Method and system for detecting and maintaining PPP (point-to-point protocol) link

Abstract

The invention discloses a method and a system for detecting and maintaining a PPP link. The method comprises the steps as follows: an IP (internet protocol) test message is sent through a dialing end to an LAC (L2TP access concentrator) in a link connecting relation with the dialing end; the LAC receives and packages the IP test message sent by the dialing end, and then forwards the IP test message to an LNS (L2TP network server) which builds a tunnel connection with the LAC; the LNS receives the packaged IP test message, unpacks the IP test message and obtains address information of the dialing end; the IP test message which is packaged again is sent to the dialing end according to the address information of the dialing end after the IP test message is packaged again; if the dialing end receives the replied IP test message, the link is normal; otherwise, the link is abnormal, and dismounting and rebuilding are required when the link abnormity meets the limit requirement. With the design of the IP test message structure, the problem that the test message is intercepted and agented by the LAC easily in the prior art is solved, and the link detection and maintenance of the LAC are achieved.

Description

technical field [0001] The invention belongs to the technical field of data communication, and relates to a link detection and maintenance method and system, in particular to a PPP link detection and maintenance method and system capable of traversing an access concentrator LAC. Background technique [0002] VPDN (Virtual Private Dial-up Networks), also known as virtual private dial-up network, is a virtual network based on dial-up access to PSTN (Public Switched Telephone Network) public switched telephone network, ISDN (Integrated Services Digital Network) integrated service digital network, 3G, etc. Dedicated dial-up network services, due to the large number of applications of 3G technology, many operators have actively launched 3G private line network services to meet the application needs of many enterprises and administrative units, such as mobile banking, off-line ATM, mobile office dispatched, law enforcement scene Real-time presence, Internet of Things and other app...

AI Technical Summary

Problems solved by technology

[0003] However, the current PPP link detection mechanism still uses sending PPP Echo-request and receiving PPP Echo-replay to realize link detection. A PPP Echo-replay message must be responded to as a response. If one end fails to receive the PPP Echo-replay from the other end for several times in a row, it means that there is a problem with the link, and maintenance operations such as link teardown and reconstruction are required. The reason is that the PPP Echo-request message sent from the dial-up end to the LNS end will be terminated by the LAC and will respond to the PPP Echo-replay message to the dial-up end. Echo-replay, so that the detection message cannot be sent directly from the user's dial-up end to the user's LNS end, resulting in the original PPP Echo link detection mechanism only between the dial-up user end and the LAC, and between the LAC and the LNS. Separate detection, the disconnection of any link cannot be sensed by the corresponding link, causing the dial-up end or LNS end to mistakenly think that the entire link is normal, and cannot truly and effectively reflect the actual link situation

As a result, the problem is that when the line between the 3G dial-up user and the LAC is still normal, but the line between the LAC and the customer's LNS is abnormal, the 3G dial-up user side will mistakenly think that the entire link is normal and continue to send Service data without rebuilding the line, which seriously affects the business and wastes a lot of 3G resources; when the 3G dial-up user is disconnected, and the upper-end LNS cannot perceive and cannot be removed in time, it will increase the occupation of local resources on the LNS side , not easy to maintain

Images