WO2014027687A1

WO2014027687A1 - Communication system, control information recording device, control device, control information recording method and program

Info

Publication number: WO2014027687A1
Application number: PCT/JP2013/071993
Authority: WO
Inventors: 雅明大石
Original assignee: 日本電気株式会社
Priority date: 2012-08-17
Filing date: 2013-08-16
Publication date: 2014-02-20

Abstract

In a centralized control network, in order to facilitate investigation and analysis of control information stored in switches, this communication system is provided with: a switch which processes received packets using that stored control information which has match conditions applying to the received packets; a control device which manipulates the control information stored in the switch; and a control information recording device which, on the basis of the content of the manipulations of the control information by the control device, records the control information stored by the aforementioned switch at a prescribed time.

Description

COMMUNICATION SYSTEM, CONTROL INFORMATION RECORDING DEVICE, CONTROL DEVICE, CONTROL INFORMATION RECORDING METHOD, AND PROGRAM

[Description of related applications]
The present invention is based on a Japanese patent application: Japanese Patent Application No. 2012-180732 (filed on August 17, 2012), and the entire description of the application is incorporated herein by reference.
The present invention relates to a communication system, a control information recording device, a control device, a control information recording method, and a program, and in particular, includes a control device that controls a switch by operating control information held in the switch. The present invention relates to a control information recording device, a control device, a control information recording method, and a program.

In recent years, a technique called OpenFlow has been proposed (see Non-Patent Documents 1 and 2). OpenFlow captures communication as an end-to-end flow and performs path control, failure recovery, load balancing, and optimization on a per-flow basis. The OpenFlow switch specified in Non-Patent Document 2 includes a secure channel for communication with the OpenFlow controller, and operates according to a flow table that is appropriately added or rewritten from the OpenFlow controller. For each flow, a set of match conditions (Match Fields), flow statistical information (Counters), and instructions (Instructions) that define processing contents are defined for each flow (non-patented). (Refer to “4.1 Flow Table” in Document 2).

For example, when the OpenFlow switch receives a packet, the OpenFlow switch searches the flow table for an entry having a matching condition (see “4.3 Match Fields” in Non-Patent Document 2) that matches the header information of the received packet. If an entry that matches the received packet is found as a result of the search, the OpenFlow switch updates the flow statistical information (counter) and processes the processing (designated) in the instruction field of the entry for the received packet. Perform packet transmission, flooding, discard, etc. from the port. On the other hand, if no entry matching the received packet is found as a result of the search, the OpenFlow switch sends an entry setting request to the OpenFlow controller via the secure channel, that is, a control for processing the received packet. An information transmission request (Packet-In message) is transmitted. The OpenFlow switch receives a flow entry whose processing content is defined and updates the flow table. As described above, the OpenFlow switch performs packet transfer using the entry stored in the flow table as control information.

Various attempts have been made to improve the above OpenFlow. For example, Patent Document 1 discloses a method for reducing the load on a path control device corresponding to an open flow controller by changing the timeout value of the flow entry for each section of a packet communication path.

Further, in Patent Document 2, in order to obtain statistical information for each application (corresponding to the above flow statistical information), the controller uses the application name of the application that uses the port number that received the new flow notified from the switch. The configuration in which the application name and the flow set in the switch are associated with each other and recorded in a storage device is disclosed.

In Patent Document 3, although different from the above-described open flow, even if the capacity to hold the flow information corresponding to the number of flows to be controlled is limited in the network node, the traffic is appropriately limited for all the flows. A communication system that can perform the above is disclosed.

JP 2011-101245 A JP 2011-82834 A International Publication No. 2009/098819

The following analysis is given by the present invention. In the centralized control type networks described in Non-Patent Documents 1 and 2 and Patent Documents 1 and 2, the control device rewrites control information (for example, flow entry) held in a switch (packet transfer device). Done. In addition, as described in Patent Document 1, individual control information (for example, flow entry) may be deleted on the switch side when a certain time elapses without receiving the corresponding packet. Furthermore, the control information (for example, flow entry) disappears when a failure occurs in the switch itself or when it is restarted.

For example, consider a case where the switch 20 holds the flow entries # 1 to #M at a certain time N as shown in FIG. Thereafter, when a predetermined time elapses, for example, flow entry # M-1 is deleted due to timeout, a new flow is generated, and when flow entry # M + 1 is added, the flow entry held by switch 20 is as shown in FIG. become.

For example, after the flow table 21 of the switch 20 is rewritten as shown in FIG. 5, if it is determined that a packet loop or abnormal traffic has occurred at the time of FIG. 4, the switch 20 at the time of FIG. There is a case where it is desired to grasp control information (for example, flow entry) to be performed.

However, since the control information (for example, flow entry) held by the switch 20 at the time of FIG. 4 is no longer held, it can only be reproduced by using a control message issuance history from the control device. There is a problem that it takes time and effort.

The present invention provides a communication system, a control information recording device, and a control having a function for facilitating the investigation and analysis of control information held by each switch in a centralized control network represented by the above-described OpenFlow. It is an object to provide an apparatus, a control information recording method, and a program.

According to the first aspect, the switch that processes the received packet using the control information having the matching condition that matches the received packet from the control information that is held, and the control information that is held in the switch is operated. And a control information recording device that records control information held by the switch at a predetermined time on the basis of the operation content of the control information by the control device.

According to the second aspect, the switch that processes the received packet using the control information having the matching condition that matches the received packet from the control information that is held, and the control information that is held in the switch And a control information recording device for recording the control information held by the switch at a predetermined time based on the operation content of the control information by the control device. The

According to a third aspect, the control that is connected to a switch that processes a received packet using control information having a matching condition that matches the received packet among the control information that is held, and that is held in the switch A control device that operates information, and causes a predetermined control information recording device to record the control information held by the switch at a predetermined time based on the operation content of the control information by the control device A control device is provided.

According to a fourth aspect, the control that is connected to a switch that processes a received packet using control information having a matching condition that matches the received packet from the control information that is held, and that is held in the switch A control device for operating information operating the control information held in the switch; and a predetermined time based on the operation content of the control information by the control device with respect to a predetermined control information recording device. And recording the control information held by the switch. The method for recording the control information held by the switch is provided. The method is tied to a specific machine, the control device that controls the switch.

According to a fifth aspect, the control that is connected to a switch that processes a received packet using control information having a matching condition that matches the received packet from the control information that is held, and that is held in the switch A process for operating the control information held in the switch to a control apparatus for operating information, and a predetermined time based on the operation content of the control information by the control apparatus for a predetermined control information recording apparatus And a process for recording the control information held by the switch. This program can be recorded on a computer-readable (non-transient) storage medium. That is, the present invention can be embodied as a computer program product.

According to the present invention, it is possible to facilitate investigation and analysis of control information held by individual switches in a centralized control type network.

It is a figure which shows the structure of the communication system of the 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the communication system of the 1st Embodiment of this invention. It is a figure which shows the modification of the 1st Embodiment of this invention. It is a figure for demonstrating the change of the control information (flow entry) in the switch of a nonpatent literature 1,2. It is a figure for demonstrating the change of the control information (flow entry) in the switch of a nonpatent literature 1,2.

First, an outline of an embodiment of the present invention will be described with reference to the drawings. Note that the reference numerals of the drawings attached to this summary are attached to the respective elements for convenience as an example for facilitating understanding, and are not intended to limit the present invention to the illustrated embodiment.

In one embodiment of the present invention, as shown in FIG. 1, a switch 20 that processes a received packet using control information having a matching condition that matches the received packet, and control information ( In the example of FIG. 1, the control information recording device 50 is added to the configuration including the control device 10 that operates the flow entries 21-1 to 21-M).

Specifically, the control information recording device 50 records the control information held by the switch 20 at a predetermined time based on the operation content of the control information by the control device. Since this recording process is held for a predetermined time, for example, at time N + 1 when a predetermined time has elapsed from time N, as shown in FIG. Then, the flow entries 21-1 to 21-M) can be confirmed.

[First Embodiment]
Next, the configuration of the first exemplary embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a communication system according to a first embodiment of this invention. Referring to FIG. 1, by operating the flow entry held in the switch 20, the control device 10 that controls the switch 20, and when a packet is received, a matching condition that matches the received packet from the held flow entries A configuration is shown in which a recording device (control information recording device) 50 is connected to a configuration including a switch 20 that searches for a flow entry having and processes a packet according to the searched flow entry. The control device 10 and the switch 20 are connected via a control link 30. The control device 10 and the recording device 50 are connected via a recording link 40.

Upon receiving the flow entry request message from the switch 20 (“Packet-In message” in Non-Patent Document 2), the control device 10 refers to the packet information included in the flow entry request message, generates a flow entry, and A flow entry setting message (“Flow-Mod message” of Non-Patent Document 2) is transmitted to the switch 20 that performs the above-described operation. FIG. 1 shows a state in which flow entries # 1 to #M are registered in the flow table 21 of the switch 20 at a certain time N.

Further, when registering the flow entries # 1 to #M, the control device 10 also transmits a flow entry setting message (“Flow-Mod message” in Non-Patent Document 2) to the recording device 50, and the recording device Recording is also performed on the flow table 51 on the 50 side. In the example of FIG. 1, it is assumed that there is one switch, but when the control device 10 also operates the flow entries of a plurality of switches, the contents of the flow table of these switches can also be recorded. .

Note that the operation of the control device 10 described above can also be realized by a computer program that causes a computer constituting the control device 10 to execute the above-described processes using its hardware.

Subsequently, the operation of the present embodiment will be described in detail with reference to the drawings. FIG. 4 shows that the switch 20 assigns a flow entry # M-1 (reference numeral 21- (M-1)) in accordance with a control message from the control device 10 between a certain time N and a time N + 1 when a predetermined time has elapsed. It shows a state in which it has been deleted and a new flow entry # M + 1 (reference numeral 21- (M + 1)) has been registered.

On the other hand, the recording device 50 creates a copy of the flow table 51 at a predetermined time interval (first time interval). When receiving the control message from the control device 10, the recording device 50 applies the content of the control message from the control device 10 to the switch 20 to the latest flow table (flow table at time N + 1) 51. The flow table 51 replicated at a predetermined time interval (first time interval) is held until the predetermined time elapses.

As a result, both the flow table 51 at time N and the flow table 51 at time N + 1 are recorded in the recording device 50 at the time shown in FIG. Further, when a predetermined time further elapses, the flow table 51 to which the content of the control message received during the first time interval is applied to the flow table 51 at time N + 1 is duplicated and stored.

As described above, according to the present embodiment, since the contents of the past flow table are recorded in the recording device 50, the contents of the flow table at any past time can be confirmed. Further, by comparing the contents of the flow table 51 at the time N and the time N + 1, the network state at an arbitrary time may be investigated and analyzed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and further modifications, substitutions, and adjustments are possible without departing from the basic technical idea of the present invention. Can be added. For example, the network configuration and the configuration of each device used in the description of the above-described embodiments are examples for helping understanding of the present invention, and are not limited to the configurations shown in these drawings.

For example, in the above-described embodiment, the control device 10 and the recording device 50 are described as being provided independently. However, as illustrated in FIG. 3, the recording device in the control device 10 is a flow entry. It can also be used as a recording device. In this case, it is the same as in the first embodiment except that a control message is sent from the flow entry generation unit 11 of the control device 10 to the switch 20 and the recording device 50.

In the above embodiment, the flow entry is duplicated in the recording device 50 at the first time interval. However, the control is performed at a time interval (second time interval) shorter than the first time interval. The operation content of the flow entry by the device 10 may be recorded. In this case, the entire flow entry is not saved as in the flow table 51 at time N and time N + 1. For example, time N such as addition of flow entry # M + 1 and deletion of flow entry # M−1 in FIG. If only the difference from is stored, the first time interval can be widened, the recording area in the recording apparatus 50 can be saved, and the processing load on the recording apparatus 50 can be reduced.

In the above-described embodiment, the time information such as the time N and the time N + 1 is recorded in the flow table 51 in association with each other. However, the update time information may be stored in association with each flow entry.

In the above-described embodiment, the recording apparatus 50 receives the control message from the control apparatus 10 and updates and stores the flow table. However, instead of issuing the control message, the control apparatus 10 itself It is also possible to adopt a configuration in which processing is performed and the flow table 51 of the recording device 50 is copied, stored, and updated.

Finally, a preferred form of the invention is summarized.
[First embodiment]
(Refer to the communication system according to the first viewpoint)
[Second form]
In the communication system of the first form,
The control device transmits a message requesting operation of control information to the switch and the control information recording device,
The control information recording device is a communication system for recording control information held by the switch at the predetermined time based on the message.
[Third embodiment]
In the communication system of the second form,
The control information recording device records all of the control information held by the switch at a first time interval,
After recording the control information for each of the first time intervals, the switch recorded at the first time interval is held based on the message at a second time interval shorter than the first time interval. The communication system which records the difference of the control information.
[Fourth form]
In the communication system according to any one of the first to third aspects,
The control information recording device is a communication system that records the control information held by the switch in association with the update time of the control information by the message.
[Fifth embodiment]
In the communication system according to any one of the second to fourth aspects,
The switch and the control information recording device have a table for holding control information, and update an entry in the table based on the message.
[Sixth embodiment]
(Refer to the control information recording apparatus according to the second viewpoint)
[Seventh form]
In the control information recording apparatus of the sixth aspect,
A control information recording device for recording control information held by the switch at the predetermined time based on a message for requesting an operation of control information transmitted from the control device.
[Eighth form]
(Refer to the control device from the third viewpoint)
[Ninth Embodiment]
(Refer to the control information recording method from the fourth viewpoint.)
[Tenth embodiment]
(Refer to the program from the fifth viewpoint above)

It should be noted that the disclosures of the above patent documents and non-patent documents are incorporated herein by reference. Within the scope of the entire disclosure (including claims) of the present invention, the embodiments and examples can be changed and adjusted based on the basic technical concept. Further, various combinations or selections of various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) within the scope of the claims of the present invention. Is possible. That is, the present invention of course includes various variations and modifications that could be made by those skilled in the art according to the entire disclosure including the claims and the technical idea. In particular, with respect to the numerical ranges described in this document, any numerical value or small range included in the range should be construed as being specifically described even if there is no specific description.

DESCRIPTION OF SYMBOLS 10 Control apparatus 20

Switch

21, 51 Flow table 21-1 to 21-M + 1, 51-1 to 51-M + 1 Flow entry 30 Control link 40 Recording link 50 Control information recording apparatus

Claims

A switch that processes a received packet using control information having a matching condition that matches the received packet from the control information held;
A control device for operating the control information held in the switch;
A control information recording device for recording the control information held by the switch at a predetermined time based on the operation content of the control information by the control device;
A communication system including:
The control device transmits a message requesting operation of control information to the switch and the control information recording device,
The communication system according to claim 1, wherein the control information recording device records control information held by the switch at the predetermined time based on the message.
The control information recording device records all of the control information held by the switch at a first time interval,
After recording the control information for each of the first time intervals, the switch recorded at the first time interval is held based on the message at a second time interval shorter than the first time interval. The communication system according to claim 2, wherein a difference in control information is recorded.
The communication system according to any one of claims 1 to 3, wherein the control information recording device records the control information held by the switch in association with the update time of the control information by the message.
The communication system according to any one of claims 2 to 4, wherein the switch and the control information recording device have a table for holding control information, and update an entry in the table based on the message.
A switch that processes the received packet using control information having a matching condition that matches the received packet from the control information to be held;
Connected to a communication system including a control device for operating the control information held in the switch,
A control information recording device that records the control information held by the switch at a predetermined time based on the operation content of the control information by the control device.
The control information recording apparatus according to claim 6, wherein the control information held by the switch at the predetermined time is recorded based on a message requesting an operation of control information transmitted from the control apparatus.
A switch that processes received packets using control information having matching conditions that match the received packets from the control information that is held;
A control device for operating the control information held in the switch,
A control device that causes a predetermined control information recording device to record the control information held by the switch at a predetermined time based on the operation content of the control information by the control device.
A switch that processes a received packet using control information having a matching condition that matches the received packet from among the held control information, and a control device that is connected and operates the control information held in the switch,
Manipulating control information held in the switch;
Recording the control information held by the switch at a predetermined time on the basis of the operation content of the control information by the control device with respect to a predetermined control information recording device. How to record information.
Among the control information to be held, a switch that processes the received packet using control information having a matching condition that matches the received packet, and a controller that is connected and operates the control information held in the switch,
A process for operating control information held in the switch;
A program for causing a predetermined control information recording device to execute a process of recording the control information held by the switch at a predetermined time based on the operation content of the control information by the control device.