CN1780231A - Backup system and method for access servo interface - Google Patents

Abstract

The invention relates to the field of communication, and discloses a backup system and method for an access server interface, so that when the working access server interface fails, it can also ensure that the accessing network can be accessed without manual intervention. Users are not affected. The principle of the present invention is that the access server interfaces with mutual active and standby relationship are equipped, and the active access server interface periodically sends the first message to the standby access server interface. When the interface of the main access server fails, the interface of the standby access server determines that it has failed by not receiving the first message from the interface of the main access server within a predetermined time, and automatically sets itself as the interface of the main access server, and continues Provide access services to users.

Description

Backup system and method for accessing server interface

technical field

The invention relates to the communication field, in particular to an access server interface backup technology in data communication.

Background technique

The development of the network has brought people into the information society. With the popularization of the Internet, the Internet Protocol (Internet Protocol, referred to as "IP") has occupied a leading position in various terminal applications, and users' demand for network bandwidth is getting higher and higher. , Broadband network has become the trend of current network development. Due to the rapid growth of the backbone network bandwidth, the traditional access network has become the bottleneck of the broadband network, and the construction of a broadband access network has become a new hot spot. How to transmit IP data more efficiently, at high speed and at low cost will be the focus of telecom network research in the future.

As one of the Internet (Internet) access methods provided by telecommunication service providers, the Ethernet network is directly oriented to Ethernet access users. It is the best Layer 2 broadband access method for carrying IP data services and has been widely used. Using the network as a supporting platform, users can carry out various community intelligent services such as security management, property management, user interconnection, online shopping, and video-on-demand. Therefore, it is required that the Ethernet network should be a network with high bandwidth, high reliability, low construction and low maintenance costs, and a network that realizes operation and provides services.

As shown in Figure 1, in the current Ethernet network, users 15 and 16 are generally connected to the Layer 2 access device 14 first. Those skilled in the art know that the Layer 2 access device 14 is usually only An Ethernet switch that provides layer-2 switching functions, or other layer-2 devices that can provide transparent transmission of Ethernet data frames. The Layer 2 access device 14 generally plays the role of converging, and then connects to the access server 13. The main function of the access server 13 is to control the access users, including authentication, billing, authority control, flow control, QOS, etc., the Ethernet network can be operated and managed, and it can be distinguished from ordinary computer networks, the key lies in the role played by the access server 13 . Through the legal data flow of the access server 13, the router 12 and the router 11 of the upper layer are forwarded, and finally connected to the Internet 10. It should be noted that, because the network system of the Internet 10 is very large, it is generally still necessary to use the router 12 for The edge routes are aggregated, and then the router 11 is used for core route forwarding, so as to make the network hierarchy clear and easy to maintain and manage.

It can be seen that the access server 13 occupies a very important position in the entire Ethernet network. Without it, it is impossible to manage users and the network. If it is directly skipped, the second-layer access device 14 is connected to the router 11. In fact, it is an ordinary computer network, and it is clear to those skilled in the art that an ordinary computer network cannot provide telecommunication-level services. The importance of the access server 13 also requires that the interface connection between it and the Layer 2 access device 14 is very reliable, but in practice, there will always be various abnormal situations. Therefore, if the user-side interface of the access server 13 experiences abnormal restart of the server, hardware damage, etc., the users below it will not be able to re-access the network until it recovers. Such a situation does not have a carrier-level service commitment for users. , It is not conducive to the promotion of Ethernet network access methods.

At present, the solution to the failure of the access server is to update the hardware by the network maintenance personnel, or reset the access server, or switch the affected users to the standby access server.

In practical application, the above solution has the following problem: although the network can be restored to normal eventually, it takes a long time. Even beyond the range of user tolerance. This phenomenon is especially serious when maintenance personnel are not on site.

The main reason for this situation is that the above solution is manually maintained. Therefore, not only the cost of manpower and material resources is higher, but also time-consuming.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a backup method and system for an access server interface, so that when a working access server fails, it can also ensure that the access server is being accessed without manual intervention. Users of the network are not affected.

In order to achieve the above object, the present invention provides a backup method for accessing the server interface, comprising the following steps:

A Multiple access server interfaces that are mutually backed up determine their master-backup relationship according to their own interface priorities;

The main access server interface of B regularly sends the first message to the standby access server interface during the active state;

C. When the standby access server interface has not received the first message from the main access server interface within a predetermined period of time, enter step A.

Wherein, the step A includes the following sub-steps:

Multiple access server interfaces that are mutually backed up by A1 send first packets containing their own interface priorities to each other;

A2 The access server interface judges whether the priority of the other party's interface in the received first message is higher than the priority of this interface, if yes, then set this interface as the standby access server interface, otherwise set this interface Set as the main access server interface.

In the step B, the primary access server interface sends the first packet to the standby access server interface at a frequency of 1 time per second.

The multiple access server interfaces that are mutually backed up may be distributed on different servers.

The multiple access server interfaces that are mutually backed up may be distributed on the same server.

The first message contains the following content:

Version number, packet type, backup group identifier, interface priority, sending time interval of the first packet, and a checksum for verifying the validity of the first packet.

The first message also includes authentication type, random number and authentication value used in authentication.

The present invention also provides a backup system for an access server interface, which includes a plurality of access server interfaces that back up each other, wherein the access server interface determines the master-backup relationship according to the interface priorities of both parties, and,

The main access server interface is used to periodically send the first message to the standby access server interface during the active state;

The standby access server interface is used to monitor the first message from the main access server interface, and when the first message is not received within a predetermined time, set itself as the main access server interface .

Wherein, the multiple access server interfaces that are mutually backed up are distributed on different servers.

The multiple access server interfaces that are mutually backed up are distributed on the same server.

Through comparison, it can be found that the difference between the technical solution of the present invention and the prior art is that access server interfaces in a master-standby relationship are equipped with each other, and the master access server interface periodically sends the first message to the standby access server interface. When the interface of the main access server fails, the interface of the standby access server judges that it has failed by not receiving the first message from the interface of the main access server within a predetermined time, and automatically sets itself as the interface of the main access server, and continues Provide access services to users.

The difference in this technical solution has brought obvious beneficial effects, that is, it can detect the failure of the main access server interface in a relatively timely manner, and immediately replace it with the standby access server interface to work. Therefore, it is avoided that when the interface of the main access server fails, the obvious impact on the users who are accessing the network is avoided, and the user satisfaction is improved. Moreover, compared with the prior art, this method saves manpower and material cost more.

Description of drawings

Fig. 1 is a schematic diagram of Ethernet network structure in the prior art;

Fig. 2 is a schematic diagram of ASSP multicast message format according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a backup system for an access server interface according to an embodiment of the present invention;

Fig. 4 is a schematic diagram of an active-standby switchover process of an access server interface according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

The present invention utilizes the idea of redundant backup and adopts a new access server backup protocol (Access Server Standby Protocol, referred to as "ASSP") to backup and protect the key access server interface of the Ethernet network. Redundant backup requires at least two identical components to be realized. In the present invention, for example, two or more access server interfaces are used, one is used as the main access server interface, and the rest are used as backup access server interfaces. Real-time Obtain the state of the other party to maintain its own state machine, thereby defining ASSP, and the active and standby access server interfaces for mutual backup communicate through ASSP multicast messages. It should be pointed out that the active and standby access server interfaces can be on the same access server or on different access servers. The interface of the access server realizes the backup.

Due to the important role of the ASSP in the present invention, the format of its multicast message will be described below in conjunction with FIG. 2 . In Fig. 2, the total length of the ASSP multicast message is 28 bytes, that is, 224 bits. For the convenience of illustration, Fig. 2 divides it into 7 segments every 4 bytes and overlaps them. In the whole message, some special fields are defined according to different lengths, which are used to transfer information between the active and standby access server interfaces. The meanings of each field from the beginning to the end are as follows:

1. Version number (Version): currently 1;

2. Message type (Type): Currently there is only one type, namely ADVERTISEMENT, with a value of 1;

3. Backup Group ID: identifies the backup group where the interface is located;

4. The priority of the interface (Priority);

5. Authentication type (Auth Type): At present, there are two types of authentication: non-authentication and Message-Digest algorithm 5 (MD5 for short);

6. The time interval for sending ASSP messages (Adver Interval);

7. Reserved (Reserved): temporarily not used, for future expansion;

8. Checksum (Check Sum): used to verify the legitimacy of the entire ASSP message;

9. Random number (Random): It is useful for MD5 authentication, but useless for non-authentication;

10. Authentication Value (Auth Value): It is useful for MD5 authentication, but useless for non-authentication.

What needs to be explained here is that the use of the MD5 algorithm does not require any copyright fees, so it is a security algorithm widely used in the authentication of non-top-secret applications. Its function is to allow large-capacity information to be signed with digital signature software. The private key is "compressed" into a confidential format, that is, a byte string of any length is transformed into a large integer of a certain length, in this way the purpose of encrypting the information that needs to be authenticated is achieved. Finally, it should be added that the message format in Figure 2 is only a form, and can be partially modified as needed.

The above is the detailed description of the ASSP multicast message in the present invention. In addition, the present invention also needs to do the following simple settings in advance for the active and standby access servers.

First, set up a backup group for the primary and backup access servers that need to back up each other. Only interfaces in the same backup group can send ASSP packets to each other. Minimize the scope of multicast ASSP packets to avoid crowding the bandwidth of user data streams.

Secondly, the priority of each interface in the backup group is identified, which is used to elect the main access server interface in the backup group.

Next, make the interface of the main access server active and able to send and receive uplink or downlink packets normally. The packets here mainly refer to a large amount of data between the access server and the Layer 2 access device, including user authentication, Control flow data such as billing, authority control, flow control, QOS, etc., also includes the data flow exchanged between the user and the external Internet, and of course ASSP multicast message data.

Finally, set the interface of the access server of the device to be in an inactive state, which can only receive ASSP packets and not send or receive any other packets. The standby access server monitors the changes of ASSP messages at all times. When the main access server interface is abnormal, the standby access server interface is automatically upgraded to the main access server interface. The switching time between these is only limited by electronic devices, which is far less In manual switching time, it fully meets the carrier-grade requirements.

The backup system of the access server interface and the backup method of the access server interface proposed according to the principles of the present invention are described below in conjunction with FIG. 3 and FIG. 4 .

As shown in FIG. 3 , the backup system of the access server interface in this embodiment mainly includes two access server interfaces 330 and 340 that are mutually backup, and they determine the master-backup relationship according to the interface priorities of both parties. Specifically, they send ASSP messages containing their own interface priority to each other, and judge whether the priority of the other party's interface in the received message is higher than the priority of this interface, and if so, set this interface as standby access server interface, otherwise, set this interface as the main access server interface. What needs to be explained here is that, according to the principle of the present invention, the number of access server interfaces that are mutually backup is not limited to 2, and can be any number, one of which is the main access server interface, and the rest are standby access servers interface.

The main access server interface is used to periodically send the first message to the standby access server interface during the active state, and the standby access server interface is used to monitor the first message from the main access server interface, and When the first packet is not received within a predetermined time, set itself as the main access server interface.

The operation of the above system is further described below. Users 36 and 37 are first connected to the Layer 2 access device 35, and after being aggregated by the Layer 2 access device 35, they are then connected to an interface 330 of the access server 33. At the same time, they are connected to the interface 330 The interface 340 of another access server 34 for backup is also connected to the access device 35 on the second floor, and they are all allocated in the same virtual local area network (Virtual Local Area Network, referred to as "VLAN"). Yes, dividing them into the same VLAN can reduce the scope of the impact of the broadcast storm between the two, and can also avoid crowding the user's bandwidth. The uplinks of the two access servers are connected to the same router 32, and then connected to the Internet 30 through the router 31 step by step.

The network topology modification is described above. Next, further explain the process of implementing ASSP access server interface backup on the software, as shown in Figure 4:

First, step 410 is a default setting process. By default, all the interfaces accessing the server are the main access server interfaces in the initial state, that is, the interfaces 330 and 340 are the backups of each other, and there is no distinction between the main and backup at this time, and any packets can be sent and received normally.

Next, when the mutual backup interface 330 and interface 340 are configured in the same backup group and the ASSP protocol is enabled, they will send ASSP multicast packets to each other, and the packets carry their own interface priorities. In the same VLAN, therefore, the interface 330 can receive the ASSP message sent by the interface 340 , and similarly, the interface 340 will also receive the ASSP message sent by the interface 330 .

Then, step 430 is a judging process, which is also a watershed for the interface 330 and the interface 340 to distinguish between the active and standby states. After the two interfaces receive the ASSP message sent by the other party, they take out the priority in the message and compare it with the priority of their own interface. If the priority of the other party is found to be high, the interface enters step 440. is not higher than its own priority, go to step 431.

In step 431, since the interface judged in the previous step 430 that the other party's priority is not higher than its own priority, it keeps itself in the master access server state in this step. In this embodiment, the interface 330 is set to be in this state, that is, the priority of the interface 330 is higher than that of the interface 340, and there are only two interfaces in the backup group. In this way, after the exchange of ASSP messages, it becomes the main access The service interface is responsible for the data flow transfer task between the access server 33 and the layer 2 access device 35 in the entire network when it works normally, and can send and receive any message normally. After being set as the main access server interface, it will periodically send ASSP messages to the standby access server interface during the active state, which will be described in the subsequent step 470 .

In step 440, since the interface judged in the previous step 430 that the other party's priority is higher than its own priority, in this step, its own device needs to be connected to the server interface. In this embodiment, the interface 340 is set to be in this state, that is, the priority of the interface 330 is lower than that of the interface 340. In this way, after the interaction of the ASSP message, it becomes the standby access service interface, and becomes the new master in the future. Before accessing the service interface, only ASSP packets can be received.

Then enter step 450, where the standby access server interface judges whether the ASSP message from the main access server interface has not been received within a predetermined time period. This step is a judging process for the access server interface 340, and the judging is made according to the time interval monitoring of received ASSP messages. If it does not exceed the set limit value, it will continue to maintain the status of the standby access server interface. If the limit value is exceeded, go to step 460 .

In step 460, when the primary interface is abnormal, all the standby interfaces will not receive the first message sent by the primary interface. In this way, all the standby interfaces will be upgraded to the primary interface after a predetermined time. At this time, it is equivalent to returning to the default setting state, and all interfaces will send ASSP packets containing their own priorities, and finally a primary interface will be elected, and the others will become standby interfaces.

Finally, in step 470, the primary access server interface periodically sends ASSP messages to the standby access server interface during its active state.

To sum up the above steps, when the interface 330 and the interface 340 work normally, all users of the Layer 2 access device 35 can only access the Internet through the interface 330 after they elect the active and standby interfaces. When the interface 330 is in an active state, it will periodically send an ASSP message, for example, once a second. In this way, as long as the interface 330 is normal, the interface 340 can always receive the ASSP message, thereby knowing that the interface 330 is in the active state, and always maintains the state of the standby access server interface. Those skilled in the art can understand that the frequency of periodically sending out ASSP packets can be configured and modified as required.

When an exception occurs on the interface 330, the interface 340 cannot receive the ASSP message. If it exceeds the set limit, such as not receiving the ASSP message sent by the interface 330 for 3 consecutive seconds, the interface 340 will know that an exception has occurred on the interface 330. Automatically become the primary access server interface. At this point, all users under the Layer 2 access device 35 will access the Internet through the interface 340 . Since the time for the interface 340 to switch from the standby access server interface to the main access server interface is very short, usually a few seconds, for the user, due to the processing of the upper layer protocol of the IP network, the relevant changes cannot be felt, obviously It meets the requirements of telecom-grade service.

The above is an embodiment of two interfaces belonging to different access servers to implement backup. If the two interfaces belong to the same access server, the process is similar, but only has interface-level redundant backup, and lacks access server-level Redundant backup.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein, and without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. the backup method of an access servo interface is characterized in that, comprises following steps:

The mutually redundant a plurality of access servo interfaces of A are determined its main and standby relation according to the interface priority of self;

The described main access servo interface of B regularly sends first message to being equipped with access servo interface during being in active state;

C when being equipped with access servo interface and surpassing predetermined amount of time and do not receive first message from described main access servo interface yet, enters steps A when described.

2. the backup method of access servo interface according to claim 1 is characterized in that, described steps A comprises following substep:

The mutually redundant a plurality of access servo interfaces of A1 send first message that comprises himself interface priority mutually;

The described access servo interface of A2 judges whether the other side's interface priority in described first message of receiving is higher than this interface priority, if then this interface is set to access servo interface fully, otherwise this interface is set to main access servo interface.

3. the backup method of access servo interface according to claim 1 is characterized in that, among the described step B, described main access servo interface can send described first message to the described access servo interface that is equipped with 1 time/second frequency.

4. according to the backup method of any described access servo interface of claim 1 to 3, it is characterized in that described mutually redundant a plurality of access servo interfaces can be distributed on the different servers.

5. according to the backup method of any described access servo interface of claim 1 to 3, it is characterized in that described mutually redundant a plurality of access servo interfaces can be distributed on the identical server.

6. the backup method of access servo interface according to claim 4 is characterized in that, comprises following content in described first message:

The transmission time interval of version number, type of message, backup group sign, interface priority, described first message and be used for described first message validity of verification verification and.

7. the backup method of access servo interface according to claim 6 is characterized in that, described first message also comprises auth type and authenticates employed random number and authentication value.

8. the standby system of an access servo interface is characterized in that, comprises mutually redundant a plurality of access servo interface, and wherein, described access servo interface is determined main and standby relation according to both sides' interface priority, and,

Described main access servo interface is used for during being in active state, regularly sends first message to being equipped with access servo interface;

The described access servo interface that is equipped with is used to monitor first message from described main access servo interface, and surpassing the scheduled time when not receiving described first message yet, self is set to main access servo interface.

9. the standby system of access servo interface according to claim 8 is characterized in that, described mutually redundant a plurality of access servo interfaces are distributed on the different servers.

10. the standby system of access servo interface according to claim 8 is characterized in that, described mutually redundant a plurality of access servo interfaces are distributed on the identical server.

Images