the selection entity SEL belongs to a range of IP addresses or to an administrative domain associated with a maximum level of confidence (ie level 1 above), then the filter passes the entire information field when it is inserted in the Resp_IAS response message.

 On the other hand, if this IP address belongs to a range of IP addresses associated with a trusted level 3, then the filter blocks the information relating to the state of the entity, to the AS number and to the root of the postal code, so that only the data "FR.092142202252.isp.fr" is inserted into the response message Resp_IAS.

 The information field, inserted by the IAS address storage server into the response message Resp_IAS returned to the selection entity SEL, can advantageously be encrypted to protect access to the information it contains.

 Once the selection of the entity (s) to be used to provide the content

C1 to the UE, the SEL selection entity may transmit to the UE, via the CRE routing entity, a signaling message (designated by Redir (CSl)) designating the entity (s) to use, this message containing the IP address of this entity (s). Such a signaling message Redir (CSl) may be a redirection message, when the same protocol is used for this message and for the request to obtain the content Cl, or a signaling message using a different protocol.

 Having the address of the network entity CSl (in the case where a single network entity provides the content), the user equipment UE can then transmit a download request Req '(Cl) to this network entity CS1 , in order to receive in return the digital content Cl.

Referring now to FIGS. 2A-2C, which illustrate in more detail the method of selecting one or more network entity (s) to be used when downloading digital content C1 by UE user equipment, according to the present invention. .

The method starts, in FIG. 2A, with the sending, by the user equipment UE, of a request Req (Cl) for obtaining the digital content C1 to the routing entity CRE (step 105), which corresponds to here also to the SEL selection entity. This sending can be triggered, at the level of the UE, by clicking on a URL designating this content Cl on a web page of the portal of the ISP access provider. This request Req (Cl) can be of the form "Get url www.ispl.fr/Cl".

The selection entity SEL has the list of the different network entities able to provide part, or all, of this digital content C1, ie the entities CS1 and CS2. Such a list can be predefined and locally updated in the SEL selector entity, regularly or in real time, by means of update requests sent to this SEL selection entity when a content change occurs. available on one of these CSl and CS2 entities. Alternatively, the SEL selection entity may query another third party server, by means of a URI or a URL or an API, or a Web service, in order to obtain this list, including This time is managed by this other third party server.

 In the present invention, the selection entity SEL addresses the address storage server IAS to obtain information on these entities CS1 and CS2, here successively to first obtain information relating to the entity CS1. (step 120), then information relating to the entity CS2 (step 130).

 These different steps of obtaining information can be implemented in the following manner, for each network entity CSi (with i = 1 or 2):

 a) the selection entity SEL generates a request for information on the IP address of the network entity CSi (hereinafter referred to as Rev_IAS (IPi)), including the IP address of this network entity, which it sends to the IAS address storage server (steps 125, 135).

 These information requests can thus be respectively of the form "Reverse DNS 139.100.1.1" and "Reverse DNS 131.100.1.1", when "139.100.1.1" and "131.100.1.1" are the respective IP addresses of the entities CS1 and CS2 and that the IAS server is a DNS server.

 If the SEL selection entity does not have the IP address of the CSi entity, it can retrieve it first from a DNS domain name server, as will be seen later.

 b) upon receiving this request Rev_IAS (IPi), the IAS address storage server retrieves the information relating to the network entity CSi, which it has stored in association with the IP address of this entity CSi, and builds a response message Resp_IAS (CSi) including this information, which it sends back to the selection entity SEL (steps 127, 137).

 These response messages can thus be respectively of the form "RBCI.FR.690.111011.CSl.ispl.fr" and "ASdm.FR.750.111011.CS2.isp2.fr".

In a particular particularly advantageous embodiment, the selection entity SEL also addresses the address storage server IAS to obtain information on the terminal equipment UE (step 110), when such information is stored in memory. association with the IP address of this UE terminal equipment in the IAS address storage entity. This step of obtaining information on the UE includes a step of sending a request Rev_IAS (IP1) (step 115), containing the IP1 address of this UE, and a step of transmission, in return , a response message Resp_IAS (UE) comprising this information (step 117), similar to the steps 125 and 127 described above.

 This embodiment makes it possible to treat in the same manner, at the level of the address storage server, the entities providing the content and the entities requesting it, by memorizing the information concerning them in a similar manner. Thus, a network entity can easily switch from the content provider role to the content requester role by simply updating status information about it.

 The UE equipment information may be of the same nature as the CSi network entity information as previously introduced. In particular, the UE user state information data may be used to select an encoding format of the digital content C1 that is appropriate for that state.

 At the end of these steps of obtaining information on the network entities able to provide at least a part of the digital content C1, made to the address server IAS, the selection entity SEL can select a or more network entity (s) CSi to use to provide this content Cl, using this information, applying criteria as explained above (step 140). FIG. 2A illustrates a particular example where the network entity CS1 is selected to provide the set of content C1.

 The selection entity SEL then instructs the UE to address the selected CSl network entity to download the content C1 (step 150).

 This instruction step is here implemented by supplying the UE with the address of this entity CS1 (step 151) by means of a signaling message Redir (CS1) sent by the routing entity CRE. Such a message can take the form "http redirect www.ispl.fr/Cl to CSl. ispl.fr/Cl "and then constitutes a redirection message insofar as it uses the http protocol. It is clear here the efficiency of the method where the UE equipment is directed quickly (i.e. with a single signaling message) to Pentité CSl network to use, unlike the solutions proposed in the prior art.

The UE may then transmit a request to download the digital content Cl (designated by Req '(Cl) and which may take the form "Get url CSl. ispl.fr/HD/Cl ") to this entity CS1 (step 153), so that the latter sends back to it the digital content C1 (step 155).

 This phase 150 of instruction of the entity selected to the user equipment UE is here implemented in a "pull" mode (ie the UE user device requires the download from the selected entity), but it is also possible to implement it in a push mode in which the selection entity SEL instructs the selected entity to transmit the content C1 to the user equipment UE, provided that it has previously reserved resources for this purpose. effect at the UE user equipment.

Reference is then made to FIG. 2B which illustrates another embodiment of the selection method according to the present invention, when the information relating to the network entities able to supply all or part of the digital content is already available. In particular, this embodiment can follow the process of FIG. 2A.

 In such a case, when the UE wishes to download a second digital content C2 that can be provided by the network entities CS1 and CS2 for which the information is already available, it is not necessary to apply again to the IAS address storage server.

 Here, following the reception by the routing entity CRE of a request Req (C2) for obtaining this second digital content C2 (step 171), which can take the form "Get url www.ispl.com/C2 The selection entity SEL verifies which network entities can provide this digital content C2.

 If the selection entity SEL already has information relating to these entities (ie the network entities CS1 and CS2 in the case of FIGS. 2A and 2B), then it can directly select the entity CS1 to be used (step 172), here the CSl entity, without requiring information from the address storage server.

The selection entity SEL can then directly redirect the user equipment UE to the selected CSl entity, by sending it a signaling message Redir (CSl) including the address of this content server CS1 (step 173), for example in the form "http redirect www.ispl.fr to CSl.ispl.fr". The user equipment UE then sends to this entity CS1 a request Req '(C2) for downloading the content C2 (step 175), by using the IP address transmitted in this message Redir (CSl), for example in the form "Get url CSl.ispl.com/CS2 ", in order to download this content C2 (step 177). Advantageously, when a network entity becomes saturated following its selection for downloading digital content, it can send an update request to the IAS storage server, so that the latter updates the information of the network. status of this server. Thus, in FIG. 2B, the content server CS1 sends a update request MaJ (CS1) to the storage server IAS (step 179) so that the latter modifies the data relating to the operating state of this entity.

 In particular, if this operating state data corresponds to a bit of a status status field in the form of a register, then the request MaJ (CS1) comprises a modified information field in which this bit is set. to zero, to indicate the unavailability of the CS1 entity. The IAS address storage server, receiving such a modified information field, replaces the old information field associated with the CS1 entity with this modified information field.

 Thus, by resuming the information field 11110100 previously discussed, the second bit concerning the state of the processor of this server is set to zero in order to obtain an information field 10110100, transmitted in the request MaJ (CSl) of the CS1 entity to the IAS address storage server. Such a update request MaJ (CSl) can take the form "PTR RBCI.FR.223.10110100.CSl.ispl.fr" in order to replace the information field in the PTR field associated with the entity CS1 . Referring now to FIG. 2C, which illustrates another embodiment of the selection method according to the present invention, in which the network entity to be used is selected based on the state information of the servers storing the digital content to be used. Download. In particular, this embodiment may follow the process of FIG. 2B in which the network entity CS1 has indicated to the IAS address storage server that it is saturated, following its selection for downloading the content. C2.

 In this embodiment, the UE wishes to download digital content C3 stored on CS1 and CS2 servers. To do this, it sends a request Req (C3) to the routing entity CRE (step 181), in the form "Get url www.ispl.fr/C3".

 Following reception of this request Req (C3) by the routing entity CRE, the selection entity SEL determines that the content C3 is available on the network entities CS1 and CS2 which it already has IP addresses.

The selection entity SEL then sends a request to obtain information Rev_IAS (IP2), comprising the IP address (here the IP2 address) of the first network entity CS1, to the address storage server IAS ( step 182), in order to obtain in return state information relating to this first entity CS1, stored by the IAS address storage server within an information field associated with the IP address of this entity CS1, this information field being inserted into a response message Resp_IAS (CSl) issued by the IAS server (step 183). Similar steps (steps 184, 185) are performed for the second entity CS2.

 Here, the response messages Resp_IAS (CSl) and Resp_IAS (CS2) returned can take the form "RBCI.FR.690.10100100.CSl.ispl.com" and

"ASdm.FR.750.11100100.CS2.isp2.fr", respectively.

 The selection entity SEL then selects the entity CSi to be used on the basis of the state information contained in the information fields received for each entity CSI and CS2 (step 186).

 Here, the first CSI network entity being unavailable, because saturated, the information field received for this entity contains a status information indicating this unavailability (ie the second bit of the "Status" status field of this field). information is at zero), while the information field received for the second entity CS2 contains status information indicating the availability of this entity (ie the second bit of the status field "Status" of this information field is at a). Therefore, the selection entity SEL this time selects the second entity CS2 on the basis of this availability information.

 It then transmits a signaling message Redir (CS2) designating the second entity CS2 to the UE equipment (step 187) and can take the form "http redirect www.ispl.fr/C3 to CSl.ispl.fr/SD/ C3 ", so that the latter sends a Req 'download request (C3) to the entity CS2 (step 188) (in the form" Get url CSl.ispl.fr/SD/C3 ") so that it supply in return the digital content C3 (step 189). This method is particularly effective, compared to what is proposed in the prior art, in that the user equipment UE is quickly directed to the single unsaturated network entity, with a single signaling message.

Reference is now made to FIGS. 3A and 3B which illustrates an embodiment of the present invention relating more particularly to the selection of content servers by means of a domain name server.

FIG. 3A illustrates in particular the architecture of a downloading system according to this embodiment, which differs from the system according to the general principle of the invention as presented in FIG. 1, by the following points: • The selection entity and the routing entity are combined within a P-ISP entity that is the gateway to an access provider network (referred to as ISP).

 • The address storage server is a domain name server, designated by DNS.

 • The network entities CSI, CS2, capable of providing the digital content C1, are data servers. The CSI server belongs to the ISP network while the data server CS2 belongs to a content delivery network (designated by CDN).

Figure 3B illustrates, for its part, a method of selecting a data server, capable of providing the digital content, according to this embodiment.

 This method comprises a set of steps 205 to 255 which are similar, respectively, to steps 105 to 155 already described with reference to Figure 2A.

 Here, the UE UE seeks to obtain a digital content Cl by sending a request to the P-ISP access portal of the ISP network of its ISP. This portal selects the data server to be used between a first CSI data server belonging to the ISP network and a second data server CS2 belonging to a CDN network, by means of requests for obtaining information Rev_DNS (IPi) on the addresses. IP of these servers CSi and the user equipment UE, transmitted to the DNS domain name server, which returns this information in an information field (typically a PTR field associated with each IP address) transmitted in response messages Resp_DNS (PTR_IPi) respectively associated with the user equipment UE, the server CSI and the server CS2.

 Compared to the method already mentioned in FIG. 2A, the method according to this embodiment is distinguished in that the P-ISP selection entity does not necessarily have the prior knowledge of the IP addresses of the data servers. The steps 210 and 220 for obtaining information then comprise the following additional steps: a) in a first step, the selection entity P-ISP sends a request to obtain the IP address of the data server CSi ( designated by DNS (CSi)) this request typically comprising the domain name assigned to this data server (steps 211, 231).

These requests can be respectively of the form "DNS CSl.ispl.fr" and "DNS CS2.isp2.fr". b) following reception of this DNS request (CSi), the DNS domain name server returns to the selection entity P-ISP an IPi message including the IP address of the data server CSi (steps 223, 233), this which allows the P-ISP selection entity to have this IP address. These messages can be respectively of the form "139.100.1.1" and "131.100.1.1".

 The information obtaining steps 220 and 230 can then continue similarly to the steps 120 and 130 described in FIG. 2A.

Reference is now made to FIGS. 4A and 4B which illustrate another embodiment of the present invention in which the user equipment UE is in a mobility situation.

FIG. 4A illustrates in particular the architecture of a downloading system according to this embodiment.

 In this system, the data servers CSI and CS2 belong respectively to two distinct ISP1 and ISP2 networks, the P-ISP selection entity and the DNS server always being located in the first ISP1 network.

 Here, the UE user device is a device capable of moving (such as a mobile phone) and thus take different positions that can influence the selection of a data server to use.

 Thus, in a first position (symbolized by Φ), the user equipment UE is in proximity (geographical or administrative) of the first CSI server, to which the P-ISP selection entity sends it to download digital content.

 When the user UE UE moves to a second position (symbolized by ©), it is then in proximity (geographical or administrative) of the second server CS2, to which the P-ISP selection entity sends it back to download a content digital.

 Figure 4B illustrates in more detail a method of selecting a data server, capable of providing the digital content, when the user equipment UE is in such a mobility situation.

 This method comprises a set of steps 305 to 350 which are similar, respectively, to steps 105 to 150 already described with reference to Figure 2A.

Here, however, the user equipment is required to change its position during a movement (step 360), which results in the update of the "Geo" field stored in the PTR field which is associated with its IP address in the DNS server (step 365). For example, a PTR field

"3215.FR.223.111010.092142202252.ispl.fr" becomes

 "76543.PL.WS.111010.092142202252.ispl.fr" when the terminal moves from administrative domain 3215 located in France to a 76543 administrative domain located in Poland.

 Such an update can be performed by the UE or by a proxy (the "Home Agent" server) when this UE indicates its mobility, for example to a visitor network, by means of a CoA address.

 Thus, when issuing a new request for obtaining the content C1 by the user equipment UE (step 370), and following a step of obtaining information on the terminal equipment from the DNS server ( step 375), the P-ISP selection entity has the new position data of the UE and can make the selection based on this updated data (step 380). Here, it is the server CS2 which is selected, in which case the user equipment UE is directed to this server CS2 to retrieve the content Cl (step 390).

Reference is now made to FIGS. 5A and 5B which illustrates another embodiment of the present invention involving downloading of content through network entities belonging to a peer-to-peer network. FIG. 5A illustrates in particular the architecture of a downloading system according to this embodiment. In this system, in addition to an ISP1 network comprising a P-ISP access portal, a DNS server and a CS1 data server, two user equipments UE1 and UE2 form a peer-to-peer network.

The UE1 user equipment can download from the server CS1 chkl part of a digital content C1 at first (symbolized by Φ). When the user UE2 wishes to obtain the same part chkl of this content C1 in a second time (symbolized by ©), it addresses the access portal P-ISP which selects an entity from the server CS1 and the equipment user UE1 both having this part chkl. In this case, it is the user equipment UE1 which is selected (for example on a criterion of geographical proximity), the access portal P-ISP returning the UE2 equipment to this equipment UE1 to download this part chkl of the digital content. FIG. 5B illustrates in more detail a method of selecting a network entity in a system implementing a peer-to-peer network, according to this embodiment of the invention.

 This method starts by obtaining, by the user equipment UE1, a part chkl of the digital content C1 with the data server CSl by the implementation of steps 405 to 420 similar to the steps described above. At the end of this first phase, the equipment UE1 and the server CS1 both have the chkl portion of the content Cl.

Subsequently, UE2 user equipment in turn requires this part chkl from the access portal P-ISP (step 425). The latter then sends a request for information on the user equipment UE2, designated by Rev_DNS (IP2), containing the IP address ^" (here, IP2) of this equipment, to the DNS server which retrieves the information associated with this address. IP2 it has and returns in a response message Resp_DNS (PTR_IP2) (step 430).

 The access portal 440 then selects the entity to use using the information it has on UE1, UE2 equipment and CSl server (step 440). Here, since the UE1 is closer to the UE2, this UE1 is selected to provide the chk1 portion to the UE2.

 This equipment UE1 can also be selected for other reasons, for example because the data server CS1 is overloaded, or because the application requires the content Cl on the UE2 device in "Replay mode" and this server CSl does not necessarily have the chkl part of this content at the time of the request.

 The equipment UE2 is then directed to the UE1 equipment to obtain this part chkl (step 450), similarly to what has been described above. The content chkl can be stored and served directly from a Web browser of UE1 equipment, via a dedicated programming interface, for example the HTML5 API "LocalStorage".

Through this embodiment, it is clear that the network entities providing all or part of the digital content can be both server entities and client entities, and that the principle of the invention can be applied to a network P2P or even any combination of P2P network, CDN content delivery network and ISP network. The chkl content can be stored and served directly from the web browser of the UE1 device via the aforementioned HTML5 LocalStorage API. Finally, reference is made to FIGS. 6A and 6B, which describe a process for updating the state information concerning a network entity CS 1, able to supply all or part of a digital content.

In particular, Figure 6A describes such a process according to an embodiment in which a third party MNT server is involved.

 In this first alternative, the update is thus performed via a third party MNT server. In this case, a CSl network entity wishing to perform an update sends an update request (step 601) to the IAS address storage server, this request containing a "monitoring" field in which information is inserted. intended for the third party MNT server (here, the code "51.80"). The IAS address storage server then transfers a filtered update request containing at least a part of this request containing this information (step 603), as well as the IP address of the entity CS1 (here 139.100.1.1). to the third party server MNT, which can identify the CSl entity by means of this IP address, memorize this information, interpret it and possibly act with the IAS storage server.

 Thus, in the example illustrated in FIG. 6, the code "51" indicates a duration, in minutes, before the deactivation of the network entity CS1. Also, at the end of this period, the third party server MNT returns to the IAS address storage server an update request (step 605) containing the status data concerning the entity CS1, updated (here the second and sixth bits of the status field are set to zero to indicate the deactivation of this entity). The IAS address storage server can then store this new state data, in the information field associated with the IP address of the CSl entity, during a step 607 of updating this server.

Another example of a request for the MNT server is then illustrated. This request is also sent by the entity CSl to the IAS storage server (step 608) and contains information for the MNT server (here, the code "103.80435"). The storage server IAS then transfers a filtered request containing this information and the IP address of the entity CS1 (step 609). In the illustrated example, the code "103" designates information on the number of packets transmitted during the last minute, the number of which is indicated by "80435". Since this information does not bring about an update of the IAS address storage server, no update request is transmitted to it. Figure 6B, for its part, describes an updating process according to an embodiment involving the selection entity.

 In this alternative, the user equipment UE sends an update request to the IAS storage server (step 611), this request containing information for the selection entity SEL (here, the code "4.KZzCWTT9iP "). The storage server IAS then transfers to this entity SEL a filtered request containing this information and the IP address of the UE entity (step 613).

 In the illustrated example, the code "4" designates information on a content identifier, the value of which is indicated by "KZzCWTT9iP". Since this information does not bring about an update of the IAS address storage server, no other update action is performed on this storage server. The value "KZzCWTT9iP" is for example the hash key of a content or a family of available content, or content sought by the UE. This information is exploited by the content delivery services, for example directly by the SEL selection entity, by adding this code in a table containing the contents known by the SEL entity (step 615).

Of course, the invention is not limited to the embodiments described above and shown, from which we can provide other modes and other embodiments, without departing from the scope of the invention. .

 Thus, the selection entity SEL has previously been described as the CRE content request routing entity to which the UE addresses its request for obtaining the digital content CI. However, the invention is not limited to not in this case alone, and this selection entity may be another unit, or another server, connected to both the access entity P-ISP (to be informed of the reception a request from the user equipment UE) to the DNS server (to obtain the information on the content servers storing the desired digital content) and interacting with this DNS server after receiving the request from the user transiting through the P-ISP access entity.

Furthermore, embodiments where a single network entity is selected have been discussed previously. The invention is not limited to this case alone, and several network entities can be selected to provide or store all or part of the service associated with the distribution of the desired digital content, for example the n closest network entities (geographically or administratively) equipment requiring this content. In addition, in the previous embodiments, a single IAS address storage server and a single DNS server have been described. However, the invention also applies when several servers of this type are used. Thus, it is customary to have several DNS servers among which a DNS server acts as an authoritative DNS server, the other secondary DNS servers constituting copies of it. In such a case, the UE and / or the selection entity can exchange requests and messages with the nearest DNS server, in order to decrease the signaling times. In this embodiment, the choice of a level of semantic precision of the returned information field applies.

Claims

A method of selecting at least one network entity to be used for providing digital content (C1) to a user equipment (UE), among a plurality of network entities (CS1, CS2) capable of providing at least one a part of the digital content (C1), characterized in that the method comprises, following the reception (105) of a request (Req (Cl)) for obtaining at least one digital content by a routing entity of Content Request (CRE) for each of the network entities capable of providing at least a portion of the digital content:  sending (115,125) an information request on the IP address of said network entity (Rev_IAS) to an address storage server (IAS); and  receiving (117,127) a response message (Resp_IAS) issued by the address storage server, the response message containing an information data field comprising information data relating to said network entity; said at least one network entity to be used being selected (130) using the information data relating to said network entities. 2. Selection process according to claim 1, characterized in that it further comprises:  send an information request on the IP address of said user equipment (UE) to the address storage server (IAS); and  receiving (117,127) a response message (Resp_IAS) issued by the address storage server (IAS), the response message containing an information data field comprising information data relating to said user equipment (UE),  the at least one network entity to be used being further selected (130) by means of the information data relating to said user equipment (UE). A selection method according to claim 2, wherein the address storage server (IAS) is a domain name server (DNS) and where for each of the network entities able to provide at least a portion of the content digital, the information request on the IP address of the network entity is a reverse DNS request and the information data field is inserted into a PTR field associated with the network entity and stored in the name server domain name (DNS). 4. Selection method according to one of claims 1 to 3, wherein the information data relating to each network entity capable of providing at least a portion of the digital content comprises geographical location data of said network entity, the network entity to be used being selected based on the geographic location data of the network entities capable of providing at least a portion of the digital content and geographical location data of the user equipment (UE). 5. Selection method according to one of claims 1 to 4, wherein the information data relating to each network entity capable of providing at least a portion of the digital content comprise data characterizing the administrative domain of the network of said entity. of network, the network entity to be used selected based on the data characterizing the administrative domains of the network of network entities capable of providing at least a portion of the digital content and data characterizing the administrative domain of the network of the user equipment (EU). The selection method according to one of claims 1 to 5, wherein the information data relating to each network entity capable of providing at least a portion of the digital content comprises status information of said network entity, the network entity to be used being selected based on said status information data of network entities capable of providing at least a portion of the digital content. A method of downloading digital content (C1) by a user equipment (UE) comprising the steps of:  sending (105) a request (Req (Cl)) for obtaining the digital content to a Content Request Routing (CRE) entity; receiving (140) at least one signaling message (Redir (CSl)) designating at least one network entity (CS1) to be used for obtaining at least a portion of the digital content, said at least one network entity to be used (CS1) being selected from among a plurality of network entities capable of providing the digital content (CS1, CS2), by means of information data relating to said network entities obtained from an address storage server (IAS); sending (150) at least one download request (Req '(Cl)) of the digital content to the at least one network entity to be used (CS1); and  receiving (160) at least a portion of the digital content (C1) of the at least one network entity to be used (CS1). Selection entity (SEL) of at least one network entity to be used for providing at least one digital content (C1) to a user equipment (UE), characterized in that the selection entity comprises a processing module capable of selecting said at least one network entity to be used, from among a plurality of network entities (CS1, CS2) able to supply at least a portion of the digital content, by implementing the selection method according to one of the Claims 1 to 6. 9. Selection entity according to claim 8, characterized in that it corresponds to a content request routing entity (CRE) comprising communication means adapted to receive a request for obtaining a digital content (Cl) issued by the user equipment (UE). 10. Address storage server (IAS), able to interact with a selection entity to implement the method of selecting at least one network entity to be used, to provide digital content (Cl) to a device user (UE) according to one of claims 1 to 6, the address storage server comprising:  a storage unit configured to store, for each network entity of a plurality of network entities capable of providing at least a portion of the digital content, the IP address of said network entity associated with related information data; to said network entity;  a communication unit adapted to receive at least one information request (Rev_IAS) on the IP address of one of said network entities able to supply at least a portion of the digital content and configured to transmit at least one response message ( Resp_IAS) comprising the information data relating to said network entity able to provide at least a portion of the digital content. An address storage server (IAS) according to claim 10, characterized in that: the storage unit is further configured to store the IP address of the user equipment (UE) associated with information data relating to said network entity; and  the communication unit is furthermore able to receive an information request (Rev_IAS) on the IP address of said user equipment (UE) and configured to send a response message (Resp_IAS) comprising the information data relating to the said user equipment. 12. Address storage server (IAS) according to claim 10 or 11, characterized in that the communication unit is furthermore able to:  receiving (601) a first request for updating information relating to one of said network entities or user equipment (UE);  relaying (603) a portion of said first update request to a third party server (M NT); and 5 receiving (605), from the third party server (MNT), a second update request, consolidated from the first update request by said third party server (MNT). Address storage server according to one of claims 10 to 12, characterized in that said address storage server is a domain name server (DNS), the address information request. IP is a reverse DNS request and the information data field is inserted in a PTR field associated with the network entity and stored in the domain name server. 5 User equipment (UE) comprising communication means capable of receiving digital content (C1) from at least one network entity (CS1), the communication means being configured to:  sending (105) a request (Req (Cl)) for obtaining the digital content to a content request routing entity (IAS); and Sending (150) a download request (Req '(Cl)) of at least a portion of the digital content to a network entity to be used (CSl) to obtain at least a portion of the digital content, following reception ( 140) of a signaling message (Redir (CSl)) designating said entity to be used, said entity to be used (CSl) being selected from among a plurality of network entities (CS1, CS2) capable of providing at least a portion digital content, by means of information data relating to said network entity obtained from an address storage entity (IAS) by querying information about the IP addresses of said network entities. 15. A computer program comprising instructions for executing the steps of the selection method according to any one of claims 1 to 6, respectively the steps of the downloading method according to claim 7, when said program is executed by a module. processing a selection entity, respectively a user equipment (UE). 16. A computer-readable recording medium on which a computer program is recorded according to claim 15.