KR100529275B1 - Method for Processing PPP over Ethernet Service in ATM base MPLS network - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a point-to-point protocol service method over Ethernet in an ATM-based MPLS network.

2. The technical problem to be solved by the invention

The present invention, in order to provide Internet services to PPPoE subscribers on the Asymmetric Subscriber Line (ADSL) in the ATM-based MPLS system, the PPPoE frame that is delivered to the ATM by loading the PPP that is already used in the existing Internet service in the Ethernet frame To provide a point-to-point protocol service method over Ethernet in an ATM-based MPLS network for processing in an MPLS system.

3. Summary of Solution to Invention

The present invention provides a point-to-point protocol service method on an Ethernet applied to an ATM-based MPLS network. The present invention provides a logical link control by establishing a forwarding control channel for transmitting a control packet and receiving a point-to-point protocol (PPPoE) subscriber packet on the Ethernet. A header parsing step of parsing the (LLC) header; As a result of the LLC header analysis, when the Ethernet type field check value in the PPPoE frame is a PPPoE discovery control packet, a PPPoE discovery control is performed by adding a forwarding control channel (FCC) header. Control step; As a result of the LLC header analysis, when the Ethernet type field check value in the PPPoE frame is a point-to-point protocol (PPP) session control packet, the protocol type in the PPP frame is checked to indicate that the protocol type is a PPP control packet. A PPP session control step of generating an assigned FCC header to perform PPP session control; And an exception processing step of performing an IP datagram exception processing by matching a forwarding entry with an IP address when referring to an Internet Protocol (IP) datagram according to a result of checking the protocol type in the PPP frame.

4. Important uses of the invention

The present invention is used for high speed internet service.

Description

Point-to-point protocol service over Ethernet in asynchronous transmission mode based MPS network {Method for Processing PPP over Ethernet Service in ATM base MPLS network}

The present invention relates to a Point-to-Point Protocol (PPPoE) service method over Ethernet in an Asynchronous Transfer Mode (ATM) based MPLS (MultiProtocol Label Switching) network.

In line with the increasing demand for the Internet, Asynchronous Digital Subscriber Line (ADSL) technology is used to provide high-speed data communication using existing copper wire. A device that allows such ADSL subscribers to connect is a Digital Subscriber Line Access Multiplexer (DSLAM), and most systems are provided with ADSL based on ATM, and access the Internet using an existing analog modem. It is provided based on PPP (Point-to-Point) protocol which is a dial-up networking method. In this case, PPPoA (Point to Point over ATM) technology that delivers a PPP frame directly on the ATM has been recognized as a more convenient method because of the increased cost and complexity of the user's point of view. In other words, users can deliver Internet services using ADSL without changing the user environment by delivering PPP frames directly over Ethernet using the existing Ethernet interface card, and also share them using only one Ethernet hub with one ADSL. You could do it. However, the PPPoE service should be able to be accommodated in an ATM-based MPLS system, but a specific method has not been provided yet. Therefore, a method for providing a PPPoE service in an MPLS system is urgently required.

The present invention has been proposed in order to meet the above-described needs. In order to provide Internet services to PPPoE subscribers on an asymmetric Subscriber Line (ADSL) in an ATM-based MPLS system, the present invention uses a PPP that is already used in an existing Internet service. An object of the present invention is to provide a point-to-point protocol service method over Ethernet in an ATM-based MPLS network for processing PPPoE frames carried on an Ethernet frame in an ATM.

The present invention for achieving the above object, in the point-to-point protocol service on the Ethernet applied to the Asynchronous Transfer Mode (ATM) based MPLS (MPLS) network, establishing a forwarding control channel for transmitting control packets, Ethernet A header analysis step of receiving a point-to-point protocol (PPPoE) subscriber packet on the terminal and analyzing a logical link control (LLC) header; As a result of the LLC header analysis, when the Ethernet type field check value in the PPPoE frame is a PPPoE discovery control packet, a PPPoE discovery control is performed by adding a forwarding control channel (FCC) header. Control step; As a result of the LLC header analysis, when the Ethernet type field check value in the PPPoE frame is a point-to-point protocol (PPP) session control packet, the protocol type in the PPP frame is checked to indicate that the protocol type is a PPP control packet. A PPP session control step of generating an assigned FCC header to perform PPP session control; And an exception processing step of performing an IP datagram exception processing by matching a forwarding entry with an IP address when referring to an Internet Protocol (IP) datagram according to a result of confirming the protocol type in the PPP frame. It is done.

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The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary configuration diagram of an ATM-based MPLS system to which the present invention is applied.

As shown in FIG. 1, an ATM switch is used as an L2 forwarding device of an MPLS domain in an ATM-LSR (Label Switching Router) 102, which is an intermediate node of an MPLS domain, and an edge ATM-LSR that is a boundary of an MPLS domain. At 102, it is used as an ATM connection path device connecting a non-MPLS domain 105. L2 forwarding is performed between the Edge ATM-LSR 102 and the ATM-LSR 106 and between the ATM-LSRs 106 instead of the IP forwarding scheme in the IP domain, which is a Label Switched Path (LSP) 104. Through. The mapping between the LSPs 104 and the IP domains is performed by the Edge ATM-LSR 102. The main control unit that performs the LSP 104 setting function and the management function in the ATM-LSR 106 is called an Internet Protocol Control Processor (IPCP) 101, and the FE is provided in the Edge ATM-LSR 102. (Forwarding Engine) 107 is included.

Most packets sent from the Internet Protocol (IP) domain are forwarded to the FE 107, converted into labeled packets via IP lookup, and then sent to the MPLS domain. Packets that cannot be processed by the FE 107 are It is delivered to IPCP 101 through a separate control channel established between FE 107 and IPCP 101 and processed. Label distribution protocols, routing protocols, and management messages are communicated using a particular ATM channel established between ATM-LSRs 106. In addition, in order to implement open networking, the IPCP 101 controls the MPLS resource using the General Switch Management Protocol (GSMP) 103 so that each label information is allocated inside the ATM switch.

2 is a diagram illustrating an embodiment of an ADSL service network and a protocol using PPPoE to which the present invention is applied.

As shown in FIG. 2, the subscriber is connected to the ADLS line via the ADSL modem 202 using the existing Ethernet interface card 201. In this case, the personal computer (PC) carries the PPP frame to the Ethernet Media Access Control (MAC) frame using PPPoE (203). In the ADSL modem, the PPPoE frame received from the PC is loaded on the ATM on the ADSL and transmitted to the DSLAM (204). The DSLAM is loaded on the ATM physical layer and transmitted to the MPLS system having the PPP server (205). The MPLS system processes the PPPoE frame carried in the ATM to provide the PPP service to the subscriber (206).

3 is a structural diagram of an embodiment of a PPPoE frame in the MPLS system according to the present invention.

As shown in FIG. 3, the frame format includes a forwarding control channel (FCC) header 301 used when transmitting and receiving a control packet between an internet protocol control processor (IPCP) and a forwarding engine (FE), which are main control boards. ) And a logical link control (LLC) header 302 for distinguishing when multiple protocols are transmitted in one ATM virtual channel (VC), and a PPPoE frame including Ethernet and PPP information (303). ) And an ATM Adaptation Layer 5 (AAL5) hereinafter referred to as AAL-5 (AAL5) trailer 304. When a non-MPLS domain transmits and receives an ATM to an MPLS system, the LLC header and the PPPoE frame portion are composed of the data payloads of AAL5, and are delivered to the forwarding engine in the form of AAL5 frames, and process the PPPoE and PPP control packets. For this purpose, an FCC header is added when communicating with the main control board.

The FCC header 301 is a type field that distinguishes the types of packets transmitted between the main control board and the forwarding engine, a cause field indicating the cause of abnormal packet processing, and a message transmitted by the forwarding engine. It consists of a Ch_id field indicating an interface identifier with an ATM switch. The LLC header 302 includes an LLC field indicating the type of data to be transmitted, an Organizationally Unique Identifier (OUI) field that identifies the protocol type of the data to be transmitted, and a packet identifier identifying the media type of the data to be transmitted. PID: Packet Identifier) field.

The PPPoE frame 303 consists of a source and destination MAC address field, an Ethernet type field, and a payload. The payload includes a ver field having a fixed value of 1, a type field, a code field related to PPPoE protocol processing, a session ID (session_id) field for distinguishing a PPP session, and a length indicating a data length ( length) field, an actual PPP control packet, and a data payload field through which an IP datagram is transmitted.

4 is a structural diagram of an embodiment of a connection identifier management table applied to the present invention.

As shown in FIG. 4, in PPPoE, after checking the Ethernet MAC address of the server and going through the discovery control stage of PPPoE to form a PPP session, a PPP session stage is used to exchange PPP control frames. Proceed to the Session Stage. In summary, PPPoE's Discovery Control Stage procedure states that all servers that receive PPPoE Active Discovery Indication (PADI) advertise their server's Media Access Control (MAC) address to PPPoE Active Discovery Offer (PADO). After receiving a PPPoE Active Discovery Request (PADR), one server selected by the user assigns a 16-bit unique Session ID 402 to the PPPoE Active Discovery Session Control (PADS) to perform a PPP session stage. Let me know. Therefore, the PPP server must manage its MAC address and notify it when receiving PADI (PPPoE Active Discovery Indication). In addition, when transmitting a packet using PPPoE in the IP layer, a new connection identifier having not only the corresponding ATM channel information 401 but also session information for distinguishing several sessions created in each channel is required. In addition, the MAC address 403 for each connection must also be managed.

5A and 5B are a flowchart illustrating an exemplary PPPoE subscriber service procedure according to the present invention.

As shown in FIGS. 5A and 5B, a forwarding control channel for transmitting a control packet between the main control board IPCP and the forwarding engine FE is set (501). When the PPPoE subscriber packet in the AAL5 frame is received by the MPLS system, the forwarding engine stores the interface channel with the ATM switch receiving the subscriber packet in the FE_CH variable (502). Subsequently, it is checked that the value of the LLC field is 0xAAAA03 in the LLC header of the received packet (503). If the value of the LLC field is not 0xAAAA03, an exception is thrown. If the value of the LLC field is 0xAAAA03, In operation 504, it is checked whether the OUI field is 0x0080C2 which means a bridged protocol. If the OUI field is not 0x0080C2, which means the bridged protocol, the exception is thrown. If the OUI field is 0x0080C2, which means the bridged protocol, the packet identifier (PID) field is again set to Ethernet protocol data unit (PDU: It is checked whether 0x0001 or 0x0007, which stands for Protocol Data Unit) (505). As a result of the check, if the PID field is not 0x0001 or 0x0007, which means an Ethernet PDU, an exception is handled. If the PID field is 0x0001 or 0x0007, which means an Ethernet PDU, an Ethernet type field in the PPPoE frame is checked. (506). Here, 0x0001 of the PID field of the LLC header means that the LAN Frame Check Sequence (FCS) is included in the PPPoE frame format, and 0x0007 means that the LAN FCS is not included.

On the other hand, if the Ethernet_type field check value is 0x8863, which means that the PPPoE Discovery control packet, the FCC header is added to transmit the received packet to the main control board (IPCP) (507). At this time, the type field in the FCC header assigns a PPPOE_CONTROL value indicating that the packet is a PPPoE control packet, a NORMAL value indicating a case where the cause field is normal, and a ch_id field as an already stored FE_CH value. Subsequently, the PPPoE packet including the FCC header is transmitted to the PPP server in the main control board (IPCP) (508), and performs the PPPoE Discovery control procedure in the PPP server (509). If the Ethernet_type field check value is 0x8864, which means that the PPP session control packet is detected, the protocol type in the PPP frame is checked (510). If the protocol type is 0xC021, 0xC023, 0xC025, 0xC223, and 0x8021, indicating that the protocol type is a PPP control packet, a corresponding FCC header is generated (511). In this case, a type field in the FCC header is assigned a PPP_CONTROL value indicating that the packet is a PPP control packet, a NORMAL value indicating a case where the cause field is normal, and a ch_id field is assigned to a pre-stored FE_CH value. The PPP control packet with the FCC header added is transmitted to the PPP server in the main control board (IPCP) (512), and performs the PPP control procedure in the PPP server (513). If the protocol type is 0x0021, meaning IP datagram, it is checked whether there is an IP address that matches the received IP datagram among the forwarding entries (514). As a result of the check, if there is a matched entry, forwarding is performed to the corresponding interface (518). If there is no matched entry, an exception is generated, and an FCC header is generated to transmit the received packet to the main control board (IPCP). 515). In this case, the type field in the FCC header assigns an IP_DATAGRAM value indicating an IP datagram, an error value indicating a case where the cause field is abnormal, and a ch_id field as a pre-stored FE_CH value. The IP datagram packet including the FCC header is transmitted to the IP datagram exception processing unit in the main control board (IPCP) (516), and the exception case processing is performed (517).

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention provides the PPPoE service in the ATM-based MPLS network, so that the subscriber side can use the ADSL-based Internet service through the MPLS system in a convenient environment, thereby speeding up the Internet service and providing desired service quality. I can receive it. In addition, the present invention has the effect of enabling the use of a highly secure service using a VPN (Virtual Private Network).

1 is an exemplary configuration diagram of an ATM-based MPLS system to which the present invention is applied.

2 is a diagram illustrating an embodiment of an ADSL service network and a protocol using PPPoE to which the present invention is applied.

3 is a structural diagram of an embodiment of a PPPoE frame in the MPLS system according to the present invention;

4 is a structural diagram of an embodiment of a connection identifier management table according to the present invention;

5A and 5B are flow diagrams of an embodiment of a PPPoE subscriber service procedure in accordance with the present invention.

* Explanation of symbols for the main parts of the drawings

101: Internet Protocol Control Processor (IPCP)

102: Perimeter ATM-Label Switching Router (Edge ATM-LSR)

103: GSMP protocol 104: Label Switching Paths (LSPs)

105: Non-MPLS Domain

106: ATM-Label Switching Router (ATM-LSR)

107 forwarding engine (FE)

Claims (6)

In the point-to-point protocol service method on the Ethernet applied to the asynchronous transmission mode (ATM) -based MPLS network, A header analysis step of establishing a forwarding control channel for carrying control packets, receiving a Point-to-Point Protocol (PPPoE) subscriber packet on Ethernet and analyzing a logical link control (LLC) header; As a result of the LLC header analysis, when the Ethernet type field check value in the PPPoE frame is a PPPoE discovery control packet, a PPPoE discovery control is performed by adding a forwarding control channel (FCC) header. Control step; As a result of the LLC header analysis, when the Ethernet type field check value in the PPPoE frame is a point-to-point protocol (PPP) session control packet, the protocol type in the PPP frame is checked to indicate that the protocol type is a PPP control packet. A PPP session control step of generating an assigned FCC header to perform PPP session control; And An exception processing step of performing an IP datagram exception processing by matching a forwarding entry with an IP address when referring to an IP protocol datagram according to a result of checking the protocol type in the PPP frame. Point-to-point protocol service method over Ethernet in ATM-based MPLS network comprising a. The method of claim 1, The header analysis step, A channel setting step of setting a forwarding control channel for transferring control packets between an Internet Protocol control processor (IPCP) and a forwarding engine (FE); When the PPPoE subscriber packet included in the ATM adaptation layer 5 (AAL5) frame is received through the MPLS network, the forwarding engine stores the interface channel with the ATM switch receiving the subscriber packet in the FE_CH variable, and the LLC in the LLC header of the received packet. A first checking step of checking that a value of the field is 0xAAAA03; If the value of the LLC field is not 0xAAAA03 as a result of the inspection in the first inspection step, exception processing is performed, and if the value of the LLC field is 0xAAAA03, 0x0080C2 indicating a bridged protocol again. A second inspection step of examining cognition; And If the value of the LLC field is not 0x0080C2 as a result of the inspection of the second inspection step, an exception is processed. If the value of the LLC field is 0x0080C2, the PID field means Ethernet protocol data unit (PDU) again. Third inspection step to check whether it is 0x0001 or 0x0007 Point-to-point protocol service method over Ethernet in ATM-based MPLS network comprising a. The method according to claim 1 or 2, The PPPoE discovery control step, If the LLC header check succeeds, the Ethernet type field in the PPPoE frame is checked, and if the Ethernet_type field check value is 0x8863, which means that the PPPoE discovery control packet, the forwarding control channel (FCC) is used to transmit the received packet to IPCP. The Type field in the Forwarding Control Channel header indicates a PPPOE_CONTROL value, meaning that it is a PPPoE control packet, a NORMAL value for the cause field, and a ch_id field for a forwarding control channel (FCC) assigned to a pre-stored FE_CH value. Channel header addition step of adding a header; And Performing a discovery control procedure of transmitting the PPPoE packet including the FCC header to a point-to-point protocol (PPP) server in IPCP and performing a PPPoE discovery control procedure in the PPP server; Point-to-point protocol service method over Ethernet in ATM-based MPLS network comprising a. The method of claim 3, wherein The PPP session control step, If the Ethernet_type field check value in the PPPoE frame is 0x8864, which means that it is a PPP session control packet, then the protocol type is checked in the PPP frame. A header for generating an FCC header assigned with a PPP_CONTROL value representing a PPP control packet, a NORMAL value representing a normal case, and a ch_id field assigned a pre-stored FE_CH value. Generation step; And Performing a PPP control procedure for transmitting a PPP control packet including the FCC header generated in the header generation step to a PPP server in IPCP and performing a PPP control procedure in the PPP server; Point-to-point protocol service method over Ethernet in ATM-based MPLS network comprising a. The method of claim 4, wherein The exception processing step, If the protocol type in the PPP frame is 0x0021, meaning IP datagram, a fourth checking step of checking whether there is an IP address matching the received IP datagram among the forwarding entries; As a result of the inspection in the fourth inspection step, if there is a matched entry, forwarding is performed to the corresponding interface. If there is no match, the type field in the FCC header is set to IP datagram to transmit the received packet to IPCP. An FCC header generation step of generating an FCC header assigned an IP_DATAGRAM value indicating an error value, an ERROR value indicating a cause field abnormality, and a ch_id field assigned with a pre-stored FE_CH value; And An exception processing step of transmitting an IP datagram packet including the generated FCC header to an IP datagram exception processing unit in IPCP to perform exception case processing Point-to-point protocol service method over Ethernet in ATM-based MPLS network comprising a. delete