KR20120068585A - Route cofiguration method for qos(quality of service) between proxy domains - Google Patents

Abstract

The present invention relates to a path setting method for providing an inter-domain quality assurance service, and more particularly, to a method for providing end-to-end quality assurance service through inter-domain routing based on link state information.
In the QoS routing method between routers located in different domains according to the present invention, a router belonging to a first domain, such as a source router, connected to an external link having the largest available bandwidth to a destination router located in a second domain. Requesting QoS path establishment, requesting QoS path establishment to a router of a second domain connected to an external link by using a representative value of a prestored BGP path vector through a router according to the QoS path establishment request; In response to a QoS routing request from the router in the first domain, it is determined whether the QoS routing with the source router is possible, and the QoS path between the originating router and the router located in the second domain is set or the QoS routing is set to another domain. Requesting.
According to this aspect of the present invention, QoS routing between domains can be efficiently established.

Description

Route cofiguration method for quality of service (QoS) between proxy domains}

The present invention relates to a path setting method for providing an inter-domain quality assurance service, and more particularly, to a method for providing end-to-end quality assurance service through inter-domain routing based on link state information.

Internet routing is divided into intra-domain routing and inter-domain routing depending on the routing area. Intra-domain routing is managed by one administrator, supporting data communication between hosts flowing between data transmission and data exchange equipment within a single domain. In addition, inter-domain routing is managed by independent autonomous system administrators, and supports data communication between hosts through data transmission between hosts and transmission and exchange equipment connecting various areas.

On the other hand, in the past, many studies have been conducted to ensure quality assurance service (hereinafter referred to as QoS), but most studies have been conducted on link state-based intra-domain routing. There is no situation. Therefore, even though intra-domain routing guarantees QoS, if the intra-domain routing does not provide QoS, end-to-end QoS cannot be guaranteed. In other words, QoS guarantee is required in intra-domain routing and inter-domain routing to guarantee end-to-end QoS. However, because BGP (Border Gateway Protocol) actually used in inter-domain routing is based on path vector, It is difficult to guarantee.

The router must manage the link state database to guarantee QoS, and establish a path that satisfies the service requirements based on this. In other words, intra-domain routing operates in one domain, so that the router only needs to manage link information for one domain to guarantee QoS. Therefore, the router is easy to manage and update the link state database because the amount of link state information in the intra-domain routing is small. On the other hand, routing between domains is performed when a source and a destination exist in different domains. In order to guarantee QoS in inter-domain routing that operates when there are at least two different domains as described above, all the link information between the source and the destination, as well as all link information of the domain where the source is located and the destination, are used. You need to know the link information of the domain. Accordingly, the size of the link state database to be managed by the router increases, and the amount of link state update messages for delivering each link information increases, making it difficult to manage and update.

That is, in order to guarantee QoS in inter-domain routing, it is practically difficult for a router to manage link information of all domains, and sending a link state update message to all routers for link state update wastes network system resources. . Accordingly, there is a need for efficient management of link state databases and effective use of network system resources, while ensuring QoS in inter-domain routing.

Meanwhile, a method of calculating a QoS path in conventional inter-domain routing may be divided into a basic method and an existing method. The basic method is to extend the QoS guarantee in the existing intra-domain routing and apply it to the inter-domain routing. The router manages link state information of all domains, and can calculate the QoS path in the inter-domain routing most accurately. In other words, in the inter-domain routing, the QoS path setting method is the same as the intra-domain routing. Since the source router knows the link state information of the entire network configuration, the QoS path can be accurately set with reference to this. However, in this case, since the link state information for the entire network configuration needs to be updated, not only the waste of network system resources caused by the link state update message is caused, but the router has to manage all the link state information. have.

In the case of the existing method, BGP, which is an inter-domain routing protocol based on the existing path vector, is used. As such, in the existing method of using only BGP information for inter-domain routing, the gateway router can know only the abbreviated information such as the reachability and the path vector to other domains through the BGP update message, and the network structure or link state information. Can't. In other words, there is a limit in information exchanged between domains, which makes it difficult to guarantee QoS in inter-domain lighting compared to intra-domain routing.

On the other hand, since it is practically difficult to share all the link information when the domains are different, inter-domain routing in the Internet currently only informs the gateway router of the route vector and reachability by BGP. Therefore, when only BGP information is used for inter-domain routing, it is difficult to establish a path capable of guaranteeing QoS because the source router and the gateway router cannot know the link state of another domain.

The present invention is to solve such a problem, it is an object to enable efficient management of the link state information of the router while ensuring the inter-domain QoS through the present invention.

Furthermore, an object of the present invention is to minimize the consumption of network system resources by a link state update message when providing inter-domain routing based on link state information.

The foregoing technical problem is achieved by the characteristic aspects of the present invention described below. In the QoS routing method between routers located in different domains according to the present invention, a router belonging to a first domain, such as a source router, connected to an external link having the largest available bandwidth to a destination router located in a second domain. Requesting QoS path establishment, requesting QoS path establishment to a router of a second domain connected to an external link by using a representative value of a prestored BGP path vector through a router according to the QoS path establishment request; In response to a QoS routing request from the router in the first domain, it is determined whether the QoS routing with the source router is possible, and the QoS path between the originating router and the router located in the second domain is set or the QoS routing is set to another domain. Requesting.

According to this aspect of the present invention, QoS routing between domains can be efficiently established.

As described above, the present invention enables efficient management of the link state information of the router while guaranteeing the inter-domain QoS, and consumes network system resources by the link state update message when providing inter-domain routing based on the link state information. There is an effect that can be minimized.

1 is a flow chart of a method for setting up inter-domain routing for providing QoS according to an embodiment of the present invention;
2 is an exemplary diagram of link information of a gateway router according to an embodiment of the present invention;
3 is an exemplary diagram illustrating an external link advertisement message according to an embodiment of the present invention;
4 is an exemplary diagram of inter-domain QoS path establishment according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and further aspects of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings. Hereinafter, the present invention will be described in detail so that those skilled in the art can easily understand and reproduce the present invention through these embodiments.

Before describing FIG. 1, the service flow in inter-domain routing will be briefly described. In inter-domain routing, service flows are delivered to other domains through gateway routers. If there are no destinations in the domains, service flows are transferred to the next domain through gateway routers. Therefore, since the link connected to the gateway router is a link that must pass through the inter-domain routing path, the state information of the link becomes important information compared to the state information of other links. Meanwhile, the main link connected to the gateway router may be divided into an external link and an internal link, where the external link is a link connecting different domains (BGP peer link), and the internal link is a remaining link except the external link. Say. The present invention will be described in detail how the gateway manages the state information of the external link to guarantee the inter-domain quality of service (hereinafter referred to as QoS).

1 is a flowchart of a method for configuring inter-domain routing for providing QoS according to an embodiment of the present invention.

As shown in FIG. 1, in response to a QoS routing request from a user, a source router within a first domain obtains main link information having a large representative value among representative values included in main link information associated with an address of a destination router. (100). Here, the main link information includes a path vector capable of moving to the destination router and a representative value which is a minimum bandwidth value available in the path vector. The main link information is generated from the gateway router, and the gateway router transmits the generated main link information to the source router belonging to the same link as itself. In this case, the gateway router may periodically transmit the main link information to the source router or transmit the updated main link information to the source router when the main link information is updated. That is, the gateway router belongs to an external link and receives link information from the gateway router connected to the gateway router. That is, the gateway router connected to the source router receives link information of all gateway routers located between the destination routers as shown in FIG. 2.

2 is a diagram illustrating link information of a gateway router according to an embodiment of the present invention.

As shown, the gateway router manages the available bandwidth of all gateway routers on the external link. That is, the gateway router extends the BGP update message to exchange link information of the gateway router between the gateway routers to store the available bandwidth value 200 of the gateway router and the address 210 of the corresponding gateway router. Accordingly, the gateway router may transmit and receive BGP update messages of the gateway routers on the external link.

On the other hand, the gateway gateway receiving the BGP update message from the gateway routers on the external link is used to provide information of the external domain to each router on the same link in the open shortest path first (OSPF). The external link advertisement message (AS External LSA) is used to transmit to a router belonging to the same link. Here, OSPF solves the difficulties of the RIP and has a new function, and is one of the standard candidates for the multimedia protocol of the Internet. OSPF is a protocol that supports routing with the shortest path by combining routing information with distance information and status information in real time so that the user can set the shortest path in the Internet network. In the OSPF, the external link advertisement message used to provide information of the external domain to each router in the domain is shown in FIG. 3.

3 is an exemplary diagram illustrating an external link advertisement message according to an embodiment of the present invention.

As shown, when the gateway gateway receives the BGP update message from the gateway routers on the external link, the gateway router generates an external link advertisement message including the link path, the address information of the gateway router, and the main link information. Send to router, ie source router. Accordingly, the source router may acquire the main link information having the largest representative value among the representative values included in the main link information related to the address of the destination router through the external link advertisement message.

Meanwhile, when main link information having a large representative value is obtained according to the QoS routing request, the source router determines a first gateway router related to the obtained representative value, and sends a QoS routing request message to the determined first gateway router. Transmit (101, 102). Upon receiving the QoS routing request message, the first gateway router selects an external link by using the representative value of the prestored BGP path vector (103, 104). If the external link is selected, the first gateway router sends 105 a QoS routing request message to the second gateway router in the second domain associated with the selected external link. Thereafter, the second gateway router receives a QoS routing request message from the first gateway router (106), calculates a route from the received QoS routing request message, and the destination router belongs to the second domain associated with the second gateway router. Check (107, 108).

If the check result indicates that the destination router is a second domain to which the second gateway router belongs, the second gateway router establishes a path to the destination router by using the link state information and network configuration information of the prestored second domain to set the QoS path to the destination router. The setup request message is transmitted (109). Accordingly, the destination router receives the QoS path setting request message and sets the source router and the QoS path according to the received QoS path setting request message, thereby completing the inter-domain QoS path setting (110, 111).

On the other hand, if the check result indicates that the destination router is not the second domain to which the second gateway router belongs, the second gateway router transmits the QoS routing request message through the representative value included in the main link information by using the same method as in steps 100 and 101. After determining the third gateway router, the QoS routing request message is transmitted to the determined third gateway router (112,113). Accordingly, when the QoS routing request message is received from the second gateway router, the third gateway router selects an external link connected with itself by using the representative value of the prestored BGP path vector (114 and 115). If the external link is selected, the third gateway router sends a QoS routing request message to the gateway router of another domain associated with the selected external link (116). Accordingly, the gateway router of another domain sets a route to the destination router and transmits a QoS routing request message to the destination router. Accordingly, the destination router sets up the source router and the QoS path according to the received QoS path setting request message, thereby completing the inter-domain QoS path setting (117).

So far, the method of configuring the inter-domain routing for providing QoS has been described in detail. Hereinafter, the present invention will be described through an embodiment of establishing an inter-domain QoS path.

4 is an exemplary diagram of inter-domain QoS path establishment according to an embodiment of the present invention.

As shown, the source router (hereinafter referred to as R1) may establish a QoS path through gateway routers (hereinafter referred to as G1 to G6) in two paths to the destination router (hereinafter referred to as R2). First, G1 and G5 belonging to the same domain as R1 (hereinafter referred to as AS1) store link state information including actual available bandwidth of an external link connected to them as shown in Table 1 below. <Table 1> is an example of link state information including the actual available bandwidth of the external link to which G1 and G5 are connected.

Main link Available Bandwidth G1, G2 30 Mbps G3, G4 40 Mbps G5, G6 20 Mbps

G1 and G5 storing such link state information manage the minimum value of the main link belonging to the path vector together with the existing path vector as a representative value, as shown in <Table 2>. <Table 2> is an example of managing the minimum value of the main link belonging to the path vector together with the existing path vector in G1 and G5 as representative values.

destination Path vector Representative value R2 G1-> G2-> G3-> G4 30 Mbps G5-> G6 20 Mbps

That is, G1 stores and manages the path vectors G1, G2, G3, and G4 to the destination R2 and representative values (30 Mbps) of the main link belonging to the path vectors, and G5 stores the path vectors G5 and G6 to the destination R2. ) And the representative value (20Mbps) of the main link belonging to the path vector. Such G1 and G5 generate and transmit an external link advertisement message as shown in Table 3 to R1 of AS1 to which they belong. <Table 3> is an example of an external link advertisement message transmitted from G1 and G5 to R1.

Gateway router Information to Tell Routers in the Same Domain G1 (G1, R2, 30 Mbps) G5 (G5, R2, 20Mbps)

Receiving the external link advertisement message as shown in Table 3 from G1 and G5, R1 compares the representative value (20Mbps) included in the external link advertisement message received from G1 and G5 according to the QoS routing request. Determine the gateway router with a large representative value. That is, R1 compares the representative values of G1 and G5 and selects a path via G1 if it is determined that the representative value of G1 (30 Mbps) is larger than the representative value of G5 (20 Mbps_). Sending a QoS routing request message, G1 sends a QoS routing request message to G2 with reference to link state information including the actual available bandwidth of the pre-stored external link, so that R1 sends G1-> G2-. The QoS path with R2 is established via> G3-> G4.

So far I looked at the center of the preferred embodiment for the present invention.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

200: bandwidth value 210: gateway router address

Claims (1)

In the QoS routing method between routers located in different domains,
Requesting QoS path establishment to a destination router located in the second domain to a router belonging to the same domain as the source router and having an external link having the largest available bandwidth value;
In response to the QoS routing request, requesting QoS routing to a router of the second domain connected to the external link by using a representative value of a BGP path vector previously stored through the router;
In response to a QoS routing request from the router of the first domain, it is determined whether the QoS routing with the originating router is possible, and the QoS path between the originating router and the router located in the second domain is set or another domain is determined. Requesting QoS path establishment;
QoS routing between domains comprising a.

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