CN1734991A

CN1734991A - A method for detecting service loopback of multi-service transmission platform equipment

Info

Publication number: CN1734991A
Application number: CN 200410058370
Authority: CN
Inventors: 鱼明杰
Original assignee: ZTE Corp
Current assignee: CHINA TECHNOLOGY EXCHANGE Co Ltd; State Grid Beijing Electric Power Co Ltd; State Grid Economic and Technological Research Institute
Priority date: 2004-08-13
Filing date: 2004-08-13
Publication date: 2006-02-15
Anticipated expiration: 2024-08-13
Also published as: CN1734991B

Abstract

This invention discloses a method to detect loop-return business in multi business transmission platform device,, which comprises following steps: 1. generating unique track mark accorded with ITUT for every channel; 2. writing the mark on overhead position and sending; 3. abstracting the mark when receiving data; 4. comparing the received mark and send track mark to decide whether there is ring return. The method can find out the happen and disappear quickly, soles the problem that data exchange palsy for ring-return in SDH line, and makes MSTP device more stale.

Description

A kind of method that detects multi-service transport platform appliance services loopback

Technical field

The present invention relates to the multi-service transport platform technology of communication transmission field.

Background technology

The multi-service transport platform MSTP (Multi-ServiceTransport Platform) that is called as second generation transmission equipment is accepted by numerous telecom operators.It becomes the visual plant that makes up metropolitan area network with its cheap cost, high reliability and level and smooth upgrading ability.His architecture generally is divided into three parts: data are multiplexing to the intersection of the cascade of SDH mapping, SDH container and SDH container.

Because MSTP is the fusion of data and two kinds of technology of SDH, so the problem that can bring some not have at the general data network inevitably.In the general data network, the packet that port sends can not receive from same port again, and this is by the principle decision of data network exchange; But in MSTP equipment, the data that FPDP is sent are mapped on the SDH synchronous data-link, and loopback is the important means of SDH network debugging, therefore, at the line side of MSTP equipment port, packet just loopback might occur, and as shown in Figure 1: user data enters data switching networks by user port, under normal circumstances will exchange, and send by corresponding ports according to the network address of its packet; In MSTP equipment, if packet sends from the line side port, then can enter the framer of SDH, packet is mapped in the SDH synchronization link, and transmits by the SDH network; If loopback has appearred in the SDH link, data will be returned same line side port this moment, and at this moment, data are sent and accepted from same port, and this phenomenon is exactly the loopback of MSTP equipment.

The consequence of data service loopback is very serious, will directly cause exchanges data normally not carry out.Therefore, loopback is will avoid in the MSTP equipment as far as possible.At present in data network and SDH network, do not find general loop detection method as yet, do not see relevant method of on MSTP equipment, carrying out loopback detection in publication or the technical literature yet.

Summary of the invention

Purpose of the present invention just is to solve the problem that can't find the data loopback in the prior art, proposes a kind of method that detects multi-service transport platform appliance services loopback.

Core concept of the present invention is: utilize the tracking mark in the SDH path overhead to carry business, carry unique channels track sign, by the tracking mark that relatively receives whether with the consistent loopback that quick and precisely detects that sends, make MSTP equipment can take corresponding actions to avoid network paralysis.

A kind of method that detects multi-service transport platform appliance services loopback comprises the following steps:

Step 1,, each passage meets the unique tracking mark of ITUT to tracking mark byte regulation for generating;

Step 2, the tracking mark that generates is write corresponding expense position send;

Extract the tracking mark of corresponding expense position when step 3, reception data;

Step 4, according to channel information, whether the tracking mark by the channels track sign that relatively receives and transmission identical judges whether to have taken place loopback.

If detect loopback having taken place, then the line side port has been carried out corresponding operating, stops data to enter the exchanges data layer; State before the recovery port arrives and operates after loopback disappears.

Adopt the method that detects the data loopback in the MSTP equipment that is applied in that the present invention proposes, can find the generation and the disappearance of loopback rapidly and accurately, can make the loopback discovery time reduce to quite little degree (I to 2 millisecond).The method that the present invention proposes can solve based on MSTP and make up the intrinsic problem that causes exchanges data to be paralysed because of the SDH line loopback of metropolitan area network institute, makes MSTP equipment more stable.

Description of drawings

Fig. 1 is the schematic diagram of multi-service transport platform equipment generation loopback;

Fig. 2 is the flow chart of the method that proposes of the present invention;

Fig. 3 is the flow chart of a specific embodiment of the present invention.

Embodiment

The present invention is described in further detail below in conjunction with drawings and Examples.

Fig. 1 had carried out explanation in background technology.

Fig. 2 is the flow chart of the method that proposes of the present invention.As shown in Figure 2, the method for the detection multi-service transport platform appliance services loopback that the present invention proposes comprises the following steps: 1, meets the unique tracking mark of ITUT to tracking mark byte regulation for each passage generates.If the sign that generates is not unique, when receiving relatively erroneous judgement will appear.The tracking mark information that generates will meet the regulation of ITUT to the tracking mark byte, can be 1 such as the highest order of having only the CRC check byte.A kind of reliable tracking mark generation method is: CRC check sign indicating number+NE ID+sub-frame number+slot number+CPU number+channel number+random number; Perhaps the employing time generates: CRC check sign indicating number+year+date+time+channel number.2, the tracking mark that generates being write corresponding expense position sends.Because the different stage of SDH has different expenses, the writing position of tracking mark is also different, and for regenerator section, writing position is the J0 byte; For higher order path, writing position is a j1 byte; For low order channel, writing position is the J2 byte.In addition, the length of tracking mark is defined as 16 or 64 bytes, should guarantee that two kinds of forms can both send the sign with uniqueness, and can be identified and detect.Extract the tracking mark of corresponding expense position when 3, receiving data.Because the generation of tracking mark and the standard that transmission meets ITUT so general overhead extraction method is still adopted in the extraction of tracking mark, can not increase extra processing.4, according to channel information, whether the tracking mark by the channels track sign that relatively receives and transmission identical judges whether to have taken place loopback.For single pass loopback detection, if the tracking mark of the channels track sign that receives and transmission is identical then loopback has taken place; For the passage of Adjacent Concatenation, if the tracking mark of the tracking mark in the path overhead after the cascade and transmission is identical then loopback has taken place.For virtual cascade group, because the member in each cascaded series still has the expense of oneself, therefore still to detect the loopback situation of each member in the cascaded series, and determine the wrapped state of whole cascaded series according to different situations.A kind of feasible method is: think when loopback appears in arbitrary member in detecting cascaded series that cascade curses the generation loopback, and think that when all members do not have loopback cascaded series does not have loopback.When detecting loopback and occur, should stop port to continue to send or receive data to avoid the paralysis of whole node, such as this port of BLOCKING, forbid that it transmits data; When detecting the loopback disappearance, the result of binding data agreement operation that this port is operated, recover port to the preceding state of operation.

Fig. 3 is the flow chart of a specific embodiment of the present invention.In conjunction with Fig. 3, in a specific embodiment of the present invention, the method for detection multi-service transport platform appliance services loopback of the present invention comprises the following steps:

1, to obtain network element ID information, equipment unique address information in order to claim the unique information of path overhead at the device power initial phase.Such as network element ID is 0x00000024, and the veneer address is 0xB1, can generate following unique path overhead (hexadecimal) according to preceding method to first passage:

e700024b1004146167e20da

Second passage is:

ed00024b1014146167e20da

The rest may be inferred, can determine the expense that each passage has unique sign

2, the mapping particle of supposing SDH is the VC12 virtual container, and then the transmission position of tracking mark is the J2 byte, and the multi-frame of per 500 microseconds sends a byte, and 8 milliseconds have been transmitted one group of complete tracking mark.

3, extract the tracking mark of the J2 byte of each passage, the tracking mark that will correctly extract is delivered comparing unit and is compared then.

4, comparing unit is determined these channel group cascade situations according to user's configuring condition, and cascaded series and line side port corresponding relation, and whether each member's receive path sign is identical with transmission in the detection cascaded series.For example: cascaded series is made up of 1,2 two passage, if when finding tracking mark that 1 passage receives and transmission identical, can think that loopback has taken place the data of this virtual cascade group.When finding the cascaded series loopback, can carry out corresponding operating to the line side port, such as this port of BLOCKING, avoid data to enter the exchanges data layer; State before should recovering port after the loopback disappearance to arrive operation.

Because the channels track flag information can dynamically be set, therefore, must have and to allow the user that the position of channels track flag information is set, and utilize remaining expense to carry out loopback detection as far as possible.Artificially set particular value when some passage of cascaded series, then should not have been made the wrapped state that detects these passages in this way, but remaining passage still can have been detected with the method that the present invention proposes, therefore still can have been found the loopback of port data.

The method that the present invention proposes can be realized by software, also can finish by hardware, if realize by software, then hardware only need provide writing and read out function of SDH channels track flag information, the judgement of loopback is transferred to software and is realized, the time of detecting can postpone to some extent, but realizes that cost then can reduce greatly.

Claims

1. A method for detecting service loopback of multi-service transmission platform equipment, characterized in that it comprises the following steps:

Step 1. Generate a unique tracking flag that complies with ITUT's regulations on the tracking flag byte for each channel;

Step 2, write the generated tracking flag into the corresponding overhead position and send it;

Step 3, extracting the tracking flag of the corresponding overhead position when receiving the data;

Step 4: According to the channel information, it is judged whether a loopback has occurred by comparing whether the received channel trace flag is the same as the sent trace flag.

2. The method according to claim 1, characterized in that: if it is detected that a loopback has occurred, corresponding operations are performed on the line side port to prevent data from entering the data exchange layer; when the loopback disappears, the port is restored to the state before the operation .

3. The method according to claim 1 or 2, characterized in that the tracking flag generation method in said step 1 is: CRC check code + network element ID + subrack number + slot number + CPU number + channel number + random number.

4. The method according to claim 1 or 2, characterized in that the tracking mark generation method in the first step is: CRC check code + year + date + time + channel number.

5. The method according to claim 1 or 2, characterized in that: in the second step, the tracking flag is written into the J0 byte of the regeneration section, written into the J1 byte of the high-order channel, and written into the low-order channel the J2 byte.

6. The method according to claim 5, wherein the length of the tracking flag is 16 bytes or 64 bytes.

7. The method according to claim 1 or 2, characterized in that in said step 4: for a single channel, if the received channel trace flag is the same as the sent trace flag, a loopback occurs; for adjacent cascaded channel, loopback occurs if the trace flag in the concatenated channel overhead is the same as the trace flag sent.

8. The method according to claim 1 or 2, characterized in that in said step 4: for the virtual concatenation group, the loopback of the entire cascade group is determined by judging the loopback situation of each member in the cascade group state.

9. The method according to claim 8, wherein if a loopback occurs in any member of the cascading group, it is judged that the entire cascading group is looped back.