JP2021068973A - Transfer device, transfer system, and transfer program - Google Patents

Abstract

To achieve simple and fair control.SOLUTION: A transfer device that transfers data includes a holding unit that can store the data in the input order and output the data in the input order, a storage unit that stores correspondence information in which first data amount and a band are associated with each other such that the band becomes smaller as the amount of the first data stored in the holding unit increases, and an input determination unit that identifies specific first data amount from the corresponding information according to a recording band recorded in the input target data, and determines whether to input or discard the input target data to the holding unit on the basis of the specific first data amount and the data amount acquired from the holding unit.SELECTED DRAWING: Figure 9

Description

The present invention relates to a transfer device, a transfer system, and a transfer program that transfer data.

With the spread of the Internet, virtualization technology for servers and services is evolving. As a result, it is better to rent servers and services from the data center and use them via the Internet than to purchase and manage the servers individually by the user organization. It has an advantage in many aspects such as tees. As a result, the number of servers housed in data centers continues to grow. At the same time, traffic is constantly increasing in the data center network.

Data center operators anticipate future traffic volumes in response to increased traffic, and increase lines and network transfer devices (hereinafter referred to as "switches") in advance. This manages traffic so that it does not exceed the bandwidth of the network. However, in a data center, in general, the bandwidth when all servers send packets at maximum performance is not provided in the data center network. Therefore, if the server sends more traffic than expected, the traffic will exceed the bandwidth of the line and part of the traffic will be discarded.

There is a method called fair control as a method of using the line bandwidth when the traffic exceeds the network bandwidth. As a method of realizing fair control, for example, there is a method of using a fair queue. In this method, the traffic sent to the line at each switch is separated into individual flows, queues are prepared for each flow, packets of the corresponding flow are retained in the corresponding queue, and packets are extracted from each queue by round robin. Send. As a result, when the total bandwidth of the traffic exceeds the line bandwidth, the traffic of the flow with a large bandwidth is discarded. Therefore, fairness between flows is realized. An example of a method of realizing fair control by using a fair queue is disclosed in Patent Document 1.

The fair access network system of Patent Document 1 belongs to the case where a queue corresponding to each VLAN is created according to the number of logically multiplexed VLANs and this packet is transmitted based on the destination IP address of the received packet. The data of this packet is distributed to the queue of the VLAN to be used, and then the data of the packet distributed to each of the plurality of queues is sent from each queue in a predetermined order.

Further, when fair control is realized by using Random Early Detection (hereinafter referred to as "random initial detection") presented in Non-Patent Document 1, the bandwidth of each flow or the retention state of packets is determined by fair queue or the like. Grasp and detect and discard packets by random initial detection aiming at a flow with a large bandwidth. This makes it possible to improve the fairness between flows while operating the random initial detection.

Further, as a method of using the line bandwidth when the traffic exceeds the network bandwidth, there is a method called Two Rate Three Marker introduced in Non-Patent Document 2. In this method, for example, a guaranteed bandwidth (Committed Information Rate (CIR)) and a peak bandwidth (Peek Information Rate (PIR)) are set for each source server, and traffic below the guaranteed bandwidth and peak bandwidth above the guaranteed bandwidth. The packets in the traffic are classified into the following three types of traffic and the traffic exceeding the peak band, and recorded in the DS field of each packet.

Then, in this method, the guaranteed band and the peak band are set for each server at the edge switch which is the entrance of the data center network, and three types are recorded in the packet according to the Two Rate Three Marker. As a result, at the congestion point in the network, these three types are distinguished and the packet below the guaranteed band is treated as the highest priority, and the packet above the guaranteed band and below the peak band is treated as the second highest priority. Therefore, fairness between traffic is realized.

Japanese Unexamined Patent Publication No. 2004-104708

Floyd, S.M. , And Jacobson, V "Random Early Detection gateways for Congestion Availability", IEEE / ACM Transportations on Networking, V.I. 1 N. 4, August 1993, "A Two Rate Three Color Marker", RFC 2698, September 1999.

However, in order to use fair queues, at least as many queues as flows are required, and each queue requires at least one packet buffer. As the number of servers in the data center increases, so does the number of flows, which requires a large amount of queue and buffer memory on the switch. Therefore, a switch that realizes fair control for a data center is expensive. Furthermore, if there is an upper limit on the number of queues on the switch, the fairness control function of the switch may become unavailable due to the increase in flow accompanying the increase in the number of accommodated servers.

FIG. 20 is an explanatory diagram showing an example of a network configuration of a data center. Here, with reference to FIG. 20, the number of queues required for the core switch when the fair queue is used will be described. In the data center shown in FIG. 20, there are 1000 servers S1 to S1000 including the device omitted from FIG. 20. When the servers S1 to S1000 are not distinguished, it is simply referred to as the server S.

In order to connect these servers S1 to S1000 to the network, there are 100 edge switches E1 to E100 including the device omitted from FIG. 20. When the edge switches E1 to E100 are not distinguished, they are simply referred to as edge switches E. The 10 servers from S1 to S10 are connected to the edge switch E1. Similarly, 990 servers from S11 to S1000, including the devices and lines omitted from FIG. 20, are also connected to 99 edge switches from E2 to E100, 10 each.

In order to connect these 100 edge switches E1 to E100, there are 10 core switches C11 to C20 including the device omitted from FIG. 20. The 10 edge switches E1 to E10 are connected to the core switch C11. Similarly, 99 edge switches E2 to E100 including the devices and lines omitted from FIG. 20 are also connected to the corresponding 9 core switches C12 to C20, 10 each.

Further, in order to connect these 10 core switches C11 to C20, there is one core switch C1. The 10 core switches C11 to C20 are connected to the core switch C1. When the core switches C1 to C20 are not distinguished, they are simply referred to as core switches C.

It is assumed that the bandwidths of the lines connecting the server S and the edge switch E in FIG. 20, between the edge switch E and the core switch C, and between the core switches C are all 10 [Gbit / s]. ..

Here, it is assumed that 100 servers from S1 to S100 are transmitting traffic to any of the 100 servers from S901 to S1000 at 100 [Mbit / s] (total 10 [Gbit / s]). s] traffic). It is also assumed that 800 servers from S101 to S900 are also transmitting traffic at 10 [Mbit / s] to any of the 100 servers from S901 to S1000 (total 8 [Gbit / s]]. Traffic).

All of this assumed traffic passes through line 2000 from core switch C1 to core switch C20. This line 2000 has 10 [Gbit / s], but since the total traffic from the servers S1 to S900 is 18 [Gbit / s], it exceeds 8 [Gbit / s]. When fair control is targeted for each of the source servers S1 to S900, the 100 [Mbit / s] traffic transmitted by the servers S1 to S100 is discarded by 80 [Mbit / s] to 20 [Mbit / s] each. A total of 10 [Gbit / s] is appropriate.

When a fair queue is used, at the interface to which the line of the core switch C1 to the core switch C20 is connected, packets of passing traffic are packetized from each of the individual queues of the 900 servers S1 to S900 according to the fair queue. As long as there is, the packet is pulled out by round robin and transmitted. For example, 10 [Mbit / s] traffic is transmitted from 900 queues corresponding to 900 servers S1 to S900 (total 9 [Gbit / s] traffic). Additional [10 Mbit / s] traffic is transmitted from 100 queues corresponding to the servers S1 to S100 that cannot be transmitted with 10 [Mbit / s] for the remaining 1 [Gbit / s] bandwidth. (Total 1 [Gbit / s] of traffic). As a result, fair control is performed.

However, in order to realize a fair cue, 900 cues are required for the core switch C1. This number is about the same as the number of servers in the data center. Therefore, as the number of servers accommodated in the data center increases, so does the number of queues required. As a result, the scale of the data center is limited by the number of queues of the core switch C.

Further, when the Two Rate Three Marker of Non-Patent Document 2 is used, each of the edge switches E1 to E100 identifies the traffic transmitted by the 10 servers connected to each of the edge switches E1 to E100, and each server identifies the traffic transmitted by each of the edge switches E1 to E100. 20 [Mbit / s] is set as the peak band, and the Two Rate Three Marker is operated to record in the DS field.

When the packet transmission queue is changed according to the value of the DS field in the interface to which the line to the core switch C20 of the core switch C1 is connected, 20 [Mbit / s] packets of the traffic transmitted by the servers S1 to S100 are packet. (Total 2 [Gbit / s] traffic) and packets for 10 [Mbit / s] of the traffic transmitted by the servers S101 to S900 (total 9 [Gbit / s] traffic) are transmitted. As a result, fair control is performed.

However, the bandwidth limit of traffic per source server S for proper fair control varies depending on the situation. In the case of the above example, it was fair to limit the peak band to 20 [Mbit / s], but when the servers S101 to S900 are transmitting at 11 [Mbit / s] (total 9.9 [Gbit / s]). ] Traffic) becomes fair when the servers S1 to S100 are limited to 12 [Mbit / s] (total 1.2 [Gbit / s] traffic).

The peak bandwidth for fairness depends on traffic conditions. Therefore, it is necessary to obtain an appropriate band according to the situation and reflect it in the setting of Two Rate Three Marker of the edge switch E. However, in order to obtain an appropriate bandwidth for fair control in the core switch C, it is necessary to check the bandwidth of each flow, and in the end, resources proportional to the number of servers in the data center are required. Further, the traffic bandwidth may change while the appropriate bandwidth is sought and reflected on the edge switch E, and the reflection may not be in time and the operation may not be appropriate.

Therefore, in order to achieve fairness in the data center network, resources proportional to the number of servers are not required for each switch as in the fair queue, and the traffic bandwidth for each server is used as in the Two Rate Three Marker. There is a need for a simple method for realizing fair control that does not require corresponding peak band calculation.

An object of the present invention is to realize simple fair control.

The transfer device, which is one aspect of the invention disclosed in the present application, is a transfer device that transfers data, and is a holding unit that can store the data in the input order and output the data in the input order, and a first holding unit stored in the holding unit. In the storage unit that stores the correspondence information in which the first data amount and the band are associated with each other so that the band becomes smaller as the amount of data increases, and the recording band recorded in the data to be input to the holding unit. Correspondingly, a specific first data amount is specified from the corresponding information, and the input target data is input to the holding unit based on the specific first data amount and the amount of data acquired from the holding unit. It is characterized by having an input determination unit for determining whether to discard or discard.

The transfer device according to another aspect of the invention disclosed in the present application is a transfer device for transferring data, which is provided for each band and holds a plurality of holdings capable of accumulating data in the corresponding band in the input order and outputting the data in the input order. It is characterized by having a unit and an input determination unit that determines to which of the plurality of holding units the input target data should be input based on the recording band recorded in the input target data. And.

A transfer device that is another aspect of the invention disclosed in the present application is a transfer device that transfers data, and is a flow that specifies a flow and a plurality of communication units that are communicably connected to each of the plurality of communication devices. With reference to the storage unit that stores the correspondence information in which the specific information is associated with the band measurement number different for each flow and the band information in which the band is added for each band measurement number, and the correspondence information. The band measurement number of the determination target data is specified based on the flow identification information included in the determination target data from any of the plurality of communication units, and the band measurement number of the determination target data is used in the band information. A flow determination unit that adds the size of the determination target data to the corresponding band and records the added band to which the size is added in the determination target data, and the determination that the flow is determined by the flow determination unit. It is characterized by having a transfer destination determination unit that determines a specific communication unit connected to the specific communication device specified by the destination address based on the destination address of the target data.

The transfer system, which is one aspect of the invention disclosed in the present application, is a transfer system including a first transfer device and a second transfer device communicably connected to the first transfer device. The transfer device includes a plurality of communication units that are communicably connected to each of the plurality of communication devices, correspondence information that associates flow specific information that specifies a flow with a band measurement number that is different for each flow, and the band. With reference to the storage unit that stores the band information in which the band is added for each measurement number and the corresponding information, the flow specific information included in the determination target data from any of the plurality of communication units Based on this, the band measurement number of the determination target data is specified, the size of the determination target data is added to the band corresponding to the band measurement number of the determination target data in the band information, and the size is added. Based on the flow determination unit that records the later band in the determination target data and the destination address of the determination target data whose flow is determined by the flow determination unit, the destination address is specified among the plurality of communication devices. The second transfer device has a transfer destination determination unit that determines a specific communication unit connected to the second transfer device, and the second transfer device accumulates data from the first transfer device in the order of input and in the order of input. A holding unit that can be output, a storage unit that stores correspondence information in which the amount of data and the band are associated with each other so that the band becomes smaller as the amount of first data stored in the holding unit increases, and the first unit. A specific amount of data is specified from the corresponding information according to the recording band recorded in the data to be input from the transfer device to the holding unit, and the specific amount of data and the amount of data acquired from the holding unit are obtained. Based on the above, the data is characterized by having an input determination unit for determining whether to input the input target data to the holding unit or discard the data.

The transfer program, which is one aspect of the invention disclosed in the present application, is a transfer program that causes a processor to execute data transfer by a plurality of communication units communicably connected to each of a plurality of communication devices. It is possible to access a storage unit that stores the corresponding information in which the flow specific information for specifying the flow and the band measurement number different for each flow are associated with each other, and the band information in which the band is added for each band measurement number. With reference to the corresponding information, the processor identifies the band measurement number of the determination target data based on the flow identification information included in the determination target data from any of the plurality of communication units. A flow determination process in which the size of the determination target data is added to the band corresponding to the band measurement number of the determination target data in the band information, and the added band to which the size is added is recorded in the determination target data. , A transfer destination determination process for determining a specific communication unit connected to a specific communication device specified by the destination address based on the destination address of the determination target data whose flow is determined by the flow determination process. Is characterized by executing.

According to a typical embodiment of the present invention, simple fair control can be realized.

FIG. 1 is a block diagram showing a configuration example of the edge switch E according to the first embodiment. FIG. 2 is a block diagram showing a configuration example of the flow determination unit shown in FIG. FIG. 3 is an explanatory diagram showing an example of the packet format according to the first embodiment. FIG. 4 is a table showing an example when the band value is converted into a logarithm having the base of 2. FIG. 5 is a line connection diagram between the server S of the edge switch and the core switch. FIG. 6 is an explanatory diagram showing an example of setting a flow table in the edge switch. FIG. 7 is a table showing a band example 1 recorded in a packet. FIG. 8 is a block diagram showing a configuration example of the core switch according to the first embodiment. FIG. 9 is a block diagram showing a configuration example of a transmission unit of the core switch shown in FIG. FIG. 10 is an explanatory diagram showing an aggregation example 1 of the number of transmitted packets, the amount of transmitted information, the total bandwidth of all servers, and the discard queue length for each packet recording band. FIG. 11 is an explanatory diagram showing a modification 1 of the flow table. FIG. 12 is an explanatory diagram showing a modification 2 of the flow table. FIG. 13 is a table showing a band example 2 recorded in a packet. FIG. 14 is an explanatory diagram showing an aggregation example 2 of the number of transmitted packets, the amount of transmitted information, the total bandwidth of all servers, and the discard queue length for each packet recording band. FIG. 15 is an explanatory diagram showing a modified example of the flow table. FIG. 16 is a block diagram showing a configuration example of a transmission unit of the core switch according to the second embodiment. FIG. 17 is an explanatory diagram showing an aggregation example of the number of transmitted packets, the amount of transmitted information, the total bandwidth of all servers, and the transmission queue number for each packet recording band. FIG. 18 is a block diagram showing a configuration example of a transmission unit of the core switch C according to the third embodiment. FIG. 19 shows, in Case 3 or Case 4, the number of packets per 1 [ms] for each recording band of packets to be transmitted to the line by the transmitting unit, the amount of transmitted information per 1 [ms], the band, and the discard confirmation queue length. It is a table which shows the random discard queue length. FIG. 20 is an explanatory diagram showing an example of a network configuration of a data center.

Each of the following embodiments relates to a transfer device, transfer system, and transfer program that transfers data, and is applicable to private networks and VPN networks that accommodate a large number of terminals and support communication, such as a data center network. is there.

The first embodiment is an example in which fair control is realized by utilizing the length of the transmission queue in the interface of the core switch C. Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 16 and 20.

<Configuration example of edge switch E>
FIG. 1 is a block diagram showing a configuration example of the edge switch E according to the first embodiment. The edge switch E is a transfer device having a control unit 101, a packet processing unit 102, a data bus 103, and a plurality of interface units 104. The packet processing unit 102 includes a packet buffer 110, a flow determination unit 111, and a transfer destination determination unit 112. Each interface unit 104 has a receiving unit 113 and a transmitting unit 114.

The packet transmitted by the server S is received by the receiving unit 113 of the interface unit 104 of the edge switch E connected to the server S. The received packet is stored in the packet buffer 110 in the packet processing unit 102 via the data bus 103.

The flow determination unit 111 executes a flow determination process for each of the packets stored in the packet buffer 110, and rewrites the packet when necessary according to the determination result. Details of the flow determination unit 111 will be described later in FIG.

The forwarding destination determination unit 112 determines the transmission interface to which the packet should be transmitted based on the destination address of the packet. Finally, the transmission unit 114 of the interface unit 104 determined as the transmission interface by the transfer destination determination unit 112 reads the packet from the packet buffer 110 and transmits the packet. As a result, the packet is forwarded.

The flow determination unit 111 and the transfer destination determination unit 112 may be functions realized by executing the program stored in the memory by the processor, or may be executed by the LSI.

<Structure example of flow determination unit 111>
FIG. 2 is a block diagram showing a configuration example of the flow determination unit 111 shown in FIG. The flow determination unit 111 includes a flow determination processing unit 201, a flow table 202, a band table 203, and a band reset unit 204. The flow table 202 and the band table 203 are stored in a memory (not shown).

The flow determination processing unit 201 executes the flow determination process for each packet. The flow table 202 is a table for determining the flow, and holds the reception interface 221, the source address 222, the band measurement number 223, and the band recording coefficient 224 as fields. In the receiving interface 221, the identification information of the interface unit 104 in which the packet is received is recorded as a value. At the source address 222, the source address of the received packet is recorded as a value. The receiving interface 221 and the source address 222 are flow-specific information that specifies the flow.

In the band measurement number 223, a different number is recorded for each flow as a value. A preset value is recorded as a value in the band recording coefficient 224. For example, in the column of band recording coefficient 224, "1" is set for all flows. The band recording coefficient 224 is a value related to the communication cost and weights the band. The smaller the value of the band recording coefficient 224, the easier it is for the packet to be transmitted, and the higher the communication cost.

The band table 203 records the band 230 measured for each band measurement number 223. The band reset unit 204 resets the band 230 recorded in the band table 203. The operation of the flow determination processing unit 201 will be described in detail.

The flow determination processing unit 201 reads the reception interface, source address, and packet size of the determination target packet from the packet buffer 110.

The flow determination processing unit 201 searches the flow table 202 for rows of the receiving interface 221 and the source address 222 that match the receiving interface and the source address read from the packet buffer 110, and records the bandwidth measurement number 223 and the bandwidth of the corresponding row. Read the coefficient 224. If there is no corresponding line, the flow determination processing unit 201 does nothing further.

The flow determination processing unit 201 reads the line of the corresponding band measurement number 223 from the band table 203, and adds the packet size read from the packet buffer 110 to the band 230 of that line. Then, the flow determination processing unit 201 takes out the added band 230, multiplies it by the band recording coefficient 224 of the line read from the band table 203, and records it in the band field of the determination target packet. Apart from the flow determination process, the band reset unit 204 accesses all the rows of the band table 203 in a cycle of 1 [ms], and resets the band 230 of the accessed rows to 0.

<Packet format>
FIG. 3 is an explanatory diagram showing an example of the packet format according to the first embodiment. The packet 300 has an IP header 301 and a payload 302 for storing data. The IP header 301 has a plurality of fields for storing information necessary for forwarding the packet 300. Of these fields, the field of service type 303 can be used as the band field described above. However, since the portion of the service type 303 that can be used to store the bandwidth is 6 bits, only 64 numerical values from 0 to 63 can be expressed. Therefore, for example, a method of taking a logarithm with the base of the band value 2 and storing the value is an example.

FIG. 4 is a table showing an example when the band value is converted into a logarithm having the base of 2. According to this method, values up to 2 to the 64th power can be stored in the standard field of the IP header 301, although there is a rounding error. As another storage method, if it is not a big problem that the length of the IP header 301 is longer than the standard, a unique storage method can be defined and stored in the extended information 304 of FIG.

<Line connection with server S and core switch C of edge switch E>
FIG. 5 is a line connection diagram of the edge switch E with the server S and the core switch C. In FIG. 5, the edge switch E1 as the edge switch E, the servers S1 to S10 as the server S, and the core switch C1 as the core switch C will be described as an example.

The edge switch E1 has 11 interface units 501 to 511 as the interface unit 104. The interface unit 501 is line-connected to the server S1. Similarly, the interface unit 502 is the server S2, the interface unit 503 is the server S3, the interface unit 504 is the server S4, the interface unit 505 is the server S5, the interface unit 506 is the server S6, and the interface unit 507 is the server S7. The interface unit 508 is connected to the server S8, the interface unit 509 is connected to the server S9, the interface unit 510 is connected to the server S10, and the interface unit 511 is connected to the core switch C11.

<Setting example of flow table 202>
FIG. 6 is an explanatory diagram showing a setting example of the flow table 202 in the edge switch E1. The edge switch E1 separates the flow for each source server S using the flow table 202, and records the bandwidth of the flow in the packet 300. It is assumed that the servers S1 to S10 are assigned addresses "10.0.0.1" to "10.0.0.10", respectively.

Each row in the flow table 202 corresponds to servers S1 to S10, respectively. Specifically, for example, in the column of the receiving interface 221, reference numerals 501 to 510 of the interface units 501 to 510 are set for convenience as identification information of the interface units 501 to 510 connected to the servers S1 to S10. The interface. The addresses "10.0.0.1" to "10.0.0.10" of each server S1 to S10 are set in the column of the source address 222. In the column of band measurement number 223, a different number is set for each flow.

<Bandwidth example 1 recorded in packet 300>
FIG. 7 is a table showing a band example 1 recorded in the packet 300. In FIG. 7, as an example, when the server S1 divides the traffic of 100 [Mbit / s] into 1250-byte packets 300 and transmits the divided packets 300 in a cycle of 100 [μs], the edge switch E1 performs the packet 300. An example of the band to be recorded in is shown.

As shown in FIG. 7, for the packet 300 in which the server S1 has a cycle of 100 [μs], the flow determination unit 111 of the edge switch E1 sets the value “1” of the band measurement number 223 in the first row of the flow table 202 of FIG. The value "1" of the band recording coefficient 224 is acquired from the flow table 202. Next, when the time is 50 [μs], the flow determination unit 111 sets the packet size to 1250 [Byte] in the value “0” of the band 230 in the line which is the value “1” of the band measurement number 223 in the band table 203. Is added.

For a series of packets 300 transmitted by the server S1 at a time after this, the cumulative value in 1250 [Byte] units such as 1250 [Byte], 2500 [Byte], 3750 [Byte], ... At the edge switch E1 is calculated. calculate. These cumulative values are recorded in the corresponding packet 300 and band 230 in band table 203. However, on the other hand, since the band reset unit 204 resets the value of the band 230 in the band table 203 with "0" in a cycle of 1 [ms], the band recorded in the packet 300 does not exceed 15000 [Byte] and is 1250. Return to [Byte].

<Configuration example of core switch C>
FIG. 8 is a block diagram showing a configuration example of the core switch C according to the first embodiment. The core switch C is a transfer device having a control unit 801, a packet processing unit 802, a data bus 803, and a plurality of interface units 804. The packet processing unit 802 has a packet buffer 810 and a transfer destination determination unit 812. Each interface unit 804 has a receiving unit 813 and a transmitting unit 814.

Similar to the edge switch E, the core switch C also receives the packet 300 transmitted to the core switch C by the connection destination switch connected to the core switch C by the interface unit 804 connected to the connection destination switch in the core switch C. Received by unit 813. The connection destination switch is the core switch C11 to C20 if the core switch C is the core switch C1, and the core switch C1 and the edge switch E (for example, if the core switch C is any of the core switches C11 to C20). If the core switch C is the core switch C11, the edge switches E1 to E10). The received packet 300 is stored in the packet buffer 810 in the packet processing unit 802 via the data bus 803.

The transfer destination determination unit 812 determines the transmission interface to which the packet 300 should be transmitted based on the destination address of the packet 300 for each of the packets 300 stored in the packet buffer 810. Finally, the transmission unit 814 of the interface unit 804 determined as the transmission interface by the transfer destination determination unit 812 reads the packet 300 from the packet buffer 810 and transmits the packet 300. As a result, the packet 300 is transferred.

<Configuration example of transmitter 814 of core switch C>
FIG. 9 is a block diagram showing a configuration example of the transmission unit 814 of the core switch C shown in FIG. The transmission unit 814 of the core switch C has a transmission queue 901, a line transmission unit 902, an input determination unit 903, and a disposal priority table 904. The discard priority table 904 is stored in a memory (not shown).

The transmission queue 901 has a list structure (FIFO memory) in which packets 300 are first-in first-out. The transmission queue 901 holds packets 300 up to, for example, 1000 packets. The line transmission unit 902 transmits the packet 300 output from the transmission queue 901 to the interface unit of the switch to which the line transmission unit 902 is connected.

The input determination unit 903 determines whether or not the packet 300 from the packet buffer 810 should be input to the transmission queue 901 based on the discard priority table 904. The discard priority table 904 is a table in which the discard queue length 942 is preset for each band 941 as a field. The discard queue length 942 is a parameter for determining whether the packet 300 read from the packet buffer 810 by the input determination unit 903 is mounted on the transmission queue 901 or discarded. Based on the transmission queue length, which is the number of packets mounted on the transmission queue 901, the discard queue length 942 is set to the minimum transmission queue length for packet discard. The operation of the transmission unit 814 of the core switch C will be described in detail.

When the input determination unit 903 reads the packet 300 from the packet buffer 810, the input determination unit 903 selects the smallest band 941 among the bands 941 larger than the band (recording band) recorded in the band field of the packet 300 from the discard priority table 904. Search for the line you wrote. For example, if the recording band is 10000 [bit / s], the smallest band 941 among the bands 941 (18000 to 1250000 [bit / s]) larger than 10000 [bit / s] is 18000 [bit / s]. s] line is searched.

The input determination unit 903 acquires the discard queue length 942 of the searched row. In the above example, the input determination unit 903 acquires "500" which is the discard queue length 942 of the row of 18000 [bit / s] which is the band 941.

Next, the input determination unit 903 acquires the number of packets 300 staying in the transmission queue 901 (hereinafter, referred to as “retention queue length”) from the transmission queue 901. The input determination unit 903 compares the retention queue length with the disposal queue length 942 obtained from the disposal priority table 904. When the stay queue length is smaller than the value of the discard queue length 942, the input determination unit 903 inputs the packet 300 read from the packet buffer 810 to the transmission queue 901.

When the packet 300 is accumulated in the transmission queue 901, the line transmission unit 902 extracts the first packet of the transmission queue 901 and transmits it to the line according to the line speed. On the other hand, when the stay queue length is equal to or greater than the value of the discard queue length 942, the input determination unit 903 discards the packet 300 read from the packet buffer 810.

FIG. 10 is an explanatory diagram showing an aggregation example 1 of the number of transmitted packets, the amount of transmitted information, the total bandwidth of all servers, and the discard queue length 942 for each recording band of the packet 300. In the aggregation example 1, a configuration that realizes fair control by utilizing the length of the transmission queue 901 in the interface unit 804 of the core switch C is applied.

Specifically, for example, when a certain traffic is transmitted from the server group and the edge switch E1 uses the flow table 202 shown in FIG. 6, the core switch C1 transmits the traffic that should be originally transmitted to the core switch C20 of the packet 300. This is an example of totaling by recording band.

More specifically, for example, in FIG. 10, the following cases 1 and 2 are assumed. (Case 1) Servers S1 to S100 transmit 100 [Mbit / s] traffic to any of servers S900 to S1000 in 1250-byte packets 300 at 100 [μs] intervals.

(Case 2) Servers S101 to S900 transmit 10 [Mbit / s] traffic to any of servers S900 to S1000 in 1250-byte packets 300 at 1 [ms] intervals.

In FIG. 10, in the case of case 1 or case 2, the number of packets per 1 [ms] for each recording band of the packets 300 that should be originally transmitted in the transmission unit 814 of the interface unit 804 connected to the core switch C20 of the core switch C1. 1, Indicates the amount of information per [ms], communication bandwidth, and discard queue length.

Here, consider the case where the retention queue length is "650". In this case, as shown in FIG. 10, according to the disposal priority table 904 of FIG. 9, the band 941 corresponding to the value “650” of the disposal queue length 942 is less than 5800 [bit / s]. Therefore, packets 300 of less than 5800 [bit / s] are loaded on the transmission queue 901.

According to FIG. 10, the cumulative value of the total bandwidth of all servers by recording bandwidth of the packet 300 whose recording bandwidth is less than 5800 [bit / s] is a total bandwidth of 12 [Gbit / s] (= 9 + 1 + 1 + 1), but the core switch C The interface unit 804 has a transmission speed of only 10 [Gbit / s]. Therefore, there are more packet inputs to the transmission queue 901 by the input determination unit 903 than packet outputs from the transmission queue 901 by the line transmission unit 902. As a result, the retention queue length is extended.

Further, when the retention queue length is "850", as shown in FIG. 10, according to the disposal priority table 904 of FIG. 9, the band 941 corresponding to the value "850" of the disposal queue length 942 is 1800 [bit / s]. ] Is less than. Therefore, only packets 300 less than 1800 [bit / s] are loaded on the transmission queue 901.

The cumulative value of the total bandwidth of all servers for each recording bandwidth of packets 300 with a recording bandwidth of less than 1800 [bit / s] is 9 [Gbit / s], but the transmission speed of the interface unit 804 of the core switch C is 10 [Gbit / s]. / S] is faster. Therefore, the number of packet inputs to the transmission queue 901 by the input determination unit 903 is smaller than the packet output from the transmission queue 901 by the line transmission unit 902. As a result, the retention queue length is shortened.

Then, in a state where the retention queue length is 701 to 800, packets 300 (total 10 [Gbit / s]) whose bandwidth 941 is less than 3200 [bit / s] are loaded on the transmission queue 901. Therefore, the traffic in FIG. 10 is stable in balance with the transmission speed 10 [Gbit / s] of the interface unit 804 of the core switch C.

As a result, for the 10 [Mbit / s] traffic of the servers S101 to S900 (Case 2), all 1250 byte packets 300 at 100 [μs] intervals are transmitted. On the other hand, the traffic of 100 [Mbit / s] of the servers S1 to S100 (case 1) is transmitted in 10 packets per 1 [ms]. Of these 10 packets, only 2 packets having recording bands of 1250 and 2500 pass through, so that the value is 20 [Mbit / s], and fair control can be realized.

In the first embodiment, the flow determination is performed based on the source address of the packet 300, but other elements in the packet 300 may be used for the flow determination.

FIG. 11 is an explanatory diagram showing a modification 1 of the flow table 202. The flow table 1102 of FIG. 11 is a table in which the destination address 1101 is added to the flow table 202 of FIG. Using the flow table 1102, the flow determination processing unit 201 can perform flow determination by combining the source address 222 and the destination address 1101.

Here, in FIG. 11, the value "*" of the destination address 1101 means all the destination addresses. Therefore, the flow determination processing unit 201 executes the search of the flow table 1102 in order from the top row until a matching row is found.

Explaining with the example of FIG. 11, the packet 300 is transmitted from the server S3 having the value "10.0.0.3" of the source address 1201 connected to the interface unit 503 where the value of the receiving interface 221 is "603". Suppose. For this packet group, different band measurement numbers 223 are assigned to the packet 300 whose destination address is 192.168.0.1 and the other packets 300. Therefore, the bandwidth of only the packet 300 for the value "192.168.0.1" of the specific destination address 1101 can be measured individually.

For example, in the case where the flow is determined only by the source address 222, the measurement band is larger than in the case where the flow is determined by the combination of the source address 222 and the destination address, and the effect of disposal is large. On the other hand, if the bandwidth of only the packet 300 for the specific destination address 1101 is individually measured and the result is a smaller bandwidth than the case where the flow is determined only by the source address 222, the packet 300 is not affected by the discard. ..

Further, in the example in which the flow table 1102 is applied, the traffic of the specific server S is reduced by reducing the bandwidth recorded in the packet 300 transmitted by the specific server S as compared with the case where the flow is determined only by the source address 222. It can be more than other servers S.

FIG. 12 is an explanatory diagram showing a modification 2 of the flow table 202. FIG. 12 shows a flow table 202 of the flow determination unit 111 of the edge switch E1. In the flow table 202, the band recording coefficient 224 of the row of the value “602” of the reception interface 221 is “0.5”. The value "602" of the receiving interface 221 indicates an interface unit 502 connected to the server S2. Since the band recording coefficient 224, which is the weight of the fair control packet 300, is half that of the other band recording coefficient 224, the server S2 flows twice as much traffic as the other server S.

FIG. 13 is a table showing a band example 2 recorded in the packet 300. In FIG. 13, as an example, when the server S2 transmits a 1250-byte packet 300 in a cycle of 100 [μs], the flow determination unit 111 of the edge switch E1 assigns a bandwidth to the packet 300 when the flow table 202 shown in FIG. 12 is set. The recorded example is shown. Unlike the case of FIG. 8, in FIG. 12, since the band recording coefficient 224 of the line where the reception interface 221 is “602” is “0.5”, all the band values recorded in the packet 300 are 0.5. Is multiplied and halved.

FIG. 14 is an explanatory diagram showing an aggregation example 2 of the number of transmitted packets, the amount of transmitted information, the total bandwidth of all servers, and the discard queue length 942 for each recording band of the packet 300. In the aggregation example 2, the conditions are the same as those in the aggregation example 1 except that the edge switch E1 uses the flow table 202 shown in FIG.

Here, consider the case where the retention queue length is less than "800". In FIG. 14, the packet 300 having a recording band of less than 3200 [bit / s] is loaded on the transmission queue 901. Then, the total bandwidth of the traffic input to the transmission queue 901 becomes 10.03 [Gbit / s], which exceeds the transmission speed of 10 [Gbit / s] of the interface unit 804 of the core switch C. As a result, the retention queue length is extended.

When the retention queue length is extended to 800 or more, only packets 300 having a recording bandwidth of less than 1800 [bit / s] in FIG. 14 are loaded on the transmission queue 901. As a result, the total bandwidth of the traffic input to the transmission queue 901 becomes 9.01 [Gbit / s], which is lower than the transmission speed of 10 [Gbit / s] of the interface unit 804 of the core switch C. As a result, the retention queue length is shortened.

In this way, the retention queue length increases or decreases at around 800. Then, all of the traffic 9.01 [Gbit / s] having a recording band of 625 [bit / s] and 1250 [bit / s], and the recording band of 1875 [bit / s], 2500 [bit / s] and A traffic of 10 [Gbit / s], which is a total of a part of the traffic of 1.01 [Gbit / s] of 3125 [bit / s], is transmitted.

At this time, out of the 10 [Gbit / s] transmitted, all the traffic of 9.01 [Gbit / s] of the former is transmitted, so that the remaining band of 0.99 [Gbit / s] is 1. 02 Used to transmit [Gbit / s] traffic. That is, of the latter traffic 1.02 [Gbit / s], 0.99 [Gbit / s] (about 97%) is actually transmitted, and the remaining about 3% is discarded.

As a result of the above operation, in the traffic of the server S1 in which the value of the bandwidth recording coefficient 224 is "1" in the flow table 202, the recording bandwidths are 1250 [bit / s] and 2500 [bit / s] per 1 [ms]. It can be expected that a certain two packets will pass. On the other hand, in the traffic of the server S2 in which the value of the bandwidth recording coefficient 224 is "0.5", most of the four packets having the recording bandwidths of 625, 1250, 1875, and 2500 [bit / s] per [ms]. You can expect it to pass.

In this way, by recording the value considering the weight with respect to the actual bandwidth of the flow as the bandwidth in the packet 300, the difference in the weight of the traffic with respect to the other flow is expressed, and the important traffic is recorded at the time of congestion at the core switch C. It becomes possible to send with priority.

In the flow determination according to the flow table 202, even when the band recording coefficient 224 is used, elements other than the source address 222 may be used as in the flow table 1102 of FIG. 11 with respect to FIG.

FIG. 15 is an explanatory diagram showing a modified example of the flow table. The flow table 1502 of FIG. 15 is a table in which the destination address 1101 is added to the flow table 202 of FIG. Using the flow table 1502, the flow determination processing unit 201 can perform flow determination by combining the source address 222 and the destination address 1101.

In FIG. 15, among the packets 300 transmitted from the server S having the source address 222 value “10.0.0.3”, the packet 300 having the destination address 1101 value “192.168.0.1”. Only another band recording factor 224 can be applied. As a result, the packet 300 can be treated as important traffic.

The second embodiment shows an example in which a plurality of transmission queues 901 are applied to the interface of the core switch C to realize fair control. The structure of the transmission unit 814 of the core switch C of the second embodiment is different from that of the first embodiment. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 16 is a block diagram showing a configuration example of the transmission unit 814 of the core switch C according to the second embodiment. The transmission unit 814 has a plurality of transmission queues 901, a line transmission unit 1602, an input determination unit 1603, and a queue number table 1604. The queue number table 1604 is stored in a memory (not shown).

It is assumed that the plurality of transmission queues 901 have transmission queue numbers starting from 1, and each packet 300 can be loaded up to 100 packets.

When the packet 300 is retained in any one of the plurality of transmission queues 901, the line transmission unit 1602 extracts one packet 300 from the transmission queue 901 having the smallest transmission queue number 1642 and transmits the packet 300 to the line. To do.

The input determination unit 1603 determines in which transmission queue 901 the packet 300 should be input from the packet buffer 810 based on the queue number table 1604. The queue number table 1604 is a table in which transmission queue numbers 1642 assigned to each transmission queue 901 are preset for each band 941. The operation of the transmission unit 814 of the core switch C will be described in detail.

The input determination unit 1603 reads the packet 300 from the packet buffer 810, and searches the queue number table 1604 for the line in which the smallest band 941 among the bands 941 larger than the band recorded in the packet 300 is recorded. For example, if the recording band is 10000 [bit / s], the smallest band 941 among the bands 941 (18000 to 1250000 [bit / s]) larger than 10000 [bit / s] is 18000 [bit / s]. s] line is searched.

The input determination unit 1603 acquires the transmission queue number 1642 of the searched line. In the above example, the input determination unit 1603 acquires "7" which is the transmission queue number 1642 of the row of 18000 [bit / s] which is the band 941.

Next, the input determination unit 1603 mounts the packet 300 on the transmission queue 901 of the acquired transmission queue number 1642. If there is no space in the acquired transmission queue 901 of transmission queue number 1642, the input determination unit 1603 discards the packet 300.

FIG. 17 is an explanatory diagram showing an aggregation example of the number of transmitted packets, the amount of transmitted information, the total bandwidth of all servers, and the transmission queue number 1642 in each recording band of the packet 300. In this aggregation example, the conditions are the same as those in aggregation example 1 except that the discard queue length 942 is changed to the transmission queue number 1642. The transmission queue 901 whose value is # in the transmission queue number 1642 is referred to as transmission queue 901- #.

When the line transmission unit 1602 transmits the packet 300 with the line bandwidth of 10 [Gbit / s] for the traffic shown in FIG. 17, the transmission unit 814 first transmits the transmission queues 901-2 to 9 [Gbit / s]. Packet 300 is output to the line transmission unit 1602.

Since the line bandwidth is 1 [Gbit / s] surplus, packets 300 of transmission queues 901-3 to 1 [Gbit / s] are output to the line transmission unit 1602. As a result, since all the line bandwidth is consumed, the packet 300 staying in the transmission queue 901-4 and thereafter is not output to the line transmission unit 1602. Then, all packets 300 of the traffic of 10 [Mbit / s] of the servers S101 to S900 are transmitted. On the other hand, for the traffic of 100 [Mbit / s] of the servers S1 to S100, only 2 packets having recording bandwidths of 1250 [bit / s] and 2500 [bit / s] out of 10 packets per 1 [ms], respectively. Passes. As a result, the packet 300 of the traffic for 10 [Mbit / s] from the servers S1 to S100 is transmitted, so that fair control can be realized.

Example 3 is an example of realizing disposal by random initial detection. The internal structure of the transmission unit 814 of the core switch C of the third embodiment is different from that of the first embodiment. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 18 is a block diagram showing a configuration example of the transmission unit 814 of the core switch C according to the third embodiment. The transmission unit 814 has a transmission queue 901, a line transmission unit 902, an input determination unit 1803, and a random discard priority table 1804.

The input determination unit 1803 determines whether or not the packet 300 from the packet buffer 810 should be input to the transmission queue 901 based on the random discard priority table 1804. The random discard priority table 1804 is a table in which the discard confirmed queue length 1842, the random discard queue length 1843, and the random discard probability 1844 are preset for each band 941. The discard confirmation queue length 1842, the random discard queue length 1843, and the random discard probability 1844 determine whether the packet 300 read from the packet buffer 810 by the input determination unit 1803 is input to the transmission queue 901 or discarded. It is a parameter.

The discard confirmation queue length 1842 is the minimum transmission queue length that always discards packets based on the retention queue length, which is the number of packets mounted on the transmission queue 901. The random discard queue length 1843 is the minimum retention queue length for randomly discarding the packet 300 based on the discard probability. Random disposal probability 1844 is a disposal probability when performing random disposal. Here, the discard confirmation queue length 1842 is set to be equal to or greater than the value of the random discard queue length 1843. In other words, the random discard queue length 1843 is set to a value equal to or less than the discard confirmed queue length 1842. The operation of the transmission unit 814 of the core switch C will be described in detail.

The input determination unit 1803 reads the packet 300 to be transmitted from the packet buffer 810, and records the smallest band 941 among the bands 941 larger than the band recorded in the packet 300 from the random discard priority table 1804. To search for. For example, if the recording band is 10000 [bit / s], the smallest band 941 among the bands 941 (18000 to 1250000 [bit / s]) larger than 10000 [bit / s] is 18000 [bit / s]. s] line is searched.

The input determination unit 903 acquires the discard confirmation queue length 1842, the random discard queue length 1843, and the random discard probability 1844 of the searched row. In the above example, the input determination unit 903 has a value "400" of the discard confirmation queue length 1842, a value "300" of the random discard queue length 1843, and a random discard probability of the row of the band 941 18000 [bit / s]. Acquire the value "1%" of 1844. Next, the input determination unit 903 acquires the retention queue length from the transmission queue 901.

The input determination unit 903 compares the discard confirmation queue length 1842 and the random discard queue length 1843 obtained from the random discard priority table 1804 with the acquired retention queue length. When the value of the random discard queue length 1843 to be compared is set to be less than the value of the discard confirmed queue length 1842 to be compared, the result is as follows.

When the retention queue length is 1843 smaller than the random discard queue length, the input determination unit 903 inputs the packet 300 to the transmission queue 901. When the retention queue length is the random discard queue length 1843 or more and shorter than the discard confirmation queue length 1842, the input determination unit 903 discards the packet 300 with the value of the random discard probability 1844 obtained from the random discard priority table 1804. .. On the other hand, if not discarded, the input determination unit 903 inputs the packet 300 into the transmission queue 901. When the retention queue length is the discard confirmation queue length 1842 or more, the input determination unit 903 discards the packet 300.

When the value of the random discard queue length 1843 to be compared is set to be the same as the value of the discard confirmed queue length 1842 to be compared, the result is as follows.

When the retention queue length is smaller than the random discard queue length by 1843 (= discard confirmation queue length 1842), the input determination unit 903 inputs the packet 300 to the transmission queue 901. When the retention queue length is the random discard queue length 1843 or more (= discard confirmed queue length 1842), the input determination unit 903 discards the packet 300.

Next, a setting example of the random discard priority table 1804 when the core switch C1 realizes random initial discard will be described. Specifically, for example, in the following case 3 or case 4, the operation of the transmission unit 814 connected to the core switch C20 of the core switch C1 will be described.

(Case 3) Servers S1 to S100 transmit 20 [Mbit / s] traffic to any of servers S900 to S1000 in 1250-byte packets at intervals of 500 [μs].

(Case 4) Servers S101 to S900 transmit 10 [Mbit / s] traffic to any of servers S900 to S1000 in 1250 byte packets at 1 [ms] intervals.

FIG. 19 shows, in case 3 or case 4, the number of packets per 1 [ms] for each recording band of the packet 300 to be transmitted to the line by the line transmission unit 902, the amount of transmission information per 1 [ms], the band, and the determination of disposal. It is a table which shows the queue length and the random discard queue length.

When the retention queue length is less than "600", all traffic of 11 [Gbit / s] by the packet 300 having a recording bandwidth of 1250 [bit / s] to 3750 [bit / s] is loaded on the transmission queue 901. As a result, the total of the traffic to be transmitted is 11 [Gbit / s] larger than the line bandwidth of 10 [Gbit / s]. As a result, the retention queue length is extended.

When the retention queue length is extended to 600 to 699, all traffic of a total of 10 [Gbit / s] by the packet 300 having a recording bandwidth of 1250 [bit / s] and 2500 [bit / s] is loaded on the transmission queue 901. Is done. On the other hand, for 1 [Gbit / s] traffic by the packet 300 having a recording bandwidth of 3750 [bit / s], since the retention queue length is longer than the random discard queue length 1843, the packet 300 with a random discard probability of 1% is discarded. Therefore, only 0.99 [Gbit / s] is loaded in the transmission queue 901.

In this way, when the total bandwidth of the traffic to be transmitted is larger than the line bandwidth and the retention queue length is extended, the packet 300 including the packet 300 whose recording bandwidth is larger than the traffic transmitted by the servers S101 to S900 (that is,). (The transmission traffic bandwidth is also large) Only the traffic transmitted by S1 to S100 is targeted for discard by the random initial detection, and a fair random initial detection is realized.

As described above, in each of the above-described embodiments, the edge switch E of the network separates the packet 300 received from the outside of the network into flows, measures the bandwidth for each flow, and records the bandwidth in the packet 300. When transferring the packet 300, the core switch C refers to the recording band of the packet 300 and preferentially transmits a packet having a small recording band.

As a result, when the total bandwidth of the traffic to be transmitted to the corresponding line is larger than the line bandwidth in the core switch C, the packet having a large recording bandwidth can be discarded. As a result, the packet 300 of the flow having a large bandwidth is preferentially discarded, and as a result, the bandwidth can be fairly controlled among the plurality of flows.

In addition, since the functions are shared between the edge switch E and the core switch C to realize fair control in the entire network, the edge switch E requires as many bandwidth measurement functions as the number of flows, but passes through the edge switch E. The packet 300 that enters the network is the data transmitted by the server S connected to the edge switch E. Therefore, the number of flows to be managed by the edge switch E is sufficiently small regardless of the number of flows in the entire data center. Further, since the core switch C does not operate for each flow, it is not necessary to consider the number of flows in the entire data center.

For example, in a network in which a large number of terminals are connected, it is possible to fairly control the bandwidth between terminals during congestion on the line without preparing resources proportional to the number of terminals on any switch on the network.

Further, the above-mentioned transfer device and transfer system can also be configured as described in (1) to (20) below.

(1) The core switch C, which is an example of a transfer device that transfers the packet 300, is, for example, as shown in the first embodiment, a holding unit (for example, a transmission queue 901) capable of accumulating the packets 300 in the input order and outputting them in the input order. ) And the corresponding information (for example, discard priority) in which the first data amount and the band are associated with each other so that the band 941 becomes smaller as the amount of the first data stored in the holding unit (for example, the discard queue length 942) increases. A specific first data amount is specified from the corresponding information according to the storage unit that stores Table 904) and the recording band recorded in the input target packet, and the specific first data amount and the data acquired from the holding unit. It has an input determination unit 903 that determines whether to input or discard the input target packet to the holding unit based on the retention queue length, which is an amount.

As a result, the larger the recording band, the easier it is for the input target packet to be discarded, and the smaller the recording band, the easier it is for the input target packet to be input to the holding unit. Therefore, simple fair control can be realized.

(2) In the core switch C of the above (1), the input determination unit 903 specifies a first data amount corresponding to a band larger than the recording band as a specific first data amount. As a result, the specific first data amount can be set smaller than the first data amount corresponding to the recording band, and the input target packet is likely to be discarded.

(3) In the core switch C of the above (2), the input determination unit 903 specifies the first data amount corresponding to the smallest band in the band larger than the recording band as a specific first data amount. As a result, it is possible to suppress a decrease in a specific first data amount smaller than the first data amount corresponding to the recording band, and it is possible to maintain a balance between the ease of discarding the input target packet and the ease of input. it can.

(4) In the core switch C of the above (1), when the acquired data amount is smaller than the specific first data amount, the input determination unit 903 inputs the input target data to the holding unit. As a result, the retention queue length can be extended.

(5) In the core switch C of the above (1), the input determination unit 903 discards the input target data when the acquired data amount is equal to or larger than the specific first data amount. As a result, it is possible to suppress the extension of the retention queue length.

(6) In the core switch C of the above (1), for example, as shown in the third embodiment, the correspondence information (for example, the random discard priority table 1804) is the first data amount (for example, the discard confirmed queue length 1842). ), The second data amount equal to or less than the first data amount (for example, random discard queue length 1843), the discard probability of the input target packet (for example, random discard probability 1844), and the band 941. The input determination unit 1803 specifies a specific first data amount, a specific second data amount, and a specific discard probability from the corresponding information according to the recording band, and specifies a specific first data amount and a specific second data amount. , And, based on the specific discard probability and the amount of data acquired from the holding unit, it is determined whether to input or discard the input target packet to the holding unit.

As a result, it is possible to simplify the disposal of the input target packet by the random initial detection.

(7) In the core switch C of (6) above, the input determination unit 1803 specifies a first data amount corresponding to a band larger than the recording band as a specific first data amount, and sets the first data amount to a specific first data amount. The corresponding second data amount is specified as a specific second data amount, and the disposal probability corresponding to the specific first data amount is specified as a specific disposal probability.

As a result, in the random initial detection, the specific first data amount can be set smaller than the first data amount corresponding to the recording band, and the input target packet is likely to be discarded.

(8) In the core switch C of the above (7), the input determination unit 1803 specifies the first data amount corresponding to the smallest band among the bands larger than the recording band as a specific first data amount. As a result, in the random initial detection, it is possible to suppress a decrease in a specific first data amount smaller than the first data amount corresponding to the recording band, and the ease of discarding the input target packet and the ease of input are achieved. You can keep the balance.

(9) In the core switch C of the above (6), when the acquired data amount is smaller than the specific second data amount, the input determination unit 1803 inputs the input target data to the holding unit. As a result, the retention queue length can be extended in the random initial detection.

(10) In the core switch C of the above (6), the input determination unit 1803 is in the case where the specific second data amount is set to less than the specific second data amount in the corresponding information, and the acquired data amount is When the amount of data is equal to or greater than the specific amount of second data and smaller than the amount of specific first data, it is determined whether to input or discard the input target data to the holding unit based on the specific discard probability.

This makes it possible to simplify the expansion / contraction control of the retention queue length in the random initial detection.

(11) In the core switch C of the above (6), the input determination unit 1803 discards the input target data when the acquired data amount is equal to or larger than the specific first data amount. As a result, it is possible to suppress the extension of the retention queue length in the random initial detection.

(12) In the core switch C of the above (1), for example, as shown in the first and third embodiments, when the total band of the acquired data amount is smaller than the remaining band of the line, it is retained. It has a line transmission unit 902 that transmits packets accumulated in the unit to the line in the order of input.

As a result, the larger the bandwidth, the more preferentially the packets 300 belonging to the flow are discarded, and as a result, the bandwidth can be fairly controlled among the plurality of flows.

(13) The core switch C, which is an example of a transfer device that transfers packets 300, is provided for each band, for example, as shown in the second embodiment, and can accumulate packets in the corresponding band in the input order and output them in the input order. Based on the plurality of holding units (for example, a plurality of transmission queues 901) and the recording band recorded in the input target packet, it is determined which of the plurality of holding units the input target packet should be input to. It has an input determination unit 1603 and.

Thereby, the expansion / contraction control of the retention queue length can be performed for each band 941.

(14) The core switch C of the above (13) has correspondence information (for example, a queue number table) in which the identification information (for example, transmission queue number 1642) of each of the plurality of holding units and the band 941 different for each identification information are associated with each other. It has a storage unit that stores 1604), and the input determination unit 1603 identifies specific identification information from the corresponding information according to the recording band, and is a holding unit specified by the specific identification information among the plurality of holding units. Input the input target packet.

As a result, the retention queue length can be extended for each band 941.

(15) The core switch C of the above (13) has a line transmission unit 1602 connected to a line and transmitting packets 300 from a plurality of holding units to the line, and the line transmission unit 1602 has a plurality of holding units. Among them, the packets 300 stored in the second holding unit, which has a smaller band than the first holding unit, are transmitted to the line in the order of input.

As a result, the packets 300 in which the band 941 stays in the small holding unit are preferentially transmitted, and as a result, the band can be fairly controlled among the plurality of flows.

(16) The edge switch E, which is an example of a transfer device that transfers the packet 300, can communicate with each of a plurality of communication devices (for example, server S and core switch C), for example, as shown in the first embodiment. Correspondence in which a plurality of connected communication units (for example, interface unit 104) are associated with flow specific information (for example, reception interface 221 and source address 222) that specifies a flow and a band measurement number 223 that is different for each flow. A plurality of communications with reference to the storage unit that stores the information (for example, the flow table 202) and the band information (for example, the band table 203) in which the band 230 is added for each band measurement number 223, and the corresponding information. The band measurement number 223 of the judgment target packet is specified based on the flow identification information included in the judgment target packet from any of the units, and the band 230 corresponding to the band measurement number 223 of the judgment target packet in the band information is assigned. , The flow determination unit 111 that adds the size of the determination target packet (for example, 1250 Byte) and records the added band 230 in the determination target packet, and the determination target for which the flow is determined by the flow determination unit 111. It has a transfer destination determination unit 112 that determines a specific communication unit connected to a specific communication device (for example, core switch C) specified by the destination address based on the destination address of the packet.

As a result, the core switch C at the transfer destination of the determination target packet can perform flow determination and expansion / contraction control of the retention queue length by using the recording band of the transfer target packet.

(17) In the edge switch E of the above (16), the flow determination unit 111 resets the band of the band information in predetermined time units. As a result, it is possible to suppress an excessive increase in the band 230, and the band 230 can be evenly distributed for each flow.

(18) In the edge switch E of the above (16), the correspondence information (for example, the flow table 202) is associated with the band recording coefficient 224 that weights the band 230, and the flow determination unit 111 refers to the correspondence information. Then, the band measurement number and the band recording coefficient of the judgment target packet are specified based on the flow specific information, and the judgment target packet is set to the band corresponding to the band measurement number 223 of the judgment target packet in the band information and the size of the judgment target packet. The value obtained by multiplying the band recording coefficient 224 of the above is added, and the added band 230 to which the size is added is recorded in the determination target packet.

Thereby, the band 230 can be weighted for each flow. For example, the smaller the value of the bandwidth recording coefficient 224, the easier it is for the packet to be transmitted, and the higher the communication cost.

(19) In the edge switch E of the above (18), in the correspondence information, the first band recording coefficient 224 corresponding to the first band measurement number 223 and the second band measurement number 223 different from the first band measurement number 223 are set. Is different from the corresponding second band recording coefficient 224.

As a result, the communication cost can be set to be different for each flow due to the difference in the band recording coefficient 224.

(20) The transfer system includes the edge switch E of the above (16) and the core switch C of the above (1). As a result, the edge switch E of the network separates the packet 300 received from the outside of the network into flows, measures the bandwidth for each flow, and records the bandwidth in the packet 300. When transferring the packet 300, the core switch C refers to the recording band of the packet 300 and preferentially transmits a packet having a small recording band.

As a result, when the total bandwidth of the traffic to be transmitted to the corresponding line is larger than the line bandwidth in the core switch C, the packet having a large recording bandwidth can be discarded. As a result, the packet 300 of the flow having a large bandwidth is preferentially discarded, and as a result, the bandwidth can be fairly controlled among the plurality of flows.

101 Control unit 102 Packet processing unit 104 Interface unit 110 Packet buffer 111 Flow judgment unit 112 Transfer destination determination unit 113 Reception unit 114 Transmission unit 201 Flow judgment processing unit 202 Flow table 203 Band table 204 Band reset unit 221 Reception interface 222 Source address 223 Band measurement number 224 Band recording coefficient 230 Band 300 Packet 801 Control unit 802 Packet processing unit 804 Interface unit 810 Packet buffer 812 Transfer destination determination unit 813 Reception unit 814 Transmission unit 901 Transmission queue 902 Line transmission unit 903 Input judgment unit 904 Discard priority Degree Table 941 Band 942 Discard Queue Length 1102 Flow Table 1502 Flow Table 1602 Line Transmitter 1603 Input Judgment Unit 1604 Queue Number Table 1642 Transmission Queue Number 1803 Input Judgment Unit 1804 Random Discard Priority Table 1842 Discard Confirmed Queue Length 1843 Random Discard Queue Length 1844 Random discard probability C Core switch E Edge switch S Server

Claims (21)

A transfer device that transfers data
A holding unit that can store the data in the input order and output it in the input order,
A storage unit that stores correspondence information in which the first data amount and the band are associated with each other so that the band becomes smaller as the amount of the first data stored in the holding unit increases.
A specific first data amount is specified from the corresponding information according to the recording band recorded in the data to be input to the holding unit, and the specific first data amount and the acquired data amount from the holding unit are used. Based on, an input determination unit that determines whether to input or discard the input target data to the holding unit, and
A transfer device characterized by having. The transfer device according to claim 1.
The input determination unit specifies a first data amount corresponding to a band larger than the recording band as the specific first data amount.
A transfer device characterized by that. The transfer device according to claim 2.
The input determination unit specifies the first data amount corresponding to the smallest band among the bands larger than the recording band as the specific first data amount.
A transfer device characterized by that. The transfer device according to claim 1.
When the acquired data amount is smaller than the specific first data amount, the input determination unit inputs the input target data to the holding unit.
A transfer device characterized by that. The transfer device according to claim 1.
When the acquired data amount is equal to or larger than the specific first data amount, the input determination unit discards the input target data.
A transfer device characterized by that. The transfer device according to claim 1.
The corresponding information associates the first data amount, the second data amount equal to or less than the first data amount, the discard probability of the input target data, and the band.
The input determination unit specifies a specific first data amount, a specific second data amount, and a specific disposal probability from the corresponding information according to the recording band, and the specific first data amount and the specific Based on the second data amount, the specific discard probability, and the amount of data acquired from the holding unit, it is determined whether to input or discard the input target data to the holding unit.
A transfer device characterized by that. The transfer device according to claim 6.
The input determination unit specifies a first data amount corresponding to a band larger than the recording band as the specific first data amount, and a second data amount corresponding to the specific first data amount is the specific amount. It is specified as the second data amount, and the disposal probability corresponding to the specific first data amount is specified as the specific disposal probability.
A transfer device characterized by that. The transfer device according to claim 7.
The input determination unit specifies the first data amount corresponding to the smallest band among the bands larger than the recording band as the specific first data amount.
A transfer device characterized by that. The transfer device according to claim 6.
When the acquired data amount is smaller than the specific second data amount, the input determination unit inputs the input target data to the holding unit.
A transfer device characterized by that. The transfer device according to claim 6.
In the input determination unit, when the specific second data amount is set to be less than the specific second data amount in the corresponding information and the acquired data amount is equal to or more than the specific second data amount. If it is smaller than the specific first data amount, it is determined whether to input or discard the input target data to the holding unit based on the specific discard probability.
A transfer device characterized by that. The transfer device according to claim 6.
When the acquired data amount is equal to or larger than the specific first data amount, the input determination unit discards the input target data.
A transfer device characterized by that. The transfer device according to claim 1.
When connected to a line and the total band of the acquired data amount is smaller than the remaining band of the line, a transmission unit that transmits the data accumulated in the holding unit to the line in the input order, and a transmission unit.
A transfer device characterized by having. A transfer device that transfers data
A plurality of holding units provided for each band, which can store data of the corresponding band in the input order and output in the input order, and
An input determination unit that determines to which of the plurality of holding units the input target data should be input based on the recording band recorded in the input target data.
A transfer device characterized by having. The transfer device according to claim 13.
It has a storage unit that stores the identification information of each of the plurality of holding units and the corresponding information in which different bands are associated with each identification information.
The input determination unit identifies specific identification information from the corresponding information according to the recording band, and inputs the input target data to the holding unit specified by the specific identification information among the plurality of holding units. ,
A transfer device characterized by that. The transfer device according to claim 13.
It has a transmitter that is connected to the line and transmits data from the plurality of holdings to the line.
The transmitting unit transmits data stored in the second holding unit having a band smaller than that of the first holding unit among the plurality of holding units to the line in the input order.
A transfer device characterized by that. A transfer device that transfers data
Multiple communication units that are communicably connected to each of the multiple communication devices,
A storage unit that stores the corresponding information in which the flow specific information for specifying the flow and the band measurement number different for each flow are associated with each other, and the band information in which the band is added for each band measurement number.
With reference to the corresponding information, the band measurement number of the determination target data is specified based on the flow identification information included in the determination target data from any of the plurality of communication units, and the band measurement number is specified in the band information. A flow determination unit that adds the size of the determination target data to the band corresponding to the band measurement number of the determination target data and records the added band to which the size is added in the determination target data.
A transfer destination determination unit that determines a specific communication unit connected to a specific communication device specified by the destination address based on the destination address of the determination target data whose flow is determined by the flow determination unit.
A transfer device characterized by having. The transfer device according to claim 16.
The flow determination unit resets the band of the band information in predetermined time units.
A transfer device characterized by that. The transfer device according to claim 16.
The correspondence information is associated with a band recording coefficient that weights the band.
The flow determination unit specifies the band measurement number and the band recording coefficient of the determination target data based on the flow identification information with reference to the corresponding information, and the band measurement number of the determination target data in the band information. The value obtained by multiplying the size of the determination target data by the band recording coefficient of the determination target data is added to the band corresponding to, and the added band to which the size is added is recorded in the determination target data.
A transfer device characterized by that. The transfer device according to claim 18.
In the corresponding information, the first band recording coefficient corresponding to the first band measurement number and the second band recording coefficient corresponding to the second band measurement number different from the first band measurement number are different.
A transfer device characterized by that. A transfer system including a first transfer device and a second transfer device communicatively connected to the first transfer device.
The first transfer device is
Multiple communication units that are communicably connected to each of the multiple communication devices,
A storage unit that stores the corresponding information in which the flow specific information for specifying the flow and the band measurement number different for each flow are associated with each other, and the band information in which the band is added for each band measurement number.
With reference to the corresponding information, the band measurement number of the determination target data is specified based on the flow identification information included in the determination target data from any of the plurality of communication units, and the band measurement number is specified in the band information. A flow determination unit that adds the size of the determination target data to the band corresponding to the band measurement number of the determination target data and records the added band to which the size is added in the determination target data.
Based on the destination address of the determination target data whose flow is determined by the flow determination unit, a specific communication unit connected to the second transfer device specified by the destination address is determined among the plurality of communication devices. Has a transfer destination determination unit and
The second transfer device is
A holding unit capable of accumulating data from the first transfer device in the order of input and outputting the data in the order of input,
A storage unit that stores correspondence information in which the data amount and the band are associated with each other so that the band becomes smaller as the amount of the first data stored in the holding unit increases.
A specific amount of data is specified from the corresponding information according to the recording band recorded in the data to be input to the holding unit from the first transfer device, and the specific amount of data and the acquisition from the holding unit are obtained. An input determination unit that determines whether to input or discard the input target data to the holding unit based on the amount of data.
A transfer system characterized by having. A transfer program that causes a processor to execute data transfer by multiple communication units that are communicably connected to each of a plurality of communication devices.
The processor stores, in a storage unit, stores correspondence information in which flow specific information for specifying a flow is associated with a band measurement number different for each flow, and band information in which a band is added for each band measurement number. It is accessible and
To the processor
With reference to the corresponding information, the band measurement number of the determination target data is specified based on the flow identification information included in the determination target data from any of the plurality of communication units, and the band measurement number is specified in the band information. A flow judgment process in which the size of the judgment target data is added to the band corresponding to the band measurement number of the judgment target data, and the added band to which the size is added is recorded in the judgment target data.
A transfer destination determination process for determining a specific communication unit connected to a specific communication device specified by the destination address based on the destination address of the determination target data whose flow is determined by the flow determination process.
A transfer program characterized by executing.

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