JP6591946B2 - Server device, transfer device, and program for content distribution system - Google Patents

Description

  The present disclosure relates to a server device, a transfer device, and a program of a content distribution system that performs routing based on a content name.

  A content distribution system that requests and distributes content based on a name indicating the content has been proposed. Patent Document 1 and Non-Patent Document 1 disclose a content centric network (CCN) which is one of such systems.

JP 2009-277234 A

V. Jacobson, et al. , "Networking Named Content", in Proceedings of ACM CoNEXT 2009, December 2009

  In CCN, a server device that publishes content divides the content into one or more objects called chunks, and a client device acquires content in units of the divided objects. In addition, a communication device (hereinafter referred to as a transfer device) that has transferred an object in the CCN can store (cache) the object. When the transfer device receives an interest packet (request packet) requesting an object cached by the own device from the client device, the transfer device caches the interest packet without forwarding the interest packet to the server device. Can be transmitted to the client device that is the source of the interest packet.

  Below, an example of operation | movement of a transfer apparatus is demonstrated. The transfer apparatus manages CS (Contents Store), FIB (Forward Information Base), and PIT (PIT: Pending Interest Table). CS is information indicating an object cached by the own device. The FIB is information indicating a relationship between an object requested by the interest packet and an interface to which the interest packet is to be transferred. The PIT is information indicating the relationship between the object requested by the transferred interest packet and the interface that has received the transferred interest packet.

  When the transfer device receives the interest packet, the transfer device searches the CS and determines whether or not the object requested by the interest packet is cached. If it is cached, the data packet including the object cached by the own device is transmitted to the client device that is the source of the interest packet. The interface that transmits the data packet is an interface that has received the interest packet. On the other hand, when the object requested by the received interest packet is not cached, the transfer device searches for the PIT, and already transfers the interest packet requesting the same object as the interest packet. It is determined whether it is in the state of waiting for reception. In the state of waiting for reception, the received interest packet is not transferred, and the PIT is updated so that the reception interface of the interest packet is associated with the object requested by the interest packet. On the other hand, if the received interest packet is not waiting for the requested object, the interest packet is transferred from the interface determined based on the FIB and the PIT is updated. Further, when the transfer apparatus receives a data packet including an object, the transfer apparatus determines and transfers the transfer destination interface of the object based on the PIT, and deletes information related to the object from the PIT. The transfer destination interface is an interface that has received an interest packet requesting the object. In addition, the transfer device updates CS when it caches the received and transferred object.

  As described above, in the CCN, a data packet including an object is transmitted to the interface that has received the interest packet requesting the object. Therefore, the object is transferred in the reverse direction along the same route as the interest packet requesting the object, and is distributed to the client device that requested the object. The interest packet includes information (object name) indicating the requested object, but does not include information for specifying the client device that is the source of the interest packet. Therefore, the server device or transfer device that distributes the stored object cannot recognize in which region or network the client device that requested the object is located.

  On the other hand, in the current content distribution over the Internet, the IP address of the requesting client device is set in the IP packet requesting the content. Therefore, the server device that distributes content can determine the region / network in which the requesting client device is located based on the IP address of the requesting client device. Therefore, the server device determines in advance a region in which each content can be distributed, for example, a country, and if the client device from which the content is requested is in a region where the content can be distributed, the requested content is displayed. It is possible to perform control such that the requested content is not distributed unless it is distributed within a distributable region.

  The present invention provides a mechanism capable of controlling a content distribution destination in a content distribution system that transfers routing of a content request packet based on a content name.

According to one aspect of the present invention, a transfer device of a content distribution system that transfers a request packet including a content name of content for which distribution is requested based on the content name, the content requested by the request packet, and the request packet A request for requesting the content based on the identifier of the own device and the list information when receiving a publicity message indicating the content and including the list information, holding means for holding transfer information indicating the relationship with the transfer destination interface A determination unit that determines whether or not to transfer the request packet when the packet is received, and a request for requesting the content indicated by the publicity message to the reception interface of the publicity message when the determination unit determines to transfer the packet The transfer information as the packet transfer destination interface And pressurizing, when the determination means determines not to transfer, and processing means for adding information indicating that no forward the request packet requesting the content which the publicity message indicates to the transfer information, and wherein the content delivery The identifiers of the plurality of transfer devices in the system are indicated by a plurality of bits, and the list information included in the publicity message is the transmission destination of the content indicated by the publicity message among the plurality of transfer devices of the content distribution system. The identifier of the transfer device that can be generated by a logical operation for each bit of the identifier of the transfer device that can be used, or cannot be the destination of the content indicated by the publicity message among the plurality of transfer devices of the content distribution system Are generated by a bitwise logical operation .

  According to the present invention, it is possible to control a content distribution destination in a content distribution system that transfers routing of a content request packet based on a content name.

The lineblock diagram of the contents distribution system by one embodiment. The sequence diagram of the public information message delivery by one Embodiment. 1 is a diagram illustrating an FIB according to one embodiment. FIG. The sequence diagram of the public information message delivery by one Embodiment. Explanatory drawing of the restriction | limiting of the content name by one Embodiment. The block diagram of the server apparatus by one Embodiment. The block diagram of the transfer apparatus by one Embodiment.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In addition, the following embodiment is an illustration and does not limit this invention to the content of embodiment. In the following drawings, components that are not necessary for the description of the embodiments are omitted from the drawings. In the following, the embodiment of the present invention will be described assuming that the content distribution system is a CCN. However, the present invention provides a content distribution system in which the transfer device performs routing based on the content name, so that the region where the client device that requested the content is located or the network cannot be immediately determined from the content request packet. Can be applied.

  FIG. 1 is a configuration diagram of a content distribution system according to the present embodiment. In FIG. 1, the content distribution system includes four networks 31, 32, 33 and 34. For example, each network can be distinguished by the operating operator. Each network can be distinguished by a predetermined region such as a country. In other words, a network that accommodates client devices arranged in a predetermined area can be a single network. In the present invention, distribution control is performed by setting whether or not content can be transmitted for each network. In the configuration of FIG. 1, the network 31 includes the transfer device 21, the transfer device 22, and the server device 1, the network 32 includes the transfer device 23, the network 33 includes the transfer device 24, and the network 34 includes the transfer devices 25 and 26. Is included. Note that FIG. 1 shows only a transfer apparatus that interconnects networks. That is, each network can include a plurality of transfer devices (not shown). Further, in FIG. 1, only one server device 1 is shown, but a server device (not shown) may be included in the networks 31 to 34. Further, in FIG. 1, the transfer devices 21 and 22 are connected to the server device 1 through the interface # 1 (IF # 1), and the transfer device 23 is connected to the transfer device 21 through the interface # 1 (IF # 1). The transfer device 25 is connected to the transfer device 22 by the interface # 1 (IF # 1).

<First embodiment>
Hereinafter, a case will be described in which the content held by the server device 1 is distributed to the networks 31 and 32 but is not distributed to the networks 33 and 34. For this reason, in this embodiment, an identifier (ID) is given to each network. In FIG. 1, “0001” is assigned to the network 31, “0010” is assigned to the network 32, “0100” is assigned to the network 33, and “1000” is assigned to the network 34. In this way, in this embodiment, an identifier is assigned in which the bit value at one position in the bit string is different from the bit value at another position. Since there are four networks in the example of FIG. 1, a 4-bit identifier is assigned. According to the identifier assigning method of this embodiment, the number of digits of the identifier is equal to or greater than the number of networks.

  The transfer apparatuses 21 to 26 hold the identifier of the network to which the own apparatus belongs. That is, for example, the transfer device 21 holds the identifier “0001”, and the transfer device 25 holds the identifier “1000”. Hereinafter, the identifier of the network to which the transfer device belongs, which is held by the transfer device, is also referred to as the identifier of the transfer device. In addition, each transfer device exchanges an identifier set in a transfer device directly connected by a link by communication. Therefore, the transfer device 22 recognizes that the identifier of the transfer device 25 is “1000”, and the transfer device 25 recognizes that the identifier of the transfer device 22 is “0001”. In this way, the plurality of transfer devices of the content distribution system are grouped in the network, and the same identifier is assigned to the transfer devices in the same group.

  Furthermore, in the server device 1, a network capable of transmitting (distributing) content is designated by the user. When a network that can transmit content is designated by the user, the server device 1 obtains a logical sum (OR) for each bit of the identifier of the designated network. In this example, the networks 31 and 32 are designated as the networks capable of transmitting content, and therefore the logical OR for each bit of the network identifier is “0011”. This value indicates all the networks that can be the destinations of content by identifiers, and is hereinafter referred to as distributable list information.

  The server device 1 transmits a publicity message indicating the content held by the server device 1 to each transfer device to be connected. Thereby, each transfer apparatus updates FIB which is transfer information. Further, each transfer device transmits a publicity message received from an interface other than the received interface. Thus, when each transfer device receives an interest packet, it creates a FIB for determining an interface to transfer the interest packet. In this embodiment, the distributable list information is included in this publicity message. FIG. 2 is a sequence diagram when the server device 1 distributes a publicity message indicating that the content having the content name “/ A / B” is held.

  In S1, the server device 1 transmits a publicity message including information indicating the content name “/ A / B” and the distributable list information “0011” to the transfer device 21, and in S5, the same publicity message is transmitted to the transfer device 22. Send to. Upon receiving the publicity message, each transfer device normally performs FIB so that the destination interface of the interest packet that requests the content name “/ A / B” included in the publicity message is the reception interface of the publicity message. Update. However, in this embodiment, when the transfer device receives the publicity message, the transfer device calculates the logical product for each bit of the identifier of the own device and the distributable list information included in the publicity message, and the calculation result is “0000”. If not, the FIB is updated so that the transfer destination interface of the interest packet requesting the content name “/ A / B” included in the publicity message is the reception interface of the publicity message. On the other hand, if the operation result of the logical product for each bit of the identifier of the own device and the distributable list information included in the publicity message is “0000”, the transfer device has a content name “/ A included in the publicity message”. The FIB is updated so that the destination interface of the interest packet requesting / B "is set to a null value. Note that the null value means that the received interest packet is discarded without being transferred in the present embodiment.

  Since the identifier of the transfer device 21 is “0001” and the distributable list information included in the publicity message is “0011”, the logical product operation result for each bit is not “0” as “0001”. 21 is S2, and the entry shown in FIG. 3A is added to the FIB. Further, the identifier of the transfer device 22 is the same as the identifier of the transfer device 21, so the transfer device 22 adds the entry shown in FIG. 3A to the FIB in S6. In addition, the transfer device that has received the publicity message transmits the received publicity message from an interface other than the interface that has received the publicity message. Therefore, the transfer device 21 transmits a public information message to the transfer device 23 in S3, and the transfer device 22 transmits the public information message to the transfer device 25 in S7.

  Since the identifier of the transfer device 23 is “0010” and the distributable list information included in the publicity message is “0011”, the logical product operation result for each bit is “0010” and is not 0 at all. In S4, an entry shown in FIG. 3A is added to the FIB. On the other hand, since the identifier of the transfer device 25 is “1000” and the distributable list information included in the publicity message is “0011”, the operation result of the logical product for each bit is “0000”, which is all 0. Therefore, the transfer device 25 adds the entry shown in FIG. 3B to the FIB in S8.

  Therefore, when receiving the interest packet requesting the content name “/ A / B”, the transfer device 25 discards the received interest packet without transferring it based on the FIB. As a result, the content with the content name “/ A / B” can be prevented from being distributed to the network 34. In addition, the number of interest packet transfers in the transfer device can be reduced.

  In this embodiment, only one bit is set to “1” and the other bits are set to “0” in the present embodiment. Conversely, only one bit is set to “0” and the other bits are set to “1”. Can be used. In this case, the server device 1 obtains a logical product for each bit of the identifier of the network to which the content can be distributed, and uses it as the distributable list information. Then, each transfer device obtains a logical sum for each bit of the distributable list information and the identifier of its own device, and if all bits are 1, sets a null value in the FIB transfer destination interface, If not, the PRB receiving interface is added to the FIB forwarding interface. That is, the explanation of FIG. 1 reverses the operation of logical product and logical sum. In any case, if all bits have the same value as a result of the logical operation of the distributable list information and the identifier of the own device, the forwarding interface is set to a null value. Otherwise, the PR message is sent to the forwarding interface. Add a receiving interface.

  Further, in the present embodiment, the user designates a network that can be a content transmission destination to the server device 1, and the server device 1 generates distributable list information thereby. However, it is also possible for the server device 1 to designate a network that cannot be used as a content transmission destination and for the server device 1 to generate undeliverable list information by the logical sum of the identifiers of the designated network. For example, in the configuration of FIG. 1, the networks 33 and 34 are designated, and thus the server apparatus 1 generates the undeliverable list information “1100” by the logical OR for each bit of the identifier “0100” and the identifier “1000”. . Then, the server device includes undeliverable list information in the publicity message.

  Even in this case, each transfer device obtains a logical product for each bit of the undeliverable list information and the identifier of the own device. In this case, if all the logical product calculation results are 0, a PR message reception interface is added to the FIB transfer destination interface. Otherwise, a null value is set to the FIB transfer destination interface. To do. For example, since the logical product for each bit of the identifier “0001” of the transfer devices 21 and 22 and the undeliverable list information “1100” is “0000”, the transfer devices 21 and 22 send the PR message to the transfer destination interface. Add a receiving interface. Further, since the logical product for each bit of the identifier “0010” of the transfer device 23 and the undeliverable list information “1100” is “0000”, the transfer device 23 adds a publicity message reception interface to the transfer destination interface. To do. On the other hand, since the logical product for each bit of the identifier “1000” of the transfer device 25 and the undeliverable list information “1100” is “1000”, the transfer device 25 adds a null value to the transfer destination interface. Furthermore, even when using the non-deliverable list information, an identifier in which only one bit is set to “0” and the other bits are set to “1” can be used.

<Second embodiment>
In the first embodiment, each transfer device performs a logical operation on the distributable list information and the identifier of the own device to determine a value to be set in the FIB transfer destination interface. In this embodiment, when each forwarding device receives a publicity message, the operator calculates the logical product of the identifier of the destination forwarding device to which the publicity message is forwarded and the distributable list information included in the publicity message, and the result To determine whether to forward the publicity message. FIG. 4 is a distribution sequence diagram of a publicity message according to the present embodiment.

  In S10, the server device 1 transmits a public information message including information indicating the content name “/ A / B” and the distributable list information “0011” to the transfer device 21, and in S13, the server device 1 transmits the same public information message. The message is transmitted to the transfer device 22. In S <b> 11, the transfer device 21 determines whether to transmit a publicity message to the transfer device 23. Therefore, the transfer device 21 calculates a logical product for each bit of the identifier of the transfer device 23 and the distributable list information included in the publicity message. In this example, since the calculation result is “0010” and not all 0, the transfer device 21 determines in S11 that the publicity message can be transmitted to the transfer device 23. Therefore, the transfer device 21 transmits a publicity message to the transfer device 23 in S12. Similarly, in step S14, the transfer device 22 determines whether or not the public information message can be transferred to the transfer device 25. In order to determine whether or not the identifier of the transfer device 25 and the distributable list information included in the public information message, Calculate the product. In this example, since the calculation results are all “0000” and “0”, the transfer device 22 determines that the public information message cannot be transmitted to the transfer device 25 in S14. In addition, each transfer apparatus will update FIB similarly to normal CCN, if a public information message is received.

  As shown in FIG. 4, the transfer device 25 does not receive the publicity message indicating the content name “/ A / B”. Therefore, the transfer is performed when the interest packet requesting the content name “/ A / B” is received. Information indicating the destination interface is not created in the FIB of the transfer device 25. The transfer apparatus according to the present embodiment discards the received interest packet when the transfer destination cannot be determined from the FIB. Therefore, the content with the content name “/ A / B” is not distributed to the network 34 to which the transfer device 25 belongs, and the distribution destination of the content can be controlled.

  In the case of this embodiment, there is a restriction on the content name assigning method. For example, as shown in FIG. 5A, the server device 1 has transmitted a publicity message of content (content name / A / C and / A / D) that does not restrict the distribution area to the transfer device 22 in S20. Shall. In this case, in S <b> 21, the transfer device 22 determines that the public information message can be transmitted to the transfer device 25, and thus the transfer device 22 transmits the public information message to the transfer device 25 in S <b> 22. The FIB entry may indicate a transfer destination interface for each content name. However, in order to reduce the number of entries, a plurality of contents having a common prefix and the same transfer destination interface are used. , FIB entries can be aggregated. That is, the FIB can indicate a transfer destination interface for a common prefix. Therefore, the transfer device 25 may add the entry shown in FIG. 5B to the FIB based on the publicity message received in S22. In this case, for example, an interest packet requesting the content name “/ A / B” is received even if it is determined that the publicity message received by the transfer device 22 in S14 of FIG. 4 cannot be delivered to the transfer device 25. The transfer device 25 transfers the interest packet to the transfer device 22 based on the FIB shown in FIG. 5B without discarding the interest packet. Therefore, in the present embodiment, for the content that restricts the distribution destination, the content name is assigned so as not to have a prefix portion that is common to other content.

<Device configuration>
FIG. 6 is a configuration diagram of the server device 1 in each of the above embodiments. The content holding unit 11 holds content to be released. The list holding unit 12 generates and holds distributable list information or non-distributable list information based on a network that can be a content destination specified by the user or a network that cannot be a content destination. To do. Note that the user may directly input distributable list information or non-distributable list information. When transmitting the content public information message, the processing unit 13 includes distributable list information or non-distributable list information of the content in the public information message, and transmits the public information message via the communication unit 14.

  FIG. 7 is a configuration diagram of the transfer device in each of the above embodiments. The holding unit 21 holds CS, PIT, FIB, and cached objects. When the processing unit 22 receives the publicity message via the communication unit 23, the processing unit 22 forwards the content included in the publicity message based on the identifier of the own device and the distributable list information or the non-distributable list information included in the received publicity message As an interface, it is determined whether the interface that received the publicity message is set to FIB or a null value, and the FIB is updated according to the determination result. In this case, the processing unit 22 transmits the public information message received from an interface other than the public information message reception interface. Alternatively, when the processing unit 22 receives the public information message, for each transfer device connected to an interface other than the reception interface of the public information message, the identifier of the transfer device and the distributable list information included in the received public information message Alternatively, it is determined whether or not to transmit the received publicity message based on the non-delivery list information. Based on the determination result, the received publicity message is transmitted.

  The server device 1 and the transfer device according to the present invention can be realized by programs that cause the computer to operate as the server device 1 and the transfer device, respectively. These computer programs can be stored in a computer-readable storage medium or distributed via a network.

  21: Holding unit, 22: Processing unit, 23: Communication unit

Claims (11)

A transfer device of a content distribution system for transferring a request packet including a content name of a content requesting distribution based on the content name,
Holding means for holding transfer information indicating the relationship between the content requested by the request packet and the transfer destination interface of the request packet;
When a PR message indicating content and including list information is received, whether or not to transfer the request packet when receiving a request packet requesting the content based on the identifier of the device and the list information. Determination means for determining;
When it is determined that the determination unit transfers, the reception interface of the public information message is added to the transfer information as a transfer destination interface of a request packet for requesting the content indicated by the public information message, and the determination unit determines that it does not transfer, Processing means for adding information indicating that a request packet requesting the content indicated by the publicity message is not transferred to the transfer information;
With
The identifiers of the plurality of transfer devices of the content distribution system are indicated by a plurality of bits,
The list information included in the public information message is generated by a logical operation for each bit of the identifier of the transfer device that can be the destination of the content indicated by the public information message among the plurality of transfer devices of the content distribution system. Alternatively, the transfer device is generated by a logical operation for each bit of the identifier of the transfer device that cannot be the destination of the content indicated by the publicity message among the plurality of transfer devices of the content distribution system. . The identifier of the transfer device has only one bit as a first value and the remaining bits as a second value different from the first value,
The list information included in the publicity message is generated based on an identifier of a transfer device that can be a destination of the content indicated by the publicity message among a plurality of transfer devices of the content distribution system,
The determination means determines the content indicated by the publicity message when all bits of the plurality of bits have the same value as a result of a logical operation for each bit of the list information included in the publicity message and the identifier of the own device. upon receiving a request packet for requesting the transfer apparatus according to claim 1, characterized in that to determine not to forward the request packet. The identifier of the transfer device has only one bit as a first value and the remaining bits as a second value different from the first value,
The list information included in the publicity message is generated based on an identifier of a transfer device that cannot be a destination of the content indicated by the publicity message among a plurality of transfer devices of the content distribution system,
The determination means determines the content indicated by the publicity message when all bits of the plurality of bits have the same value as a result of a logical operation for each bit of the list information included in the publicity message and the identifier of the own device. upon receiving a request packet for requesting the transfer apparatus according to claim 1, wherein determining that transfers the request packet. A transfer device of a content distribution system for transferring a request packet including a content name of a content requesting distribution based on the content name,
When receiving a publicity message indicating content and including list information, determination means for determining whether to transfer the public information message to another transfer device based on the identifier of the other transfer device and the list information When,
When the determination means determines to transfer, the public information message is transferred to the other transfer device, and when the determination means determines not to transfer, the processing means does not transfer the public information message to the other transfer device;
With
The identifiers of the plurality of transfer devices of the content distribution system are indicated by a plurality of bits,
The list information included in the public information message is generated by a logical operation for each bit of the identifier of the transfer device that can be the destination of the content indicated by the public information message among the plurality of transfer devices of the content distribution system. Alternatively, the transfer device is generated by a logical operation for each bit of the identifier of the transfer device that cannot be the destination of the content indicated by the publicity message among the plurality of transfer devices of the content distribution system. . The identifier of the transfer device has only one bit as a first value and the remaining bits as a second value different from the first value,
The list information included in the publicity message is generated based on an identifier of a transfer device that can be a destination of the content indicated by the publicity message among a plurality of transfer devices of the content distribution system,
The determination means determines the advertisement message when all bits of the plurality of bits have the same value as a result of a logical operation for each bit of the list information included in the advertisement message and the identifier of the other transfer device. The transfer apparatus according to claim 4 , wherein the transfer apparatus determines not to transfer to the other transfer apparatus. The identifier of the transfer device has only one bit as a first value and the remaining bits as a second value different from the first value,
The list information included in the publicity message is generated based on an identifier of a transfer device that cannot be a destination of the content indicated by the publicity message among a plurality of transfer devices of the content distribution system,
The determination means determines the advertisement message when all bits of the plurality of bits have the same value as a result of a logical operation for each bit of the list information included in the advertisement message and the identifier of the other transfer device. The transfer apparatus according to claim 4 , wherein the transfer apparatus determines to transfer to the other transfer apparatus. A plurality of transfer devices of the content distribution system are grouped,
Transfer device according to any one of claims 1 to transfer device of the same group, characterized in that the same identifier is assigned 6. Program for causing a computer to function as a transfer device according to any one of claims 1 to 7. A server device of a content distribution system for transferring a request packet including a content name of a content requesting distribution based on the content name,
The content distribution system includes a plurality of networks each including one or more transfer devices,
The server device
A holding unit for holding content list information indicating a network that can be a content transmission destination or a network that cannot be a content transmission destination among the plurality of networks;
Information indicating content; and communication means for transmitting list information of the content to the transfer device of the content distribution system;
Equipped with a,
Each of the plurality of networks is given an identifier represented by a plurality of bits,
The content list information is generated by a logical operation for each bit of a network identifier that can be a destination of the content in the plurality of networks, or cannot be a destination of the content. A server device generated by a logical operation for each bit of a network identifier . Before SL server apparatus, a network which may be a transmission destination of the content, or when the network can not be a destination of content is designated, generated for generating the list information on the basis of the identifier of the specified network The server apparatus according to claim 9 , further comprising means. Program for causing a computer to function as a server device according to claim 9 or 10.

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