JP2022053105A - Transfer device and program of content distribution system - Google Patents

Abstract

To provide a technique that can prevent decrease in throughput and reduce packet loss.SOLUTION: A transfer device of a content distribution system that transfers packets based on the names of content associated with the packets includes: a plurality of communication interfaces; a plurality of pieces of transfer processing means that perform transfer processing of packets; and control means that performs control to determine the transfer processing means that performs transfer processing of a packet from the plurality of pieces of the transfer processing means when a communication interface among the plurality of communication interfaces receives the packet. The control means classifies content into first content, and second content that is less popular than the first content, based on packets received by the plurality of communication interfaces, and distributes the transfer processing means that performs transfer processing of packets associated with the first content to the plurality of pieces of the transfer processing means.SELECTED DRAWING: Figure 3

Description

Patent Law Article 30, Paragraph 2 Application Applicable ▲ 1 ▼ Website Publication Date: August 21, 2nd Reiwa Website Address https: // IEEEXplore. IEEE. org / document / 9173693

The present disclosure relates to transfer devices and programs of content distribution systems that perform routing based on the name of the content.

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

In the CCN, the server device that publishes the content divides the content into one or more chunks, and the client device acquires the content in units of the divided chunks. Further, in the CCN, the communication device (hereinafter referred to as a transfer device) that has transferred the chunk can store (cache) the chunk. When the transfer device receives an interest packet (request packet) requesting a cached chunk from the client device, the transfer device transfers the cached chunk to the server device without forwarding the interest packet to the server device. -Can be sent to the client device that sent the packet.

An example of the operation of the transfer device will be described below. The transfer device manages CS (Contents Store), FIB (Forward Information Base), and PIT (Pending Interest Table). CS is information indicating a cached chunk. The FIB is information indicating the relationship between the chunk requested by the interest packet and the interface that transmits the interest packet for the transfer of the interest packet. The PIT is information indicating the relationship between the chunk requested by the interest packet and the interface that received the interest packet.

When the transfer device receives the interest packet, it searches the CS and determines whether or not the chunk requested by the interest packet (hereinafter referred to as the request chunk) is cached. When the request chunk is cached, the data packet including the cached request chunk is transmitted to the client device that is the source of the interest packet. The interface for transmitting the data packet is the interface for receiving the interest packet. On the other hand, if the request chunk is not cached, the transfer device searches the PIT to forward another interest packet requesting the request chunk and determines whether the request chunk is waiting to be received. When in the reception wait state, the transfer device does not forward the received interest packet and adds the reception interface of the interest packet to the entry of the request chunk of the PIT. On the other hand, when the request chunk is not in the reception waiting state, the transfer device transmits (forwards) the interest packet from the interface determined based on the FIB, and adds the request chunk entry to the PIT. This entry has information indicating a request chunk (chunk name) and information indicating the interface on which the interest packet was received.

Further, when the transfer device receives the data packet including the chunk, the transfer device determines the interface for transmitting the data packet based on the PIT, transmits the data packet from the determined interface, and makes an entry for the chunk from the PIT. delete. The interface for transmitting the data packet is the interface for receiving the interest packet requesting the chunk, and is set in the entry related to the chunk in the PIT. Further, the transfer device updates the CS when the chunk included in the received data packet is cached.

Thus, in the CCN, the data packet containing the chunk is transmitted to the interface that received the interest packet requesting the chunk. Therefore, the chunk is forwarded in the reverse direction on the same route as the interest packet requesting the chunk, and is delivered to the client device requesting the chunk.

A transfer device generally includes an interface unit that performs packet transmission / reception processing and a transfer processing unit that performs packet transfer processing. In addition, in this specification, a packet means a generic term of an interest packet and a data packet. Here, in order to increase the throughput of the transfer device, it is considered to provide a plurality of transfer processing units in the transfer device.

When a packet is received, the transfer processing unit of the transfer device performs entry processing for the PIT entry. In the present specification, the entry process is a general term for an entry addition process to the PIT, an entry content update process, and an entry deletion process. If the transfer device is provided with a plurality of transfer processing units, it is possible that each transfer processing unit accesses the same entry of the PIT at the same time and performs entry processing. If entry processing by different transfer processing units occurs simultaneously for the same entry in the PIT, a problem such as loss of information to be stored in the PIT may occur in the PIT.

Therefore, Non-Patent Document 2 discloses a configuration in which the same transfer processing unit processes an interest packet requesting the same chunk and a data packet carrying the same chunk. Specifically, the correspondence between the hash value and the transfer processing unit is determined in advance, and the information indicating this correspondence is stored in the transfer device. Then, when the transfer device receives the packet, the chunk requested by the packet or carried by the packet (hereinafter, the chunk requested by the packet or carried by the packet) is transferred to the transfer device. Non-Patent Document 2 discloses that a hash value of the name of "chunk associated with a packet") is obtained, and the transfer processing unit corresponding to the obtained hash value is made to perform the transfer processing of the packet. There is. With this configuration, since the entry processing for an entry having a PIT is performed only by the same one transfer processing unit, it is possible to prevent a problem from occurring in the PIT.

Further, Non-Patent Document 3 proposes to perform exclusive control in the entry processing of PIT. Specifically, a locked state field is provided in the PIT. A value "0" or a value "1" is set in the lock state field, a value "0" indicates an unlock state, and a value "1" indicates a lock state. The transfer processing unit that performs PIT entry processing checks the value of the lock field of the entry to be processed, and if the value is "1", that is, in the locked state, the value is "0", that is, in the unlocked state. Wait until it becomes. When the PIT entry to be processed is in the unlocked state, the transfer processing unit starts the entry processing. At this time, the transfer processing unit first sets the value of the lock state field of the entry to be processed to "1". Set to lock the entry to be processed. Then, the transfer processing unit executes the transfer process and the entry process, and when these processes are completed, the value of the lock state field of the entry to be processed is set to "0" to bring it into the unlock state. In Non-Patent Document 3, this exclusive control prevents different transfer processing units from accessing the same entry of PIT at the same time.

V. Jacobson, et al. , "Networking Named Content", in Proceedings of ACM CoNEXT 2009, December 2009 D. Kirchner, et al. , "Augustus: a CCN router for program networks", ACM ICN, 2016 J. Takemasa, et al. , "Analysis of mutual exclusion overhead of NDN packet forwarding on multi-core software router", ACM ICN 2018 Poster Session

In the configuration of Non-Patent Document 3, even if the transfer processing unit receives a packet, if the entry of the PIT corresponding to the chunk associated with the packet is in the locked state, the transfer processing unit must wait until the packet is unlocked. However, the throughput is reduced. Further, in the configuration of Non-Patent Document 2, since the transfer processing unit that performs the transfer processing of the packet is determined by the name of the chunk associated with the packet, when the packets associated with the chunk with the same name arrive consecutively, Processing is concentrated on one transfer processing unit, which may cause packet loss.

The present invention provides a technique capable of preventing a decrease in throughput and reducing packet loss.

According to one aspect of the present invention, the transfer device of the content distribution system that transfers the packet based on the name of the content associated with the packet includes a plurality of communication interfaces and a plurality of transfer processing means that perform the transfer process of the packet. When the communication interface among the plurality of communication interfaces receives the packet, the plurality of transfer processing means are provided with a control means for controlling the transfer processing means for performing the transfer processing of the packet. Based on the packet received by the plurality of communication interfaces, the control means classifies the content into a first content and a second content which is less popular than the first content, and is associated with the first content. It is characterized in that the transfer processing means for performing the transfer processing of the packet is distributed to the plurality of transfer processing means.

According to the present invention, it is possible to prevent a decrease in throughput and reduce packet loss.

The block diagram of the transfer apparatus by one Embodiment. The figure which shows the header area of a packet. The block diagram of the control part by one Embodiment. The figure which shows the example of the 1st information and the 2nd information. The figure which shows PIT by one Embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the plurality of features described in the embodiments may be arbitrarily combined. In addition, the same or similar configuration will be given the same reference number, and duplicated explanations will be omitted.

Hereinafter, the present embodiment will be described assuming that the content distribution system (content distribution network) is CCN. However, the present invention can be applied to any content distribution system that routes based on the name indicating the content. In particular, in the following, the present embodiment will be described in the form of distributing the content in units of pieces of content called chunks according to the distribution of the content by CCN, but the present invention also applies to a network that distributes the content without dividing the content. Can be applied. Further, in CCN, since the content is distributed in units of chunks that are fragments of the content, the name of this chunk is referred to as "chunk name" in the following description, but since the chunk is also the content, this embodiment. The "chunk name" in can be replaced with the "content name".

FIG. 1 is a configuration diagram of a transfer device 100 according to the present embodiment. The transfer device 100 includes a communication interface (IF) unit 1, a plurality of transfer processing units 20, and a storage unit 30. The IF unit 1 includes a plurality of communication interfaces (IF) 10 and a control unit 11. Each of the plurality of transfer processing units 20 can be realized by a CPU (processor). In this case, for example, the CPU can realize the function of the transfer processing unit 20 described below by executing the program stored in the storage unit 30. Further, the plurality of transfer processing units 20 can be realized by a multi-core CPU having a plurality of cores. In this case, each core functions as the transfer processing unit 20 described below by executing the program stored in the storage unit 30, for example, by the multi-core CPU. The function of the transfer processing unit 20 can also be realized by hardware such as an ASIC. Further, the function of the transfer processing unit 20 can be realized by a combination of an arbitrary processor that executes an appropriate program and hardware such as an ASIC. In FIG. 1, the number of IF10s in the IF unit 1 is N (N is an integer of 2 or more). Further, the number of transfer processing units 20 is M (M is an integer of 2 or more). In order to distinguish individual IF10s, the nth IF10 (n is an integer from 1 to N) is also referred to as IF # n. Similarly, in order to distinguish individual transfer processing units 20, the m-th (m is an integer from 1 to M) transfer processing unit 20 is also referred to as transfer processing unit #m.

The IF 10 is connected to another device (another transfer device, a server device, a client device, etc.) via a communication line, and transmits / receives packets to / from another connected device. Specifically, when the IF 10 receives a packet, it outputs the packet to one of the transfer processing unit # 1 to the transfer processing unit # M. The control unit 11 determines the transfer processing unit 20 for which the IF 10 outputs a packet. How the control unit 11 determines the transfer processing unit 20 for outputting the packet will be described later. Further, when the IF 10 receives a packet from the transfer processing unit 20, the IF 10 transmits the packet to another device via a communication line.

The storage unit 30 includes one or more storage devices (memories) including a volatile memory and a non-volatile memory, and holds a PIT and a FIB. Further, the storage unit 30 caches the chunks and also holds the cached chunk information (CS).

When the transfer processing unit 20 receives a packet from the IF 10, the transfer processing unit 20 performs processing according to the packet. Specifically, when the packet is an interest packet and the request chunk is cached, the data packet including the cached chunk is transmitted to the IF10 that received the packet. Also, if the packet is an interest packet and the request chunk is not cached, but there is an entry for the request chunk in the PIT, the PIT is updated and the interest packet is discarded. Further, if the packet is an interest packet, the request chunk is not cached, and the PIT does not have an entry for the request chunk, an entry for the request chunk is added to the PIT, and the interest is in IF10 determined based on the FIB. -Forward packets. Further, if the packet is a data packet, the data packet is transmitted to the IF10 determined based on the PIT, and the PIT entry regarding the chunk carried by the data packet is deleted.

FIG. 2 shows a part of the packet header. The packet header contains a chunk name field and a nonce value field. The chunk name field stores the chunk name. In the case of an interest packet, the chunk name of the requested chunk is stored, and in the case of a data packet, the chunk name of the chunk stored in the payload is stored. In the present specification, the chunk name stored in the chunk name field of the packet is referred to as "chunk name associated with the packet". Further, the chunk indicated by the chunk name stored in the chunk name field of the packet is referred to as "chunk associated with the packet". Similarly, "packet associated with a chunk name" shall mean a packet in which the chunk name is stored in the chunk name field. Further, "packet associated with a chunk" shall mean a packet in which the chunk name of the chunk is stored in the chunk name field. The nonce value field stores a nonce value, which is a randomly generated number. The nonce value is provided to detect a packet transfer abnormality such as a packet being transferred in a loop.

Subsequently, when the IF 10 receives a packet from another device, how the control unit 11 determines the transfer processing unit 20 of the output destination of the received packet will be described. When a packet is received from another device, the IF 10 notifies the control unit 11 of the chunk name stored in the chunk name field of the packet and the nonce value stored in the nonce value field. do. FIG. 3 is a functional block diagram of the control unit 11. For example, the control unit 11 is composed of one or more processors, and the functional block of FIG. 3 can be realized by executing a program stored in the storage unit 30 by the one or more processors. The control unit 11 can also be realized by hardware. Further, the control unit 11 can be realized by a combination of an arbitrary processor that executes an appropriate program and hardware such as an ASIC.

The chunk name notified from the IF 10 is input to the second hash value calculation unit 110 and the first hash value calculation unit 112. Further, the nonce value notified from the IF 10 is input to the first hash value calculation unit 112. The second hash value calculation unit 110 takes the chunk name as an input of the second hash function, obtains the hash value (second hash value), and notifies the selection unit 111 of the second hash value. The selection unit 111 selects one of the chunk name and the nonce value based on the second information 114 and the second hash value, and notifies the first hash value calculation unit 112 of the selection result.

FIG. 4A is an example of the second information 114. The second information 114 is correspondence information indicating the correspondence between the second hash value and the input value used as the input of the first hash function. In the example of FIG. 4A, when the second hash value is "0" or "1", the selection unit 111 notifies the first hash value calculation unit 112 of the chunk name as the selection result. On the other hand, when the second hash value is "2", the selection unit 111 notifies the first hash value calculation unit 112 of the nonce value as the selection result.

The first hash value calculation unit 112 obtains the hash value (first hash value) by using the value notified from the selection unit 111 of the chunk name and the nonce value as the input of the first hash function, and causes the determination unit 113 to obtain the hash value. Notify the first hash value. The determination unit 113 determines and determines one transfer processing unit 20 among the transfer processing unit # 1 to the transfer processing unit #M based on the first information 115 and the first hash value, and determines the transfer processing unit 20. Is notified to IF10 which has notified the chunk name and the nonce value. The IF 10 outputs the received packet to the transfer processing unit 20 notified from the determination unit 113.

FIG. 4B is an example of the first information 115. The first information 115 is information indicating the correspondence between the first hash value and the transfer processing unit 20. In the example of FIG. 4B, when the first hash value is "0", the determination unit 113 notifies the IF 10 that the packet is output to the transfer processing unit # 1.

For example, it is assumed that the chunk name notified from IF # 1 is "Ca", its second hash value is "0", and its first hash value is "1". The second information 114 and the first information 115 are as shown in FIGS. 4 (A) and 4 (B). Since the second hash value is "0", the selection unit 111 notifies the first hash value calculation unit 112 that the chunk name "Ca" is used for the calculation of the first hash value. Therefore, the first hash value calculation unit 112 notifies the determination unit 113 of "1" as the first hash value. Therefore, the determination unit 113 notifies the IF # 1 of the transfer processing unit # 2 based on the first information 115. As described above, when the chunk name of the received packet is "Ca", the packet is always processed by the transfer processing unit # 2.

On the other hand, it is assumed that the chunk name notified from IF # 1 is "Cb" and the second hash value is "2". The second information 114 and the first information 115 are as shown in FIGS. 4 (A) and 4 (B). Since the second hash value is "2", the selection unit 111 notifies the first hash value calculation unit 112 that the nonce value is used for the calculation of the first hash value. Therefore, the first hash value calculation unit 112 calculates the first hash value based on the nonce value and notifies the determination unit 113. Here, since the nonce value is a randomly generated value, the nonce value differs for each packet even if the chunk name of the packet is "Cb". Therefore, even if the chunk name of the packet is "Cb", the first hash value calculated by the first hash value calculation unit 112 is also different for each packet. Therefore, even if the chunk name of the packet is "Cb", the transfer processing unit 20 determined by the determination unit 113 as the output destination is not the same, but is different for each packet.

For example, even if a packet associated with a chunk having a small number of requests is processed by the same transfer processing unit 20, the processing capacity of the transfer processing unit 20 is not exceeded, and it cannot cause packet loss or the like. Further, since the same forwarding processing unit 20 processes the packets associated with the same chunk, it is possible to prevent PIT defects that may occur when different forwarding processing units 20 access the same PIT entry at the same time. Therefore, in the second information 114, the control unit 11 sets the input value corresponding to the second hash value of the chunk name of the chunk with a small number of requests to the "chunk name". On the other hand, if a packet associated with a chunk having a large number of requests is processed by the same transfer processing unit 20, the processing capacity of the transfer processing unit 20 may be exceeded, which may cause packet loss. Therefore, in the second information 114, the control unit 11 sets the input value corresponding to the second hash value of the chunk name of the chunk with the larger number of requests to the "nonce value". As a result, the packets associated with the chunks having a large number of requests are distributed and processed by the plurality of transfer processing units 20, and the occurrence of packet loss can be suppressed.

Therefore, the control unit 11 obtains the popularity of each chunk based on the chunk name notified from the IF 10 when the IF 10 receives the packet. The popularity of a chunk can be, for example, the total number of interest packets requesting the chunk received in a predetermined period. Then, the control unit 11 classifies the chunks into a first chunk having a high popularity and a second chunk having a low popularity by comparing the popularity (total number) with the threshold value. The first chunk is a chunk whose total number is larger than the threshold value, and the second chunk is a chunk whose total number is equal to or less than the threshold value. The control unit 11 obtains the second hash value by the chunk name of the first chunk, sets the input value corresponding to this second hash value of the second information 114 to the "nonce value", and sets the other second hash values. Set the input value corresponding to to "chunk name". The control unit 114 repeats a process of determining the popularity of each chunk to determine the first chunk and a process of updating the second information 114 based on the determination result at predetermined intervals. With this configuration, packet transfer processing can be distributed to a plurality of transfer processing units 20 while suppressing packet loss, and the throughput of the transfer device 100 can be increased.

Due to the above configuration, the packet associated with the second chunk whose popularity is less than or equal to the threshold value is processed by the same transfer processing unit 20, so that different transfer processing units 20 may access the same entry of the PIT at the same time. Therefore, there is no problem with PIT. However, since the packet relating to the first chunk whose popularity is larger than the threshold value is processed by the different transfer processing units 20, different transfer processing units 20 may access the same entry of the PIT at the same time. Therefore, in the present embodiment, when the transfer processing unit 20 processes the packet associated with the first chunk, the transfer processing unit 20 is made to perform exclusive control of the PIT.

For example, when the transfer processing unit 20 is determined using the nonce value, the control unit 11 may be configured to notify the determined transfer processing unit 20 of performing exclusive control of PIT. In the present embodiment, the header area of the packet is used to notify the transfer processing unit 20 to perform exclusive control of PIT. Therefore, a lock field is provided in the header area of the packet shown in FIG. Then, when the "chunk name" is notified as the selection result, the first hash value calculation unit 112 notifies the determination unit 113 of the information indicating "lock unnecessary" together with the first hash value. On the other hand, when the "nonce value" is notified as the selection result, the first hash value calculation unit 112 notifies the determination unit 113 of the information indicating "lock required" together with the first hash value. The determination unit 113 notifies the IF 10 of the information indicating "lock not required" or "lock required" notified from the first hash value calculation unit 112 together with the information indicating the determined transfer processing unit 20.

When the IF10 outputs a packet to the transfer processing unit 20 notified by the determination unit 113, if "lock not required" is notified from the determination unit 113, the lock field of the packet is, for example, a value "0". Is set, and when "lock required" is notified, for example, a value "1" is set in the lock field of the packet. The transfer processing unit 20 does not perform exclusive control of PIT when the value "0" is set in the lock field, and performs exclusive control of PIT when the value "1" is set in the lock field. ..

Specifically, as shown in FIG. 5, a locked state field is provided in the PIT. A value "0" or a value "1" is set in the locked state field, a value "0" indicates an unlocked state, and a value "1" indicates a locked state. When the value of the lock field of the received packet is "0", the transfer processing unit 20 performs the transfer processing of the packet and the entry to be processed regardless of the value of the lock state field of the entry to be processed by PIT. Perform entry processing. On the other hand, when the value of the lock field of the received packet is "1", the value of the lock state field of the entry to be processed by PIT is first checked. Then, if the value of the lock state field of the entry to be processed by PIT is "1", that is, the lock state, the value waits until the value is "0", that is, the unlock state. When the PIT entry to be processed is in the unlocked state, the transfer processing unit 20 starts the transfer process and the entry process. At this time, the transfer processing unit 20 first starts the value of the lock state field of the entry to be processed. Is set to "1" to lock the entry to be processed. Then, the transfer processing unit 20 executes the transfer process and the entry process, and when these processes are completed, the value of the lock state field of the entry to be processed is set to "0" to bring it into the unlock state.

As described above, in the present embodiment, the exclusive control of the PIT is not performed in the processing of all packets, but the exclusive control of the PIT is performed only in the processing of some packets, so that the throughput is reduced due to the execution of the exclusive control. Can be suppressed.

In the present embodiment, the control unit 11 uses two hash functions, a first hash function and a second hash function, but the first hash function and the second hash function may be different functions. , May be the same function. Further, in the present embodiment, the transfer processing unit 20 that performs packet transfer processing based on the first hash value is determined, and the input value of the first hash function for obtaining the first hash value is based on the second hash value. I was in control. However, the packets associated with the first chunk are distributed and processed by a plurality of transfer processing units 20, and the packets associated with the second chunk are basically processed by the same transfer processing unit 20. The method of distributing the packets associated with the first chunk to a plurality of transfer processing units 20 is not limited to the above configuration.

For example, the control unit 11 determines the first chunk based on the threshold value as described in the above embodiment. Then, for the chunk (second chunk) that is not determined to be the first chunk, one transfer processing unit 20 is determined based on the chunk name and notified to IF10, as in the above embodiment. On the other hand, the first chunk may be configured to randomly select one transfer processing unit 20 from the plurality of transfer processing units 20 and notify the IF 10. For example, for the first chunk, a random number may be generated, and the transfer processing unit 20 for transferring the packet associated with the first chunk may be determined based on the first hash value obtained based on the generated random number. can. Further, the selection order of the plurality of transfer processing units 20 is determined in advance in a round-robin format, for example, and for the first chunk, one transfer processing unit 20 is selected from the plurality of transfer processing units 20 according to the selection order. It can also be configured to notify the IF10.

In the above embodiment, the control unit 11 determines the most popular first chunk, and in the second information 114, the input value corresponding to the second hash value of the name of the first chunk is set as the nonce value. rice field. In this case, it is possible that the second hash value of the less popular second chunk name matches the second hash value of the first chunk name. In such a case, the second chunk whose second hash value matches the second hash value of the name of the first chunk is not processed by the same transfer processing unit 20, but is processed by a plurality of transfer processing units 20. It will be processed. However, the probability that such a case will occur is low, and there is no problem because exclusive control of PIT is performed when processing is performed by a plurality of transfer processing units 20.

In summary, the transfer processing of the packet associated with the popular first chunk is distributed to a plurality of transfer processing units 20. On the other hand, the forwarding process of the packet associated with the second chunk, which is less popular, is basically processed by the same one forwarding processing unit 20. That is, the present invention is not only a form in which the forwarding process of the packet associated with the less popular second chunk is processed by the same one forwarding processing unit 20, but also the packet associated with the less popular second chunk. A part of the above includes a form in which the transfer processing unit 20 can be distributed and processed.

Further, the transfer device 100 according to the present invention can be realized by a device having a plurality of IFs 10, one or more processors, and one or more memories for storing a program. In this case, the program stored in one or more memories includes an instruction for functioning and operating the device as the transfer device 100 when executed by one or more processors. The program can also be stored in a computer-readable storage medium or distributed over a network.

The invention is not limited to the above embodiment, and various modifications and changes can be made within the scope of the gist of the invention.

10: Interface, 20: Transfer processing unit, 11: Control unit

Claims (11)

A transfer device of a content distribution system that transfers the packet based on the name of the content associated with the packet.
With multiple communication interfaces
A plurality of forwarding processing means for performing the forwarding processing of the packet, and
When the communication interface among the plurality of communication interfaces receives the packet, the control means for controlling the plurality of transfer processing means to determine the transfer processing means for performing the transfer processing of the packet, and the control means.
Equipped with
Based on the packet received by the plurality of communication interfaces, the control means classifies the content into a first content and a second content which is less popular than the first content, and is associated with the first content. A transfer device, characterized in that the transfer processing means for performing the transfer processing of the packet is distributed to the plurality of transfer processing means. The transfer device according to claim 1, wherein the control means determines the transfer processing means for performing the transfer processing of the packet associated with the first content based on a random number. The transfer device according to claim 1 or 2, wherein the control means determines the transfer processing means for performing the transfer processing of the packet associated with the second content based on the name of the second content. .. The control means is
The first calculation means for obtaining the first hash value by the first hash function,
A determining means for determining the forwarding processing means for performing the forwarding processing of the packet based on the first hash value, and
Equipped with
When the control means determines the transfer processing means that performs the transfer processing of the packet associated with the first content, the random number is input to the first calculation means, and the control means associated with the second content. The method according to any one of claims 1 to 3, wherein when the transfer processing means for performing the packet transfer processing is determined, the name of the second content is input to the first calculation means. Transfer device. The transfer device according to claim 2 or 4, wherein the random number is a value stored in the packet. The control means determines the number of packets requesting the content for each content based on the packets received by the plurality of communication interfaces, and compares the determined number of packets for each content with the threshold value. The transfer device according to any one of claims 1 to 5, wherein the content is classified into the first content and the second content. The control means further includes a second calculation means for obtaining a second hash value by a second hash function.
The control means manages correspondence information indicating whether the content corresponding to the second hash value is the first content or the second content, and performs the transfer processing of the packet. Was associated with the packet based on the second hash value obtained by inputting the name of the content associated with the packet as the input of the second calculation means and the correspondence information. It is determined whether the content is the first content or the second content, and the content is determined.
The control means is characterized in that when the content is classified into the first content and the second content based on the packet received by the plurality of communication interfaces, the correspondence information is updated based on the classification result. The transfer device according to claim 6. When the control means determines the transfer processing means for performing the transfer processing of the packet, the communication interface determines whether the determined transfer processing means and the content associated with the packet are the first content. Notify if it is the second content,
The communication interface sets information indicating whether the content associated with the packet is the first content or the second content in a predetermined field of the packet, and controls the packet by the control means. The transfer device according to any one of claims 1 to 7, wherein the transfer device is output to the transfer processing means notified from. Further provided with a storage means for storing a table indicating that the packet requesting the content is forwarded and waiting for reception of the packet carrying the content and the communication interface for transmitting the packet carrying the content is provided.
The transfer processing means is characterized in that when it receives the packet from the communication interface, it determines whether or not exclusive control is performed in the processing for the table based on the information set in the predetermined field of the packet. The transfer device according to claim 8. When the transfer processing means indicates that the information set in the predetermined field is the first content, the transfer processing means performs the exclusive control, and the information set in the predetermined field is the second content. The transfer device according to claim 9, wherein the exclusive control is not performed when shown. When executed by the one or more processors of the device having one or more processors, the device having the one or more processors functions as the transfer device according to any one of claims 1 to 10. A program featuring.

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