JP2015019144A - Device, system and method for packet transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable priority control on a session-by-session basis.SOLUTION: A packet transmission device includes: an identification unit for identifying the session of a received packet; a queue setting unit for allocating one queue to one session and for setting a weight associated with the session; a storage processing unit for storing the received packet into a queue associated with the identified session; and a packet output unit for reading out a packet from each queue according to the weight of each queue. The packet transmission device further includes a calculation unit for calculating the weight of each queue on the basis of relationship with a priority coefficient of each session allocated to each session.

Description

  The present invention relates to a packet transmission apparatus, a packet transmission system, and a packet transmission method for performing priority control in packet transmission.

  In recent years, the IP network handles data of multimedia communication such as voice communication of VoIP (Voice over IP (Internet Protocol)) and video distribution. Conventionally, QoS (Quality of Service) control has been performed on IP networks for priority control of these multimedia communications.

On the other hand, in recent years, there is a technique for virtually constructing a network on a physically connected network called SDN (Software Defined Network). SDN is realized by OpenFlow, which is a technique for controlling network devices with software. Since the SDN virtually constructs a network, the network can be flexibly constructed according to the purpose, and individual control in session units can be realized on the virtual network. In this specification, a session refers to a packet group having the same transmission source, destination, and application, and includes both TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) packet groups. The session in this specification is identified by, for example, a transmission source IP address, a destination IP address, a port number, application identification information, and the like.

JP 2000-49787 A JP 10-93571 A

  However, in QoS control on a physical network in which a virtual network is constructed, for example, flexible priority control for each session cannot be performed. Therefore, even when a virtual network is constructed by SDN, priority control for each session is not performed at the physical network level, and sufficient performance cannot be exhibited in multimedia communication or the like.

  According to one aspect, an object of the present invention is to provide a packet transmission device, a packet transmission system, and a packet transmission method that enable priority control in session units.

One aspect of the present invention is:
An identifier for identifying the session of the received packet;
A queue setting unit that assigns a queue to one session and sets a weight corresponding to the session in the queue;
A storage processing unit for storing the received packet in a queue corresponding to the identified session;
According to the weight of each queue, a packet output unit that reads packets from each queue,
Is a packet transmission device.

Another aspect of the present invention is as follows:
A server that holds the priority factor for each session;
An identifier for identifying the session of the received packet;
A queue setting unit that assigns one queue to one session and sets a weight corresponding to the session in the queue;
A storage processing unit for storing the received packet in a queue corresponding to the identified session;
A packet transmission device comprising: a packet output unit that reads packets from each queue according to the weight of each queue;
Is a packet transmission system.

  Another aspect of the present invention is a packet transmission method in which a packet transmission apparatus performs the above-described processing. Another aspect of the present invention may include a program that causes a computer to function as the above-described packet transmission device, and a computer-readable non-transitory recording medium that records the program. A non-temporary recording medium that can be read by a computer or the like is a recording medium in which information such as data or programs is accumulated by electrical, magnetic, optical, mechanical, or chemical action and can be read from a computer or the like. Say.

  According to the disclosed packet transmission apparatus, packet transmission system, and packet transmission method, priority control can be performed in session units.

It is a figure which shows one of the comparative examples of 1st Embodiment. It is a figure which shows an example (session addition) of the priority control process for every session of the packet transmission apparatus which concerns on 1st Embodiment. It is a figure which shows an example (session deletion) of the priority control process for every session of the packet transmission apparatus which concerns on 1st Embodiment. It is a figure which shows the structural example of a packet transmission system. It is a figure which shows an example of the hardware constitutions of a packet transmission apparatus. It is a figure which shows an example of the functional block of the packet transmission apparatus which concerns on 1st Embodiment. It is a figure which shows an example of a session management table. An example of the queue management table is shown. It is an example of a priority control policy table. It is an example of the flowchart of a process of a packet transmission apparatus. It is a figure which shows an example of transmission of the packet in the output port of the packet transmission apparatus which concerns on 1st Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configuration of the following embodiment is an exemplification, and the present invention is not limited to the configuration of the embodiment.

<First Embodiment>
FIG. 1 is a diagram illustrating one of comparative examples of the first embodiment. FIG. 1 shows an example of a weighted round robin scheduling process in the packet transmission apparatus. Scheduling is a process of sending packets at a rate corresponding to the group to which the packets belong.

  In the comparative example shown in FIG. 1, since the weighted round robin method is used, the packet transmission apparatus sets a plurality of queues in advance for each output port, and a weight is assigned to each queue. The number and weight of queues are fixed, and are set by an administrator, for example. The weight assigned to the queue indicates, for example, the ratio of the number of outgoing packets from the corresponding queue to the number of outgoing packets per cycle or unit time at the output port. For example, in the example shown in FIG. 1, the higher the weight ratio of each queue, the higher the priority, and the number of output packets per cycle or unit time increases. One cycle is the time required to access all the queues when accessing one queue at a time in order to send packets at one output port. In the following description of the first embodiment, it is assumed that the weight of each queue is the ratio of the number of packets sent from the corresponding queue to the number of packets sent per cycle at the output port. However, it is not limited to this.

Also, in which queue the packet is stored is determined by priority information in the packet header, for example. The priority information in the packet header is, for example, a value stored in a TOS (Type Of Service) field in the IP header or a priority in a VLAN (Virtual Local Area Network) tag of an Ethernet (registered trademark) frame. The value stored in the field. These values are given by, for example, a packet transmission source or a relay device. Moreover, these values are given according to the kind of application, for example.

  In the example shown in FIG. 1, if packets of user A's session 1 and user B's session 2 hold the same priority information in the header, the packets of these sessions are stored in the same queue. . Therefore, for example, in the case where the user A is a user contracting for a service with a higher fee than the user B, the session 1 is a session having a higher urgency than the session 2, and the session 1 of the user A is also performed. And the session 2 of the user B are handled in the same row in the packet transmission apparatus shown in FIG. Therefore, in the comparative example shown in FIG. 1, it is not possible to perform fine control for each session such as differentiation of users according to contract services and priority of sessions with high urgency.

  The user can be identified by, for example, the transmission source IP address.

  2A and 2B are diagrams illustrating an example of priority control processing for each session of the packet transmission device according to the first embodiment. In the first embodiment, the packet transmission apparatus does not have a fixed queue at each output port, creates a queue when a new session is received, and deletes the corresponding queue when the session is deleted. In other words, in the first embodiment, the packet transmission apparatus has a queue dynamically for each session at each output port. In the first embodiment, priority coefficients are set in advance in accordance with the type of session in the system, and the weight of each queue corresponds to the sum of priority coefficients of all sessions at each output port. It is determined according to the ratio of the priority factor of the session assigned to each queue. The type of session is identified by, for example, a user, an application, or the like.

  FIG. 2A is a diagram illustrating an example of processing of the packet transmission device when a session handled at the output port is added. In the example shown in FIG. 2A, it is assumed that the session 1 of the user A and the session 2 of the user B are relayed at one output port, and the respective priority coefficients are 10 and 4. User A's session 1 is assigned to the queue 51, and user B's session 2 is assigned to the queue 52.

The weight of the queue 51 is 10/14 of the ratio of the priority coefficient (10) of the session 1 to the sum (10 + 4) of the priority coefficients of all sessions at the output port. The weight of the queue 52 is 4/14 of the ratio of the priority coefficient (4) of the session 2 to the sum (10 + 4) of the priority coefficients of all sessions at the output port. Therefore, packets are sent from the queue 51 and the queue 52 at a ratio of 10/14 and 4/14, respectively, per cycle.

  Assume that a new queue 53 is created at the output port and assigned to the session 3 of the user C when a new packet of the session 3 of the user C arrives at the packet transmission device. It is assumed that the priority coefficient of the session 3 of the user C is 6.

  In the first embodiment, the weights of all sessions are recalculated at the output port when a new session is added. The weight of the queue 51 is 10/20 of the ratio of the priority coefficient (10) of the session 1 to the sum (10 + 4 + 6) of the priority coefficients of all sessions at the output port. The weight of the queue 52 is 4/20 of the ratio of the priority coefficient (4) of the session 2 to the sum (10 + 4 + 6) of the priority coefficients of all sessions at the output port. The weight of the new queue 53 is 6/20 of the ratio of the priority coefficient (6) of the session 3 to the sum (10 + 4 + 6) of the priority coefficients of all sessions at the output port.

  FIG. 2B is a diagram illustrating an example of processing performed by the packet transmission apparatus when a session handled at an output port is deleted. FIG. 2B shows a state in which the session 2 of the user B is deleted from the state of FIG. 2A.

  Along with the deletion of the session 2 of the user B, the queue 52 assigned to the session 2 is also deleted. The deletion of the queue is, for example, that the memory resource allocated to the queue is released.

  In the first embodiment, when the session is deleted, the weights of all remaining sessions are recalculated at the output port. The weight of the queue 51 is 10/16 of the ratio of the priority coefficient (10) of the session 1 to the sum (10 + 6) of the priority coefficients of all sessions at the output port. The weight of the queue 53 is 6/16 of the ratio of the priority coefficient (6) of the session 3 to the sum (10 + 6) of the priority coefficients of all sessions at the output port.

  In the first embodiment, the packet transmission device creates a queue at the output port according to the session to be relayed, and dynamically determines the weight of the assigned queue based on the priority coefficient assigned to each session. To perform priority control for each session.

<System configuration>
FIG. 3 is a diagram illustrating a configuration example of a packet transmission system. The packet transmission system 100 includes a policy server 2 and a plurality of packet transmission apparatuses 1A, 1B, and 1C. The policy server 2 and the packet transmission devices 1A, 1B, and 1C can communicate with each other via a network.

  The policy server 2 is a dedicated or general-purpose computer including a processor, a memory, and the like, for example. The policy server 2 holds a priority control policy table in the memory. The priority control policy table is a table that retains settings of priority coefficients corresponding to the types of sessions that occur in the packet transmission system 100. Details of the priority control policy table will be described later with reference to FIG.

The packet transmission devices 1A, 1B, and 1C are devices having a routing function such as a router and a layer 3 switch, for example. The packet transmission devices 1A, 1B, and 1C acquire a priority coefficient corresponding to the type of each session from the policy server 2, and perform priority control for each session in packet transmission using the priority coefficient.

  In the example shown in FIG. 3, the packet transmission devices 1A, 1B, and 1C are shown, but the number of packet transmission devices included in the packet transmission system 100 is not limited to a predetermined number. Further, the priority control policy table may be held by any one or all of the packet transmission apparatuses in the packet transmission system 100. However, when all the packet transmission devices in the packet transmission system 100 hold the priority control policy table, the priority control policy table must be consistent among all the packet transmission devices by using a predetermined protocol. And Hereinafter, when the packet transmission devices 1A, 1B, and 1C are not distinguished from each other, they are simply referred to as the packet transmission device 1.

<Configuration of packet transmission device>
FIG. 4 is a diagram illustrating an example of a hardware configuration of the packet transmission device 1. The packet transmission device 1 includes a plurality of IF cards 110, a SW card 120 that relays packets between the IF cards 110, and a control card 130 that controls each card.

Each IF card 110 performs packet transmission / reception and termination processing. Each IF card 110 includes, for example, a processor, a memory, and a plurality of ports not shown. The processor provided in the IF card 110 is, for example, a network processor. Of each port, a port that performs output processing is provided with a scheduler function that performs scheduling processing. The scheduler may be a circuit such as an FPGA (Field-Programmable Gate Array, not shown), or may be a function realized by a network processor executing a program. In this specification, a port that performs output processing is referred to as an output port.

  The SW card 120 performs packet relay processing between the IF cards 110. For example, the SW card 120 includes a circuit such as an FPGA (Field-Programmable Gate Array, not shown) in addition to a processor and a memory (not shown).

The control card 130 controls each IF card 110 and SW card 120. For example, the control card 130 includes a processor 131 and a memory 132. The processor of the control card 130 is, for example, a CPU (Central Processing Unit). Memory 13
Reference numeral 2 denotes a semiconductor memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory) as a main storage device. The memory 132 may include an auxiliary storage device such as an EPROM (Erasable Programmable ROM).

  The hardware configuration of the packet transmission device 1 is not limited to the example illustrated in FIG. 4 and can be changed as appropriate. Further, the packet transfer processing of the packet transmission device 1 described above is an example, and the present invention is not limited to this, and is appropriately changed depending on the architecture of the packet transmission device 1.

  FIG. 5 is a diagram illustrating an example of functional blocks of the packet transmission device 1 according to the first embodiment. The packet transmission device 1 includes a line termination unit 11, a session control unit 12, a priority management unit 13, a priority setting unit 14, and a queue control unit 15.

  The line termination unit 11 is an interface with the network and performs termination processing. The line termination unit 11 is one of the functions of the IF card 110. For example, hardware corresponds to a circuit that performs PHY / MAC termination processing of an input port or an output port.

Each of the session control unit 12, the priority management unit 13, and the priority setting unit 14 is, for example,
This is one of the functions realized when the processor 131 of the control card 130 executes a program stored in the memory 132.

  The session control unit 12 manages a session relayed by the packet transmission device 1. Specifically, the session control unit 12 identifies the session of the received packet from the session identification information obtained from the received packet, and detects the start of a new session, the end of an existing session, and the like. The session identification information includes, for example, a destination IP address, a source IP address, a destination port number, a source port number, etc. in the packet header. The session identification information may include application identification information, for example. Information on the session relayed by the packet transmission apparatus 1 is stored in a session management table, which will be described later, and the session control unit 12 can execute a new or existing session depending on whether or not the corresponding record exists in the session management table. Determine that there is.

  If the session of the received packet is an existing session, the session control unit 12 transfers the received packet to the queue control unit 15. In addition, the session control unit 12 resets the session timer of the received packet. A survival time is set for each session, and when the survival time timer expires, the end of the session is detected. The timer for the lifetime of each session is managed by, for example, a session management table described later.

  The detection of the end of the session is not limited to the expiration of the timer for the lifetime of the session, and may be detected by receiving a packet indicating a session disconnection request such as a TCP FIN packet, for example. Upon detecting the end of the session, the session control unit 12 deletes the record of the corresponding session from the later-described session management table and the corresponding later-described queue management table. In addition, the session control unit 12 requests the priority setting unit 14 to set priority when the end of the session is detected.

  When the session of the received packet is a new session, the session control unit 12 adds a record to the session management table described later, adds a record to the queue management table described later of the corresponding output port, and performs the corresponding queue control. The received packet is forwarded to the unit 15 and a priority setting unit 13 is requested to set the priority of the new session. The output port of the received packet is acquired from the routing table (not shown) of the packet transmission device 1. Since the packet transmission apparatus 1 has a routing function, it naturally includes a routing table. In the routing table, for example, a correspondence between a destination IP address (network address, host address, etc.) and an output port is stored. The session control unit 12 is an example of an “identification unit”.

  Upon receiving a request from the session control unit 12, the priority management unit 13 acquires the priority coefficient of the new session of the received packet from the policy server 2. For example, the priority management unit 13 transmits the session identification information of the received packet to the policy server 2 together with the request for the priority coefficient, and acquires the priority coefficient of the new session as a response to the request. The priority management unit 13 stores the acquired priority coefficient in a session management table, which will be described later, and requests the priority setting unit 14 to set the priority. The priority management unit 13 is an example of an “acquisition unit”.

  The priority setting unit 14 receives a priority setting request from the priority management unit 13 or the session control unit 12, and calculates the priority of each session at the output port corresponding to the addition or termination of the session. In the case of adding a session, the output port of the priority calculation target of each session is specified based on a received packet that is a packet of the additional session. The output port of the received packet is acquired from the routing table (not shown) of the packet transmission device 1.

  For example, the output port information is sent together with the priority setting request transmitted when the session end is detected from the session control unit 12 in order to specify the priority calculation target output port of each session in the case of session termination. Alternatively, the session control unit 12 may send the end session information together with the priority setting request, and the information and the routing table may be used.

  In the first embodiment, the priority of each session is obtained by the ratio of the priority coefficient of each session to the sum of the priority coefficients of all sessions at the output port. The priority of the session becomes the weight of the queue storing the corresponding session. The calculated priority (weight) of each session is stored in a queue management table (to be described later) corresponding to the output port by the priority setting unit 14. The priority setting unit 14 is an example of a “calculation unit”.

  The queue control unit 15 corresponds to one of the functions of the IF card 110. The queue control unit 15 is provided for each output port provided in the IF card 110, and performs processing related to transmission of packets to the output port, that is, queue management, packet storage in the queue, and scheduling. In FIG. 5, for convenience, one queue control unit 15 is displayed. Further, the packet output from the session control unit 12 is actually output from the control card 130 to the SW card 120, transferred to the corresponding IF card 110 by the SW card 120, and the queue control unit 15 of the corresponding output port. Is input.

  The queue management performed by the queue control unit 15 is specifically as follows. The queue control unit 15 creates and deletes queues and sets the weight of each queue according to a session management table and a queue management table described later. The queue is an area having a predetermined capacity secured in the memory in the IF card 110. When the session control unit 12 notifies the start of a new session, the queue control unit 15 secures a queue area for the new session in the memory. When the session control unit 12 notifies the end of the session, the queue control unit 15 releases the memory area secured as a queue for the corresponding session and deletes the queue. In the first embodiment, it is assumed that a memory area of the same capacity is secured in any session queue. However, the present invention is not limited to this. For example, the capacity of the memory area secured as a queue may be determined according to the type of session. For the notification of the start of a new session and the notification of the end of a session from the session control unit 12, for example, a notification signal may be transmitted from the session control unit 12 to each queue control unit 15, or the session control unit 12 The queue control unit 15 may detect the addition or deletion of a record in a queue management table, which will be described later.

  The queue control unit 15 stores the received packet in the queue of the corresponding session according to the session management table and the queue management table. The queue control unit 15 performs priority control according to the weight of each queue. Specifically, the queue control unit 15 reads the number of packets corresponding to the weight from each queue per cycle and outputs the packets to the line termination unit 11. In the first embodiment, the queue control unit 15 increases the number of packets read from the queue per cycle as the queue weight increases. However, the present invention is not limited to this, and the larger the queue weight, the smaller the number of packets read from the queue per cycle. Further, the number of packets is not limited, and for example, the amount of data read from the queue per cycle may be determined according to the weight of the queue, and the number of packets less than the data amount may be read. The queue control unit 15 is an example of a “setting unit”, “storage processing unit”, and “packet output unit”.

Note that the correspondence between each functional block and hardware components is not limited to this, and varies depending on the architecture of the packet transmission device 1. For example, one session control unit 12 may be provided in each IF card 110 on the output side.

<Data in the packet transmission system>
Next, information handled in the packet transmission system 100 will be described. The packet transmission device 1 holds a session management table and a queue management table. The policy server 2 holds a priority control policy table.

  FIG. 6 is a diagram illustrating an example of the session management table. The session management table is a table in which information on sessions relayed by the packet transmission apparatus 1 is stored. For example, one session management table is created in the packet transmission device 1. The session management table is stored in, for example, a storage area of the memory 132 of the control card 130 of the packet transmission device 1. A record in the session management table is created by the session control unit 12 when a packet for a new session is received.

  The session management table shown in FIG. 6 includes "session ID", "source IP address" ("Src Add." In the figure), "destination IP address" ("Dst Add." In the figure) for each record. ), “Port Number”, “Priority Factor”, and “Retention Time” fields.

  The “session ID” field stores a session ID that is internally assigned to each session by the session control unit 12 in order to identify the session in the packet transmission apparatus 1. The session ID is, for example, alphanumeric characters.

The “source IP address”, “destination IP address”, and “port number” are obtained from the packet that arrived first in the corresponding session. In the “port number” field, a well-known port number of TCP or UDP managed by IANA (Internet Assigned Numbers Authority) stored in the header of the received packet is stored.

  In the “priority coefficient” field, the priority coefficient of the corresponding session acquired from the policy server 2 by the priority management unit 13 is stored. The “holding time” field is a field for managing a timer for the lifetime of the session. In the “holding time” field, an elapsed time since the last received packet of the corresponding session measured by an internal clock (not shown) in the packet transmission apparatus 1 is stored. When the elapsed time stored in the “holding time” field reaches a predetermined time, the lifetime timer expires, and the session control unit 12 deletes the record of the corresponding session from the session management table. When the record is deleted from the session management table, the queue control unit 15 in the output port of the corresponding session deletes the queue of the corresponding session.

  Note that the session management table shown in FIG. 6 is an example, and the information stored in the session management table is not limited to the example shown in FIG. For example, the record of the session management table may further include a field for storing application identification information in the application layer. For example, in the example shown in FIG. 6, the “holding time” field stores the elapsed time since the last packet was received, but the remaining time of the lifetime timer may be stored.

  FIG. 7 shows an example of the queue management table. For example, the queue management table is stored in the storage area of the memory 132 of the control card 130 of the packet transmission apparatus 1. The queue management table is created for each output port in the packet transmission apparatus 1 and stores information on queues existing in each output port. Records in the queue management table are created by the session control unit 12.

  One record of the queue management table shown in FIG. 7 includes fields of “session ID”, “queue ID”, and “weight”. Similar to the “session ID” field of the session management table, the “session ID” field stores an internal session ID in the packet transmission apparatus 1. The record of the queue management table and the record of the session management table are linked by the value of the “session ID” field. The “queue ID” field stores queue identification information for identifying a queue in the scheduler.

  The “weight” field stores the relative weight of the queue at the output port. The relative weight of the queue is calculated by the priority setting unit 14 as a ratio of the priority coefficient of the session assigned to the corresponding queue with respect to the sum of the priority coefficients of all sessions at the output port.

  The records in the queue management table are deleted by the session control unit 12 while the records having the same “session ID” are deleted from the session management table. The queue management table shown in FIG. 7 is an example, and the information stored in the queue management table is not limited to the example shown in FIG.

  FIG. 8 is an example of a priority control policy table. The priority control policy table is stored in the storage device of the policy server 2. The priority control policy table is a table that stores the priority coefficient of each session.

  One record of the priority control policy table includes fields of “user”, “service”, and “priority coefficient”. Information for identifying a user is stored in the “user” field. The information for identifying the user is, for example, an IP address assigned to the user. Alternatively, the information for identifying the user may be, for example, a subscriber identification number, an individual identification number of the terminal, or the like associated with the IP address assigned to the user.

  The “service” field stores a port number indicating an application. When the priority coefficient is set for the user regardless of the application, for example, “Any” is stored in the “service” field. A priority coefficient is stored in the “priority coefficient” field. The priority coefficient is set in advance by the administrator of the packet transmission system 100.

  Note that the priority control policy table shown in FIG. 8 is an example, and the information held in the priority control policy table is not limited to the example shown in FIG.

<Process flow>
FIG. 9 is an example of a flowchart of processing of the packet transmission apparatus 1. The flowchart shown in FIG. 9 is started when the packet transmission apparatus 1 receives a packet, for example.

  In OP1, the session control unit 12 determines whether a session record of the received packet is held in the session management table. When the session record of the received packet is held in the session management table (OP1: YES), the process proceeds to OP8. If the session record of the received packet is not held in the session management table (OP1: NO), the process proceeds to OP2.

OP2 to OP7 are processes when the session record of the received packet is not held in the session management table, that is, when the received packet is a packet of a new session.

  In OP2, the session control unit 12 creates a new session record in the session management table. For example, when the session management table has the configuration shown in FIG. 6, the session control unit 12 extracts the source IP address, the destination IP address, and the well-known port number from the received packet. Stored in the fields of “original IP address”, “destination IP address”, and “port number”. Further, the elapsed time from reception of the received packet is stored in the “holding time” field. In addition, the session control unit 12 creates a record in the queue management table corresponding to the transfer destination port of the received packet. In addition, the session control unit 12 requests the priority management unit 13 to set priority. The session control unit 12 then proceeds to OP3.

  In OP3, the priority management unit 13 inquires and acquires the priority coefficient of the session of the received packet from the policy server 2. Specifically, the priority management unit 13 transmits, for example, a transmission source IP address, a destination IP address, a well-known port number, and a priority coefficient request of the received packet to the policy server 2. The policy server 2 acquires information for identifying the user from the destination IP address or the source IP address of the received packet, specifies the service from the well-known port number, and determines the session priority coefficient from the priority control policy table. Obtain it and send it to the packet transmission device 1. When acquiring the priority coefficient, the priority management unit 13 stores the acquired priority coefficient in the “priority coefficient” field of the record of the session in the session management table. The priority management unit 13 requests the priority setting unit 14 to set priority. Next, the process proceeds to OP4.

  In OP4, the priority setting unit 14 refers to the queue management table corresponding to the output port to which the received packet is transferred, and calculates the weight of each queue corresponding to each session at the output port. The weight of each queue is obtained by the ratio of the priority coefficient of the corresponding session to the sum of the priority coefficients of all sessions at the output port. Next, the process proceeds to OP5.

  In OP5, the priority setting unit 14 writes the weight of each queue calculated in OP4 in the queue management table corresponding to the corresponding output port. Next, the process proceeds to OP6.

  In OP6, the queue control unit 15 in the output port to which the received packet is transferred creates a queue corresponding to the record newly added to the corresponding queue management table, that is, a queue for storing a new session. The queue is created in the memory of the IF card 110. Next, the process proceeds to OP7.

  In OP7, the queue control unit 15 sets the weight of each queue at the output port to the scheduler according to the corresponding queue management table. Next, the process proceeds to OP9.

  In OP8, since the session record of the received packet is held in the session management table, the session control unit 12 resets the value of the “holding time” field of the corresponding record. The session control unit 12 outputs the received packet to the SW card 120, and the received packet is transferred by the SW card 120 to the queue control unit 15 in the output port of the transfer destination IF card 110. Next, the process proceeds to OP9.

  In OP9, the queue control unit 15 refers to the session management table and the queue management table and stores the received packet in the corresponding queue. Next, the process proceeds to OP10.

In OP10, packets are sent out according to the weight of each queue by the scheduler in the queue control unit 15. Thereafter, the process shown in FIG. 9 ends.

<Operation and Effect of First Embodiment>
FIG. 10 is a diagram illustrating an example of packet transmission at the output port of the packet transmission device 1 according to the first embodiment. In the example shown in FIG. 10, it is assumed that session 1 and session 2 exist at the output port and the priority coefficients are 10 and 20, respectively. That is, the weight ratio between session 1 and session 2 is 1: 2.

  For example, when the number of packets transmitted in one cycle is 6, the number of packets transmitted per cycle for session 1 and session 2 is 2 and 4, respectively. Therefore, the packet of session 2 having a high queue weight, that is, a high priority coefficient, is transmitted in preference to the packet of session 1.

  According to the first embodiment, it is possible to perform priority control for each session by assigning a queue to each session and setting a weight for each queue.

  Also, in the example shown in FIG. 10, when session 3 with priority coefficient 30 is added, the ratio of the weights of session 1, session 2, and session 3 is 1: 2: 3. In this case, the number of packets transmitted per cycle of each session is one for session 1, two for session 2, and three for session 3, and session 3 has the highest priority.

  In this way, by increasing the priority coefficient of the added session, the session is transmitted preferentially in each packet transmission apparatus 1 in the packet transmission system 100. In addition, since the priority coefficient is centrally managed in the policy server 2, setting and changing the priority coefficient of a new session is performed on the policy server 2, thereby transmitting all packets in the packet transmission system 100. It is reflected in the device 1 and is easy to manage.

  Note that the first embodiment does not limit the order of queues to which packets are sent. The order of queues to which packets are sent is, for example, queue (session) creation order, priority coefficient order, priority order that defines a sending order different from the priority coefficient, or random order. Also good.

  As described above, according to the first embodiment, since priority setting and priority control of a session are dynamically performed at the start and end of a session, for example, the following service can be realized. it can.

  (1) By setting a priority coefficient for each application used according to the amount paid by the user, it is possible to perform priority processing for a user session with a high contract amount. For example, a user session with a high contract amount is preferentially processed in access to a ticket purchase site or HTTP communication to an auction site.

(2) By setting the priority coefficient of the application to be used according to the user group, it becomes possible to perform priority processing for important communication sessions. The important communication session is, for example, a VoIP (Voice over IP) communication such as a call to an affected area or an emergency call.

(3) By setting a low priority coefficient to limit the use of a specific application for a user, it becomes possible to perform low priority processing for the communication of the user of the user.

  Further, according to the first embodiment, the priority (queue weight) of the session is determined dynamically and relatively. In a network in which the queue weight is fixed and assigned, if the highest priority class is already used, no higher priority class can be set dynamically. However, in the packet transmission system 100 of the first embodiment, the priority coefficient of the session to be prioritized is set to be high so that all packet transmission apparatuses 1 are prioritized over other existing sessions. You can also.

<Others>
The embodiment described above discloses the following supplementary notes.
(Appendix 1)
An identifier for identifying the session of the received packet;
A queue setting unit that assigns one queue to one session and sets a weight corresponding to the session in the queue;
A storage processing unit for storing the received packet in a queue corresponding to the identified session;
According to the weight of each queue, a packet output unit that reads packets from each queue,
A packet transmission apparatus comprising:
(Appendix 2)
A calculation unit that calculates a weight of each queue based on a relationship with a priority coefficient of each session assigned to each queue;
The packet transmission apparatus according to appendix 1, further comprising:
(Appendix 3)
The calculating unit calculates, as a weight of each queue, a ratio of a priority coefficient of sessions assigned to each queue with respect to a sum of priority coefficients of each session assigned to each queue;
The packet transmission device according to attachment 2.
(Appendix 4)
An acquisition unit for acquiring a priority coefficient of the new session when the session of the received packet is a new session;
The queue setting unit creates a queue assigned to the new session,
The calculation unit calculates a weight for each queue including the created queue.
The packet transmission device according to appendix 2 or 3.
(Appendix 5)
The queue setting unit deletes the queue assigned to the terminated session when the termination of the session is detected,
The packet transmission device according to any one of appendices 2 to 4, wherein the calculation unit calculates a weight for each remaining queue among the plurality of queues.
(Appendix 6)
A server that holds the priority factor for each session;
An identifier for identifying the session of the received packet;
A queue setting unit that assigns one queue to one session and sets a weight corresponding to the session in the queue;
A storage processing unit for storing the received packet in a queue corresponding to the identified session;
A packet transmission device comprising: a packet output unit that reads packets from each queue according to the weight of each queue;
Including packet transmission system.
(Appendix 7)
The packet transmission device includes:
A calculation unit for calculating a weight of each queue based on a relationship with a priority coefficient of each session assigned to each queue;
The packet transmission system according to appendix 6, further comprising:
(Appendix 8)
The calculating unit calculates, as a weight of each queue, a ratio of a priority coefficient of sessions assigned to each queue with respect to a sum of priority coefficients of each session assigned to each queue;
The packet transmission system according to appendix 7.
(Appendix 9)
When the session of the received packet is a new session, further comprising an acquisition unit for acquiring a priority coefficient of the new session from the server,
The queue setting unit creates a queue assigned to the new session,
The calculation unit calculates a weight for each queue including the created queue.
The packet transmission system according to appendix 7 or 8.
(Appendix 10)
The queue setting unit deletes the queue assigned to the terminated session when the termination of the session is detected,
The packet transmission system according to any one of appendices 7 to 9, wherein the calculation unit calculates a weight for each remaining queue among the plurality of queues.
(Appendix 11)
Packet transmission device
Identifies the session of the incoming packet,
A queue setting unit that assigns one queue to one session and sets a weight corresponding to the session in the queue;
Storing the received packet in a queue corresponding to the identified session;
Read packets from each queue according to the weight of each queue,
Packet transmission method.

DESCRIPTION OF SYMBOLS 1 Packet transmission apparatus 2 Policy server 12 Session control part 13 Priority management part 14 Priority setting part 15 Queue control part

Claims (7)

An identifier for identifying the session of the received packet;
A queue setting unit that assigns one queue to one session and sets a weight corresponding to the session in the queue;
A storage processing unit for storing the received packet in a queue corresponding to the identified session;
According to the weight of each queue, a packet output unit that reads packets from each queue,
A packet transmission apparatus comprising: A calculation unit that calculates a weight of each queue based on a relationship with a priority coefficient of each session assigned to each queue;
The packet transmission device according to claim 1, further comprising: The calculating unit calculates, as a weight of each queue, a ratio of a priority coefficient of sessions assigned to each queue with respect to a sum of priority coefficients of each session assigned to each queue;
The packet transmission apparatus according to claim 2. An acquisition unit for acquiring a priority coefficient of the new session when the session of the received packet is a new session;
The queue setting unit creates a queue assigned to the new session,
The calculation unit calculates a weight for each queue including the created queue.
The packet transmission device according to claim 2 or 3. The queue setting unit deletes the queue assigned to the terminated session when the termination of the session is detected,
The packet transmission device according to claim 2, wherein the calculation unit calculates a weight for each remaining queue among the plurality of queues. A server that holds the priority factor for each session;
An identifier for identifying the session of the received packet;
A queue setting unit that assigns one queue to one session and sets a weight corresponding to the session in the queue;
A storage processing unit for storing the received packet in a queue corresponding to the identified session;
A packet transmission device comprising: a packet output unit that reads packets from each queue according to the weight of each queue;
Including packet transmission system. Packet transmission device
Identifies the session of the incoming packet,
One queue is assigned to one session, a weight corresponding to the session is set in the queue,
Storing the received packet in a queue corresponding to the identified session;
Read packets from each queue according to the weight of each queue,
Packet transmission method.