JP6175766B2 - Communication node, control device, communication system, entry aggregation method, and program - Google Patents

Description

  The present invention relates to a communication node, a control device, a communication system, an entry aggregation method, and a program, and in particular, a communication node, a control device, a communication system, and an entry aggregation method that process a received packet with reference to an entry set from the control device. And the program.

  Non-Patent Documents 1 and 2 propose a technique called open flow. 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. In the flow table, for each flow, a set of a match condition (Match Fields) to be matched with a packet header, flow statistical information (Counters), and an instruction (Instructions) defining processing contents is defined (non-patented). (Refer to the section “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.

  Patent Document 1 discloses an interface control method for realizing an implementation capable of searching both a link aggregation group and a physical port belonging to the link aggregation group in the interface control of the network device corresponding to the OpenFlow switch. More specifically, this network device has a logical interface that is an interface of a logical group, a physical port that belongs to the logical group, and a predetermined function that is enabled for each of the logical interface and the physical port. In the case where it is carried out, it is described that it comprises an interface control unit that is managed by incorporating both the logical interface and the physical port into the management interface.

JP 2011-160171 A

Nick McKeown and seven others, “OpenFlow: Enabling Innovation in Campus Networks”, [online], [October 24, 2012 search], Internet <URL: http://www.openflow.org/documents/ openflow-wp-latest.pdf> “OpenFlow Switch Specification” Version 1.1.0 Implemented (Wire Protocol 0x02), [online], [searched on October 24, 2012], Internet <URL: http://www.openflow.org/ documents / openflow-spec-v1.1.0.pdf>

  The following analysis is given by the present invention. In the open flows of Non-Patent Documents 1 and 2, by using a wild card as a match condition, a plurality of flows can be processed with one flow entry, and the number of flow entries held by each switch can be reduced. It is possible. However, there are cases in which the use of wildcards cannot be aggregated, which causes the number of flow entries to increase.

  For example, as shown in FIG. 7, it is assumed that there is an open flow switch (OFS) X20 having ports a, b, c, and d, and terminals 10A to 10D are connected to these ports. In this configuration, when packets transmitted from the terminal 10A, the terminal B, and the terminal 10C are transferred to the terminal 10D via the port d, as shown in FIG. 8, the connection port of each terminal is set as a match condition, and the action As described above, three entries that are set to output from the port d are required. These entries cannot be aggregated using wildcards. Further, since the packet directly received from the terminal is targeted, it is impossible to rewrite the header with a switch in the middle. Even when an IP address, a MAC address, or the like is set as a match condition, it may not be possible to aggregate using a wild card, and the same situation may occur.

  It is an object of the present invention to provide a communication node, a control device, a communication system, an entry aggregation method, and a program that can contribute to the reduction of the number of flow entries held by the communication node.

  According to a first aspect, an entry storage unit capable of storing an entry in which a plurality of match conditions and a common processing content applied to a packet that matches any of the plurality of match conditions are associated; and the entry There is provided a communication node including a packet processing unit that searches an entry having a matching condition that matches a received packet from a storage unit and processes the received packet.

  According to a second aspect, the control device for controlling the communication node described above, an entry generation unit that generates an entry to be set in the entry storage unit in response to a request from the communication node, and the communication node If the entry storage unit stores an entry in which the same content as the processing content of the generated entry is stored, instead of transmitting the generated entry, the same processing content as the generated entry is stored. A control device is provided that includes an entry update unit that executes a process of adding a match condition of the generated entry to a match condition of an entry whose contents are set.

  According to a third aspect, an entry storage unit capable of storing an entry in which a plurality of match conditions and a common processing content applied to a packet that matches any of the plurality of match conditions are associated; and the entry A search is made for an entry having a matching condition that matches the received packet from the storage unit, and a packet processing unit that processes the received packet; and for the communication node, an entry to be stored in the entry storage unit There is provided a communication system including a control device for transmission.

  According to the fourth aspect, communication including an entry storage unit capable of storing an entry in which a plurality of match conditions and a common processing content applied to a packet that matches any of the plurality of match conditions are associated with each other. A computer mounted on either the node or the control device connected to the communication node has the same content as the processing content among the entries held in the entry storage unit at a predetermined timing. There is provided an entry aggregation method including the steps of extracting entries and aggregating them into one entry having a matching condition for each of the extracted entries. The method is associated with a specific machine, a computer that sets a control entry in a communication node.

  According to a fifth aspect, communication includes an entry storage unit capable of storing an entry in which a plurality of match conditions and a common processing content applied to a packet that matches any of the plurality of match conditions are associated with each other. The computer connected to the node generates an entry to be set in the entry storage unit in response to a request from the communication node, and the same processing content of the generated entry as to the entry storage unit of the communication node If an entry in which the content of the entry is set is stored, the matching condition of the entry in which the same content as the processing content of the created entry is set in the communication node instead of transmitting the generated entry And an instruction to add a match condition for the generated entry. The method is associated with a specific machine, a computer that sets a control entry in a communication node.

  According to a sixth aspect, there is provided a program that causes a computer to function as the entry aggregation unit of the communication node or control device described above. 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 contribute to the reduction of the number of flow entries held by a communication node.

It is a block diagram which shows the structure of the 1st Embodiment of this invention. It is a figure which shows an example of the entry (flow entry) which can be set to the communication node of the 1st Embodiment of this invention. It is a figure which shows another example of the entry (flow entry) which can be set to the communication node of the 1st Embodiment of this invention. It is a block diagram which shows the structure of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the 4th Embodiment of this invention. It is a figure for demonstrating the background art of this invention. It is a figure which shows the structure of the entry (flow entry) which the open flow switch of a nonpatent literature 1 and 2 hold | maintains.

[First Embodiment]
Next, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the first exemplary embodiment of the present invention. Referring to FIG. 1, a configuration in which a communication node 20 and a control device 30 are connected is shown.

  The communication node 20 includes an entry storage unit 21 and a packet processing unit 22 that searches the entry storage unit 21 for an entry having a matching condition that matches the received packet and processes the received packet. The communication node 20 is connected to a terminal or another communication node, and exchanges packets with these devices.

  As shown in FIG. 2, the entry storage unit 21 can store entries in which a plurality of match conditions are associated with common processing contents (instructions) applied to packets that match any of the plurality of match conditions. It has become. In the example of FIG. 2, an entry for outputting a packet from the port d, in which the port (In port) that received the packet is any of the ports a, b, and c is set (match condition: In Port = a or b or c). In the example of FIG. 2, an example in which entries having a plurality of match conditions are stored is shown. However, it is not necessary to limit the entries to a plurality of match conditions, and there is one match condition. An entry may also be stored.

  The packet processing unit 22 searches the entry storage unit 21 for an entry having a matching condition in the reception port information and header information of the received packet. As a result of the search, when an entry having a matching condition that matches the received packet is found, the packet processing unit 22 executes the processing content stored in the instruction field of the entry for the received packet. Further, as a result of the search of the entry storage unit 21, the packet processing unit 22 transmits the received packet or the information extracted from the received packet to the control device 30 when no entry matching the received packet is found. Request entry creation. Note that the OpenFlow protocol of Non-Patent Document 2 can be used for the exchange of various control messages between the control device 30 and the communication node 20. In this case, a Packet-In message can be used as a message requesting creation of this entry.

  Note that such a communication node 20 has an entry holding function capable of setting a plurality of match conditions described above in the OpenFlow switches of Non-Patent Documents 1 and 2, and a plurality of match conditions set in the one entry. This can also be realized by adding a verification function.

  In addition to the network switch, the communication node 20 can also be realized as a personal computer having a built-in switch function for relaying a packet exchanged between an installed application program or the like and an external device, or a mobile terminal such as a smartphone. .

  Based on the entry creation request from the communication node 20 or a predetermined network management policy, the control device 30 generates an entry to be held in the entry storage unit 21 of the communication node 20 and transmits the entry to the communication node 20. Such a control device 30 can use a device corresponding to the open flow controller of Non-Patent Documents 1 and 2. The entries shown in FIGS. 2 and 3 may be set by the control device 30 or may be manually set by a network administrator using a command line interface or the like.

  As described above, according to the present embodiment, it is possible to process a process that required three entries in FIG. 8 with one entry. In the example of FIG. 2, the port (In port) that received the packet is designated as the match condition. However, as shown in FIG. 3, a plurality of other match conditions such as a MAC address can be set. is there. Of course, the match condition: In Port = a & Src MAC = AA: AA: AA: AA: AA: AA or In Port = b & Src MAC = BB: BB: BB: BB: BB: BB are combined. A plurality of match conditions may be set.

  Note that each unit (processing means) of the communication node 20 shown in FIG. 1 can be realized by a computer program that causes a computer mounted on the communication node 20 to execute the above-described processes using the hardware thereof. .

[Second Embodiment]
Next, a second embodiment in which an entry aggregation function for aggregating two or more entries and generating entries in which a plurality of match conditions are set is added to the communication node 20 side will be described in detail with reference to the drawings. To do.

  FIG. 4 is a block diagram showing the configuration of the second exemplary embodiment of the present invention. The difference from the first embodiment shown in FIG. 1 is that an entry aggregation unit 23 is added to the communication node 20A. Hereinafter, the second embodiment of the present invention will be described focusing on the differences from the first embodiment.

  The entry aggregation unit 23 included in the communication node 20A according to the present embodiment reads the entries stored in the entry storage unit 21 at a predetermined timing, and selects a plurality of entries having different matching conditions but having the same processing content set. The operation of rewriting (aggregating) to the entry in which the match condition is set is performed. Note that the predetermined timing includes the passage of a certain time, the timing when the number of entries newly registered in the entry storage unit 21 reaches a predetermined value, and the free space in the entry storage unit 21 is less than the predetermined value. Timing.

  For example, as shown in FIG. 8, it is assumed that the entry storage unit 21 holds three entries with different match conditions. The entry aggregating unit 23 extracts entries whose contents of the instruction field (output from the port d; Output port d) are the same processing contents, integrates these matching conditions, and aggregates the entries as shown in FIG. To do.

  Note that this operation causes a difference between the contents of the entry held by the communication node 20 ascertained on the control device 30 side and the entry actually held by the communication node 20, so that entry aggregation is performed. It is desirable that the unit 23 transmits the result of collecting the entries to the control device 30.

  As described above, according to the present embodiment, the entry aggregation process can be executed by the communication node 20 alone. In the present embodiment, the control device 30 only needs to have an entry generation and setting function in which one match condition is set. There is also an advantage that it is not necessary to add a special function.

[Third Embodiment]
Next, a third embodiment in which the entry aggregation function arranged on the communication node 20 side in the second embodiment is arranged on the control device side will be described in detail with reference to the drawings. FIG. 5 is a block diagram showing the configuration of the third exemplary embodiment of the present invention. The difference from the second embodiment shown in FIG. 4 is that the entry aggregation unit 33 is installed on the control device side.

  Referring to FIG. 5, the control device 30 </ b> A includes an entry generation unit 31 and an entry aggregation unit 33.

  Upon receiving an entry creation request from the communication node 20, the entry generation unit 31 generates an entry to be held in the entry storage unit 21 of the communication node 20 and registers it in the entry storage unit 21 of the communication node 20. The entry generation unit 31 can use the same flow entry generation function provided in the OpenFlow controller described in Non-Patent Documents 1 and 2.

  The entry aggregating unit 33 reads the entry stored in the entry storage unit 21 of the communication node 20 or the set entry of each communication node managed on the control device 30A side at a predetermined timing, and the matching conditions are different. Performs the operation of rewriting (aggregating) an entry in which the same processing content is set to one entry in which a plurality of match conditions are set. In the present embodiment as well, the predetermined timing includes the passage of a certain time, the timing when the number of entries newly registered in the entry storage unit 21 reaches a predetermined value, and the free space in the entry storage unit 21. For example, the timing when becomes less than a predetermined value.

  In the present embodiment, there is no difference between the contents of the entry held by the communication node 20 grasped on the control device 30A side and the entry actually held by the communication node 20, so that the communication There is no need to send the result of collecting the entries from the node 20 to the control device 30A.

  As described above, according to the present embodiment, the entry aggregation process can be executed as in the second embodiment. Further, in the present embodiment, the entry aggregation unit 23 can be omitted on the communication node 20 side, and therefore, there is an advantage that the communication node 20 can have a simpler configuration compared to the second embodiment.

[Fourth Embodiment]
Next, a fourth embodiment in which the aggregation operation is executed when a new entry is generated by the control device will be described in detail with reference to the drawings. FIG. 6 is a block diagram showing the configuration of the fourth exemplary embodiment of the present invention. The difference from the third embodiment shown in FIG. 5 is that the control device 30B includes an entry update unit 34, and the entry generation unit 31A and the entry update unit 34 operate in cooperation when generating a new entry.

  Referring to FIG. 6, the control device 30B includes an entry generation unit 31A and an entry update unit 34.

  Upon receiving an entry creation request from the communication node 20, the entry generation unit 31 </ b> A generates an entry to be held in the entry storage unit 21 of the communication node 20 and transmits the entry to the entry update unit 34.

  When the entry update unit 34 receives a newly generated entry from the entry generation unit 31A, the entry update unit 34 sets the entry stored in the entry storage unit 21 of the communication node 20 or each communication node managed on the control device 30B side. To check whether there is an entry with the same processing contents but different match conditions. As a result of the confirmation, if there is an entry with different matching conditions but the same processing content, the entry updating unit 34 adds the matching condition of the entry generated by the entry generating unit 31A to the matching condition of the entry. Then, an operation of rewriting (updating) to one entry in which a plurality of match conditions are set is performed. On the other hand, when there are no entries with different match conditions but the same processing content set, the entry update unit 34 performs an operation of registering the entry generated by the entry generation unit 31A in the entry storage unit 21.

  As described above, according to the present embodiment, the entry aggregation process can be executed at the time of entry registration, so that the number of entries held by the communication node 20 can be minimized.

  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 elements shown in the drawings are examples for helping understanding of the present invention, and are not limited to the configurations shown in these drawings.

  Further, for example, the above-described embodiments can be combined. For example, a configuration in which both the communication node 20A and the control device 30A include the entry aggregation units 23 and 33 by combining the second embodiment and the third embodiment can be employed. According to this configuration, the load on the communication node 20A and the control device 30A can be distributed by changing the timing at which the entry aggregation unit 23 and the entry aggregation unit 33 aggregate entries, respectively.

Finally, a preferred form of the invention is summarized.
[First embodiment]
(Refer to the communication node from the first viewpoint)
[Second form]
In the communication node of the first form,
At a predetermined timing, out of the entries held in the entry storage unit, entries having the same contents as processing contents are extracted and aggregated into one entry having a matching condition for each extracted entry. A communication node comprising an entry aggregation unit.
[Third embodiment]
In the communication node of the second form,
A communication node for notifying a predetermined control device of the aggregated result.
[Fourth form]
(Refer to the control device according to the second viewpoint)
[Fifth embodiment]
In the control device of the fourth form,
In place of the entry update unit, an entry having the same content as the processing content is extracted from the entries held in the entry storage unit at a predetermined timing, and the matching condition of each extracted entry A control device comprising an entry aggregating unit for aggregating into one entry having
[Sixth embodiment]
(Refer to the communication system according to the third viewpoint)
[Seventh form]
(Refer to the entry aggregation method from the fourth viewpoint.)
[Eighth form]
(Refer to the entry aggregation method from the fifth viewpoint)
[Ninth Embodiment]
(Refer to the program from the sixth viewpoint)
In addition, the said 6th-9th form can be expand | deployed to the 2nd, 3rd, 5th form similarly to the 1st, 4th form.

  Each disclosure of the above-mentioned patent document and non-patent document is 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.

10A to 10D terminal 20, 20A Communication node 21 Entry storage unit 22 Packet processing unit 23, 33 Entry aggregation unit 30, 30A, 30B Controller 31, 31A Entry generation unit 34 Entry update unit X20 Open flow switch (OFS)
X30 Open Flow Controller (OFS)

Claims (11)

A matching condition specifying that port having received the packet is one of a plurality of ports set in advance, and processing contents that apply to a received packet conforms to the match condition, the entry associating a possible memory An entry storage unit,
Before searching entries with Ki受 fits Shin packet match conditions from the entry storage unit, provided with a packet processing unit for processing the received packet in accordance with the processing contents set in the entry found by the search Communication node. A port that extracts an entry having the same processing contents from a plurality of entries held in the entry storage unit at a predetermined timing, and a port that receives a packet specifies a match condition of each of the extracted entries The communication node according to claim 1, further comprising an entry aggregating unit that rewrites an entry having a match condition that specifies any one of the above . The communication node according to claim 2, wherein the rewritten result is transmitted to a predetermined control device. A matching condition specifying that port to receive the packet is one of a plurality of ports set in advance, which can store an entry that associates processing contents that apply to a received packet conforms to the match condition An entry storage unit;
Before searching entries with Ki受 fits Shin packet match conditions from the entry storage unit, provided with a packet processing unit for processing the received packet in accordance with the processing contents set in the entry found by the search A control device for controlling a communication node,
In response to a request from the communication node, an entry generation unit that generates an entry to be held in the entry storage unit;
Control device and a entry update unit for registering entries said generating the entry storage unit.   The entry update unit rewrites an entry set with the same processing content as the generated entry when the entry storage unit holds an entry set with the same processing content as the generated entry,
  The rewritten entry specifies that the port that receives the packet is an entry in which the same processing content as the processing content of the generated entry is set or a port specified by the match condition of the generated entry The control device according to claim 4, which has a matching condition. In Jo Tokoro timing, the plurality of entries or al same processing content entries stored in the storage unit extracts an entry that is set, the ports each entry port having received the packet is the extraction is designated 6. The control device according to claim 4 or 5, further comprising an entry aggregating unit that rewrites one entry having a matching condition that designates one of them. A matching condition specifying that port having received the packet is one of a plurality of ports set in advance, and processing contents that apply to a received packet conforms to the match condition, the entry associating a possible memory An entry storage unit,
Before searching entries with Ki受 fits Shin packet match conditions from the entry storage unit, provided with a packet processing unit for processing the received packet in accordance with the processing contents set in the entry found by the search A communication node;
A communication system including a control device that transmits an entry to be stored in the entry storage unit to the communication node. A matching condition specifying that port having received the packet is one of a plurality of ports set in advance, and processing contents that apply to a received packet conforms to the match condition, the entry associating a possible memory A computer mounted on either a communication node provided with an entry storage unit or a control device connected to the communication node,
Extracting an entry in which the same content is set from a plurality of entries held in the entry storage unit at a predetermined timing;
An entry aggregation method including a step of rewriting a port having received a packet into one entry having a match condition designating that a match condition of each entry extracted in the extracting step is one of designated ports . A matching condition specifying that port having received the packet is one of a plurality of ports set in advance, and processing contents that apply to a received packet conforms to the match condition, the entry associating a possible memory A computer connected to a communication node having an entry storage unit
Generating an entry to be held in the entry storage unit in response to a request from the communication node;
Rewriting the entry set with the same processing content as the generated entry when the entry storage unit holds an entry set with the same processing content as the generated entry, and
The rewritten entry specifies that the port that receives the packet is an entry in which the same processing content as the processing content of the generated entry is set or a port specified by the match condition of the generated entry Entry aggregation method with matching conditions . A matching condition specifying that port having received the packet is one of a plurality of ports set in advance, and processing contents that apply to a received packet conforms to the match condition, the entry associating a possible memory In a computer mounted on either a communication node having an entry storage unit or a control device connected to the communication node,
A process of extracting an entry in which the same processing content is set from a plurality of entries held in the entry storage unit at a predetermined timing;
Program port receiving the packet to execute a process of rewriting a single entry with the matching condition specifying that each entry extracted in the process of the extraction is one of the ports to be specified. A matching condition specifying that port having received the packet is one of a plurality of ports set in advance, and processing contents that apply to a received packet conforms to the match condition, the entry associating a possible memory To a computer connected to a communication node having an entry storage unit,
In response to a request from the communication node, a process for generating an entry to be held in the entry storage unit;
When an entry having the same processing content as the generated entry is stored in the entry storage unit, a process for instructing rewriting of the entry having the same processing content as the generated entry is executed. Let
The rewritten entry specifies that the port that receives the packet is an entry in which the same processing content as the processing content of the generated entry is set or a port specified by the match condition of the generated entry A program that has a match condition .

Images