KR100889753B1 - Method of protection switching for link aggregation group and Apparatus thereof - Google Patents

Abstract

The present invention relates to a protection switching method and apparatus for applying protection switching according to the G.8031 standard to link aggregated Ethernet ports (link aggregation group). The protection switching device in the link aggregation group disclosed in the present specification is a LAG distribution path information derivation unit for deciding which Ethernet frame transmitted and received from a MAC client is distributed to a working LAG or a plurality of physical ports of the protection LAG. ; And an OAM frame header generation unit for generating a header of an OAM frame related to the Ethernet frame by reflecting the derived path information.

Description

Method of protection switching in a link aggregation group and its apparatus {Method of protection switching for link aggregation group and Apparatus}

The present invention relates to a method and apparatus for protection switching in a link aggregation group, and in particular, to a link aggregation Ethernet port (link aggregation group), the protection switching function according to the G.8031 standard ( The present invention relates to a protection switching method and apparatus for applying protection switching.

The present invention is derived from the research conducted as part of the IT new growth engine core technology development project of the Ministry of Information and Communication [Task management number: 2006-S-061-01, Task name: IPv6 based QoS service and terminal mobility support router technology Development].

Link aggregation is IEEE Std. A standard technology defined in 802.3ad that logically combines multiple physical Ethernet ports to enable a single, high-bandwidth logical Ethernet port (Ethernet Media Access Control, Ethernet MAC). These multiple physical Ethernet ports coupled by link aggregation are called Link Aggregation Groups (LAGs for short).

1 is a schematic diagram illustrating a frame transfer method from a transmitting end to a receiving end of a single logical Ethernet MAC generated by link aggregation.

A single logical Ethernet MAC generated by link aggregation is used to transmit a frame received from the transmitting end client to itself (to send the received frame to the MAC client receiving end), A LAG distribution algorithm, which is a type of port selection algorithm, is used to select a physical Ethernet port (ie, a port to transmit a frame received to it) from a link aggregation group (LAG). Frames transmitted through the selected Ethernet port are multiplexed and delivered to the receiving client.

However, since the standard for the LAG distribution algorithm is not defined, a unique distribution algorithm is used for each manufacturer of the Ethernet system. Generally, a destination MAC address, a destination MAC address, a destination IP address, and a destination IP of a transmission frame are used. Distribute by referring to the address, TCP port number, etc. (select the sending port).

Link aggregation causes some of the multiple physical Ethernet ports in the link aggregation group to fail, excluding the failed port from the link aggregation group and allowing only the remaining ports to work. This is an advantage of link aggregation groups over single Ethernet ports.

However, in spite of these advantages, the following problems may arise in applying the protection switching method of Ethernet ports according to the ITU-T Recommendation G.8031 standard to the link aggregation group.

First, because the G.8031 standard specifies 1 + 1 or 1: 1 protection switching in a point-to-point connection structure based on VLANs (VLANs), each frame belonging to a different VLAN Different protection switching functions should be provided, ie independent protection switching functions should be provided for each VLAN.

However, since link aggregation uses a marker protocol to control the path on a per port basis, it is impossible to provide an independent protection switching function for each VLAN. In other words, the protection switching scheme according to the G.8031 standard cannot be applied to the link aggregation group.

Second, the G.8031 standard uses the OAM (Operations, Administration and Maintenance) frame called Continuity Check Message (CCM) to monitor the status of the Ethernet link, and the protection switching function works by sending and receiving APS (Automatic Protection Switch) frames. It is prescribed. Since the G.8031 standard is based on a point-to-point connection structure, each VLAN must have its own CCM and APS frames.In an Ethernet link coupled by link aggregation, the data frames belonging to the VLAN and the corresponding OAM and APS Difficulties can cause frames to be transmitted and received via the same physical Ethernet port, resulting in unstable protection switching by the G.8031 standard.

The present invention has been made to solve the above problems, the object of the present invention and the technical problem to be achieved is to make the protection switching method according to the G.8031 standard applied to the link aggregation group protection switching in the link aggregation group It is an object of the present invention to provide a method and apparatus for protection switching in a link aggregation group that can efficiently implement a scheme.

In order to achieve the above object and technical problem, the protection switching device in the link aggregation group disclosed herein distributes Ethernet frames transmitted and received from the MAC client to any one of a plurality of physical ports of the working LAG or the protection LAG. LAG distribution path information deriving unit for deriving whether or not to be; And an OAM frame header generation unit for generating a header of an OAM frame related to the Ethernet frame by reflecting the derived path information.

In order to achieve the above object and technical problem, the protection switching method in the link aggregation group disclosed herein includes (a) an Ethernet frame transmitted and received from a MAC client is selected from a plurality of physical ports of a working LAG or a protected LAG. Deriving whether to be distributed to the port; And (b) generating a header of an OAM frame related to the Ethernet frame by reflecting the derived path information to achieve the object and technical problem of the present invention.

The core of the technical solution of the present invention is to derive the distribution path information of the working and protection LAG by the LAG distribution algorithm (port selection algorithm) in link aggregation, generate the OAM frame reflecting the information, and generate the generated OAM frame. The protection switching function for the G.8031 standard is efficiently implemented in the link aggregation group by performing the protection switching according to the above.

According to the present invention, by generating the OAM frame according to the G.8031 standard reflecting the LAG distribution algorithm implemented differently for each manufacturer of the Ethernet system to perform the protection switching according to the OAM frame, eventually the LAG distribution algorithm of the link aggregation group Regardless of how the (distribution rule) is implemented, the protection switching function by G.8031 for each VLAN can be applied independently for each VLAN.

Hereinafter, the configuration of the invention for clarifying the technical spirit and technical solutions of the present invention will be described in detail with reference to the accompanying drawings, based on the embodiments of the present invention, the same configuration in giving reference numerals to the components of the drawings The elements have been given the same reference numerals even though they are in different drawings, and it is noted that in the description of the drawings, components of other drawings may be cited if necessary.

FIG. 2A is a diagram illustrating a schematic configuration of a protection switching device in a link aggregation group.

As shown in FIG. 2A, the protection switching device of the link aggregation group includes a working LAG 20, a protection LAG 21, and a protection switching execution unit 22.

The working LAG 20 is composed of an Ethernet MAC and an Ethernet PHY, and combines a plurality of physical ports 20-1 to 20-n that transmit and receive the working LAG and Ethernet frames of other protection switching devices, thereby providing one logical Ethernet. Configure the port.

Like the working LAG 20, the protection LAG 21 is composed of an Ethernet MAC and an Ethernet PHY and includes a plurality of physical ports 21-1 to 21-n that transmit and receive Ethernet frames with the protection LAG of another protection switching device. Combine to form one logical Ethernet port.

The protection switching execution unit 22 transmits the Ethernet frame transmitted and received from the MAC client to the working LAG 20 or the protection LAG 21 or the working LAG 20 or the protection according to the LAG protection switching scheme proposed by the present invention. Performs a function received from the LAG 21.

FIG. 1B is a diagram illustrating a detailed configuration of the protection switching unit shown in FIG. 1A.

Referring to FIG. 1B, the bridge 221 first transmits the Ethernet frame a received from the transmitting unit of the MAC client to the transmitting unit of the working LAG 20 or the transmitting unit of the protection LAG 21. The selector 222 selects and transmits one of the Ethernet frames c and e of the remote MAC client received from the receiver of the working LAG 20 and the receiver of the protection LAG 21 to the receiver of the MAC client. Perform.

The LAG distribution path information deriving unit 223 performs a function of deriving distribution path information of the working and protection LAG using a LAG distribution rule (LAG distribution algorithm) from the Ethernet frame (a) received from the transmitting unit of the MAC client. The OAM frame header generation unit 124 receives a user command for directly inputting an OAM frame header or reflects the distribution path information transmitted from the LAG distribution path information deriving unit 223 to determine the OAM frame associated with the Ethernet frame a. Creates a header (b).

The first OAM frame extractor 225 extracts the OAM frame d from the Ethernet frame c of the remote MAC client received from the receiver of the working LAG 20, and the second OAM frame extractor ( 226 extracts the OAM frame f from the Ethernet frame e of the remote MAC client received from the receiver of the protection LAG 21.

The bridge and selector controller 227 receives a user command and OAM frames d and f extracted from the first and second OAM frame extractors 225 and 226 to determine a protection switching state to determine a protection switching state signal g. ), A control signal h of the bridge 221 and a selection control signal i of the selector 222 are output.

The OAM frame generator 228 receives the OAM frame header b from the OAM frame header generator 224 and the protection switching state signal g from the bridge and selector controller 227, and then works on the Ethernet frame a. A function of generating an OAM frame k for the LAG 20 and an OAM frame n for the protection LAG 21 is performed.

The first multiplexer 229-1 receives an Ethernet frame j to be delivered from the bridge 221 to the working LAG transmitter and an OAM frame k for the working LAG 20 from the OAM frame generator 228. To the working LAG transmitter, and the second multiplexer 229-2 protects the Ethernet frame m and the OAM frame generator 228 from the bridge 221 to the protected LAG transmitter. It receives the OAM frame (n) for the transmission and delivers one of them to the protection LAG transmitter.

Bridge 221, selector 222, bridge and selector control 227, OAM frame generator 228, first and second OAM frame extractors 225 and 226, first and second multiplexers 229-1, 229-2) are the building blocks generally used to implement the Ethernet protection switching function based on the G.8031 standard, and the detailed description of the functions of each building block is described in detail in the G.8031 standard.

The core for achieving the above object and technical problem of the present invention is implemented by the LAG distribution path information derivation unit 223 and the OAM frame header generation unit 224. Hereinafter, the operation of the present invention will be described centering on these functions.

The LAG distribution path information deriving unit 223 sends the working LAG 20 to the working LAG 20 so that the Ethernet frame a transmitted from the MAC client transmitting unit is delivered to the transmitting LAG 20 or the transmitting unit of the protection LAG 21. Or deriving distribution path information of which port to be distributed (through which port) among a plurality of physical ports of the transmitting unit of the protection LAG 21 (S31), and the result of the OAM frame header generation unit 124 is obtained. To pass. At this time, the criteria for deriving distribution path information are a working LAG distribution algorithm and a protected LAG distribution algorithm.

FIG. 2C illustrates a detailed configuration of the LAG distribution path information derivation unit shown in FIG. 2B.

The frame information extracting unit 2231 extracts the header from the Ethernet frame a transmitted from the MAC client transmitting unit and extracts related information of the received frame a (S311).

The working LAG distribution path information deriving unit 2232 selects information related to a parameter used by the working LAG distribution algorithm from the related information of the received frame a extracted by the frame information extracting unit 2231, and selects the selected information. Working LAG distribution path information of the received frame a is derived using the information and the working LAG distribution algorithm (S312).

The protection LAG distribution path information deriving unit 2333 selects information related to a parameter used by the protection LAG distribution algorithm from among the related information of the received frame a extracted by the frame information extraction unit 2231, and selects the selected information. The protection LAG distribution path information of the received frame a is derived using the information and the protection LAG distribution algorithm (S313).

The frame information extracted by the frame information extracting unit 1231 and the distribution path information determined by the working and protecting LAG distribution path deriving units 1232 and 1233 are collected and transferred to the OAM frame header generation unit 23.

In this case, the related information of the Ethernet frame (a) extracted from the frame information extracting unit 2231 includes various parameters used in a distribution algorithm of a typical LAG. The parameters include a destination MAC address, a source MAC address, It may be a destination IP address, a source IP address, a TCP port number, or the like, as well as ID information of a VLAN to which the Ethernet frame (a) belongs.

And, as mentioned above, LAG distribution algorithms vary among Ethernet system manufacturers, but usually use a simple algorithm of modulo N. For example, suppose a LAG consisting of four physical ports uses modulo 4's distribution algorithm, which takes a TCP port number as a parameter. In this case, when the TCP port number is 13, it is distributed to physical port 1 based on 13 mod 4 = 1, and when the TCP port number is 14, it is distributed to physical port 2 based on 14 mod 4 = 2.

The LAG distribution path information deriving unit 223 according to the present invention may use the same rules as the distribution algorithm (distribution rule) used in the LAG, but are not affected by the type of distribution rule.

FIG. 2D is a diagram showing an example of a frame header generated by the OAM frame header generator shown in FIG. 2B in the form of a table.

The OAM frame header generation unit 224 stores various parameters and distribution path information used in the distribution algorithm of the LAG, such as VLAN ID, working physical port number, protected physical port number, destination MAC address, and destination MAC address. Generate the OAM frame header by receiving the input from the deriving unit 223 as information for generating the header of the OAM frame or by receiving the above parameters and distribution path information directly from the user command as the information for generating the header of the OAM frame ( S32) Write in a table format, but the creation (creation) rules are as follows.

1) If the VLAN ID is not present in the OAM frame header table among the parameters and information received from the LAG distribution path information deriving unit 223, the OAM frame header information is newly registered in the table and generated.

2) If the VLAN ID is present in the OAM frame header table, search for the working and protection physical port number and retrieve the OAM frame header information only if there is no OAM frame header information with the same VLAN ID and the same working and protection physical port number. Create a new register in the table.

3) If the VLAN ID, working and protection physical port numbers are the same, the corresponding OAM frame header information is not registered and not regenerated.

The OAM frame generation unit 228 generates an OAM frame according to the G.8031 standard using the OAM frame header information created by such a creation rule (S33). Eventually, the generated OAM frame reflects the protection switching scheme according to the G.8031 standard in the link aggregation group, and eventually, the data frame and the OAM frame are distributed to the same physical port in the working or protection LAG for each VLAN (S34).

The present invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored.

Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention.

Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent scope will be construed as being included in the present invention.

1 is a schematic diagram illustrating a frame transfer method from a transmitting end to a receiving end of a single logical Ethernet MAC generated by link aggregation.

FIG. 2A is a diagram illustrating a schematic configuration of a protection switching device in a link aggregation group.

FIG. 2B is a view showing the detailed configuration of the protection switching unit shown in FIG. 2A.

FIG. 2C illustrates a detailed configuration of the LAG distribution path information derivation unit shown in FIG. 2B.

FIG. 2D is a diagram showing an example of a frame header generated by the OAM frame header generator shown in FIG. 2B in the form of a table.

3 is a view showing a preferred flow of the present invention.

Claims (7)

A LAG distribution path information deriving unit for deriving path information on which one of a plurality of physical ports of a working LAG or a protective LAG is transmitted and received from the MAC client; And By including an OAM frame header generation unit for generating a header of the OAM frame related to the Ethernet frame by reflecting the derived path information, It is possible to apply the protection switching method according to the G.8031 standard to the link aggregation group (LAG), so that the Ethernet frame and the OAM frame are distributed to the same physical port in the working or protection LAG for each VLAN. Protection switching device in the link aggregation group. The method of claim 1, wherein the LAG distribution path information derivation unit A working LAG distribution path information deriving unit for selecting a parameter used by a working LAG distribution algorithm from the information recorded in the header of the Ethernet frame and deriving the working LAG distribution path information of the Ethernet frame using the working LAG distribution algorithm; And A protection LAG distribution path information deriving unit for selecting a parameter used by the protection LAG distribution algorithm from the information recorded in the header of the Ethernet frame and deriving the protection LAG distribution path information of the Ethernet frame using the protection LAG distribution algorithm. A protection switching device in a link aggregation group, characterized in that the. The method of claim 2, wherein the OAM frame header generator generates the OAM frame header in the form of a table using parameters and path information transmitted from the LAG distribution path information derivation unit. If the VLAN ID, which is one of the parameters, is new or the ID already exists, the physical port number of the working LAG and the protection LAG of the Ethernet frame is searched for and only if there is no physical port corresponding to the number. A protection switching device in a link aggregation group, characterized in that it is registered and created in a table. (a) deriving path information on which Ethernet frame transmitted / received from the MAC client will be distributed to one of a plurality of physical ports of the working LAG or the protection LAG; And (b) generating a header of an OAM frame related to the Ethernet frame by reflecting the derived path information; It is possible to apply the protection switching method according to the G.8031 standard to the link aggregation group (LAG), so that the Ethernet frame and the OAM frame are distributed to the same physical port in the working or protection LAG for each VLAN. How to switch protection in link aggregation group. The method of claim 4, wherein step (a) (a2) selecting a parameter used by a working LAG distribution algorithm from information recorded in a header of the Ethernet frame and deriving working LAG distribution path information of the Ethernet frame using the working LAG distribution algorithm; And (a3) selecting the parameters used by the protection LAG distribution algorithm from the information recorded in the header of the Ethernet frame and deriving the protection LAG distribution path information of the Ethernet frame using the protection LAG distribution algorithm. A protection switching method in a link aggregation group characterized by the above-mentioned. The method of claim 5, wherein the OAM frame header of step (b) is generated in the form of a table using the parameter and the path information, If the VLAN ID, which is one of the parameters, is new or the ID already exists, the physical port number of the working LAG and the protection LAG of the Ethernet frame is searched for and only if there is no physical port corresponding to the number. A method of protection switching in a link aggregation group, characterized by being registered and generated. A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 4 to 6.

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