EP3243315A1

EP3243315A1 - Method of protocol management and operation of a content distribution network

Info

Publication number: EP3243315A1
Application number: EP16700952.1A
Authority: EP
Inventors: Soufiane Rouibia; Bastien Casalta; Imane MNIE-FILALI
Original assignee: Easybroadcast
Current assignee: Easybroadcast
Priority date: 2015-01-09
Filing date: 2016-01-08
Publication date: 2017-11-15
Also published as: FR3031643B1; US20170374142A1; WO2016110583A1; FR3031643A1

Abstract

Method of management of a peer-to-peer network operating according to at least one exchange protocol aimed at disseminating items of content within said network between a plurality of peers (P₀...P_N), in which method, during the dissemination of an item of content between two peers, the peer (P₀) receiving said item furthermore receives a piece of information relating to the state of the peer-to-peer network comprising at least one value of a parameter of the network originating from peers other than those with which said peer (P₀) is connected, and in which, after each receipt of an item, the peer (P₀) determines, on the basis of said piece of information accompanying the item received, at least one value, at least partially updated, of the parameter of the peer-to-peer network, so as to induce a manner of operation of the exchange protocol dependent on the updated values of the parameters of the network and at least one parameter representative of the state of said peer (P₀).

Description

METHOD FOR THE MANAGEMENT AND PROTOCOLIAL OPERATION OF A CONTENT DISTRIBUTION NETWORK

The present invention relates to methods and computer program products for exerting an action on the management of peer-to-peer networks, also called P2P, and the dissemination of information in these networks, operating according to an exchange protocol.

Peer-to-Peer is a network approach where all users, called peers, behave as both a client and a server depending on the nature of the request they receive. This procedure provides fast and efficient sharing in which content is available within multiple devices by replication.

Much more than data sharing, this approach makes it possible to exploit the machine resources of each connected peer rather than those of a centralized station or server. The peer-to-peer architecture adapts to changes in the size of the network, the latter generating in particular its own organization to the addition of a new peer.

However, with this scalability concept that optimizes bandwidth utilization, known peer-to-peer network management solutions, for example in BitTorrent, eDonkey, Gnutella, or Sopcast networks, provide peers with a local view of the network. which limits their decision making and does not allow them to invest, at the true level of their abilities, to ensure a good quality of sharing and service throughout the network.

The operations of the peer-to-peer networks mentioned above are globally similar to each other. The few differences are in the methods of distribution or provision of content, and in the policy of choosing the peer to serve. In a well-known manner, a peer who wants to share content makes it accessible by proposing for example a "torrent" file, in the case of the BitTorrent network, or by connecting to an application, such as eMule or Shareaza for the eDonkey networks or Gnutella, which offers a search tool and makes some of the peer's personal storage space available to other connected peers. For the choice of peer to serve, the BitTorrent network exchange protocol uses powerful bandwidth peers to ensure network survival, by randomly selecting the first list sent by a "tracker", which is a server listing which peers are involved in the distribution desired content. Other networks operate on a waiting list, for example with an age coefficient in the case of the eDonkey network.

In some networks, like BitTorrent for example, the contents are not directly available. The peer must search for a file corresponding to the desired content on Internet sites that act as directories, called meta-information files. The peer launches its application and begins sharing with a peer group built around that same content.

In the case of content broadcast in real time, "live" in English, the desired content may be available on an Internet page, which requires the launch of an extension module, or "plugin" in English, on the page. Internet browser, or "browser" in English, for example the AceStream plug-in. In one variant, launching an application after retrieving the link broadcasting the content may be necessary, for example the Sopcast or AceStream applications.

In the case of content broadcast in real time, the peer contacts a tracker, which responds with a list of peers who already have or are downloading the desired content. The peer sends queries to the list of peers sent by the tracker and starts sharing if they accept.

Exchange protocols for peer-to-peer networks are used to define a basic operation to manage different exchanges between peers. In particular, peers in the network can exchange peers lists to find the most suitable peer, a step called "peer exchange" in English. This technique makes it possible to use the bandwidth of the peers downloading content for searching for peers, information and content present in the network, instead of using the bandwidth of the network server.

A peer who has finished downloading a piece of content may send to the other peers with which he is connected an acknowledgment message, "Hâve message" in English, indicating that the peer has received a piece and has verified its integrity through hash tables. This allows to have a local vision, limited to the vicinity of said peer, that is to say to the peers with which it is connected, the progress of these neighboring peers in the download. Peers can also know who to turn to for parts that interest them. This also allows you to calculate the rarest piece in a certain neighborhood and ask for it later. In response to this acknowledgment message, peers may send a message to signal their interest, "interested" in English. In response to this message of interest, if the peer agrees to share the piece, he may send an acceptance message, "unchocke message" in English. If not, it sends a refusal message, "choke" in English, and puts the interested peer on hold. The peers can exchange with each other a message containing a string of bits indicating the possession or not of a piece, a message called "Bitfield" in English.

In the known management modes of peer-to-peer networks, trackers listing which peers are involved in the distribution of the searched content only serve as a directory role. The trackers send an initial peer list to which the current peer, called "user", can connect and passively collect information, such as the numbers of peers connected, the size of the desired content, information from hashes for the integrity of file sharing, "hash information" in English, the timestamp of content, or "timestamp" in English, especially in the case of real-time sharing. Depending on the size of the network, these trackers can quickly be overloaded.

In some known peer-to-peer networks, the power of a peer's bandwidth may further privilege it more than others, allowing it to be served throughout its connection. Some peers may have selfish behavior by not making other peers, also known as "network nodes", benefit from their good bandwidth. Thus, peers do not invest in the survival of the network and do not seek to help other peers in difficulty because of their low download rates: the notion of "super-node" or "super-peer" is nonexistent.

In this type of network, a random selection of peers is not practiced, which tends to decrease the homogeneity of the network and to form clusters of peers, or "clusters" in English, creating more advanced groups of peers in terms of downloading than others. In some peer-to-peer networks, such as the eDonkey network, powerful peers can be queued like any other peer, which can not exploit their strength.

The application FR 2 989 241 describes a method for broadcasting content in client / server mode to at least one client in a format allowing its subsequent distribution. in P2P mode. To do this, the client receives the IP coordinates and the port of the other clients of the network when broadcasting a piece of content in client / server mode.

The application EP 2 109 289 discloses a method for facilitating the distribution of content in P2P mode. A peer can know the other members of the swarm through a stream of metadata received with the content and containing information to identify the members of the swarm, these metadata being used directly by the peer to optimize the swarm and reception of content.

US application 2008/133698 discloses a method of distributing content

P2P based on the rarity of the requested pieces.

In known methods, peers only have a local view of the state of the network, which limits their actions within it. They do not know for example where the download of any particular piece at the network level, are not aware of the rarest part of the network, the average download rate, the overall power of the network nor of its real size.

In view of the limitations of the current networks, discussed above, there is a need to improve the management of peer-to-peer networks, allowing them to evolve during peer-to-peer exchanges, in order to provide the best quality of service possible and good distribution of data to share.

The aim of the invention is to meet this need and it succeeds, according to one of its aspects, thanks to a method of managing a peer-to-peer network operating according to at least one exchange protocol intended to broadcast data. pieces of content within said network between a plurality of peers,

a method in which, when broadcasting a piece of content between two peers, the peer receiving said piece further receives status information from the peer-to-peer network having at least one value of a network parameter from peers other than those with which the peer is connected,

and wherein, after each reception of a piece, the peer determines, from said information accompanying the piece received, at least one at least partially updated value of the parameter of the peer-to-peer network, in order to induce an operation of the protocol exchange dependent on said at least one updated value of the network parameter and at least one parameter representative of the state of said peer. The operation of the exchange protocol can thus depend on the updated values of the network parameters after each coin reception by a peer.

An operation of the exchange protocol depending on the updated values of the network parameters and at least one parameter representative of the state of said pair is advantageously induced.

According to this new method, the peers manage themselves, the choice of an adapted protocol position being determined locally by each pair according to its state and from precise information of the state of the network, brought locally to each peer and retrieved from other peers, including remote peers in the network and without direct data exchange with that peer. The exchange protocol is thus evolving, not fixed, taking shape, evolving and adapting through the peers that integrate the network.

Thanks to the invention, during exchanges between peers, a calculation of the dynamic aspects of the peers and the network, in particular the bandwidth, the pieces already downloaded, the rare pieces of the neighborhood, the state of the neighborhood peers, is realized simultaneously. to estimate the exact state of the network, giving the possibility to each peer to act on the network according to its state, in order to adopt the most appropriate protocol attitude.

The invention makes it possible to involve the peers of the network so that they invest themselves at their true level of capacity in the decision-making, by relating to each peer of the network the global information locally so that he can choose his protocol posture. The combination of the global parameters of the network gives the possibility to the peers to act according to their own capacities. Having a global view of the network allows peers to move forward in a harmonious way in downloading, and to reduce the phenomenon of clusters of peers, very common in this type of network. This allows optimal and decentralized management of the network.

Using the capabilities of peers and exploiting their resources avoids the use of an external help entity, such as a content delivery network (CDN). The use of CDNs is effective for example in reducing latency and load within the network, but is expensive.

The term "network-connected peer" refers to a peer connected to the network, seeking to retrieve content and / or having at least some of the content sought. By "peers other than those with which the peer is connected", one must understand distant peers, not belonging to the neighborhood of the peer, which groups together only about 20 to 30 neighboring peers.

The method according to the invention thus enables the current peer to have a precise, global and extended network vision, not limited to its vicinity.

The invention is also adapted to real-time downloading of content, including content corresponding to television programs, films or sports events. This makes it possible to quickly adapt the behavior of the network throughout the downloading of the pieces forming the content.

The content to be downloaded is preferably a multimedia content, being for example in * .arr, * .mpg, * .mov, * .esf, * .wmv, * .dvx, * .qt, * .avi format, among others . It can also be at least one musical file in * .wav format, * .mp3, * .ra, * .ram, * .aiff, * .en * .mid, among others or in images * .jpg, * .bmp, * .png, * .tif, * .ps, * .eps, among others. It can still be software packages, games or any other program, including protected by intellectual property rights. The content is advantageously divided into several pieces of content.

Each peer connects advantageously to the network and begins its exchanges by a basic protocol operation, as described above. As part of the exchange of parts between peers, the status information of the peer-to-peer network comprising at least one value of a network parameter is advantageously transmitted between the peers.

Thanks to the invention, rather quickly, for example after the download of about 10 or 15 pieces, the peer thus begins to have a good vision of the network, transported by the neighbors of his neighbors. The more we advance in the network, and the more the vision of the latter becomes global and precise, evolving by integrating more and more information.

According to an exemplary implementation of the invention, the information accompanying each piece received by the peer contains at least one value of a parameter concerning the parts shared between the peers, in particular the download rate of each piece or a list. some of the rarest pieces available on the peer-to-peer network.

The list of the rarest parts available on the peer-to-peer network can group the indices of the rarest pieces calculated according to "Bitfield" messages sent by each peer to the other peers in the network when connecting to the network and reporting the pieces it has already received, and "Have" acknowledgment messages received by network peers each time a coin is received and containing the index of said piece and the estimate of the index of the rarest part of the network at this time.

In a variant or in combination with the foregoing, the information accompanying each piece received by the peer contains at least one value of a parameter relating to the peer-to-peer network itself, in particular the overall bandwidth of the network, the number network peers, the estimated wait time for each part, a potential peer waiting list, or an index of the quality of the peer connection to the network.

The overall bandwidth of the network can be calculated from an average bandwidth using an estimate of the bandwidth of the peer made at the moment when the latter begins to download a piece and the sum of the bandwidths contained in the messages received. by peers with which said peer is connected divided by the number of peers having sent said messages.

The calculation is done for example as follows:

i = 0 ¹

with W _c = Σf _{= 0} W;

B (t): Bandwidth at the instant t of the peer P ₀

W (t): Weight at time t of the peer P ₀ with Wo = W (ti) and Po = P (ti),

And Biftj: V _\ Bandwidth Bandwidth

B ₂ (t): Bandwidth of the peer P ₂

Bnft): Bandwidth of the peer P

Wi (t): Weight, which is the number of peers who contributed to the download.

In a variant still or in combination, the information accompanying each piece received by the peer contains at least one value of a parameter concerning the security of the network, in particular the ratio between the number of pieces broadcast and the number of pieces received or a reliability index on the presence of false content pieces. This ratio makes it possible to evaluate the number of pieces "lost" on the network during their distribution. This reliability index is used to calculate the number of malicious peers, in order to measure the effectiveness of the network and its level of security. After each piece reception, the peer advantageously checks whether the piece received corresponds to the expected piece or if it is corrupted content, using hash tables, including SHA1 technology. In the second hypothesis, the peer may increment said reliability index of the number of new malicious peers transmitting the corrupted content. The maximum value between the value of the reliability index of the peer and those of neighboring peers is advantageously recorded and sent by the peer in the message "Have".

Said reliability index is preferably reset periodically, in order to avoid ending up with an erroneous index, especially in the case where malicious peers leave the network at the instant t when the corrupted content is received. This makes it possible to have a more accurate view of the security level of the network, based on the coins received from time t + 1 and on the reliability indices of neighboring peers calculated in the same way.

The parameter representative of the peer state and used to adapt the operation of the exchange protocol may concern its bandwidth, its quality of connection, the parts already received and / or the power of the processor on which the peer operates.

The peer advantageously transmits to the other peers of the network said at least one value of a parameter of the peer-to-peer network at least partially updated after receiving a piece of content, in order to contribute to the transport of the state information to other peers, who will in turn be able to update this information and adapt their protocol position.

The status information of the peer-to-peer network comprising at least one value of a network parameter and accompanying the broadcast of a piece of content is advantageously inserted into the "Have" acknowledgment message, indicating to the others network peers that such piece, in particular identified by an index, was received by the peer.

The network status information can be integrated following the message "Have" of a peer Po, in the form of indices, for example presented as follows: "Have (index piece received, index of the room the most rare, (Bandwidth, Weight), Reliability Index, ...) ", and noted P ₀ (Idp, Irp, (B (t), W (t)), Is, ...). According to the invention, depending on the values of the network parameters updated after each reception of a piece of content, a peer having a bandwidth greater than a predefined threshold and / or a power processor greater than a predefined threshold may be oriented to at least one other peer suffering from a poorer quality of connection to serve as a gateway to the network, then playing a role of "super-peer".

These predefined thresholds advantageously depend on the nature of the exchanges on the network, consisting for example of the sharing of files of the network or the exchange of content broadcast in real time, and the quality of the content, for example HD ("High Definition"). in English) or SD ("Standard Definition").

Said predefined bandwidth threshold may be equal to 300 Kb / s, better at 600 Kb / s, for example in the case of SD quality content and broadcast in real time.

Said predefined threshold of processor power may be equal to 1 GHz, for example in the case of SD quality content and broadcast in real time.

In a variant, depending on the values of the network parameters updated after each reception of a piece of content, a peer having a bandwidth less than said predefined threshold is oriented towards areas of the network comprising peers having higher bandwidths. At the beginning of its connection to the network, the peer may have sufficient bandwidth, but later, for example, other tasks may be performed on the processor of the device by which it is connected to the network, thus decreasing its bandwidth, and therefore its quality of service. Thanks to the invention, the peer can adapt its protocol position within the network according to the evolution of its bandwidth and its global knowledge of the network.

The action of the peer on the network can be in the form of a disconnection of a peer or peer group in the network to connect to another peer or group in order to smoothly advance the download. . Depending on the values of the network parameters refreshed after each reception of a piece of content, the peer may move to another peer group in the network more appropriate according to its resources.

Depending on the values of the network parameters updated after each reception of a piece of content, a peer having a bandwidth greater than the overall bandwidth of the network may be disconnected from a portion of the peers with which it is connected in order to be connected to peers in the network with lower bandwidth. In an exemplary implementation of the invention, as a function of the values of the network parameters updated after each reception of a piece of content, a peer comprising rare pieces is oriented towards areas of the network where the entropy of said parts rare is weak. This allows remote peers to also benefit from these rare contents. Indeed, in a peer-to-peer network, peers may own no part, some parts, or all parts of the content.

In the management method according to the invention, the bandwidth parameters and the list of the rarest parts can serve as orientation rule: a peer that shares a high download average represents a neighborhood with an interesting download average. Peers who have difficulty starting their downloads in a consistent manner can move on their own to be able to track the download speed of the network.

In the case where the exchange protocol allows the network to broadcast content pieces in client / server mode to at least one peer, the distribution of the pieces within the network can be switched from the peer-to-peer mode to said client / mode. server according to the values of the network parameters updated after each reception of a piece of content and at least one parameter representative of the state of said peer.

In these so-called "hybrid" networks, using one or more additional servers to implement the distribution of content in client / server mode, the method according to the invention makes it possible to determine the moment of switching between the two modes and how to proceed. . For example, if the average bandwidth and the size of the network show that the peers are not able to ensure a sufficient quality of service, the additional server or servers will be solicited by the peers most in difficulty to receive the parts and the missing bandwidth. Thanks to the invention, the intervention of servers is accurate and targeted.

Of course, the characteristics mentioned above are not limiting and may depend on the peer-to-peer network and the exchange protocol concerned.

According to another of its aspects, the invention also relates to a computer program product for implementing the method of managing a peer-to-peer network according to the invention, operating according to at least one exchange protocol. intended to broadcast pieces of content within said network between a plurality of peers, the program product computer having code instructions that, executed on a processor, cause:

when broadcasting a piece of content between two peers, the peer receiving said piece further receives status information from the peer-to-peer network comprising at least one value of a network parameter from peers other than those with which said peer is connected, and that

after each reception of a piece of content, the peer determines, from said information accompanying the piece received, at least one at least partially updated value of said peer-to-peer network parameter in order to induce an operation of the exchange protocol dependent on said at least one updated value of the network parameter and at least one parameter representative of the state of said pair.

The above characteristics for the management process apply to the computer program product.

The invention will be better understood on reading the detailed description which follows, examples of non-limiting implementation thereof, and on examining the appended drawing, in which:

- Figures 1 and 2 illustrate steps in the implementation of the method according to the invention.

As shown in FIG. 1, a peer Po can integrate, during a step 11, a peer-to-peer network in order to download and share pieces of content.

Said peer P ₀ advantageously starts its exchanges in the peer-to-peer network by basic protocol operation, using network peer lists exchanged between peers to find the best matched pair according to the desired content. Po peer, when finished downloading a piece of content advantageously sends to the other peers of the network with which it is connected a message "Hâve" of acknowledgment, indicating that he received a piece and checked his integrity through hash tables, including SHA1 technology. In response to this "Hâve" message, other peers can send an "interested" message to signal their interest. In response to this "interested" message, if the peer P ₀ agrees to share the coin, it can send an "unchocke" acceptance message. Otherwise, it sends a "choke" rejection message, and puts the interested peer on hold. Network peers also exchange advantageously between them a "Bitfield" message comprising a string of bits indicating the possession or not of a part.

In the method according to the invention, the state of the network is measured, during a step 12 shown in FIG. 1, during the diffusion of a piece of content between two peers, and the peer P ₀ receiving said piece further receives network status information having at least one value of a network parameter from peers other than the peer neighbors of said peer.

During a step 13, the state of the peer Po is also advantageously measured. After each reception of a part, the peer P ₀ can determine, from said information accompanying the received part, at least one at least partially updated value of the peer-to-peer network parameter in order to induce, in a step 14, an operation of the exchange protocol depending on the updated values of the parameters of the network and at least one parameter representative of the state of said peer.

As represented in FIG. 2, the status information of the peer-to-peer network comprising at least one value of a network parameter and accompanying the broadcasting of a piece of content, during a step 21, can be inserted in a message "Have".

After each reception of a room, as shown in FIG. 2, the peer P ₀ transmits to the other peers of the network Pi ... P _N said at least one value of a parameter of the at least partially updated peer-to-peer network.

As can be seen in FIG. 2, said information accompanying each piece received by the peer Po advantageously contains at least one value of a parameter relating to the pieces shared between the peers, for example a list of the rarest pieces available on the peer-to-peer network. peer. This list of the rarest parts available on the peer-to-peer network can gather the indices of the rarest pieces calculated according to "Bitfield" messages sent by each peer to the other peers of the network during its connection to the network and signaling the parts it has already received, and "Have" messages received by network peers each time a coin is received containing the index of the coin and the estimate of the index of the rarest coin in the network at this moment.

In peer-to-peer exchange protocols known, the default calculation of the rarest part of the network is for example as follows: Bitfield P ₂ 1111111011111111

Bitfield P ₃ 1000000011100001

Bitfield P ₄ 0011100011100110

Sum of bits 2122211033311222

A bit equal to 0 advantageously corresponds to a missing piece, a bit equal to 1 corresponding to a coin in possession. The index of the rarest piece then corresponds advantageously to: Min (sum Bitfields).

The peers Pi, P ₂ and P ₃ can include in their messages "Hâve" information Pi (index of the downloaded part, the rarest piece according to the global vision of the peer), for example: Pi (1,5), P ₂ (11, 9) and P ₃ ( _{3, 13} ). In this example, the peer P ₀ recalculates the index of the rarest part as follows:

1 - Recalculation of bitfield messages by integrating his:

Bitfield P ₀ 1000000000000000

Bitfield Vx 1111111011111111

Bitfield P 2 1000000011100001

Bitfield P 3 0011100011100110

Sum of bits 3122211033311222

2- Taking into account the rarest parts reported by the other peers, by decreasing the index of the part reported as rare (it should be noted that the decrementation is limited to zero and does not go into negative value):

Old global vision of indices 31222110333 Π222

New global view of indices 3122111023310222 In the case of several equal bits, a random calculation, in English, of low-indexed parts can be done. The index of the rarest piece Idp is then calculated by: Idp = random (min (3122111023310222)).

In a variant or in combination, the information accompanying each piece received by the peer Po contains the download rate of each piece.

The information accompanying each piece received by the peer P ₀ may also contain, as represented in FIG. 2, at least one value of a parameter relating to the peer-to-peer network itself, for example the global bandwidth of the network, the number of peers in the network, and a possible queue of parts to be recovered, particularly in the case of sharing content broadcast in real time. The overall bandwidth of the network can be calculated from an average bandwidth using the estimate of the bandwidth of the peer Po at the moment when the latter begins to download a piece and the sum bandwidths contained in the messages received by the peers with which said peer P ₀ is connected, divided by the number of peers having sent said messages.

In a variant, the information accompanying each piece received by the peer Po contains the estimated waiting time for each piece and / or an index on the quality of the peer connection to the network.

The information accompanying each piece received by the peer may also contain, as in the example shown in FIG. 2, at least one value of a parameter relating to the security of the network, in particular the ratio between the number of pieces broadcast and the number of pieces received or a reliability index on the presence of false pieces of content.

After each piece reception, the peer Po advantageously checks whether the piece received corresponds to the expected piece or if it is corrupted content, using hash tables. In the second hypothesis, the peer P ₀ can increment said reliability index of the number of new malicious peers transmitting the corrupted content. The maximum value between the value of the reliability index of the peer Po and those of the neighboring pairs is advantageously recorded and sent by the peer Po in the message "Have".

Said reliability index is preferably reset periodically. The time interval t before the reliability index is reset depends advantageously on the size of the exchanged content. For example, in the case of a 600 GB content, the time t corresponds to the time required to download 5 pieces, which corresponds to approximately 1% of the time provided for downloading the content. In this case, the calculation of the reliability index is as follows: for five_pieces_completed = <5:

if not correct_piece and new_peer:

index + = 1

index = max (indeXj index_swarm)

else:

index = 0

index = max (index index_swarm)

Said parameter representative of the peer state P ₀ used to adapt the operation of the exchange protocol may concern its bandwidth, its connection quality, the parts already received or the power of the processor on which the peer operates. According to the invention, as a function of the values of the network parameters updated after each reception of a piece of content, in the case where the peer P ₀ has a bandwidth greater than a predefined threshold and / or a power processor greater than a predefined threshold, it can be directed to at least one other peer suffering from a poorer quality of connection to serve as a gateway to the network.

In the case where the peer P ₀ has a bandwidth less than said predefined threshold, as a function of the values of the network parameters updated after each reception of a piece of content, it may be directed to areas of the network comprising peers having higher bandwidths.

According to the values of the network parameters updated after each reception of a piece of content, in the case where the peer Po has a bandwidth greater than the overall bandwidth of the network, it can be disconnected from a part of the peers with which it is connected to be connected to peers of the network having a lower bandwidth.

In an exemplary implementation of the invention, as a function of the values of the network parameters updated after each reception of a piece of content, in the case where the peer P ₀ comprises rare pieces, it may be directed towards areas of the network where the entropy of said rare pieces is low.

In the case where the network is hybrid, that is to say that the exchange protocol allows the distribution of content pieces in client / server mode to at least one peer Po, the dissemination of the parts within the network is advantageously switched from the peer-to-peer mode to said client / server mode as a function of the values of the updated network parameters after each reception of a piece of content and at least one parameter representative of the state of said peer Po.

The peer Po advantageously has a device, including a computer, a tablet or a smart mobile phone, "smartphone" in English, comprising a processor on which can run a computer product program with code instructions for the implementation of implementation of the management method according to the invention.

The invention is not limited to the examples which have just been described.

The method according to the invention can be implemented in any peer-to-peer exchange network, such as BitTorrent, Gnutella or eDonkey, for example. The network connection used may be the Internet, or a local network such as Ethernet or a university campus network. It can also be networks using wireless technologies such as telephone networks.

Of course, the invention can be applied to other exchange networks and other network connection modes.

The expression "comprising a" shall be understood as meaning "containing at least one" unless the contrary is specified.

Claims

A method of managing a peer-to-peer network operating according to at least one exchange protocol for distributing pieces of content within said network between a plurality of peers (P ₀ ... PN),

a method in which, when broadcasting a piece of content between two peers, the peer (Po) receiving said piece further receives status information from the peer-to-peer network having at least one value of a network parameter from peers other than those with which said peer (P ₀ ) is connected,

and wherein, after each reception of a piece, the peer (P ₀ ) determines, from said information accompanying the piece received, at least one at least partially updated value of the peer-to-peer network parameter, in order to induce an operation of the exchange protocol depending on said at least one updated value of the network parameter and at least one parameter representative of the state of said peer (Po).

2. The method of claim 1, wherein the information accompanying each piece received by the pair (P) contains at least one value of a parameter relating to the parts shared between peers (P _0.. .P _N), including the download rate of each piece or a list of the rarest pieces available on the peer-to-peer network.

3. Method according to claim 1 or 2, wherein the list of the rarest parts available on the peer-to-peer network, which can be contained in the information accompanying each piece received by the peer (Po), includes the indices of the parts. the rarer ones calculated according to messages sent by each peer to the other peers of the network when it connects to the network and signaling the pieces it has already received, and acknowledgment messages received by the peers (P ₀ . .P _N ) of the network at each reception of a part and containing the index of said part and the estimate of the index of the rarest part of the network at this time.

4. Method according to any one of the preceding claims, in which the information accompanying each piece received by the peer (Po) contains at least one value of a parameter concerning the peer-to-peer network itself, in particular the bandwidth. network, the number of peers (P ₀ ... _N ) of the network, a queue of parts to be recovered or an index of the quality of the peer connection (Po ... P _N ) to the network .

The method of any preceding claim, wherein the overall bandwidth of the network is computed from a bandwidth. average using an estimate of the bandwidth of the peer (Po) made at the moment when the latter begins to download a piece and the sum of the bandwidths contained in the messages received by the peers with which said peer (P ₀ ) is connected divided by the number of peers who sent said messages.

6. Method according to any one of the preceding claims, wherein the information accompanying each piece received by the peer (Po) contains at least one value of a parameter concerning the security of the network, including the ratio between the number of pieces. broadcasted and the number of coins received or a reliability index on the presence of fake pieces of content.

7. Method according to any one of the preceding claims, wherein said parameter representative of the state of the peer (P ₀ ) relates to its bandwidth, its quality of connection, the parts already received and / or the power of the processor on which the peer (P ₀ ) works.

A method according to any one of the preceding claims, wherein the peer (P ₀ ) transmits to the other peers (Pi .. .P _N ) of the network said at least one value of a parameter of the peer-to-peer network at least partially refreshed after receiving a piece of content.

A method according to any one of the preceding claims, wherein the status information of the peer-to-peer network having at least one value of a network parameter and accompanying the broadcast of a piece of content is inserted into a acknowledgment message, indicating to the other peers (Ρ _Ι ., .Ρ _Ν ) of the network that such piece, in particular identified by an index, has been received by the peer (P ₀ ).

The method as claimed in any one of the preceding claims, wherein, as a function of the values of the network parameters updated after each reception of a piece of content, a peer (P ₀ ) having a bandwidth greater than a predefined threshold and / or a power processor greater than a predefined threshold is directed towards at least one other peer suffering from a poorer quality of connection to serve as a gateway to the network.

11. The method as claimed in claim 1, in which, as a function of the values of the network parameters updated after each reception of a piece of content, a peer (P ₀ ) having a bandwidth greater than Overall network bandwidth is disconnected from some of the peers with which it is connected in order to be connected to peers in the network with lower bandwidth.

12. The method as claimed in claim 1, wherein, as a function of the values of the network parameters updated after each reception of a piece of content, a peer (P ₀ ) having a bandwidth less than a predefined threshold is oriented to areas of the network with peers having higher bandwidths.

A method according to any one of the preceding claims, wherein, depending on the values of the network parameters updated after each reception of a piece of content, a peer (P ₀ ) having rare pieces is oriented towards areas of the network. network where the entropy of said rare pieces is low.

14. Method according to any one of the preceding claims, wherein, the exchange protocol for the broadcast of content pieces in client / server mode to at least one peer (P ₀ ), the dissemination of parts within the network. is switched from the peer-to-peer mode to said client / server mode according to the values of the updated network parameters after each reception of a piece of content and at least one parameter representative of the state of said peer (P ₀ ).

15. Computer program product for implementing the method of managing a peer-to-peer network as defined in any one of the preceding claims, operating according to at least one exchange protocol for broadcasting pieces of content within said network between a plurality of peers (PO..PN), the computer program product having code instructions which, executed on a processor, cause:

when broadcasting a piece of content between two peers, the peer (P ₀ ) receiving said piece further receives status information from the peer-to-peer network having at least one value of a network parameter from peers other than those with which said peer (P ₀ ) is connected, and that

after each reception of a piece of content, the peer (P ₀ ) determines, from said information accompanying the received piece, at least one at least partially updated value of said parameter of the peer-to-peer network in order to induce an operation of the exchange protocol dependent on said at least one value updated the network parameter and at least one parameter representative of the state of said peer (P ₀ ).