KR100309187B1 - V5.2 link control method - Google Patents

Abstract

The present invention relates to a V5.2 link control method for reliably performing a communication service by resolving a failure in a V5.2 service caused by a temporary link failure state mismatch during a link identification procedure between a local exchange and a subscriber network access device. By solving the abnormal status management problem of the link that may occur during the link identification procedure when the V5.2 interface is activated after the link failure recovery between the switch connected to the V5.2 protocol and the subscriber network access device, To provide stable V5.2 services.

Description

5.2 Link control method

The present invention relates to a V5.2 link control method, and more particularly, V5 for resolving a link state mismatch in a link identification procedure performed when a link between a local exchange and a subscriber network access device is reactivated and then reactivated. .2 link control methods;

Referring to the conventional procedure for starting the failover of the link between the local switch and the subscriber network access device, as shown in FIG. 1, the local switch (LE) 12 and the subscriber network access device (AN) 11 are V5.2. PSTN and ISDN services are provided to subscribers connected to the subscriber network access device 11 using the protocol link 13. A maximum of 16 links can be allocated between the subscriber network access device 11 and the local exchange 12. The failure occurs between these links, the interface is in an unserviceable state, and then recovers to normal again. If it does, it will go through a startup procedure. A link identification procedure is a procedure for checking whether the links connected between the dual subscriber station access device 11 and the local switch 12 are normal. Here, the local exchange 12 refers to a switching system and is a single station exchange connected to the subscriber network access device 11 and the V5.2 protocol link 13. The subscriber network access device 11 is a subscriber subscriber remote access equipment connected to a terminal exchange (i.e., the local switch 12 means side) via the V5.2 protocol link 13.

When the local exchange 12 sends a link identification request (FE_IDReq; Link Identification Request) to the subscriber network access point 11 for activation, the subscriber network access point 11 receives the link state. If normal, the link flag procedure request acknowledgment (FE_IDAck) is sent to the local exchange 12 by setting a related flag (Sa7 Bit) value to '0' (16).

Accordingly, the local exchange 12, which has received this, recognizes that the link state is normal and transmits a link identification release request (FE_IDRel) to the subscriber network access device 11 (17), and the subscriber network. The connection device 11 transmits a link identification procedure release request confirmation (FE_ID Rel ACK) to the local exchange 12, thereby performing link identification between the subscriber network connection device 11 and the local exchange 12. Here, the local exchange 12 sequentially executes the link identification procedure described above with respect to the link assigned to the subscriber network access device 11 to check whether all links connected to the subscriber network access device 11 are normally connected. Check

However, due to the difference in the timing of detecting the failure recovery of the link between the local exchange 12 and the subscriber network access device 11 during the link identification procedure, the link status is still abnormal on the subscriber network access device 11 side. When the local exchange 12 performs the link identification procedure in the state, the subscriber network access device receiving the link identification procedure request (FE_IDReq) 21 (before the link failure recovery is detected) as shown in FIG. 11 requests Link Block Indication to the local exchange 12 side, and the local exchange 12 recognizes the corresponding link at this time as a blocked state.

Although the link state is kept in the blocked state even if the recovery of the link failure is detected 22 on the subscriber network access device 11 for the link, the local switch 12 remains in the state of being normal. And a link state mismatch 25 occurs between the subscriber network access device 11 and the subscriber network access device 11.

Accordingly, the present invention has been made in view of the above-mentioned conventional situation, and the communication service can be stably performed by eliminating the fault occurring in the V5.2 service caused by the temporary link failure state mismatch during the link identification procedure between the local exchange and the subscriber network access device. The purpose is to provide a V5.2 link control method.

In order to achieve the above object, the V5.2 link control method according to the preferred embodiment of the present invention is applied to all the links allocated to the subscriber network access device when the V5.2 interface which is in the unserviceable state is reactivated due to the link failure. A first step of storing a logical link number for a link that transmits a blocking request due to a failure while performing a first identification procedure; and corresponds to the logical link number stored in the first step after completing all identification procedures for the links. The second process of requesting the unblocking of the link to be released and performing a second identification procedure on the unblocked link by the request, and checking the link in the normal state after the first identification procedure as a serviceable link. Equipped.

1 is a view for explaining a procedure that is initiated in the failure recovery of a link connected between a conventional switch and a subscriber network connection device;

2 is a flowchart illustrating an abnormal case that may occur during the link identification procedure of FIG. 1;

3 is a flowchart illustrating a V5.2 link control method according to an embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

11: subscriber network access device 12: local exchange

13: V5.2 protocol link

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating a V5.2 link control method according to an embodiment of the present invention.

In the present invention, a link failure occurs between the local switch 12 and the subscriber network access device 11, so that the V5.2 interface is in an unserviceable state and then recovers to normal again. Differences in the timing of detecting link failure recovery between the local exchange 12 and the subscriber network access device 11 during the link identification procedure for checking the normality, that is, the subscriber network at the time of the link identification procedure request from the local exchange 12 side. If the access point 11 is in the state before the recovery detection of the link, the access point 11 transmits link block indication information to the local exchange 12, and receives the local exchange 12. 12 sets the link state to the blocked state and proceeds to the identification procedure for the other link. Thereafter, even after detecting a link failure recovery on the subscriber network access device 11 side, the local switch 12 side is applied when a state mismatch problem occurs in which the corresponding link blocking state is maintained.

The link receiving the link blocking request 31 from the subscriber network access device 11 during the link identification procedure is determined to be in the above state (i.e., an abnormal state maintained in the link blocking state even after the link failure recovery). The logical link number of the link for the failed link is stored (32) in a table (not shown), and then unblocked for the link corresponding to the previously stored logical link number after the identification procedure for all links is completed. (33, 34) and start link identification procedure again (35, 36, 37, 38). At this time, the link which has normally completed the link identification procedure with the subscriber network access device 11 is determined to be a service-enabled link, while the link that receives a block request from the subscriber network access device 11 is abnormal. Judgment is made to block state.

In other words, if the V5.2 link between the local exchange 12 and the subscriber network access device 11 fails and the interface is in a service unavailable state and detects a failure recovery, the procedure of starting the V5.2 interface is performed. do. When the activation procedure is performed, the link identification procedure is performed for all links assigned to the interface to check whether the link is normal. When the local exchange 12 sends the link identification procedure request (FE_ID Req) to the subscriber network access device 11 to perform the link identification procedure (35), the local exchange 12 receives the subscriber network access device 11 in the normal case. Receive the link identification procedure request confirmation (FE_IDAck) from the terminal (36) and check the relevant flag (Sa7 Bit). If the value is '0', the link status is judged as normal, whereas if the value is '1', it is abnormal. Judging by. At this time, if the local exchange 12 receives a block request from the subscriber network access device 11 after transmitting the link identification procedure request (FE_ID Req), the link state of the current subscriber network access device 11 becomes After determining that the failure state, the logical link number of the corresponding link is stored in a table (not shown), and then a link identification procedure is performed for the next link.

After performing the identification procedure for all links, the state of the subscriber network access device 11 is rechecked for the logical links stored in the table. First, the unlink request is sent to the subscriber network access device 11 and the identification procedure is performed again to make the link serviceable only when the normal identification procedure is completed.

According to the present invention as described above, when the link procedure between the switch connected to the V5.2 protocol and the subscriber network access recovery procedure proceeds with the activation procedure of the V5.2 interface, the link may be abnormal during the link identification procedure. By solving the state management problem, it is possible to provide a stable V5.2 service to the subscriber.

On the other hand, the present invention is not limited only to the above-described embodiments, but may be modified and modified without departing from the scope of the present invention.

Claims (2)

When the V5.2 interface, which is out of service due to a link failure, is reactivated, it performs the first identification procedure for all the links assigned to the subscriber network access device. A first process of storing; After the identification procedure for all the links is finished, the second linking procedure is performed for the unblocked link by requesting the unblocking of the link corresponding to the logical link number stored in the first step. And a second step of checking a link in a normal state as a serviceable link after the identification procedure. The method of claim 1, The V5.2 link control method, characterized in that the link receiving the disconnect request from the subscriber network access device in the second process to make the service unavailable.