WO2013132559A1

WO2013132559A1 - Communication apparatus, control apparatus, communication system, packet processing method, communication apparatus control method, and program

Info

Publication number: WO2013132559A1
Application number: PCT/JP2012/007060
Authority: WO
Inventors: Shuichi Karino
Original assignee: Nec Corporation
Priority date: 2012-03-06
Filing date: 2012-11-05
Publication date: 2013-09-12
Also published as: JP2015509670A

Abstract

Load of a control apparatus controlling communication apparatuses in a centralized manner is reduced or temporary disconnection of a secure channel between a control apparatus and a communication apparatus is managed. A communication apparatus includes: a packet processing unit processing a packet(s) based on a packet handling operation set by a control apparatus; an emulation unit creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and a synchronization control unit notifying the control apparatus of a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus.

Description

COMMUNICATION APPARATUS, CONTROL APPARATUS, COMMUNICATION SYSTEM, PACKET PROCESSING METHOD, COMMUNICATION APPARATUS CONTROL METHOD, AND PROGRAM

Field

(REFERENCE TO RELATED APPLICATION)
The present invention is based upon and claims the benefit of the priority of Japanese patent application No. 2012-049393, filed on March 6, 2012, the disclosure of which is incorporated herein in its entirety by reference thereto.
The present invention relates to a communication apparatus, a control apparatus, a communication system, a packet processing method, a communication apparatus control method, and a program. In particular, it relates to a communication apparatus which operates in conjunction with a control apparatus that controls communication apparatuses in a centralized manner, a control apparatus, a communication system, a packet processing method, a communication apparatus control method, and a program.

Background

Recently, a technique referred to as OpenFlow has been proposed (see Non Patent Literatures (NPLs) 1 and 2). OpenFlow recognizes communications as end-to-end flows and performs path control, failure recovery, load balancing, and optimization on a per-flow basis. An OpenFlow switch according to NPL 2 has a secure channel for communication with an OpenFlow controller and operates according to a flow table suitably added or rewritten by the OpenFlow controller. In a flow table, a set of the following three is defined for each flow: a matching condition against which a packet header is matched (see "4.3 Match Fields" in NPL 2); flow statistical information (counters); and instructions that define processing contents (see "4.1 Flow Table" in NPL 2).

For example, if the OpenFlow switch receives a packet, the OpenFlow switch searches the flow table for an entry having a match condition that matches header information of the incoming packet. If the OpenFlow switch finds an entry matching the incoming packet as a result of the search, the OpenFlow switch updates the flow statistical information (counters) and processes the incoming packet based on a processing content (transmission, flooding, drop, etc. of the packet from a specified port) written in the instruction field of the entry. If the OpenFlow switch does not find an entry matching the incoming packet as a result of the search, the OpenFlow switch requests the OpenFlow controller to set an entry via the secure channel. Namely, the OpenFlow switch requests the OpenFlow controller to determine a processing content for the incoming packet. The OpenFlow switch receives a flow entry defining a processing content and updates the flow table. In this way, by using an entry stored in the flow table as a packet handling operation, the OpenFlow switch executes packet forwarding.

Nick McKeown, and seven others, "OpenFlow: Enabling Innovation in Campus Networks", [online], [Searched on February 14, 2012], 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 February 14, 2012], Internet <URL: http://www.openflow.org/documents/openflow-spec-v1.1.0.pdf>

Summary

The entire disclosures of the above Non Patent Literatures are incorporated herein by reference thereto.
The following analyses are given by the present invention. Discussions are underway about provision of functions corresponding to the OpenFlow switch in

NPLs

1 and 2 to communication terminals such as so-called smartphones, mobile phones, and mobile routers. This configuration enables detailed control operations. For example, a control apparatus corresponding to the OpenFlow controller in

NPLs

1 and 2 can switch an access network or rewrite a header on a per-flow basis.

However, with the above configuration, since the OpenFlow controller needs to control many communication terminals (communication apparatuses), the load is increased, counted as a problem. In addition, since examples of the channel between the control apparatus and the communication terminal such as a smartphone, a mobile phone, or a mobile router include a wireless section, a case in which the secure channel between control apparatus and the communication terminal is temporarily disconnected needs to be considered.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a communication apparatus, a control apparatus, a communication system, a packet processing method, a communication apparatus control method, and a program capable of reducing load of the control apparatus or managing temporary disconnection of a secure channel even when a communication terminal (communication apparatus) such as a smartphone, a mobile phone, or a mobile router is provided with functions corresponding to the OpenFlow switch in

NPLs

1 and 2.

According to a first aspect of the present invention, there is provided a communication apparatus, comprising: a packet processing unit processing a packet(s) based on a packet handling operation set by a control apparatus; and an emulation unit creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus. The communication apparatus further comprises a synchronization control unit notifying the control apparatus of a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus.

According to a second aspect of the present invention, there is provided a control apparatus, comprising: a packet handling operation setting unit setting a packet handling operation in the above communication apparatus; and a synchronization unit synchronizing a packet handling operation for the communication apparatus with a packet handling operation for the communication apparatus among packet handling operations for respective communication apparatuses managed on a side of the control apparatus itself, based on a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus.

According to a third aspect of the present invention, there is provided a communication system comprising the above communication apparatus and the above control apparatus.

According to a fourth aspect of the present invention, there is provided a packet processing method, comprising steps of: causing a communication apparatus, including a packet processing unit that processes a packet based on a packet handling operation set by a control apparatus, to create a packet handling operation and set the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and causing the communication apparatus to notify the control apparatus of a processing content executed by an emulation unit while the emulation unit is operated instead of the control apparatus. This method is associated with a certain machine, that is, with a communication apparatus processing a packet based on a packet handling operation set by a control apparatus.

According to a fifth aspect of the present invention, there is provided a communication apparatus control method, comprising steps of: causing a control apparatus to create a packet handling operation. The control apparatus comprises: a packet handling operation setting unit setting a packet handling operation in a communication apparatus that includes: a packet processing unit processing a packet(s) based on a set packet handling operation; an emulation unit creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and a synchronization control unit notifying the control apparatus of a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus to instruct the emulation unit of the communication apparatus. The method further comprises causing the control apparatus to synchronize a packet handling operation for the communication apparatus with a packet handling operation for the communication apparatus among packet handling operations for respective communication apparatuses managed on a side of the control apparatus itself based on a processing content supplied from the synchronization control unit of the communication apparatus. This method is associated with a certain machine, that is, a control apparatus controlling a communication apparatus.

According to a sixth aspect of the present invention, there is provided a computer program(s) executed by the above communication apparatus and/or the above control apparatus. This program(s) can be recorded in a computer-readable recording medium which is non-transitory. Namely, the present invention can be embodied as a computer program product.

According to the present invention, even when a communication terminal (communication apparatus) is provided with functions corresponding to the OpenFlow switch in

NPLs

1 and 2, load of a control apparatus can be reduced or temporary disconnection of a secure channel can be managed.

Fig. 1 illustrates a configuration according to an exemplary embodiment of the present disclosure. Fig. 2 illustrates a configuration of a communication apparatus and a control apparatus according to a first exemplary embodiment of the present disclosure. Fig. 3 illustrates flow entries set in the communication apparatus according to the first exemplary embodiment of the present disclosure. Fig. 4 illustrates an example of access policies (communication policies) referred to when a flow table in Fig. 3 is operated. Fig. 5 illustrates an example of a flow entry rewritten based on an access policy (communication policy) in Fig. 4. Fig. 6 is a sequence diagram illustrating an operation (control by a controller) according to the first exemplary embodiment of the present disclosure. Fig. 7 is a sequence diagram illustrating an operation (preparation of an emulation unit) according to the first exemplary embodiment of the present disclosure. Fig. 8 is a sequence diagram illustrating an operation (from the start of autonomous control by the communication apparatus to the return to an original state) according to the first exemplary embodiment of the present disclosure. Fig. 9 is a sequence diagram illustrating an operation (preparation of an emulation unit) according to a second exemplary embodiment of the present disclosure. Fig. 10 illustrates a configuration of a communication apparatus and a control apparatus (controller) according to a third exemplary embodiment of the present disclosure. Fig. 11 is a sequence diagram illustrating an operation (from the start of autonomous control by the communication apparatus to the return to an original state) according to the third exemplary embodiment of the present disclosure. Fig. 12 illustrates a configuration of a communication apparatus and a control apparatus (controller) according to a fourth exemplary embodiment of the present disclosure. Fig. 13 is a sequence diagram illustrating an operation (preparation of an emulation unit) according to a fifth exemplary embodiment of the present disclosure. Fig. 14 is a graph illustrating a change of destination of a packet from a communication apparatus according to the fifth exemplary embodiment of the present disclosure. Fig. 15 is another graph illustrating a change of destination of a packet from a communication apparatus according to the fifth exemplary embodiment of the present disclosure.

By way of preferred modes, the following description is disclosed for better illustration.
First, an outline of an exemplary embodiment of the present disclosure will be described with reference to the drawings. However, the reference characters that denote the respective components in the following outline are merely used by way of examples to facilitate understanding of the present disclosure. Namely, the reference signs are merely used for convenience. Therefore, the reference signs are not intended to limit the present disclosure to the illustrated modes.

As illustrated in Fig. 1, an exemplary embodiment of the present disclosure can be realized by a communication apparatus 10A including: a packet processing unit 13A processing a packet based on a packet handling operation set by a control apparatus 20A; an emulation unit 12A; and a synchronization control unit 11A. The "packet handling operation" is control information in which information distinguishing a packet and a processing content applied to the packet are associated with each other, such as flow entry in

NPLs

1 and 2.

The communication apparatus 10A activates the emulation unit 12A in response to a certain event such as disconnection of a channel between the communication apparatus 10A and the control apparatus 20A, an instruction from the control apparatus, or an instruction from a user. Next, instead of the control apparatus 20A, the communication apparatus 10A starts a process of creating the packet handling operation and setting the packet handling operation in the communication apparatus 10A.
In this way, without relying on the control apparatus 20A, the communication apparatus 10A starts autonomous control operations, such as switching over of a packet destination (to a mobile communication network or a wireless LAN, for example).

Subsequently, if a predetermined termination condition is satisfied, such as reconnection of the channel between the control apparatus 20A and the communication apparatus 10A, an instruction from the control apparatus, or an instruction from a user, the communication apparatus 10A notifies the control apparatus 20A of a processing content executed by the emulation unit 12A while the emulation unit 12A is operated instead of the control apparatus 20A. In this way, the content of the packet handling operation set in the communication apparatus 10A managed by the control apparatus 20A is synchronized with the content of the packet handling operation actually set in the communication apparatus 10A.

As described above, while (i.e., as long as) the communication apparatus 10A is autonomously operated, load of the control apparatus 20A is reduced. In addition, temporary disconnection of the channel between the communication apparatus 10A and the control apparatus 20A can be coped with, too.

(First exemplary embodiment)
Next, a first exemplary embodiment of the present disclosure will be described in detail with reference to the drawings. Fig. 2 illustrates a configuration of a communication apparatus and a control apparatus according to the first exemplary embodiment of the present disclosure. In Fig. 2, a controller 20 and a communication apparatus 10 controlled by the controller 20 are connected.

The controller 20 includes a communication apparatus control unit 21 and a synchronization unit 22 and controls other communication apparatuses including the communication apparatus 10 in a centralized manner (the controller 20 corresponds to the above "control apparatus"). Such controller 20 can be realized by adding the synchronization unit 22 to the OpenFlow controller in

NPLs

1 and 2.

When the communication apparatus control unit 21 receives a request (for example, a Packet-In message in NPL 2) for setting a flow entry from a packet processing unit 13 of the communication apparatus 10, the communication apparatus control unit 21 processes a flow table 14 (addition, updating, or deletion of a flow entry), based on an access policy (communication policy) to be applied to the communication apparatus 10 and based on location information of the communication apparatus 10 (connecting location (connectability) for a 3G network or a wireless LAN). As illustrated in Fig. 2, these operations of the communication apparatus control unit 21 can be represented, for example, as some functions (functions A to C). The functions use information included in a flow entry setting request, an access policy (communication policy) to be applied to the communication apparatus 10, and location information of the communication apparatus 10 (connecting location (connectability) for a 3G network or a wireless LAN) as inputs to achieve an output (generation, updating, or deletion of a flow entry). Hereinafter, in the present exemplary embodiment, the "function B" and "function C" are configured by one or a plurality of computer programs, respectively. By supplying copies of these functions to the side of the communication apparatus 10 and causing the communication apparatus 10 to operate based on these functions, the communication apparatus 10 can be caused to have the same functions as the "function B" and "function C" of the controller 20.

When the synchronization unit 22 receives operation contents (a history of addition, updating, and deletion of flow entries) executed on the flow table 14 during a period in which the communication apparatus 10 is operated instead of the controller 20, the synchronization unit 22 synchronizes a flow entry group set in the communication apparatus 10 with a flow entry group, for the communication apparatus 10, managed by the communication apparatus control unit 21. In addition, if a predetermined condition is satisfied, the synchronization unit 22 according to the present exemplary embodiment transmits computer program(s) corresponding to the respective function(s) of the communication apparatus control unit 21 to the communication apparatus 10.

The communication apparatus 10 includes a synchronization control unit 11, an emulation unit 12, the packet processing unit 13, and the flow table 14. Examples of the communication apparatus 10 include a mobile phone terminal, a smartphone, a tablet terminal, a personal computer, a game machine, and a mobile router. Of course, the OpenFlow switch in

NPLs

1 and 2 may be used as the communication apparatus 10.

The flow table 14 stores flow entries as illustrated in Fig. 3. In each entry, a matching condition against which, for example, a packet header of an incoming packet is matched (see "4.3 Match Fields" in NPL 2), a counter, and an instruction defining a processing content are associated with each other.

For example, when the packet processing unit 13 receives a packet from the outside or an application program (not illustrated in Fig. 2) in the communication apparatus 10, the packet processing unit 13 searches in the flow table 14 for a flow entry including a matching condition that matches the incoming packet. As a result of the search, if the packet processing unit 13 finds a flow entry including a matching condition that matches the incoming packet, the packet processing unit 13 updates a value in the counter field and executes a processing content defined in the instruction field. For example, based on the table in Fig. 3, when the packet processing unit 13 receives an image-content-related packet(s), the packet processing unit 13 transfers the packet(s) to a wireless LAN AP (access point) connection port. However, when the packet processing unit 13 receives a miniblog-related packet(s), the packet processing unit 13 transfers the packet(s) to a 3G network connection port.

In contrast, as a result of the search, if the packet processing unit 13 does not find a flow entry including a matching condition that matches the incoming packet(s), the packet processing unit 13 sends a flow entry setting request to the synchronization control unit 11.

The synchronization control unit 11 relays the flow entry setting request to the controller 20 or the emulation unit 12, based on the state of a channel state detection unit 112 included in the synchronization control unit 11.

The emulation unit 12 is activated based on an instruction from the synchronization control unit 11 or the controller 20 and processes the flow table 14 (addition, updating, or deletion of a flow entry), instead of at least a part of the functions of the communication apparatus control unit 21 of the controller 20. In the present exemplary embodiment, the functions, for example, represented by the functions B and C in the communication apparatus control unit 21 of the controller 20 are emulated. In addition, operation contents (a history of addition, updating, and deletion of flow entries) executed on the flow table 14 via the emulation unit 12 are registered in a processing content storage unit 111 of the synchronization control unit 11.

Fig. 4 illustrates access policy (communication policy) to which the communication apparatus control unit 21 of the controller 20 refers when operating the flow table 14. For example, if the cumulative incoming and outgoing packet amount of the communication apparatus 10 in a certain period (month, week, day or the like) is less than a predetermined value ("AAA" in Fig. 4, for example), a default setting is applied. However, if the cumulative incoming and outgoing packet amount reaches a predetermined value or greater, a setting 1 is applied. When the default setting in Fig. 4 is applied, if the communication apparatus is connectable to a wireless LAN, image-related packet(s) are transferred via the wireless LAN. However, when the setting 1 is applied, packets other than image-related packets are also transferred via the wireless LAN. By referring to a counter of the flow table 14, the controller 20 or the emulation unit 12 can grasp the cumulative incoming and outgoing packet amount of the communication apparatus 10.

Fig. 5 illustrates a flow entry that has been rewritten by the controller 20 or the emulation unit 12 when the cumulative incoming and outgoing packet amount of the communication apparatus 10 reaches the predetermined value AAA or greater. As illustrated in Fig. 5, a flow entry has been rewritten based on an access policy (communication policy) in Fig. 4, so that the packet processing unit 13 also transfers miniblog-related packet(s) to a wireless LAN AP connection port. In this way, the controller 20 or the emulation unit 12 can switch over the network used by the communication apparatus 10, for example, based on the location or the contract status of the communication apparatus 10 or the congestion status of a 3G network.

The synchronization control unit 11 includes: the processing content storage unit 111 storing operation contents (a history of addition, updating, and deletion of flow entries) executed on the flow table 14 by the emulation unit 12; and the channel state detection unit 112 detecting a channel state between the controller 20 and the communication apparatus 10. When the channel state detection unit 112 detects disconnection of a channel between the controller 20 and the communication apparatus 10, the synchronization control unit 11 activates the emulation unit 12. In addition, when the channel between the controller 20 and the communication apparatus 10 is reconnected, the synchronization control unit 11 transmits information accumulated in the processing content storage unit 111 to the synchronization unit 22 of the controller 20.

Each of the units or components (processing means) of the communication apparatus 10 and the controller 20 illustrated in Fig. 2 can be realized by using a computer program(s). The computer program(s) causes a computer in each of the communication apparatus 10 and the controller 20 to use its hardware and to execute the above processes.

Next, an operation according to the present exemplary embodiment will be described in detail with reference to the drawings. First, a basic operation (controlled by the controller) between the communication apparatus 10 and the controller will be described with reference to Fig. 6.

First, when a packet arrives at the packet processing unit 13 of the communication apparatus 10, the packet processing unit 13 searches in the flow table 14 ("packet arrival" at the bottom left corner in Fig. 6). If the flow table 14 includes a flow entry having a matching condition that matches the incoming packet, the packet processing unit 13 determines the flow table search to be successful. Therefore, the packet processing unit 13 processes the incoming packet in accordance with the content in the instruction field ("packet transmission" in Fig. 6).

In Fig. 6, while a second packet reaches the packet processing unit 13, the flow table 14 does not include a flow entry having a matching condition that matches the incoming packet. Thus, the packet processing unit 13 determines the flow table search to be unsuccessful. In this case, the packet processing unit 13 transmits a flow entry creation request to the controller 20 via the synchronization control unit 11.

When receiving the flow entry creation request, the communication apparatus control unit 21 of the controller 20 creates a flow entry, based on contents of the flow entry setting request, the location of the above communication apparatus 10, an access policy (communication policy), and the like. Next, the communication apparatus control unit 21 of the controller 20 sets the flow entry in the flow table 14 via the synchronization control unit 11.

When receiving the set flow entry, the communication apparatus 10 processes the packet (packet transmission) in accordance with the set flow entry or an instruction (Packet-Out message) from the controller (control apparatus). Next, the packet processing unit 13 receives a subsequent packet (a third packet arrival in Fig. 6). Since the flow entry is set as described above, the packet processing unit 13 determines the flow table search to be successful. Thus, the packet processing unit 13 processes the packet ("packet transmission" in Fig. 6) in accordance with the content in the instruction field.

Next, a preparation for operating the emulation unit 12 will be described. Fig. 7 is a sequence diagram illustrating an operation (preparation of the emulation unit) according to the first exemplary embodiment of the present disclosure. Fig. 7 differs from Fig. 6 in the process executed for the second packet arrival in Fig. 6. More specifically, when the communication terminal control unit 21 receives a flow entry creation request, the synchronization unit 22 of the controller 20 checks a function module operating in a communication terminal control unit 21 (step S001) and installs the function module in the emulation unit 12 of the communication apparatus 10 (step S002). In this way, instead of the controller 20, the communication apparatus 10 can autonomously create a flow entry.

Fig. 8 is a sequence diagram illustrating an operation (from the start of autonomous control by the communication apparatus to the return to an original state) according to the first exemplary embodiment of the present disclosure. Next, when the channel state detection unit 112 of the communication apparatus 10 detects disconnection of a channel between the controller 20 and the communication apparatus 10 (step S003), the communication apparatus 10 activates the emulation unit 12 and starts autonomous control.

Subsequently, when a packet arrives and the search in the flow table 14 results in a failure, the packet processing unit 13 transmits a flow entry creation request to the controller 20 via the synchronization control unit 11.

When receiving the flow entry creation request, since the emulation unit 12 is active, the synchronization control unit 11 inputs the flow entry creation request to the emulation unit 12. The emulation unit 12 creates a flow entry, based on contents of the flow entry setting request, the location of the above communication apparatus 10, an access policy (communication policy), and the like. Next, the emulation unit 12 sets the flow entry in the flow table 14 and registers the content in the processing content storage unit 111 (step S004).

When receiving the set flow entry, the communication apparatus 10 processes the packet (packet transmission) in accordance with the set flow entry or an instruction from the emulation unit 12. In this way, according to the present exemplary embodiment, even when a channel between the controller 20 and the communication apparatus 10 is disconnected, the communication apparatus 10 can be operated as if controlled by the controller 20.

Subsequently, when the channel state detection unit 112 of the communication apparatus 10 detects reconnection of the channel between the controller 20 and the communication apparatus 10 (step S005), the communication apparatus 10 stops the emulation unit 12 and ends the autonomous control. Next, the synchronization control unit 11 of the communication apparatus 10 notifies the synchronization unit 22 of the controller 20 of the operation contents executed on the flow table 14 and accumulated in the processing content storage unit 111 (step S006).

Next, the synchronization unit 22 of the controller 20 refers to the operation contents executed on the flow table 14 during disconnection of the channel between the controller 20 and the communication apparatus 10 and synchronizes a flow entry group currently set in the communication apparatus 10 with a flow entry group set in the communication apparatus control unit 21 of the controller (step S007). In this way, the controller 20 can resume controlling the communication apparatus 10 appropriately.

Thus, according to the present exemplary embodiment, over the communication apparatus 10 whose channel with the controller 20 is frequently disconnected can be operated as if controlled by the controller 20.

(Second exemplary embodiment)
Next, a second exemplary embodiment of the present disclosure will be described in detail with reference to the drawings. In the second exemplary embodiment, the preparation of the emulation unit 12 is changed. Since the present exemplary embodiment can be realized with the same configuration as that according to the first exemplary embodiment, operational differences will be hereinafter described.

Fig. 9 is a sequence diagram illustrating an operation (preparation of the emulation unit) according to the second exemplary embodiment of the present disclosure. The difference from the preparation of the emulation unit according to the first exemplary embodiment in Fig. 7 resides in that the synchronization unit 22 of the controller 20 autonomously executes the preparation of the emulation unit, not in response to reception of a flow entry setting request.

More specifically, as illustrated in Fig. 9, when the controller 20 detects congestion of a network (a 3G network, for example) (step S101), the controller 20 installs a function module in the emulation unit 12 of the communication apparatus 10 (step S102). The controller 20 can grasp such network congestion by reading flow statistical information (corresponding to the counter field in Fig. 3) or by detecting a failure from an OpenFlow switch or the like arranged in the network.

Thus, the preparation of the emulation unit 12 of the communication apparatus 10 can be executed at an arbitrary timing. Of course, a function module may be installed in advance in the communication apparatus 10.

(Third exemplary embodiment)
Next, a third exemplary embodiment of the present disclosure will be described in detail with reference to the drawings. In the third exemplary embodiment, the activation timing of the emulation unit 12 is changed.

Fig. 10 illustrates a configuration of a communication apparatus and a control apparatus (controller) according to the third exemplary embodiment of the present disclosure. The difference from the configuration of the first exemplary embodiment in Fig. 2 resides in that a synchronization control unit 11B of a communication apparatus 10B does not include a channel state detection unit and that a synchronization unit 22B of a controller 20B includes a function of giving instructions about the start and end of creation of a flow entry. Since other configurations and basic operations of the units are the same as those according to the first and second exemplary embodiments, description thereof will be omitted.

Fig. 11 is a sequence diagram illustrating an operation (from the start of autonomous control by the communication apparatus to the return to an original state) according to the third exemplary embodiment of the present disclosure. In Fig. 11, the controller 20B autonomously instructs the communication apparatus 10B to start creating a flow entry (step S201), not in response to detection of a channel disconnection between the controller 20B and the communication apparatus 10B. The controller 20B may instruct the communication apparatus 10B to start creating a flow entry at an arbitrary timing, such as when load of the controller 20B is increased or when congestion of a network is caused.

The subsequent operation is the same as that according to the first exemplary embodiment. Namely, the communication apparatus 10B activates the emulation unit 12 and starts autonomous control. Subsequently, when a packet arrives and the search in the flow table 14 results in a failure, the packet processing unit 13 transmits a flow entry creation request to the controller 20B via the synchronization control unit 11B.

When receiving the flow entry creation request, since the emulation unit 12 is active, the synchronization control unit 11B inputs the flow entry creation request to the emulation unit 12. The emulation unit 12 creates a flow entry, based on contents of the flow entry setting request, the location of the above communication apparatus 10B, an access policy (communication policy), and the like. Next, the emulation unit 12 sets the flow entry in the flow table 14 and registers the content in the processing content storage unit 111 (step S202).

When receiving the set flow entry, the communication apparatus 10B processes the packet (packet transmission) in accordance with the set flow entry or an instruction from the emulation unit 12. In this way, according to the present exemplary embodiment, the controller 20B can activate the emulation unit 12 of the communication apparatus 10 and instruct the emulation unit 12 to create a flow entry at an arbitrary timing, such as when load of the controller 20B is increased or when congestion of a network appears.

Subsequently, when the controller 20B transmits a return instruction to the communication apparatus 10 (step S203), the communication apparatus 10 stops the emulation unit 12 and ends the autonomous control. The synchronization control unit 11B of the communication apparatus 10B notifies the synchronization unit 22B of the controller 20B of the operation contents executed on the flow table 14 and accumulated in the processing content storage unit 111 (step S204).

Next, the synchronization unit 22B of the controller 20B refers to the operation contents executed on the flow table 14 during the above autonomous control and synchronizes a flow entry group currently set in the communication apparatus 10B with a flow entry group set in the communication apparatus control unit 21 of the controller (step S205). In this way, the controller 20B can resume controlling the communication apparatus 10B appropriately.

Thus, the communication apparatus 10B can be operated as if controlled by the controller 20B at an arbitrary timing. In the present exemplary embodiment, too, by synchronizing the flow entries including those processed during the autonomous control, the controller 20B can promptly resume controlling the communication apparatus 10B.

In addition, for example, it is preferable that the controller 20B include a network state monitoring unit monitoring a state of a network to which the communication apparatus 10B is connected or a load state measuring unit measuring a state of load of the controller 20B. In this case, it is preferable that the network state monitoring unit and the load state measuring unit notify the synchronization unit 22B of the state of the network to which the communication apparatus 10 is connected and the state of load of the controller 20B, respectively.

(Fourth exemplary embodiment)
Next, a fourth exemplary embodiment of the present disclosure will be described in detail with reference to the drawings. In the fourth exemplary embodiment, the internal configuration of the communication apparatus 10 is changed.

Fig. 12 illustrates a configuration of a communication apparatus and a control apparatus according to the fourth exemplary embodiment of the present disclosure. The difference from the configuration according to the first exemplary embodiment in Fig. 2 resides in that a synchronization control unit 11C of a communication apparatus 10C does not relay a channel between the controller 20 and the communication apparatus 10C. The following description will be made with a focus on the difference.

As in the first exemplary embodiment, the emulation unit 12C is activated when disconnection of a channel between the controller 20 and the communication apparatus 10C is detected. However, unlike the first exemplary embodiment, when disconnection of a channel between the controller 20 and the communication apparatus 10 is detected, instead of the controller 20, a packet processing unit 13C according to the present exemplary embodiment establishes a channel between the controller 20 and the emulation unit 12C and transmits a flow entry setting request. A series of operations according to the present exemplary embodiment is the same as that according to the first exemplary embodiment described with reference to Figs. 6 to 8.

As described above, the present disclosure can be realized with a configuration in which the synchronization control unit 11C does not relay a channel between the controller 20 and the communication apparatus 10C.

(Fifth exemplary embodiment)
Next, a fifth exemplary embodiment of the present disclosure will be described in detail with reference to the drawings. In the fifth exemplary embodiment, the preparation of the emulation unit 12 is changed. Since the present exemplary embodiment can be realized with the same configuration as that according to the first and second exemplary embodiments, operational differences will be hereinafter described.

Fig. 13 is a sequence diagram illustrating an operation (preparation of the emulation unit) according to the fifth exemplary embodiment of the present disclosure. The difference from the preparation of the emulation unit according to the second exemplary embodiment in Fig. 9 resides in that the emulation unit is prepared in an intermittent or stepwise manner.

More specifically, based on the example in Fig. 12, the controller 20 refers to a user contract status and a cumulative incoming and outgoing packet amount to determine whether to install a function module in the communication apparatus (terminal) 10C (step S501). In Fig. 12, as a result of the determination, based on the user contract, the controller 20 determines that the communication apparatus (terminal) 10C needs to be controlled based on the cumulative incoming and outgoing packet amount. Accordingly, the function module B is installed (step S502).

Next, in response to disconnection of a channel between the controller 20 and the communication apparatus 10C or reception of an instruction from the controller 20, the communication apparatus 10C activates the emulation unit 12C and starts autonomous control. For example, as illustrated in a section represented by "flow control by default setting" in Fig. 14, the communication apparatus 10C executes network switching over in which the communication apparatus transmits some of the outgoing packets through a 3G network and transmits other packets through a wireless LAN.

When a predetermined period of time elapses, the controller 20 refers to the user contract status and the cumulative incoming and outgoing packet amount again, to determine whether or not to update the function module installed in the communication terminal 10C (step S503). In the example in Fig. 12, as a result of the determination, based on the user contract, the controller 20 determines that the cumulative incoming and outgoing packet amount is over a predetermined threshold Th. Thus, an access policy (communication policy) to which the function module B refers is updated (step S504).

Since the access policy (communication policy) is updated, for example, the communication apparatus 10C is prohibited to transmit packets to the 3G network in principle, as illustrated in a section represented by "FLOW CONTROL BY SETTING 1" in Fig. 14.

Thus, according to the present exemplary embodiment, the communication apparatus 10C is allowed to execute detailed control operations, in view of the user contract status and the cumulative incoming and outgoing packet amount. In Fig. 14, when the cumulative incoming and outgoing packet amount exceeds the predetermined threshold Th, the communication apparatus 10C is prohibited to transmit packets to a 3G network. However, for example, as illustrated in Fig. 15, a plurality of thresholds Th1 and Th2 may be set. In this case, the communication apparatus 10C can be controlled so that, as the cumulative incoming and outgoing packet amount increases, packet transmission to the 3G network is controlled in a stepwise manner.

While exemplary embodiments of the present disclosure have thus been described, the present disclosure is not limited thereto. Further variations, substitutions, or adjustments can be made without departing from the basic technical concept of the present disclosure. For example, in each of the above exemplary embodiment, a single communication apparatus 10 is connected to a single controller 20. However, similar operations are possible in a configuration where a plurality of controllers 20 and communication apparatuses 10 are connected to each other.

In addition, the above exemplary embodiments describe that each of the function modules forming the emulation unit 12 is installed from the control unit 20. However, each of the function modules forming the emulation unit 12 may be downloaded from a predetermined application server or the like.

Finally, preferable modes of the present disclosure will be summarized.
(First mode)
(See the communication apparatus according to the above first aspect)
(Second mode)
The communication apparatus may further comprises:
a channel state detection unit detecting a state of a channel between the communication apparatus and the control apparatus;
wherein the emulation unit creates and sets the packet handling operation while a channel between the communication apparatus and the control apparatus is disconnected.
(Third mode)
In the communication apparatus, the emulation unit may create and set the packet handling operation in accordance with an instruction from the control apparatus.
(Fourth mode)
In the communication apparatus, instead of the control apparatus, the emulation unit may create a packet handling operation for switching over a destination communication network based on a per-flow basis.
(Fifth mode)
In the communication apparatus, instead of the control apparatus, the emulation unit may creates a packet handling operation for switching over a destination communication network in accordance with a predetermined access policy.
(Sixth mode)
In the communication apparatus, an access policy supplied from the control apparatus may be used as the predetermined access policy.
(Seventh mode)
In the communication apparatus, the predetermined access policy may be an access policy for switching over a destination from a mobile communication network to a wireless LAN in a stepwise manner based on a cumulative communication amount of the communication apparatus.
(Eighth mode)
In the communication apparatus, the emulation unit may be configured by causing an application program installed from a predetermined server to operate on the communication apparatus.
(Ninth mode)
(See the control apparatus according to the above second aspect)
(Tenth mode)
In the control apparatus, the synchronization unit may instruct the communication apparatus to create the packet handling operation.
(Eleventh mode)
In the control apparatus may further comprises:
a network state monitoring unit monitoring a state of a network to which the communication apparatus is connected or a load state measurement unit measuring a state of load of the control apparatus itself;
wherein, when traffic of the network to which the communication apparatus is connected exceeds a predetermined level or when the state of load of the control apparatus exceeds a predetermined level, the synchronization unit instructs the communication apparatus to create the packet handling operation.
(Twelfth mode)
In the control apparatus, the control apparatus may transmit an access policy for creating a packet handling operation for switching over a destination communication network to the emulation unit of the communication apparatus.
(Thirteenth mode)
In the control apparatus, the access policy may be an access policy for switching over a destination from a mobile communication network to a wireless LAN in a stepwise manner based on a cumulative communication amount of the communication apparatus.
(Fourteenth mode)
(See the communication system according to the above third aspect)
(Fifteenth mode)
(See the packet processing method according to the above fourth aspect)
(Sixteenth mode)
(See the communication apparatus control method according to the above fifth aspect)
(Seventeenth mode)
(See the computer program according to the above sixth aspect)

The entire disclosures of the above Patent Literature and Non Patent Literatures are incorporated herein by reference thereto. Modifications and adjustments of the exemplary embodiments and examples are possible within the scope of the overall disclosure (including the claims) of the present disclosure and based on the basic technical concept of the present disclosure. Various combinations and selections of various disclosed elements (including the elements in each of the claims, exemplary embodiments, examples, drawings, etc.) are possible within the scope of the claims of the present disclosure. That is, the present disclosure of course includes various variations and modifications that could be made by those skilled in the art according to the overall disclosure including the claims and the technical concept.

10, 10A, 10B, 10C communication apparatus (terminal)
11, 11A, 11B, 11C synchronization control unit
12, 12A, 12C emulation unit
13, 13A, 13C packet processing unit
14 flow table
20, 20A, 20B control apparatus (controller)
21 communication apparatus control unit
22, 22B synchronization unit
111 processing content storage unit
112 channel state detection unit

Claims

A communication apparatus, comprising:
a packet processing unit processing a packet(s) based on a packet handling operation set by a control apparatus;
an emulation unit creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and
a synchronization control unit notifying the control apparatus of a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus.
The communication apparatus according to claim 1, further comprising:
a channel state detection unit detecting state of a channel between the communication apparatus and the control apparatus;
wherein the emulation unit creates and sets the packet handling operation while a channel between the communication apparatus and the control apparatus is disconnected.
The communication apparatus according to claim 1 or 2;
wherein the emulation unit creates and sets the packet handling operation in accordance with an instruction from the control apparatus.
The communication apparatus according to any one of claims 1 to 3;
wherein, instead of the control apparatus, the emulation unit creates a packet handling operation for switching over a destination communication network based on a per-flow basis.
The communication apparatus according to any one of claims 1 to 4;
wherein, instead of the control apparatus, the emulation unit creates a packet handling operation for switching over a destination communication network in accordance with a predetermined access policy.
The communication apparatus according to claim 5;
wherein an access policy supplied from the control apparatus is used as the predetermined access policy.
The communication apparatus according to claim 5 or 6;
wherein the predetermined access policy is an access policy for switching over a destination from a mobile communication network to a wireless LAN in a stepwise manner based on a cumulative communication amount of the communication apparatus.
The communication apparatus according to any one of claims 1 to 7;
wherein the emulation unit is configured by causing an application program installed from a predetermined server to operate on the communication apparatus.
A control apparatus, comprising:
a packet handling operation setting unit setting a packet handling operation in a communication apparatus comprising: a packet processing unit processing a packet(s) based on a set packet handling operation; an emulation unit creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and a synchronization control unit notifying the control apparatus of a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus; and
a synchronization unit synchronizing a packet handling operation for the communication apparatus with a packet handling operation for the communication apparatus, among packet handling operations for respective communication apparatuses managed on a side of the control apparatus itself, based on a processing content executed by the emulation unit supplied from the communication apparatus.
The control apparatus according to claim 9;
wherein the synchronization unit instructs the communication apparatus to create the packet handling operation.
The control apparatus according to claim 10, further comprising:
a network state monitoring unit monitoring state of a network to which the communication apparatus is connected or a load state measurement unit measuring state of load of the control apparatus itself;
wherein, when traffic of the network to which the communication apparatus is connected exceeds a predetermined level or when the state of load of the control apparatus exceeds a predetermined level, the synchronization unit instructs the communication apparatus to create the packet handling operation.
The control apparatus according to any one of claims 9 to 11;
wherein the control apparatus transmits an access policy for creating a packet handling operation for switching over a destination communication network to the emulation unit of the communication apparatus.
The control apparatus according to claim 12;
wherein the access policy is an access policy for switching over a destination from a mobile communication network to a wireless LAN in a stepwise manner based on a cumulative communication amount of the communication apparatus.
A communication system, comprising:
a communication apparatus comprising: a packet processing unit processing a packet(s) based on a set packet handling operation; an emulation unit creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of a control apparatus; and a synchronization control unit notifying the control apparatus of a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus; and
a control apparatus comprising: a packet handling operation setting unit setting a packet handling operation in the communication apparatus; a synchronization unit synchronizing a packet handling operation for the communication apparatus with a packet handling operation for the communication apparatus among packet handling operations for respective communication apparatuses managed on a side of the control apparatus itself, based on a processing content supplied from the synchronization control unit of the communication apparatus.
A packet processing method, comprising steps of:
causing a communication apparatus, including a packet processing unit that processes a packet based on a packet handling operation set by a control apparatus, to create a packet handling operation and set the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and
causing the communication apparatus to notify the control apparatus of a processing content executed by an emulation unit while the emulation unit is operated instead of the control apparatus.
A communication apparatus control method, comprising steps of:
causing a control apparatus, comprising: a packet handling operation setting unit setting a packet handling operation in a communication apparatus that includes: a packet processing unit processing a packet(s) based on a set packet handling operation; an emulation unit creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and a synchronization control unit notifying the control apparatus of a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus to instruct the emulation unit of the communication apparatus, to create the packet handling operation; and
causing the control apparatus to synchronize a packet handling operation for the communication apparatus with a packet handling operation for the communication apparatus among packet handling operations for respective communication apparatuses managed on a side of the control apparatus itself based on a processing content supplied from the synchronization control unit of the communication apparatus.
A program, causing a computer, included in a communication apparatus comprising a packet processing unit processing a packet(s) based on a packet handling operation set by a control apparatus, to execute processes of:
creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and
notifying the control apparatus of a processing content executed by an emulation unit while the emulation unit is operated instead of the control apparatus.
A program, causing a computer, included in a control apparatus comprising: a packet handling operation setting unit setting a packet handling operation in a communication apparatus that includes: a packet processing unit processing a packet(s) based on a set packet handling operation; an emulation unit creating a packet handling operation and setting the packet handling operation in the communication apparatus itself in response to a certain event, instead of the control apparatus; and a synchronization control unit notifying the control apparatus of a processing content executed by the emulation unit while the emulation unit is operated instead of the control apparatus, to execute processes of:
instructing the emulation unit of the communication apparatus to create the packet handling operation; and
synchronizing a packet handling operation for the communication apparatus with a packet handling operation for the communication apparatus among packet handling operations for respective communication apparatuses managed on a side of the control apparatus itself, based on a processing content executed by the emulation unit and supplied from the communication apparatus.