JP4884184B2 - Communication device and program for link aggregation - Google Patents

Description

  The present invention relates to a communication device and a program for link aggregation.

  At present, Ethernet (registered trademark) technology is widely used as a layer 2 network for LAN (Local Area Network). On the other hand, in recent years, FTTH (Fiber To The Home) technology has been used as an ultra-high-speed layer 2 network. With the FTTH technology and other high-speed access line technologies, the communication network including the core network and the metro network needs to be increased in capacity as the communication speed of the access network increases. In addition to the improvement in the communication speed of the entire network, it is also necessary to increase the switching processing capacity of a communication apparatus such as a layer 2 network apparatus and increase the communication speed between layer 2 network apparatuses.

  In order to realize a large-capacity main pipe, a link aggregation technology can be used between two layer 2 network devices. Link aggregation is a technology (bandwidth increase) in which a plurality of links (lines) that are extended in parallel between two layer 2 network devices are integrated and handled logically as one link. For example, two 100 Mbps links can be bundled to realize a virtual 200 Mbps high capacity link. In addition, a fault-tolerant function (redundancy) is also provided in that even if a failure occurs in one of the links that are extended in parallel, the connection is maintained by the other link.

  Service providers need to perform operation administration and maintenance (OAM) from a remote location in order to provide a stable service to subscribers at all times. Therefore, ITU-T Y.T. An Ethernet OAM frame has been defined by 1731 or IEEE802.1ag (see, for example, Non-Patent Document 1). In particular, ITU-T Y.M. 1731 is a standard that realizes an operation and maintenance management function almost equivalent to SONET (Synchronous Optical NETwork) in the Ethernet network.

  The Ethernet OAM frame is a frame having functions such as reachability management (CFM: Connectivity Fault Management), error notification, link (line) performance monitor, and the like and a function for transmitting the information. The Ethernet OAM frame includes a destination MAC (Media Access Control) address, a transmission source MAC address, an Ethernet OAM TLV (Type Length Value), and an FCS (Frame Check Sequence). The MAC address is a 48-bit identification number that is unique to the layer 2 network device that is the target of operation and maintenance management or unique to the network interface card. Usually, a unique identifier of a network interface card is not used in a layer 2 network device, and a device MAC address (CPU-MAC address) that identifies the device itself is used to recognize the device during frame transfer. . The Ethernet OAM TLV includes, for example, control information (request / response), status (power status, received light status, link disconnection, failure, etc.), vendor code, model code, and the like.

Koichiro Seto, “Standardization Trend of 802.1 / 802.3 (3)”, [online], September 25, 2006, WBB Forum, [October 31, 2006 search], Internet <URL: http: //wbb.forum.impressrd.jp/report/20060922/280?page=0%2C0>

  The Ethernet OAM frame is a frame for layer 2 and is transferred in the same band as the data frame (in-band transfer). Accordingly, it is possible to monitor via which link the Ethernet OAM frame is transferred between the layer 2 network devices for which the link aggregation is set. However, not all links can be monitored. That is, when link aggregation is used, only the link through which the Ethernet OAM frame passes can be monitored between the layer 2 network devices. In other words, even if a failure occurs in a link other than the link through which the Ethernet OAM frame passes, the failure cannot be monitored by the Ethernet OAM frame.

  Therefore, an object of the present invention is to provide a communication device and a program capable of detecting a link failure between communication devices of link aggregation using an Ethernet OAM frame.

According to the present invention, a first port that transmits and receives a data frame to and from the first communication device, and a plurality of second ports that transmit and receive a data frame by link aggregation with the second communication device; In a communication device having
Operation maintenance management frame duplicating means for duplicating the operation maintenance management frame received from the first port so as to be transmitted to all of the plurality of second ports ;
When the same operation and maintenance management frame is received from all of the plurality of second ports, one operation and maintenance management frame to be transmitted to the first port is generated, and operation is performed from a part of the plurality of second ports. In the case where the maintenance management frame cannot be received, an operation maintenance management frame integration unit for generating an operation maintenance management frame including a response message of error information is provided to return to the second port.

According to another embodiment of the communication device of the present invention,
The operation / maintenance management frame integration unit generates an operation / maintenance management frame including error information for transmission to the first port when the operation / maintenance management frame cannot be received from some of the plurality of second ports. It is also preferable.

  According to another embodiment of the communication apparatus of the present invention, the operation and maintenance management frame may be an Ethernet OAM frame.

According to the present invention, a first port that transmits and receives a data frame to and from the first communication device, and a plurality of second ports that transmit and receive a data frame by link aggregation with the second communication device; In a program for functioning a computer mounted on a communication device having
Operation maintenance management frame duplicating means for duplicating the operation maintenance management frame received from the first port so as to be transmitted to all of the plurality of second ports ;
When the same operation and maintenance management frame is received from all of the plurality of second ports, one operation and maintenance management frame to be transmitted to the first port is generated, and operation is performed from a part of the plurality of second ports. If the maintenance management frame cannot be received, the computer functions as an operation maintenance management frame integration means for generating an operation maintenance management frame including a response message of error information in order to return to the second port. It is characterized by making it.

According to another embodiment of the communication device program of the present invention,
The operation / maintenance management frame integration unit generates an operation / maintenance management frame including error information for transmission to the first port when the operation / maintenance management frame cannot be received from some of the plurality of second ports. It is also preferable.

  According to another embodiment of the communication device program of the present invention, the operation and maintenance management frame may be an Ethernet OAM frame.

  According to the communication apparatus and program of the present invention, a link failure between link aggregation communication apparatuses can be detected by an Ethernet OAM frame.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a functional configuration diagram of a layer 2 network device according to the present invention.

  According to FIG. 1, the layer 2 network device 1 includes a first port 101, a plurality of second ports 102, a link aggregation function unit 103, a frame analysis unit 104, an OAM processing unit 105, and an OAM frame. And a duplication / integration unit 106. These functional units other than the port can also be realized by a program for causing a computer mounted on the layer 2 network device to function. The communication device targeted by the present invention is a device capable of transmitting and receiving layer 2 frames, such as a layer 2 network device and a layer 2 switch device.

  The first port 101 transmits / receives OAM frames and data frames to / from other communication devices.

  The plurality of second ports 102 transmit and receive OAM frames and data frames by link aggregation with the counterpart layer 2 network device.

  The link aggregation function unit 103 uses the plurality of second ports 102 to realize a link aggregation function with the counterpart layer 2 network device. In the link aggregation function, as long as an accurate frame order can be realized, control over which link to transfer a frame to be transmitted differs depending on the implementation of each network device manufacturer.

  The frame analysis unit 104 identifies whether the frame received from the first port is an OAM frame or a data frame. The OAM frame is transferred to the OAM processing unit 105. The data frame is transferred to the link aggregation function unit 103.

  The OAM processing unit 105 confirms the destination MAC address of the OAM frame. If the destination MAC address of the OAM frame is not the MAC address of the layer 2 network device, the OAM processing unit 105 only writes status information or the like in the Ethernet OAM TLV of the OAM frame. Then, the OAM processing unit 105 notifies the OAM duplication / integration unit 106 of the OAM frame.

  Conversely, when the OAM processing unit 105 receives an integrated OAM frame from the OAM duplication / integration unit 106, the OAM processing unit 105 checks the destination MAC address of the OAM frame. If the destination MAC address of the OAM frame is not the MAC address of the layer 2 network device, the OAM processing unit 105 only writes status information or the like in the Ethernet OAM TLV of the OAM frame. Then, the OAM processing unit 105 transmits the OAM frame to the first port 101.

  The OAM duplication / integration unit 106 has a duplication function and an integration function. In the case of the duplication function, the OAM frame received from the OAM processing unit 105 is duplicated. The OAM frame is duplicated by the number of all the links constituting the link aggregation. The copied OAM frame is transferred to the link aggregation function unit 103.

  On the other hand, in the case of the integration function, the OAM frame received from the link aggregation function unit 103 is integrated. When the same OAM frame is received from all of the plurality of second ports, one OAM frame to be transmitted to the first port is generated. If an OAM frame cannot be received from some of the plurality of second ports, an OAM frame including a response message of error information is generated in order to return to the second port. Further, according to another embodiment, an OAM frame including error information is generated for transmission to the first port. The generated OAM frame is transferred to the OAM processing unit 105.

  As described above, the layer 2 network device according to the present invention transfers the OAM frame to all the links constituting the link aggregation, so that the link failure between the layer 2 network devices can be detected by the Ethernet link trace technology or the Ethernet continuous test technology. Can be detected.

  FIG. 2 is a sequence diagram when a failure occurs in a link aggregation link.

(S201) The layer 2 network device A receives an OAM frame and a data frame from the terminal or another layer 2 network device through the first port 101.

(S202) The first port 101 transfers the OAM frame and the data frame to the frame analysis unit 104. The frame analysis unit 104 analyzes whether the frame is an OAM frame or a data frame. The OAM frame is transferred to the OAM processing unit 105, and the data frame is transferred to the link aggregation function unit 103.

(S203) The OAM processing unit 105 checks the destination MAC address of the OAM frame. If the destination MAC address of the OAM frame is not the MAC address of the layer 2 network device, the OAM processing unit 105 only writes status information or the like in the Ethernet OAM TLV of the OAM frame. Then, the OAM processing unit 105 transfers the OAM frame to the OAM duplication / integration unit 106.

(S204) The OAM duplication / integration unit 106 duplicates the OAM frame so as to be transmitted to all of the plurality of second ports. The copied OAM frame is transferred to the link aggregation function unit 103.

(S205) The link aggregation function unit 103 transfers the OAM frames received from the OAM duplication / integration unit 106 to all of the plurality of second ports 102.

(S206) The second port 102 of the layer 2 network device A transmits the OAM frame to the layer 2 network device B. These OAM frames are received by the second port 102 of the layer 2 network device B.

(S207) At this time, it is assumed that a failure has occurred in one link. The OAM frame transmitted from the layer 2 network device A is not received by the layer 2 network device B for the link where the failure has occurred.

(S208) The second port 102 in the layer 2 network device B transfers the received OAM frame to the link aggregation function unit 103.

(S209) The link aggregation function unit 103 transfers the received OAM frame to the OAM duplication / integration unit 106. On the other hand, the received data frame is transferred to the first port 101 after the link aggregation process.

(S209) The OAM duplication / integration unit 106 determines whether or not the same OAM frame has been received by all the second ports. Here, one OAM frame is not received due to one link failure. Therefore, the OAM duplication / integration unit 106 notifies the OAM processing unit 105 of an OAM frame in which error information related to the failed link is included in the Ethernet OAM TLV.

(S210) The OAM processing unit 105 transfers the OAM frame including error information to the link aggregation function unit 103. According to another embodiment, the OAM processing unit 105 can also transmit an OAM frame including error information to the first port 101. As a result, not only the source communication device of the OAM frame but also the destination communication device can know that an error has occurred.

(S211) The link aggregation function unit 103 transfers the OAM frame including error information to the second port 102 that connects the normal link.

(S212) The second port 102 of the layer 2 network device B transmits an OAM frame including error information to the partner layer 2 network device A.

(S213) The second port 102 of the layer 2 network device A transfers the OAM frame including the error information to the link aggregation function unit 103.

(S214) The link aggregation function unit 103 transfers the OAM frame including error information to the first port 101.

(S215) The first port of the layer 2 network device A returns an OAM frame including error information to the transmission source communication device of the OAM frame.

  As described above, when a link failure occurs between layer 2 network devices, an OAM frame including error information is returned from the layer 2 network device, so that the transmission source device of the OAM frame knows the link failure. be able to.

  FIG. 3 is an explanatory diagram illustrating transfer control of an OAM frame in link aggregation.

  When a plurality of layer 2 network devices are connected by link aggregation, they are transferred as shown in FIG. In this case, when an OAM frame is transferred between layer 2 network devices, it is not possible to control which link is passed through. According to the present invention, duplicated OAM frames are transferred for all links. Therefore, when the failure link is passed, an OAM frame arrival error is confirmed, and when the failure is made via a normal link, no OAM frame arrival error is confirmed.

  As described above in detail, according to the communication apparatus and program of the present invention, it is possible to detect a link failure between link aggregation communication apparatuses by using an Ethernet OAM frame.

  According to the various embodiments of the present invention described above, those skilled in the art can easily make various changes, modifications and omissions within the scope of the technical idea and the viewpoint of the present invention. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

It is a functional block diagram of the layer 2 network apparatus in this invention. FIG. 11 is a sequence diagram when a failure occurs in a link aggregation link. It is explanatory drawing showing transfer control of the OAM frame in link aggregation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Layer 2 network apparatus 101 1st port 102 2nd port for link aggregation 103 Link aggregation function part 104 Frame analysis part 105 OAM processing part 106 OAM duplication / integration part

Claims (6)

In a communication device having a first port that transmits and receives data frames to and from the first communication device, and a plurality of second ports that transmit and receive data frames by link aggregation with the second communication device,
Operation maintenance management frame duplicating means for duplicating the operation maintenance management frame received from the first port so as to be transmitted to all of the plurality of second ports ;
When the same operation and maintenance management frame is received from all of the plurality of second ports, one operation and maintenance management frame to be transmitted to the first port is generated, and a part of the plurality of second ports An operation and maintenance management frame integrating means for generating an operation and maintenance management frame including a response message of error information in order to send a reply to the second port when the operation and maintenance management frame cannot be received from A communication device. The operation / maintenance management frame integration means includes an operation / maintenance management including the error information to transmit to the first port when the operation / maintenance management frame cannot be received from a part of the plurality of second ports. The communication device according to claim 1 , wherein a frame is generated. The operation and maintenance management frame, the communication apparatus according to claim 1 or 2, characterized in that the Ethernet OAM (Operation Administration and Maintenance) frame. Installed in a communication device having a first port that transmits and receives data frames to and from the first communication device, and a plurality of second ports that transmit and receive data frames by link aggregation with the second communication device In a program that causes a computer to function,
Operation maintenance management frame duplicating means for duplicating the operation maintenance management frame received from the first port so as to be transmitted to all of the plurality of second ports ;
When the same operation and maintenance management frame is received from all of the plurality of second ports, one operation and maintenance management frame to be transmitted to the first port is generated, and a part of the plurality of second ports If the operation / maintenance management frame cannot be received from the operation / maintenance management frame, the operation / maintenance management frame is integrated to generate an operation / maintenance management frame including a response message of error information in order to send a reply to the second port A program for a communication device, which causes a computer to function. The operation / maintenance management frame integration means includes an operation / maintenance management including the error information to transmit to the first port when the operation / maintenance management frame cannot be received from a part of the plurality of second ports. The program for a communication apparatus according to claim 4 , wherein the computer is caused to function so as to generate a frame. 6. The communication apparatus program according to claim 4, wherein the operation / maintenance management frame causes the computer to function as an Ethernet OAM frame.

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