KR100909341B1 - MPL network management system and method - Google Patents

Abstract

According to the present invention, all available paths capable of handling traffic are selected in real time for all network resources, giving a selection probability to all selected available paths, and randomly selecting one path according to the given probability. The present invention relates to an MPLS network management system and a method for selecting the same, wherein an idle facility in the network can be used to immediately cope with a failure of a link without data loss. It has the effect of maximizing the utilization of resources.

Description

System for managing multiprotocol label switching network and method

1 is a block diagram of an MPLS network management system according to the present invention.

2 is a flow chart of a method for selecting an optimal bypass path in accordance with the present invention.

The present invention relates to an MPLS network management system and a method thereof, and more particularly, to select all available paths capable of handling traffic in real time for all network resources, and to provide a selection probability to all selected available paths. The present invention relates to an MPLS network management system and a method for selecting one path at random according to a given probability.

Multiprotocol Label Switching (MPLS) is a two-layer switching technology developed to address the shortcomings of traditional hop-by-hop routing.

The existing routing method uses the routing table information in the router to send the packet to the final destination every time the packet passes through the router. When the packet needs to pass through multiple routers, routing is slow. Due to this, the load of the router itself is increased, quality (bandwidth) is not guaranteed and security is low.

MPLS, on the other hand, is a high-reliability and security technology that selects the best / shortest path for the quality of service within a network composed of routers, configures it as a label switched path (LSP), and transmits packets at high speed through this LSP.

Recently, MPLS has been increasingly introduced into the Internet backbone network worldwide.

In addition to high reliability and security, MPLS features bypass path control, especially as with conventional circuit-switched networks.

However, despite the fact that the MPLS routers on the market have individual path control functions, the technology for selecting an optimal path and balancing loads on the entire network has not been officially announced or recognized as a standard.

In addition, the path control method available in the current MPLS network is a method of changing the path by automatically switching in case of detecting a failure by configuring a spare path in advance or controlling the MPLS router at the discretion of the operator.

Here, the automatic switching method has a problem that the utilization rate of the entire resource is lowered because the reserve bandwidth must be secured in advance, and the determination and control by the operator may not be optimal control.

In addition, there is a method of determining a new bypass path configuration while managing a state of all paths and resources in use by a specific management system. However, this method increases the number of resources that a management system must manage as the size of the MPLS network grows. As a result, the system needs to be scaled up and requires a lot of time for the optimal calculation of the new path.

In order to solve the above problems, an object of the present invention is to select in real time the optimal path for bypassing a failure in the path of the MPLS.

Another object of the present invention is to distribute traffic across an MPLS network.

To this end, the MPLS network management system according to the present invention, SNMP management unit for monitoring whether the failure of the MPLS network occurs, and collects the data necessary for the control of the bypass path of the failure path using the SNMP object information, the SNMP management unit By selecting all available paths capable of processing traffic for all network resources with reference to the collected data in real time, and assigning a selection probability to all the available available paths, based on the given selection probability And a path controller configured to randomly select one bypass path from all selected available paths, and a path controller configured to control the path of the MPLS network with reference to the bypass path information selected by the path calculator. It is done.

In the MPLS network management method according to the present invention, a first process of determining whether the path of the MPLS network is down by collecting SNMP object information, and a second process of calculating the bandwidth of the downed path when the path is down A third step of calculating a bypass path of the down path in the MPLS network to calculate all available paths, a fourth step of assigning a selection probability to all available paths, and all available paths according to the probability values A fifth step of randomly selecting one of the selected paths as the bypass path, and if the bypass path does not exist as a result of the calculation of the bypass path in the third step, the MPLS network operator indicates that the bypass path does not exist. The notification is characterized by including a sixth process.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an MPLS network management system according to the present invention.

The MPLS network management system 100 monitors whether a failure of the MPLS network occurs and collects the data necessary for the control of the bypass path. And a path controller 30 that calculates a path according to the present invention, and a path controller 30 that controls the LSP path of the ingress router based on the path calculated by the path calculator 20.

The SNMP manager 10 periodically collects the following SNMP object information from the MPLS router and inquires about the link status, the router availability, and the LSP status.

1. ifStatus: On / Off status of the link.

2. mplsLspDown: determines whether the LSP is down.

3. mplsPathBandwidth: Query bandwidth of MPLS path.

4. ifInOctets, ifOutOctets: Represents traffic information on the link.

5. mplsLspPackets: Represents traffic information on the LSP.                     

Such information may be collected from routing protocols such as Open Shortest Path First (OSPF) or Constraint-based Routing Label Distribution Protocol (CR-LDP). Very difficult.

On the other hand, SNMP is not directly related to the routing protocol and it is easy to implement because it can collect status information relatively easily by installing a collecting device outside the MPLS network.

2 is a flowchart illustrating a method of selecting an optimal bypass path when a failure occurs in an LSP of an MPLS network by such a configuration.

The on / off state of the link is automatically received by the SNMP management unit 10 as an SNMP trap message (S210).

If the link down of the LSP being used is received as a trap message (S220), the SNMP manager 10 inquires the ifStatus and mplsLspDown objects to check whether the link is down (S230).

Therefore, when the link down is confirmed again (S240), the bandwidth value of the currently failed link is calculated using the mplsPathBandwidth and mplsLspPackets object information periodically collected before the link is down (S250).

Here, the bandwidth value of the failed link may use LSP bandwidth information in the ingress router.

In addition, the SNMP manager 10 pings all the routers periodically to check whether the router is in normal operation.                     

The normal operation of the router is used to determine the availability of the router when selecting the bypass path.

Then, using the ifInOctets and ifOutOctets information collected from each link immediately after the link down occurs, the route calculation unit 20 calculates a bypassable route (S260).

As a result of the calculation, if a bypass path exists (S270), a probability value is assigned to each path (S280), otherwise the operator is notified that there is no bypass path (S290).

Subsequently, the path controller 30 bypasses traffic by selecting one path at random based on the given probability value (S300).

Hereinafter, a method of calculating the detour path by the path calculator 20 will be described in detail.

If the LSP connection is lost due to a link failure, the MPLS network management system measures the status and load of all available links across the entire network.

Based on the measured data, the path satisfying the following conditions is selected.

<Equation 1>

R _k (i, j) = max {A _r × min [I _ir1 , I _rlr2 ,... , I _rnj ]} ≥BW _LSP ,

R _k (i, j): idle capacity of the bypass path between node i and j (k = 1, 2,…, m, number of bypass paths),

A _r : The availability of router r between nodes i and j (r = r _{1 to} r _n ), has a value of zero if the router fails, and a value of one if the router is normal.

I _ir1 : idle capacity of the link between node i and node r1 directly connected to node i,
I _r1r2: node r ₁ and an idle link capacity between nodes r ₁ and r ₂ connected directly to the node,
I _rnj : link idle capacity between node rn and node j directly connected to node rn,

BW _LSP : The bandwidth of the failed LSP. It is assumed here that the LSP in use has failed and is in a state requiring bypass.

That is, Equation 1 shows that the idle capacity of the link connecting the nodes between nodes i and j is greater than the bandwidth of the failed LSP among the plurality of bypass paths between nodes i and j connected by the smallest links. Is equal to or equal to.

When the bypass path is calculated and selected by Equation 1, a probability value is assigned to each path according to Equation 2 below.

<Equation 2>

Prob = (R _k (i, j) / h _k ) / ∑ _k {R _k (i, j) / h _k }

h _k : Number of hops on the kth path

Prob: Probability

In other words, the larger the idle capacity of the found route and the smaller the number of hops through, the greater the probability of selection.

The sum of all probability values should be 1.0 (100%).

Table 1 shows an example of assigning a probability value to each path under the assumption that the following four bypassable paths are found in case of failure of the LSP having a bandwidth of 2Mbps.                     

TABLE 1

k R _k h _k R _k / h _k Prob One 15 Mbps 5 3 0.273 2 12 Mbps 3 4 0.364 3 5 Mbps 2 2.5 0.227 4 3 Mbps 2 1.5 0.136 Sum 11.0 1.0

When a probability value is given by Equation 2, one path is randomly selected based on a given probability value to bypass traffic.

In the case of Table 1, the probability of selecting the path with k = 2 is the highest, but since it is randomly selected, it cannot be predicted which one will be selected.

That is, a path with k = 4 may be selected.

The reason for this random path selection is to increase the utilization of resources by distributing traffic across the MPLS network.

As described above, the present invention can immediately cope with a link failure without losing data by using an idle facility in the network, and by using a probability value when selecting a path, the path and load balancing are performed throughout the network to improve resource utilization rates. There is an effect that can be maximized.

And since the present invention can be implemented only by the SNMP function can be effectively utilized in a network environment consisting of various models.

Claims (5)

An SNMP management unit for monitoring whether a failure of an MPLS network occurs and collecting data necessary for controlling a detour path of the failed path using SNMP object information; By referring to the data collected by the SNMP manager, all available paths capable of processing traffic for all network resources are selected in real time, and a selection probability is assigned to all selected available paths to determine the given selection probability. A route calculation unit for randomly selecting one bypass route from all of the selected available routes by using; And And a path controller for controlling the path of the MPLS network by referring to the detour path information selected by the path calculator. The method of claim 1, The route calculation unit selects a bypassable route by Equation 1, and assigns a probability for the selected bypassable route by Equation 2. [Equation 1] R _k (i, j) = max {A _r × min [I _ir1 , I _rlr2 ,... , I _rnj ]} ≥BW _LSP , Where R _k (i, j): idle capacity (k = 1, 2, ..., m, the number of all selected available paths) of all selected available paths between nodes i and j which are network resources, A _r : Availability of the network resource r between the nodes i and j (r = r _{1 to} r _n ) and has a value of 0 if the network resource is broken and 1 if it is normal. I _ir1 : idle capacity of the link between node i and node r1 directly connected to node i, I _r1r2: node r ₁ and an idle link capacity between nodes r ₁ and r ₂ connected directly to the node, I _rnj : link idle capacity between node rn and node j directly connected to node rn, BW _LSP : Bandwidth of the failed LSP path. [Equation 2] Prob = (R _k (i, j) / h _k ) / ∑ _k {R _k (i, j) / h _k }, Where h _k is the number of hops of the k th path among the selected bypassable paths, Prob: probability value. A first step of determining whether the path of the MPLS network is down by collecting SNMP object information; If the path is down, calculating a bandwidth of the down path; A third step of calculating all available paths by calculating a bypass path of the down path in the MPLS network; A fourth step of assigning a selection probability to all the available paths; A fifth step of randomly selecting one of all available paths according to the probability value and selecting the selected path as a bypass path; And And a sixth step of notifying the MPLS network operator that the bypass path does not exist if the bypass path does not exist as a result of the calculation of the bypass path in the third step. delete delete

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