KR20130101966A - Router based on core score and method for establishing core score and providing/searching contents thereof - Google Patents

Abstract

A method of setting a core score of a router in a Content-Centric Network (CCN), further comprising: setting a core score according to proximity to a core, and transmitting the set core score to one or more neighboring routers. Include.

Description

Core score-based routers and methods for setting core scores in routers and providing content information / route {{Router based on Core Score and Method for Establishing Core Score and Providing / Searching Contents}

The present invention describes an apparatus and method for implementing a control plane based on a core score for a content query and transmission in a content-centric network (CCN).

Recently, studies on new architectures for the future Internet are actively underway. Among them, a representative example is a content-centric network (CCN).

CCN technology, a technology proposed by Van Jacobson of PARC, is a new Internet architecture technology that uses data names to perform data transfer over a network instead of the current Internet structure using IP.

Content transmission in the CCN is performed through an Interest packet in which a content name desired by the user is described, and a Data Packet responded by a node holding data requested by the user. At this time, the action of determining which node the interlist packet is to be transmitted is called routing. The router receiving the interlist packet forwards the received interlist packet using a forwarding information base (FIB). That is, when the name of the interlist packet is found in the FIB item, the interlist packet is delivered to the next node specified in the FIB. On the other hand, in the case of a transmission path of a data packet, since the reverse order of all nodes traversed until the interlist packet arrives at the content, no separate routing is necessary.

However, a typical CCN router extends a routing protocol such as Open Shortest Path First (OSPF) to configure the FIB as described above. The role of the control plane in a typical network equipment is to install meta-information at each router in the network for packet transmission. Thus, it can be said that a typical CCN router uses a control plane based on a routing protocol such as OSPF. However, using a distributed routing protocol such as OSPF, it takes time for the content location information to propagate all over the network. This problem is a limitation in supporting the mobility of the content.

The present invention provides an apparatus and method for rapidly propagating content location information to a network without using a distributed routing protocol such as OSPF.

The present invention relates to a method for setting a core score of a router in a content-centric network (CCN), the method comprising: setting a core score according to proximity to a core, and transmitting the set core score to one or more neighboring routers. It further comprises a step.

The present invention provides a method in which a router provides content information based on a core score in a content-centric network (CCN), the method comprising: generating a register message including information of content stored by the router; Sending the generated register message to one or more routers having a core score value that is greater than or equal to its core score value.

The present invention provides a method for a router in a content-centric network (CCN) to retrieve content information based on a core score, receiving an Interest Packet from one or more neighboring routers, And sending the Interest Packet to one or more routers having a core score greater than or equal to the core score.

The present invention is a core score based router, the core score setting unit for setting the core score according to the proximity to the core, and a core score transceiver for transmitting the set core score to one or more neighboring routers.

Unlike the conventional CCN control plane, the present invention can implement a CCN router simply because interlist-data packet transmission is possible without a distributed routing protocol such as OSPF. In addition, according to the configuration of the present invention can reduce the number of FIB items installed in the network it is possible to ensure a higher scale scalability (scalability).

In addition, according to the configuration of the present invention, when the location of the content moves, the content service can be resumed only by sending a register packet once in the moved CCN router, it is easier to support data mobility than when using OSPF Do.

1 is a diagram illustrating the structure of two packets used in a CCN.
2 is an internal configuration diagram of a CCN router using a core score according to an embodiment of the present invention.
3 is a diagram illustrating a configuration of a CCN in which a core score is set according to an embodiment of the present invention.
4 is a flowchart illustrating a core score setting method according to an embodiment of the present invention.
5 is a flowchart illustrating a content information providing method based on a core score according to an exemplary embodiment.
6 is a flowchart illustrating a content search method based on a core score according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

In the following description of the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the gist of the embodiments of the present invention, the detailed description thereof will be omitted.

Terms used throughout the specification are terms defined in consideration of functions in the embodiments of the present invention, and may be sufficiently modified according to the intention, custom, etc. of the user or operator, and the definitions of these terms are used throughout the specification of the present invention. It should be made based on the contents.

1 is a diagram illustrating the structure of two packets used in a CCN.

In a content-centric network (CCN), communication between end terminals is performed by using an Interest Packet and a Data Packet shown in FIG. 1. The user who wants a specific content broadcasts an Interest Packet in which the desired Content Name is described as shown in FIG. 1 to the CCN. The router that receives the Interest Packet delivers the received Interlist Packet using the Forwarding Information Base (FIB). That is, when the name of the Interest Packet is found in the FIB item, the Interest Packet is transmitted to the next node specified in the FIB. When a router having content that matches a content name included in an Interest Packet receives it, the router receives the data packet as shown in FIG. 1 in the reverse direction of the path of the Interest Packet. Packet).

However, a typical CCN router extends a conventionally used routing protocol such as Open Shortest Path First (OSPF) to configure the FIB as described above. The role of the control plane in a typical network equipment is to install meta-information at each router in the network for packet transmission. Therefore, it can be said that a typical CCN router uses a control plane based on a routing protocol such as Open Shortest Path First (OSPF). However, when using a distributed routing protocol such as Open Shortest Path First (OSPF), it takes time for the content location information to propagate all over the network. This problem is a limitation in supporting the mobility of the content.

Therefore, the present invention is characterized by setting and using a core score (core score) for all CCN routers installed in the network. Here, the core score is a value representing how close the core of the CCN router is to the core of the network. Next, an apparatus and method for providing content information using the core score will be described with reference to FIGS. 2 to 6.

2 is an internal configuration diagram of a CCN router using a core score according to an embodiment of the present invention.

Referring to FIG. 2, the router includes a storage unit 110, a core score DB 120, and a controller 130.

In detail, the storage unit 110 includes a contents store 111, a pending interest table (PIT) 112, and a forwarding information base (FIB) 113. .

The contents store 111 may be configured in a table form including a name and data of the content so as to identify the content. The controller 130 of the router first looks up its own content store 111 to determine whether it owns the content indicated by the Interest Packet.

Pending Interest Table (PIT) 112 is information for indicating that the Interest Packet (Interest Packet) has exchanged the received Interest file and the corresponding Interlist file for the transmission of the Date Packet. Save it.

The forwarding information base (FIB) 113 stores the location of the next router to forward the Interest Packet when the corresponding content is not found in the content store 111. Therefore, if the content store 111 does not find the corresponding content, the controller 130 searches the forwarding information base (FIB) 112 to determine where to forward the Interest Packet.

The core score DB 120 stores its core score and core score information of neighboring routers. As described above, the core score is a value representing how close the core of the CCN router is to the core of the network.

In detail, the controller 130 may include a core score setting unit 131, a core score transmitting / receiving unit 132, a register message generating unit 133, a register message transmitting and receiving unit 134, and an interlist packet transmitting and receiving unit 135. Include.

The core score setting unit 131 sets a core score indicating the degree of proximity of the core of the network of the router. According to the present invention, all routers installed in the network have a core score. According to one embodiment, if the value of the core score is large, it may be set to be close to the core. However, this is only an embodiment and the present invention is not limited thereto. That is, the smaller the core score value may be set to be closer to the core. In addition, the core score may be set automatically or may be set manually.

In the case of automatic configuration, the core score may be calculated based on the link bandwidth of the CCN router. For example, consider a case where the CCN router has two 100 Mbps links and two 10 Mbps links. The maximum bandwidth is first multiplied by the number of maximum bandwidth links 2 (200 in this example) and the remaining bandwidth 100 is summed therein. As a result, the CCN router has a core score of 300.

3 is a diagram illustrating a configuration of a CCN in which a core score is set according to an embodiment of the present invention.

Referring to FIG. 3, the alphabet displayed on each router is a name of a corresponding router, and is arbitrarily displayed to help understanding, and the present invention is not limited thereto. The value in parentheses next to the router's name is the value of that router's core score.

Referring back to FIG. 2, the core score transceiver 132 transmits the core score information set to itself to the neighboring routers, and stores the core score information transmitted from the neighboring routers to the core score DB 120. This will be described in more detail with reference to FIG. 4 below.

The register message generator 133 generates a register message for transmitting location information of the content. The register message contains a value indicating the name of the content, the location of the content and the distance to the content. The distance to the content indicates how many routers the content can be found through. For example, the distance value is 1 when the corresponding content can be found in the neighboring router, and the distance value is 2 when the corresponding content can be found in the neighboring router of the neighboring router.

The register message generated by the register message generating unit 133 indicates information about the content stored in its own content store 111, so the position of the content is itself and the distance value is one. This is because the neighboring router that will receive the register message has the corresponding content in the next node.

The register message transceiver 134 transmits the register message generated by the register message generator 133 to neighbor routers having a core score equal to or greater than that of the register message.

In addition, when the register message transceiver 134 receives a register message from a neighboring router, the register message transceiver 134 converts and records in FIB which router the content recorded in the register message is. In this case, when more than one register message for a specific content is received, all of the corresponding information may be converted into FIB and stored. However, when receiving a register message that can be replaced with the same contents as the existing FIB item, that is, if the register message is not new, the message is dropped.

The register message transmitting / receiving unit 134 generates a new register message for the register message recorded in the FIB, and the router receives the register message to the CCN router having a core score equal to or greater than its own. send. The router that sent the register message to itself should not be sent even if the core score is the same.

For example, referring to FIG. 3, router B records the fact that content X is in A and the distance to the content is one. Router B sends to router D, writing a register message that content X can be found in B, and if it is found in B, the distance to the content is two. This procedure is repeated until no router with the same or higher core score is found.

On the other hand, CCN routers that want to use the content registered in the CCN network finds the content using the Interest Packet as before.

Referring to FIG. 2, the interlist packet transmission / reception unit 135 searches for a terminal including content requested by the received Interlist packet. The interlist packet transmitter / receiver 135 first searches its own content store 111 to determine whether it owns the content indicated by the Interest Packet. Here, the interlist packet may be transmitted to various network devices (eg, various terminals, access points, routers, etc.) connected to the corresponding network.

However, according to the present invention, core scores are used together instead of relying only on FIB when delivering Interest Packets to a next CCN router.

In other words, the CCN router that wants to use the content creates and transmits an Interest Packet, but if there is no FIB for the content, the CCN router unconditionally transmits the Interest Packet to all routers having a high core score. . If there is an FIB, the interlist packet is transmitted in the direction of the content to be found through the FIB.

Referring to FIG. 3, when the router K makes and transmits an Interest Packet, the FIB for X is not registered in the Router K. Therefore, the Router K transmits the Interest Packet to a router having a high core score among the adjacent routers. send. I corresponds to that. If a router with a higher core score cannot be found, it will abandon sending the interlist and determine that the content cannot be found.

When receiving the Interest Packet, the router checks whether there is the corresponding content. Then, the router makes a data packet and responds to the requested content as in the conventional CCN networking method. For example, Router F corresponds to this diagram. If there is no content in the router that received the Interest Packet, follow the procedure below.

That is, if there is no FIB for the content, the router that receives the Interest Packet transmits the Interest Packet to all CCN routers having a higher core score. For example, in FIG. 3, when the router I receives the Interest Packet for X, since the FIB does not exist, the Router I relays the Interest Packet to the Router D having a higher core score. On the other hand, if there is an FIB, the Interest Packet is transmitted in the direction indicated by the corresponding FIB. When the router D receives an Interest Packet for X, the Router D relays the Interest Packet to the direction indicated by the corresponding FIB, that is, the Router B or E. Only one of the B and the E may relay the Interest Packet, or all of them. If only one of the two relays, the distance value may be shorter, or may be transmitted to a router that first registers a content location or a router that is later registered.

In the present invention, it is assumed that the method to be taken can be adjusted through the router setting. In the above embodiment, it is assumed that the interlist is relayed according to the registered FIB item for the sake of simplicity. Note that it is desirable to transmit to all routers in order to support the mobility of the data. Even if it transmits to all routers, the method proposed in the present invention works without any problem. On the other hand, when there is no FIB and a CCN router having a higher core score than itself cannot be found, the Interest Packet is dropped without further relaying.

According to the present invention, unlike when using a routing protocol, the FIB is installed only on the path from the location of the content to the router close to the core. This reduces the number of FIB entries that must be installed on the network.

It also simplifies router implementation by eliminating the need for global routing protocols such as OSPF. However, if a routing protocol such as OSPF is not used, a problem may arise that it may be difficult to monitor information about what content is located anywhere in the network.

To overcome this problem, place a monitoring server with a higher core score next to the router with the highest core score, and set up to receive register messages but not act as a relay router for the Interest Packet. will be. That way, the monitoring server can easily see which content is on which CCN router.

4 is a flowchart illustrating a core score setting method according to an embodiment of the present invention.

Referring to FIG. 4, the router sets its core score in step 410. As described above, the core score is a value representing how close the core of the CCN router is to the core of the network. According to the present invention, all routers installed in the network have a core score. According to one embodiment, if the value of the core score is large, it may be set to be close to the core. However, this is only an embodiment, and the present invention is not limited thereto. That is, the smaller the core score value may be set to be closer to the core. In addition, the core score may be set automatically or may be set manually. In the case of automatic configuration, the core score may be calculated based on the link bandwidth of the CCN router.

In operation 420, the router transmits the core score set to itself to the neighboring router. In operation 430, the router stores the core score transmitted from the neighbor router in the core score DB 120.

5 is a flowchart illustrating a content information providing method based on a core score according to an exemplary embodiment.

Referring to FIG. 5, in step 510, the router generates a register message including information of content stored in the router. The register message contains a value indicating the name of the content, the location of the content and the distance to the content. The distance to the content indicates how many routers the content can be found through. For example, the distance value is 1 when the corresponding content can be found in the neighboring router, and the distance value is 2 when the corresponding content can be found in the neighboring router of the neighboring router. Then, the generated register message is transmitted to neighboring routers, but only to routers having a core score of their own.

Therefore, in step 520, the router determines whether a router having a core score equal to or greater than its core score exists.

If there is a router having a core score equal to or greater than its core score as a result of the determination in step 520, the router transmits the register message generated in step 530 to a neighbor router having a core score equal to or greater than its core score.

However, if there is no router with a core score equal to or greater than its core score as a result of the determination in step 520, the flow proceeds to step 540.

In step 540, the router determines whether the content information held by the router has changed.

As a result of the determination in step 540, if the content information owned by the router is changed, the router returns to step 510 and performs register generation.

As a result of the determination in step 540, when the content information held by the user is not changed, the router determines whether a new register message is received in step 550.

As a result of the determination in step 550, when the new register message is received, the router stores information of the new register message received in step 560. That is, it stores what content is stored in the router at what distance.

In operation 570, the router generates a register message in which the content distance information is modified. That is, since the content distance information recorded in the received new register message means the content distance between the router in which the content is stored and the content, the content distance information should be modified to transmit the new register message to the neighboring router. That is, the content distance information should be increased by one more.

In step 520, the router transmits the modified register message to the neighbor router having a core score equal to or greater than its core score.

6 is a flowchart illustrating a content search method based on a core score according to an embodiment of the present invention.

Referring to FIG. 6, the router receives an Interest Packet in step 610. In step 620, the router first searches its own content store 111 to determine whether it owns the content indicated by the Interest Packet.

If the requested content exists in the Interest Packet as a result of the determination in step 620, the router generates a data packet including the requested content in step 630 and transmits it in the reverse direction of the requested path.

However, if the requested content does not exist in the Interest Packet as a result of the determination in step 620, the router determines whether the FIB exists for the corresponding content in step 640.

If the FIB of the corresponding content exists as a result of the determination in step 640, the router transmits an Interest Packet according to the FIB in step 650.

However, if it is determined in step 640 that there is no FIB for the corresponding content, the router transmits an Interest Packet to the router having a high core score.

That is, in step 660, the router determines whether there is a router having a core score equal to or greater than its core score.

If a router having a core score equal to or greater than its core score exists in step 660, the router transmits an Interest Packet to a neighbor router having a core score equal to or greater than its core score in step 670.

However, if there is no router with a core score equal to or greater than its core score as a result of the determination in step 660, the router discards the Interest Packet.

Claims (20)

In a method for setting a core score of a router in a content-centric network (CCN),
Setting a core score according to proximity to the core,
And transmitting the set core score to one or more neighboring routers.
The method of claim 1, wherein the core score is
A method of setting a core score characterized in that the closer to the core has a larger value.
The method of claim 1,
And storing the core scores sent from one or more neighboring routers.
In a content-centric network (CCN), the router provides content information based on the core score,
Generating a register message containing information of contents stored by the router itself;
And transmitting the generated register message to one or more routers having a core score value that is greater than or equal to a core score value thereof.
5. The method of claim 4, wherein the register message is
And a value representing a name of the content, a location of the content, and a distance to the corresponding content.
The method of claim 4, wherein the generating step
And modifying the register message as the content information owned by the user is changed.
In a content-centric network (CCN), the router provides content information based on the core score,
Receiving a register message from one or more neighboring routers;
Storing information in the received register message;
Modifying content distance information of the received register message;
And transmitting the modified register message to a neighbor router having a core score equal to or greater than its core score.
8. The method of claim 7,
Determining whether the received register message is new;
And if the register message is new, performing the step of transmitting the core score based content information.
In a method for retrieving content information based on a core score in a router in a content-centric network (CCN),
Receiving an Interest Packet from at least one neighboring router;
And transmitting the Interest Packet to one or more routers whose core score is greater than or equal to the core score. The method of claim 9,
After receiving the Interest Packet, searching whether the user owns the content indicated by the Interest Packet;
If the requested content exists in the Interest Packet, the core score further comprises the step of generating a data packet including the content and transmitting the Interlist Packet to the router that transmitted the Interlist Packet. Based content information retrieval method.
The method of claim 9,
Determining whether a forwarding information base (FIB) exists for the corresponding content;
And transmitting the Interest Packet in the routing direction indicated by the FIB when the FIB exists for the corresponding content.
The method of claim 9,
And if there is no router with a core score that is greater than its core score, the router further comprises discarding an Interest Packet.
A core score setting unit that sets a core score according to the proximity to the core,
And a core score transceiver for transmitting the set core score to one or more neighboring routers.
The method of claim 13, wherein the core score transceiver unit
A core score based router, storing core scores transmitted from one or more neighboring routers.
The method of claim 13,
A register message generating unit for generating a register message containing information of contents stored in the same;
And a register message transceiver for transmitting the generated register message to one or more routers having a core score value that is greater than or equal to the core score value thereof.
The register message generating unit of claim 15, wherein the register message generating unit
Core score based router, characterized in that for changing the register message as the content information owned by the change.
The register message transmitting and receiving unit of claim 15,
Store the register message received from at least one neighboring router, modify the content distance information of the received register message, and transmit the modified register message to the neighboring router having a core score equal to or greater than its core score. Score based router.
The register message transmitting and receiving unit of claim 15,
And if the received register message is new, send the register message to a neighboring router.
The method of claim 13,
Receiving the Interest Packet (Interest Packet) from one or more neighboring routers, and further comprises an interlist packet transceiver for transmitting the Interest Packet (Interest Packet) to one or more routers whose core score is greater than the core score; A core score based router.
20. The apparatus of claim 19, wherein the interlist packet transceiver is
And if there is no router with a core score greater than or equal to its core score, the router discards the Interest Packet.

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