KR20110037860A - Method of Providing Forwarding Information and Job Information in Flow-Based Network Device - Google Patents

Abstract

In order for the network device to provide dynamically updated information in the flow based network environment, the network device obtains the first information and the second information from the flow table in the network device based on the state information for any flow. If it is determined that an update has occurred in the first information and the second information obtained based on the route ID of the serial information, the flow table is updated to provide updated information.

Description

Method for applying dynamic updates of forwarding and QoS rules on flow based network devices}

The present invention relates to a method of providing forwarding information and QoS information in a flow-based network device.

In general, in a flow-based network apparatus, when the first packet of an arbitrary flow is input to the system, acquisition of forwarding information and QoS processing information is required for flow processing. In the case of IP, forwarding information may be extracted from various tables for determining the destination of an IP packet, including an IPv4 or IPv6 forwarding table. On the other hand, the QoS processing information may be extracted from a plurality of traffic classification tables.

Each flow may be mapped to a plurality of rules existing in the plurality of traffic classification tables, and when mapped to the plurality of rules, information of the rule having the highest priority is used as information on the final flow. The extracted information is stored for each flow in a flow table capable of storing state information about the flow.

As described above, packets that are continuously input after the first packet input for the flow in which the forwarding information and the QoS processing information are stored in the flow table are subjected to packet forwarding and QoS processing based on the forwarding information and the QoS processing information stored in the flow table. Therefore, there is a problem that forwarding information and QoS processing information updated after the first packet is input do not apply to the corresponding flow.

Accordingly, the present invention provides a method of providing forwarding information and QoS information in a flow-based network device that allows forwarding information and QoS processing information to be dynamically applied to a corresponding flow.

A method for providing information in a flow-based network environment by a network device, which is one feature of the present invention for achieving the technical problem of the present invention,

Obtaining first information and second information from a flow table in the network device based on state information for any flow; Determining whether an update has occurred in the obtained first information and second information based on the route ID of the serial information; And if it is determined that an update has occurred in the first information and the second information, updating the flow table.

Apparatus for providing information in a flow-based network environment that is another feature of the present invention for achieving the technical problem of the present invention,

A table storage unit for processing packets for a flow and storing information for processing update information; And a forwarding engine unit to determine whether an input packet is a first input packet and to update the first information and the second information based on information previously stored in the table storage unit according to a state of the input packet. do.

According to an embodiment of the present invention, when update of new forwarding information and QoS information occurs after the flow information is set once in the flow-based network device, the dynamically updated information may be applied and used.

1 is an exemplary diagram of a flow-based network device capable of applying dynamic forwarding information and QoS rule updates according to an embodiment of the present invention.
2 is an exemplary diagram of a flow table according to an embodiment of the present invention.
3 is an exemplary diagram of a forwarding table according to an embodiment of the present invention.
4 is an exemplary diagram of a traffic classification table according to an embodiment of the present invention.
5 is an exemplary diagram of a route update verification table according to an embodiment of the present invention.
6 is an exemplary diagram of a QoS rule update verification table according to an embodiment of the present invention.
7 is a flowchart illustrating a method of providing forwarding information and QoS information according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless otherwise stated.

Hereinafter, a method of dynamically providing forwarding information and QoS information in a flow-based network device according to an embodiment of the present invention will be described with reference to the drawings.

1 is an exemplary diagram of a flow-based network device capable of applying dynamic forwarding information and QoS rule updates according to an embodiment of the present invention.

In general, a flow consists of 5-tuple information. However, depending on the setting of the operator or the characteristics of the application, other header information of the IP packet may be added or may be configured without subtracting some fields from the 5-tuple information. This means that as an embodiment, a flow may be defined with only one IP source address. In this case, the 5-tuple information generally includes an IP source address, an IP destination address, a protocol number, source transport layer port information, and destination transport port information.

As shown in FIG. 1, the flow-based network apparatus processing a packet according to dynamic forwarding information update and QoS rule update application includes a forwarding engine unit 100, a flow table storage unit 200, and a forwarding table storage unit 300. ), A traffic classification table storage unit 400, a route update verification table storage unit 500, and a QoS rule update verification table storage unit 600.

When the forwarding engine unit 100 receives a packet for an arbitrary flow into the network device, the forwarding engine unit 100 determines whether the input packet is the first input packet or not. In order to confirm whether the input packet is the first packet, the forwarding engine unit 100 uses the state information of the flow maintained in the flow table of the flow table storage unit 200.

That is, if the state information of the flow is not in the flow table of the flow table storage unit 200, it means that the input packet is the first packet. Here, the state information is described using an example of a serial number assigned to a packet, but is not necessarily limited to this.

In other words, the forwarding engine unit 100 checks the state information of the packet, searches the flow table stored in the flow table storage unit 200, and then checks whether the checked state information is stored in the flow table. If the input packet is the first packet, the state information is not stored in the flow table. If the input packet is not the first packet, the state information is stored in the flow table.

In this case, the flow table stored in the flow table storage unit 200 will be described with reference to FIG. 2 first.

2 is an exemplary diagram of a flow table according to an embodiment of the present invention.

As shown in FIG. 2, a flow table according to an embodiment of the present invention includes a tree data structure, a hash data structure, a direct table data structure, It may have various types of data structures such as TCAM (Ternary CAM), or a structure in which various data structures are merged.

A flow table according to an embodiment of the present invention includes forwarding information and QoS information for processing a packet for an arbitrary flow. It also stores state information about the flow.

In this case, the forwarding information means destination information to which a packet is to be transmitted, and includes next hop information. The next hop information enables processing of forwarding updates dynamically according to an embodiment of the present invention, and the next hop information includes a route ID and a route update serial number.

QoS information is QoS information to be applied to send a packet to the destination. Traffic classification rule ID applied to the flow, traffic classification rule update serial number applied, traffic type, traffic transmission speed, packet bandwidth information, priority information. It includes information such as.

Referring to FIG. 1, the forwarding engine unit 100 is continuously described. If the state information is not stored in the flow table, the packet for the input flow is first input. Therefore, the forwarding engine unit 100 searches for the forwarding table and the traffic classification table stored in the forwarding table storage 300 and the traffic classification table storage 400, respectively, and acquires the forwarding information and the QoS information, and then flows the flow. The information obtained along with the packet status information is stored and updated in the table.

To this end, it will be described assuming that there is already some dictionary information in the forwarding table and traffic classification table. That is, it is assumed that the forwarding information and the QoS information are already set up in some way, whether the information is obtained dynamically by the routing protocol or the information directly set by the operator.

Here, the forwarding table and the traffic classification table stored in the forwarding table storage 300 and the traffic classification table storage 400 will be described first with reference to FIGS. 3 and 4.

3 is an exemplary diagram of a forwarding table according to an embodiment of the present invention, and FIG. 4 is an exemplary diagram of a traffic classification table according to an embodiment of the present invention.

As illustrated in FIG. 3, the forwarding table may have various types of data structures such as a tree structure, a hash structure, a direct table, a tertiary content addressable memory (TCAM), or a structure in which various data structures are merged. In the embodiment of the present invention, the software configuring the forwarding information allocates a unique route ID for each route. To this end, it will be described on the assumption that the software block (not shown) is included in the forwarding table storage unit 300.

That is, when one route is added, a unique ID for each route is assigned, and in the case of forwarding information, software provided to reflect routing information obtained by the routing protocol as forwarding information allocates a route ID. Since the software is not necessarily implemented in any one form and may be changed according to the system design, the limitation of the software will be omitted in the embodiment of the present invention.

If the forwarding information for that route changes, use the same route ID instead of assigning a new route ID, and simply increase the route update serial number for that route. If a route update occurs, update the route update serial number in the route update verification table and the forwarding table to one incremented value. In this case, updating of the serial number may be selectively applied or not applied to the forwarding table. In the embodiment of the present invention, the number of bits for representing the route ID must be large enough to represent the total number of route entries that can be provided by the system.

The forwarding table shown in FIG. 3 shows a forwarding table having a multi-bit tree structure. When the forwarding table has a structure in which route IDs are assigned to each route, the forwarding table may satisfy an object according to an embodiment of the present invention. Here, if the route update serial number is not given to the forwarding table, the route update serial number may use a value given in the route update verification table of FIG. 5.

Next, the traffic classification table illustrated in FIG. 4 may have various data structures such as a tree structure, a hash structure, a direct table, a TCAM, or a structure in which various data structures are merged. In addition, a QoS software block (not shown) according to an embodiment of the present invention allocates a unique QoS rule ID for each QoS rule. That is, when one QoS rule is added, a unique ID for each QoS rule is assigned. In this case, the QoS software block is a block for reflecting configuration information in an actual table when the operator sets it through a command line interface (CLI). The embodiment of the present invention does not limit the QoS software block to any one type. .

The number of bits for representing the QoS rule ID should be large enough to express the total number of QoS rules that can be provided by the system. 4 is a diagram illustrating the configuration of a traffic classification table in an embodiment of the present invention, and includes a plurality of traffic classification tables. A plurality of traffic classification tables store the rules for each QoS rule ID and share the rule tables with each other.

That is, the final result of each traffic classification table has a pointer to the QoS rule table. However, this is an example according to an embodiment of the present invention, and the traffic classification table may be generated in any form of data structure capable of storing QoS rules for each QoS rule.

1, the forwarding information according to the embodiment of the present invention is information such as a route ID, a route update serial number, and the like assigned to each forwarding entry as shown in FIG. It includes. If the route update serial number does not exist in the forwarding table, the current RUSN value may be obtained by searching the route update verification table stored in the route update verification table storage unit 500 using the route ID as a key value.

QoS information according to an embodiment of the present invention includes a QoS rule ID assigned to a QoS rule, a QoS rule update serial number, and the like. If the QoS rule update serial number is not given in the traffic classification table, the QoS rule update validation table stored in the QoS rule update validation table storage unit 600 is used as the key value of the QoS rule ID to retrieve the current QUSN value. You can get it. According to the forwarding information and the QoS information thus obtained, the forwarding engine unit 100 performs QoS processing and packet forwarding.

In this case, the route update verification table and the QoS rule update verification table will be described first with reference to FIGS. 5 and 6.

5 is an exemplary diagram of a route update verification table according to an embodiment of the present invention, and FIG. 6 is an exemplary diagram of a QoS rule update verification table according to an embodiment of the present invention.

First, as shown in FIG. 5, the route update verification table may have various types of data structures such as a hash structure, a direct table, a TCAM, or a structure in which various data structures are merged. In addition, the route update verification table according to the embodiment of the present invention allows the route update serial number value to be increased whenever an update is generated for each route ID.

In this case, when a large number of routes causes a problem such as a search speed, the route ID is shortened to a smaller number of bits, so that multiple routes can share the same route update serial number.

Meanwhile, the QoS rule update verification table may have various types of data structures such as a hash structure, a direct table, a TCAM, or a structure in which various data structures are merged as shown in FIG. 6. The QoS update serial number (QUSN) value is increased whenever an update to the QoS rule is generated for each QoS rule ID.

If the number of QoS rules causes a problem such as a search speed, the QoS rule ID is shortened to a small number of bits so that multiple actual QoS rule IDs can share the same QoS rule update serial number.

A method of dynamically providing forwarding information and QoS information in such a flow-based network device will be described with reference to FIG. 7.

7 is a flowchart illustrating a method of providing forwarding information and QoS information according to an embodiment of the present invention.

As shown in FIG. 7, when a packet for an arbitrary flow is input to the flow-based network apparatus (S100), the forwarding engine unit 100 checks whether the input packet is the first input packet or not (S110). ). The method of determining whether the first packet is input is as follows. Information of each flow is maintained in the flow table, and information of the flow, that is, state information is stored in the flow table.

That is, when a packet is input, the forwarding engine unit 100 checks whether there is a corresponding flow because state information regarding the packet exists in the flow table. If the status information of the flow is not in the flow table during this process, it means that the flow has not been created before, and the packet at this time becomes the first packet.

When a packet is first input, since the table of the flow is not stored in the flow table storage unit 200, the forwarding engine unit 100 forwards the table and the traffic classification table storage unit 400. In step S120, forwarding information and QoS information are obtained by searching for a forwarding table and a traffic classification table respectively stored in FIG. In this case, the forwarding and the QoS information for the flow in the flow table may use a method of setting dictionary information through a control message even if it is not the first data packet.

When the forwarding information and the QoS information are obtained through the step S120, the flow table is updated by storing the forwarding information and the QoS information in the flow table 300 together with the state information on the corresponding packet (S130). Then, the forwarding engine unit 100 processes the QoS and performs packet forwarding (S140).

On the other hand, if the input packet is not the first packet of the flow according to the determination of step S110, first, the flow table stored in the flow table storage unit 200 is searched and a matching flow table entry is searched (S150). . Then, the forwarding information and the QoS information stored in the flow table are obtained (S160), and based on this, it is checked whether a forwarding update or a QoS rule update has occurred (S170, S180).

To do this, first, the route update verification table is searched using the route ID value read from the flow table as a key value to confirm the forwarding update. The forwarding engine unit 100 compares the route update serial number value obtained as a result of the search in the route update verification table with the route update serial number value obtained in the flow table.

If the comparison value is different, it is determined that the forwarding information is updated, the searched forwarding table is searched again, the changed forwarding information is found and stored in the flow table again (S190). However, if the compared values are the same, it means that there is no updated forwarding information, and the existing serial number value is used as it is.

When the forwarding update is confirmed in this manner, the forwarding engine unit 100 searches for the QoS rule update verification table using the QoS rule ID value read from the flow table as a key value to confirm the update of the QoS information. Compare the QoS rule update serial number obtained from the QoS rule update verification table with the QoS rule update serial number obtained from the flow table. If the comparison value is different, it is determined that the QoS information has been changed, and the traffic classification table is searched again, the changed QoS information is found and stored in the flow table again (S190).

Using such a procedure, the forwarding information and the QoS information can be dynamically applied in the flow-based network device, thereby facilitating the flow processing.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (12)

In the method for the network device to provide information in a flow-based network environment,
Obtaining first information and second information from a flow table in the network device based on state information for any flow;
Determining whether an update has occurred in the obtained first information and second information based on the route ID of the serial information; And
If it is determined that an update has occurred in the first information and the second information, updating the flow table.
Information providing method comprising a. The method of claim 1,
Before acquiring the first information and the second information,
Determining whether a packet input for the arbitrary flow is a first input packet; And
If the input packet is not the first packet, acquiring the serial information about the packet
Information providing method comprising a. The method of claim 2,
Determining whether the update has occurred,
The first information includes a route ID and a first route update serial number,
Confirming a second route update serial number stored in a route update verification table storage unit in the network device based on the route ID;
Confirming whether the first route update serial number and the second route update serial number are the same;
If the first route update serial number is different from the second route update serial number, confirming that an update has occurred in the first information, and updating the first information in the flow table.
Information providing method comprising a. The method of claim 3,
Determining whether the update has occurred,
The second information includes a QoS rule ID and a first QoS rule update serial number,
Confirming, based on the QoS rule ID, a second QoS rule update serial number stored in a QoS rule update verification table storage in the network device;
Confirming whether the first QoS rule update serial number and the second QoS rule update serial number are the same;
Checking that an update occurs in the second information when the first QoS rule update serial number and the second QoS rule update serial number are different, and updating the second information in the flow table.
Information providing method further comprising. The method of claim 2,
After determining whether it is the first input packet,
If the input packet is a first packet, acquiring first information and second information previously stored in the network device;
Storing and obtaining the obtained first information, second information, and state information about the first packet in the flow table; And
Processing QoS for the Any Flow and Forwarding Packets
Information providing method comprising a. The method of claim 1,
And wherein the first information is forwarding information and the second information is QoS information. In the apparatus for providing information in a flow-based network environment,
A table storage unit for processing packets for a flow and storing information for processing update information; And
The forwarding engine unit determines whether the input packet is the first input packet and updates the first information and the second information based on information previously stored in the table storage unit according to the state of the input packet.
Information providing apparatus comprising a. The method of claim 7, wherein
The table storage unit,
A flow including first and second information for processing packets for any flow and storing route ID, route update serial number, QoS rule ID, QoS rule update serial number, and status information of the flow for the flow A table storage unit;
A forwarding table storage unit including a software block for assigning a unique route ID for each route, and storing first information including a route ID and a route update serial number generated through the software block; And
A traffic classification table storage unit including a QoS software block for allocating a QoS rule ID, and storing second information including a QoS rule ID and a QoS rule update serial number generated through the QoS software block.
Information providing apparatus comprising a. The method of claim 8,
The table storage unit,
A route update verification table storage unit for updating and storing the route update serial number value when an update of the route occurs for each route ID; And
A QoS rule update verification table storage unit for updating and storing the QoS update serial number value when an update to the QoS rule occurs for each QoS rule ID.
Information providing apparatus further comprising. The method of claim 7, wherein
And the QoS information includes at least one or more of a traffic classification rule ID applied to the flow, an applied traffic classification rule update serial number, a traffic type, a traffic transmission rate, bandwidth information of a packet, and priority information. The method of claim 7, wherein
And the first information includes a route ID, a route update serial number, and next hop information. The method of claim 7, wherein
And wherein the first information is forwarding information and the second information is QoS information.

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