KR100872453B1 - BFD/OAM BASED SYSTEM FOR AND BFD/OAM BASED METHOD OF MONITORING FAILURES AND MEASURING PERFORMANCE IN DiffServ-over-MPLS - Google Patents

Abstract

The present invention discloses a system and method for detecting a failure and measuring performance of a network based on a BFD / OAM using a network processor in a DiffServ-over-MPLS with a forwarding and control element separation structure. do. The system of the present invention comprises: a BFD / OAM configuration utility for setting up a BFD / OAM according to a setting of a control element and providing a control element and a GUI; A BFD / OAM configuration driver connected to the BFD / OAM configuration utility to serve as an interface between the user and kernel stages, and a handler for fault notification; A BFD / OAM core component connected to a BFD / OAM configuration driver to manage sessions of BFD / OAM, generate BFD / OAM packets, or process received BFD / OAM packets to perform failure detection and performance measurement; And set up a bidirectional LSP for BFD / OAM, export the BFD / OAM packet generated from the BFD / OAM core component to the LSP, filter the BFD / OAM packet received from the LSP, and deliver it to the BFD / OAM core component. It consists of MPLS core components that manage each LSP.

Differential service MPS, failure detection, performance measurement, BFD, OAM

Description

BFD / OAM BASED SYSTEM FOR AND BFD / OAM BASED METHOD OF MONITORING FAILURES AND MEASURING PERFORMANCE IN DiffServ-over- MPLS}

1 is a schematic diagram illustrating a performance measurement concept using OAM packets in a conventional MPLS network;

2 is a view for explaining the structure of the forwarding and control element (ForCES) used in the present invention,

3 is a block diagram of a BFD / OAM based failure detection and performance measurement system using a network processor according to the present invention;

4 is a detailed block diagram of a BFD / OAM core component shown in FIG. 3;

5 is a format example of the BFD / OAM session table shown in FIG. 4;

6 is a format example of a BFD / OAM packet according to the present invention;

7 is a flowchart illustrating an exchange procedure of a BFD / OAM packet according to the present invention.

* Explanation of symbols for main parts of the drawings

100: forwarding plane 110: BFD / OAM configuration utility

120: BFD / OAM configuration driver 130: BFD / OAM core components

131: BFD / OAM message handler 132: BFD / OAM active session list

133: BFD / OAM Session Table 134: BFD / OAM Packet Handler

135: BFD / OAM connection check 140: MPLS core component

150: MPLS ILM 160: QM

200: control plane

The present invention relates to a network management technology, and more particularly to a BFD using a network processor in a DiffServ-over-MPLS with a forwarding and control element separation (ForCES) structure. / OAM) based on the system and method for detecting the failure of the network and measuring the performance.

In general, failure management is to detect a failure of a link or a path of a transmission network or a failure of each node and notify the management plane so that failure can be recovered. Since real-time multimedia services such as VoIP and video conferencing require real-time and concurrency, information must be delivered within a limited time. Accordingly, in case of a failure, the time required for recovery of the failure should be made as soon as possible to ensure real-time multimedia service. In general, for services such as VoIP, ITU-T G.114 recommends that a good call quality can be guaranteed if the one-way latency is less than 150ms. This includes codec encoding for VoIP and delay along actual transmission, so fast failover time is required to recover from failures. For this reason, SONET sets a failure recovery time of 50ms, which includes all failure detection time, notification time, failure handling and recovery time.

In general, fault detection in an optical transmission network such as SONET can detect faults quickly by using loss of light at the physical layer, and since the time is constant, the fault detection time usually tends to be ignored. However, when mixed switches such as ATM and frame relay are mixed at the 2nd layer like MPLS network, it is difficult to perform integrated fault detection and fault management. Time will increase. Therefore, fault detection and management functions that are independent of the first and second layers are needed.

On the other hand, performance management in the DiffServ-over-MPLS network means that the performance of LPS is continuously measured and managed to maintain a defined quality of service (QoS) parameter. In general, the measurement target of the LSP measures end-to-end packet delay, jitter, packet loss, and error ratio.

As shown in FIG. 1, the monitoring of the label switch path (LSP) is performed through an OAM packet, and a time stamp is generated by periodically generating a packet at an ingress LSR for a target LSP. ) And send it to the Egress LSR to analyze it. Such analysis results are reported through a control channel or through a reverse LSP. Such performance measurement should also be made based on LSP independently of the first and second layers in the DiffServ-over-MPLS transport network. In addition, the performance measurement method using the OAM packet can put a load on the performance of the system because the traffic for the OAM packet must be transmitted in a fast cycle, and a system and structure are needed to process it quickly.

The present invention has been proposed to meet the necessity as described above, and an object of the present invention is to provide a forwarding and control element separation (ForCES) structure in a DiffServ-over-MLPS (DiffServ-over-MLPS) network. It provides a system and method for detecting network failure and measuring performance based on Bidirectional Forwarding Detection (BFD) / OAM (Operation, Administration and Maintenance) using a processor.

In order to achieve the above object, the system of the present invention, in the DiffServ-over-MPLS (DiffServ-over-MPLS) network consisting of nodes having a structure in which the control element and the forwarding element is separated,

A BFD / OAM configuration utility for setting a BFD / OAM according to the setting of the control element and providing the control element and a graphical user interface (GUI); A BFD / OAM configuration driver which is connected to the BFD / OAM configuration utility to serve as an interface between a user and a kernel, and serves as a handler for failure notification; The BFD / OAM configuration driver is connected to manage a session of a BFD / OAM, generate a BFD / OAM packet, or receive a BFD / OAM packet. A BFD / OAM core component that processes BFD / OAM packets to perform fault detection and performance measurements; And setting a bidirectional LPS for the BFD / OAM, and generating a BFD / OAM from the BFD / OAM core component. Export the packet to the LSP, filter the BFD / OAM packet received from the LSP, and forward the packet to the BFD / OAM core component. It is characterized in that it comprises a MPLS core component that manages each LPS (LSP).

The BFD / OAM core component is configured to process a message for controlling a BFD / OAM session from the BFD / OAM configuration driver. BFD / OAM message handler; A BFD / OAM active session list that keeps a list of currently active sessions of a BFD / OAM session; A BFD / OAM session table containing information of all sessions of a BFD / OAM; Receives and processes BFD / OAM packets from the MPLS core component, generates new BFD / OAM packets, and sends them to the MPLS core component A BFD / OAM packet handler; And a BFD / OAM connection check to determine whether a BFD / OAM session is currently active.

In addition, in order to achieve the above object, the method of the present invention, in the DiffServ-over-MPLS (DiffServ-over-MPLS) network consisting of nodes of the control element and the forwarding element is separated, BFD / OAM) When the configuration utility receives a BFD / OAM activation message from a graphical user interface (GUI) for a particular LSP, it sends it to the BFD / OAM configuration driver. Delivering; The BFD / OAM configuration driver causing a BFD / OAM core component to activate a session and send a BFD / OAM packet; The BFD / OAM core component manages a BFD / OAM session and transmits a BFD / OAM packet through an MPLS core component. Receiving; If a failure is detected, notifying the failure detection to a BFD / OAM configuration driver; If it is a performance measurement, calculating a measurement result in the BFD / OAM core component and notifying the BFD / OAM configuration driver; And transmitting the measurement result and the detection result to a Graphical User Interface (GUI) through the BFD / OAM configuration utility.

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

First, the present invention implements a failure detection and performance measurement system based on BFD / OAM using a network processor, and through this, effective failure detection in a DiffServ-over-MPLS transmission network And performance measurements. In other words, in the MPLS network, since various switches such as ATM or frame relay can be mixed in the second layer, the first layer is used for integrated fault detection and fault management between end-to-end. It adopts BFD / OAM, which is independent of the second and second layers, and uses a network processor for fast packet processing and fault detection. Here, Bidirectional Forwarding Detection (BFD) is a protocol proposed by the IETF to detect failures on two forwarding paths, and is easy to implement, simple, and requires little overhead. It can be used regardless of the type of link and protocol, and OAM includes management based on link or path setting and continuous performance measurement. In the present invention, BFD and OAM are integrated into one to implement BFD / OAM.

FIG. 2 is a diagram illustrating a structure of forwarding and control element separation (ForCES) used in the present invention, FIG. 3 is a structure implementing BFD / OAM using a network processor according to the present invention, and FIG. Detailed configuration diagram of the BFD / OAM core components shown in FIG.

As shown in FIG. 2, the forwarding and control element separation (ForCES) structure separates a control element (CE) and a forwarding element (FE) and then interfaces both elements according to the ForeCES protocol. . Referring to FIG. 2, the control element CE includes a user-defined control application, a routing protocol, a signaling protocol, and the like, and is connected to the forwarding element FE through the ForCES interface, and the forwarding element FE is the longest prefix matching forwarding and fur. It consists of elements such as class type queuing, network address translation, packet classification, metering & marking, and traffic saver, and is connected to the control element (CE) through the ForCES interface.

The ForCES structure is a distributed processing structure with one control element in the center and several packet processing and forwarding elements. This results in easy scalability, flexibility in development, and can also improve performance by reducing the load on distributed processing.

According to the present invention, a system implementing BFD / OAM using a network processor is divided into a forwarding plane 100 and a control plane 200 as shown in FIG. 3 so that both planes are connected according to the ForCES protocol. Plane 100 is implemented on a network processor. The forwarding plane 100 includes the BFD / OAM configuration utility 110 formed at the user side, the BFD / OAM configuration driver 120 formed at the kernel side, the BFD / OAM core component 130, and the MPLS core component 140. It is configured to insert or extract the BFD / OAM packet from elements such as MPLS ILM 150, QM 160 implemented in the micro-engine block.

Referring to FIG. 3, the forwarding plane 100 is composed of a combination of several components, and the BFD / OAM Configuration Utility 110 controls the BFD / OAM function and interacts with a graphical user interface (GUI). It serves as an interface. The BFD / OAM configuration driver 120 serves as an interface between a user stage and a kernel stage, and serves as a handler for failure notification. The BFD / OAM Core Component 130 is responsible for controlling BFD / OAM packets and managing BFD / OAM sessions, as well as detecting failures of each session and measuring performance. The MPLS Core Component 140 is responsible for filtering the BFD / OAM packet from the MPLS ILM 150 and delivering it to the BFD / OAM Core Component 130. In addition, the BFD / OAM packet generated from the BFD / OAM core component (130) is also responsible for exporting to the LSP.

As shown in FIG. 4, the BFD / OAM core component 130 includes a BFD / OAM message handler 131, a BFD / OAM active session list 132, a BFD / OAM session table 133, It consists of a BFD / OAM packet handler 134 and a BFD / OAM connection check 135.

Referring to FIG. 4, the BFD / OAM message handler 131 processes a message for controlling a BFD / OAM session from the BFD / OAM configuration driver 120. The BFD / OAM Active Session List 132 keeps a list of currently active sessions of the BFD / OAM session. The BFD / OAM Session Table 133 contains information of all sessions of the BFD / OAM, which are stored in the form of a table format shown in FIG. Referring to FIG. 5, the BFD / OAM session table has a width of 4 bytes, with an 8-bit input port and a 3-byte input label on the first line, and an output LSP handle on the second line. . Subsequently, there are two words of a RX Time Stamp, a pointer list entry, a flag, and a reserved area. The flag has a U bit indicating an uplink state and a V bit indicating whether an entry is valid.

Referring back to FIG. 4, the BFD / OAM Packet Handler 134 receives and processes the BFD / OAM packets from the MPLS Core Component 140 and generates new BFD / OAM packets to generate the MPLS Core. It transmits to the component (Core Component) 140. The BFD / OAM Connection Check 135 is responsible for checking whether a BFD / OAM session is currently active.

Meanwhile, as shown in FIG. 6, the BFD / OAM integration packet consists of three parts: BFD / mandatory 301, BFD / Optional 302, and OAM 303. In the BFD / OAM packet structure, the BFD packet part follows the BFD format defined by the IETF, and an OAM packet for performance measurement is added later. The BFD / OAM packet has a fixed size to facilitate the implementation and increase the processing speed.

The BFD / OAM packet is received from the MPLS core component, and the BFD / OAM packet transmission also uses the MPLS core component. The MPLS core component receives information from the MPLS core component because the core component required for the DiffServ-over-MPLS router implementation or BFD / OAM also has to manage each LSP. In addition, the BFD / OAM sends and receives packets in both directions. Since the LSP is unidirectional, the bidirectional LSP must be configured for the BFD / OAM.

The MPLS Core Component maps the LSP to be monitored at the request of the BFD / OAM Core Component and sets the reverse LSP of this LSP. The BFD / OAM session is created and initialized in a deactivated state for each TE-LSP, and creates a pair LSP in the reverse direction of the TE-LSP to be managed for echo packet transmission of the BFD / OAM. TE-LSP and pair LSP that BFD / OAM must manage are managed by MPLS Core Component and detect each BFD / OAM session, packet processing and fault detection in BFD / OAM Core Component. Accurate time synchronization is required for accurate fault detection and performance measurement of BFD / OAM. In the present invention, time synchronization is performed using NTP.

Next, the operation of the BFD / OAM based failure detection and performance measurement system will be described with reference to FIG. 7.

7 is a flowchart illustrating an exchange procedure of a BFD / OAM packet according to the present invention, in which a forwarding element (FE / BFD Tx) and a forwarding element (FE / BFD Rx) of a receiving side are connected to a transmitting side. Exchanging BFD / OAM packets under control of (CE). Referring to FIG. 7, according to the setting of the control element CE, the transmitting side forwarding element FE forwards the BFD / OAM packet to the receiving side forwarding element FE, and the receiving side forwarding element FE responds thereto. Send the response packet to the sender. The transmitting side forwarding element (FE) analyzes the received response packet or detects a failure and notifies the control element CE if the response packet is not received for a certain time.

First, for failure detection and performance measurement of each LSP, a session of BFD / OAM must be activated in the corresponding LSP. When the BFD / OAM Configuration Utility 110 receives a BFD / OAM activation message for a specific LSP from the GUI, the BFD / OAM Configuration Utility 110 forwards the message to the BFD / OAM Configuration Driver 120 and configures the BFD / OAM Configuration Driver. Driver 120 causes the BFD / OAM Core Component 130 to activate the session and send the BFD / OAM packet.

The BFD / OAM Core Component 130 transmits and receives a BFD / OAM packet through the MPLS Core Component 140 while managing a BFD / OAM session. At this time, if a failure is detected, it is notified to the BFD / OAM configuration driver 120. The performance measurement calculates the measurement result in the BFD / OAM configuration component (Core Component) and notifies the BFD / OAM configuration driver 120 as well as the failure detection. These results are delivered to the GUI through the BFD / OAM Configuration Driver 120 and the configuration utility 110.

Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above-described embodiments, and various changes may be made by those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention. It may be changed and implemented.

As described above, according to the present invention, after implementing a BFD / OAM based failure detection and performance measurement system using a network processor, the DiffServ-over-MPLS transmission network It can effectively detect faults and measure performance. In particular, the present invention adopts BFD / OAM independent of layers 1 and 2, and is easy to implement using a network processor, and can quickly perform packet processing and failure detection. .

Claims (5)

In the DiffServ-over-MPLS network, in which a control element and a forwarding element are composed of nodes having a structure separated from each other, The forwarding element, A BFD / OAM configuration utility for setting a BFD / OAM according to the setting of the control element and providing the control element and a graphical user interface (GUI); A BFD / OAM configuration driver which is connected to the BFD / OAM configuration utility to serve as an interface between a user and a kernel, and serves as a handler for failure notification; The BFD / OAM configuration driver is connected to manage a session of a BFD / OAM, generate a BFD / OAM packet, or receive a BFD / OAM packet. A BFD / OAM core component that processes BFD / OAM packets to perform fault detection and performance measurements; And Set a bidirectional LPS for the BFD / OAM, and create a BFD / OAM packet generated from the BFD / OAM core component. To the LPS (LSP), and filter the BFD / OAM packet received from the LSP (LSP) to pass to the BFD / OAM core component, A system for detecting failures and measuring performance based on BFD / OEM in a differential service MPL network, which comprises MPLS core components managing each LSP. . The BFD / OAM core component of claim 1, wherein the BFD / OAM core component comprises: A BFD / OAM message handler for processing a message for controlling a BFD / OAM session from the BFD / OAM configuration driver; A BFD / OAM active session list that keeps a list of currently active sessions of a BFD / OAM session; A BFD / OAM session table containing information of all sessions of a BFD / OAM; Receives and processes BFD / OAM packets from the MPLS core component, generates new BFD / OAM packets, and sends them to the MPLS core component A BFD / OAM packet handler; And Based on the BFD / OAM in the differentiated service MPS network, which is equipped with a BFD / OAM connection check to check whether the BFD / OAM session is currently active. System to detect faults and measure performance. 3. The BFD / OAM session table of claim 2, wherein Including input ports, input labels, output LSP handles, Last RX Time Stamps, pointer list entries, flags, The flag is divided into a U bit indicating an uplink state and a V bit indicating whether an entry is valid. The system for detecting a failure and measuring performance based on a BFD / OEM in a differential service MPS network. The method of claim 1, wherein the BFD / OAM packet, BFD packet part and OAM packet part, and has a fixed size to increase the processing speed based on the BFD / OEM in the MPS network System for detecting faults and measuring performance. In the DiffServ-over-MPLS network, in which a control element and a forwarding element are composed of nodes having a structure separated from each other, When the BFD / OAM configuration utility receives a BFD / OAM activation message for a particular LSP from the graphical user interface (GUI), it is sent to the BFD / OAM (BFD / OAM). Delivering to a BFD / OAM) configuration driver; The BFD / OAM configuration driver causing the BFD / OAM core component to activate a session and send a BFD / OAM packet; The BFD / OAM core component manages a BFD / OAM session and transmits a BFD / OAM packet through an MPLS core component. Receiving; If a failure is detected, notifying the failure detection to a BFD / OAM configuration driver; If it is a performance measurement, calculating a measurement result in the BFD / OAM core component and notifying the BFD / OAM configuration driver; And And transmitting the measurement results and the detection results to the graphical user interface (GUI) through the BFD / OAM configuration utility. A method for detecting faults and measuring performance based.

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