CN1992652A

CN1992652A - Method of detecting packet disordering and repetition in connectionless packet switch network

Info

Publication number: CN1992652A
Application number: CNA2005101352992A
Authority: CN
Inventors: 李贺军
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2005-12-29
Filing date: 2005-12-29
Publication date: 2007-07-04
Anticipated expiration: 2025-12-29
Also published as: CN1992652B

Abstract

The invention relates to a method for detecting disordered order and repetition of messages in a connectionless message switching network. The present invention mainly includes: firstly, the sending end sets the sequence number information of the message in the connectionless packet switching network message used for detection; then, at the receiving end, according to the sequence number information in the received message Perform out-of-sequence and duplicate detection of packets in a connectionless packet switching network. The invention can be applied in the OAM field of the carrier-level Ethernet metropolitan area network to detect disorder and repetition problems in the network. In this way, out-of-sequence, duplication, or comprehensive out-of-sequence can be detected conveniently, an OAM alarm can be provided, and a basis for evaluating network topology changes can be provided. At the same time, the realization mechanism provided by the present invention has the advantage of being concise and clear, so it is easier to realize in the chip.

Description

The detection method of packet out-ordering and repetition in the nothing connection message switching network

Technical field

The present invention relates to network communications technology field, relate in particular to the detection technique that a kind of nothing connects message among the message switching network OAM (Operations,Administration And Maintenance).

Background technology

Along with the development of the network communications technology, Ethernet (Ethernet) technology is developed to metropolitan area network by local area network (LAN) gradually with the advantage of its high performance-price ratio, and corresponding ports speed also develops into 10G from 10M.In the process of metropolitan area network development, require the Ethernet technology must satisfy the carrier class network requirement at Ethernet.Wherein, realize that in network OAM mechanism is the basic demand of carrier class network to the diverse network technology.Described OAM mechanism comprises: network failure management mechanism and network performance management mechanism.

More specifically say, mainly comprise following content at present in the fault at ETH (Ethernet) network/performance management mechanism of definition:

ETH-CC (Ethernet detection of connectivity) continuity measuring ability is used to detect between the ETH MEP connective;

ETH-LB (Ethernet Loopback) loop fuction is used for detection of connectivity between MEP and the MIP/MEP, and frame delay in the performance parameter and frame delay jitter measurement;

ETH-LT (Ethernet Link Trace) function is used for fault location;

The alarm deixis of ETH-AIS (Ethernet alarm indication signal) and ETH-RDI (Ethernet conversion check indication): be used for the fault warning forward/reverse and suppress;

ETH-LM (ethernet frame is lost measurement) and ETH-DM (Ethernet delay measurements) function are used for the frame loss rate and the delay of measurement performance parameter.

Based on above-mentioned each treatment mechanism and mutual each network performance parameter that obtains in the Ethernet of just can measuring by corresponding message, and realize the localization process of network failure.

For Ethernet, in the measuring process of network performance, also should consider the problem of packet out-ordering.The packet out-ordering problem is based on an intrinsic problem of the nothing connection message switching network of storage forwarding.Simultaneously, the problem of message repetition also may take place in nothings such as Ethernet connection exchange class network.

At the initial stage of Ethernet development, owing to be confined in the small-scale enterprise network, thereby lower for network performance and reliability requirement, influence out of order and that replication problem produces is insignificant.But, when Ethernet after carrier class network development, network size will increase greatly, network topology also can be complicated more simultaneously, at this moment, out of order and replication problem will badly influence the reliability of network.That is to say out of orderly will become multipath with replication problem (being comprehensive out-of-sequence problem) and not have a performance measurement index that is connected message switching network, be a kind of ability explanation that a network is dealt with multipath and network topology change.Therefore, Ethernet maintenance management mechanism also should be considered the detection at packet out-ordering in the network and replication problem, determines ethernet performance thereby further weigh.

At present, in the network of message switching, also do not have the mechanism of concrete out of order and duplicate detection, thereby just can't provide better network performance evaluation yet towards the OAM plane.

Summary of the invention

The purpose of this invention is to provide a kind of detection method that connects packet out-ordering and repetition in the message switching network of not having, do not have packet out-ordering and the replication problem that connects in the message switching network so that weigh exactly, and then can assist nothing connection message switching network OAM that better network performance evaluation is provided.

The objective of the invention is to be achieved through the following technical solutions:

The invention provides a kind of detection method that connects packet out-ordering and repetition in the message switching network of not having, comprising:

A, connect the carrying of message switching network message in the nothing that is used for detecting sequence number of message information is set;

B, at receiving terminal, connecting the sequence number information of carrying in the message switching network message according to the described nothing that receives does not have the out of order and duplicate detection that connects message in the message switching network.

Described steps A comprises:

Connect the carrying of message switching network message in the nothing that is used for detecting and the digital information of rule variation is set as sequence number of message.

Described nothing connects the message switching network message and comprises: ethernet operation administers and maintains the Ethernet detection messages in the process.

Described method also comprises:

C, the center detection window is set, described center detection window is a border reference of adopting sequence of message number to define, and it is used for the out of order of detection messages and repeats.

Described step C also comprises:

Anterior duplicate detection window and rear portion detection window are set, wherein, described anterior duplicate detection window is positioned at the front of center detection window, be used for as the border reference that detects duplicate message, the rear portion detection window is positioned at the back of center detection window, is used to detect the border reference of repetition and out of order message.

Described step B comprises:

When receiving the reception message, resolve the sequence number information that obtains in the described message, carry out the out of order and duplicate detection of message according to the sequence of message information in the detection window of center.

Described step B comprises:

B1, definite sequence number of message that receives;

B2, determine not out of order sequence of message number according to detection window position, center, described not out of order sequence of message number does not all occur out of order for the message of receiving in the past at this sequence number;

B3, carry out the out of order and duplicate detection of message according to the sequence number of message that receives spacing value, the center detection window width between sequence number of message and the not out of order sequence of message number and receive.

Described step B3 also comprises:

Also carry out the out of order and duplicate detection of message according to the information of anterior duplicate detection window and rear portion detection window.

Described step B3 comprises:

When receiving sequence number of message and be positioned at the center detection window, then determine not occur out of order, otherwise determine to appear as out of order;

In receiving sequence number of message and center detection window, anterior duplicate detection window and rear portion detection window, received sequence number of message when identical, then determined to duplicate, otherwise, not definite not duplicating;

Be not in center detection window, anterior duplicate detection window and the rear portion detection window when receiving sequence number of message, then determine to occur comprehensively out-of-sequence.

Among the present invention, when the center detection window only was set, described step B3 comprised:

When receiving sequence number of message and be positioned at the center detection window, then determine not occur out of order, otherwise, determine to occur out of order;

In receiving sequence number of message and center detection window, received sequence number of message when identical, then determined to duplicate, otherwise definite not duplicating.

Described step B3 comprises:

When receiving sequence number of message is that current not out of order sequence of message number adds for the moment, then determines to occur comprehensively not out-of-sequence, otherwise determines to occur comprehensively out-of-sequence.

Described step B3 also comprises:

At detect to occur out of order with repeat to be provided with each self-corresponding alarm switch, when alarm switch is closed, report and alarm not then, otherwise report and alarm.

Described step B3 also comprises:

At the center detection window corresponding bit sequence is set, whether the message that is used to identify each sequence number correspondence in the detection window of center is received, carry out out of order and duplicate detection according to this bit sequence, and/or, carry out the slip of center detection window according to this bit sequence and handle.

Described step B3 also comprises:

Window glide direction starting point in the detection window of center begins to receive not out of order message continuously, the center detection window that then slides, and upgrade window glide direction initial point position.

As seen from the above technical solution provided by the invention, Mathematical Modeling based on the sequence of message detection window provided by the invention, clearly defined and do not had out of order, repetition and the comprehensive out-of-sequence problem that connects in the message switching network, be applicable to the OAM field of message switching network of adopting as bearer network, for example, the detection of the out of order and replication problem in the network is carried out in the OAM field that is used for carrier-class ether metropolitan area network.

That is to say, in the carrier-class Ethernet, utilize the present invention can detect out of order, repetition or comprehensively out-of-sequence easily, and OAM is provided alarm.

Simultaneously, also because realization mechanism provided by the invention has short and sweet advantage, thereby be easier in chip, realize.

Description of drawings

Fig. 1 is out of order and the overall schematic of duplicate detection enforcement.

Embodiment

Core of the present invention is based on detection window and proposes definition and the testing mechanism that multipath does not have the out of order of connection message switching network and repeats, can be applicable to well that carrier-class does not have the OAM of the bearer network that connects message switching scheme, such as ether bearer network OAM.Utilize testing mechanism provided by the invention can carry out out of order and duplicate detection, thereby the relevant alarm on OAM plane is provided.

For ease of understanding the present invention, below will be at first to the explanation that makes an explanation of the implication of the basic concepts that relates among the present invention.

(1) sequence of message Frames Sequence is meant one group of message that front and back are orderly.

(2) sequence number Sequence ID is used to represent the integer of sequence of message, implements out of order and message duplicate detection all must have sequence number;

Behind the defined nucleotide sequence number, each message just can be represented with its sequence number, therefore, represent that a sequence of message only need provide a Serial No. and get final product, such as:

Sequence 1:99 100 101 102 103;

Sequence 2:88 121 111 114 182;

Orderly sequence of message of expression for convenience might as well make sequence of message number circulation increase progressively, and is 2^32-1 to the maximum such as sequence number, and then any one section of infinite sequence all is an orderly sequence of message, specific as follows shown in:

......0 1 2......2^32-1 0 1 2......2^32-1 0 1 2......。

(3) out of order Misorder is meant that a message sequence and a transmission message sequence that sends that acceptance point is received are inconsistent, the front and back entanglement of refering in particular to message sequence;

Out of order example as:

Send sequence: 012345;

Receiving sequence: 023145.

(4) repeat Duplication, be meant that acceptance point receives the message that has received the front once more;

Example that exist to repeat as:

Send sequence: 012345;

Receiving sequence: 0123245.

(5) comprehensive out-of-sequence General Misorder is meant that a sequence of message and a transmission sequence of message that sends that acceptance point is received are inconsistent, and result out of order and that repeat can both cause comprehensively out-of-sequence;

Cause receiving sequence and the inconsistent reason of transmission a lot, error code frame, LOF etc. also can both cause comprehensively out-of-sequence.

(6) center detection window Central Detection Window with the border reference that sequence number is weighed, is used for the out of order of detection messages and repetition situation.

(7) anterior duplicate detection window Foreside Duplication Detection Window in detection window front, center, is used for the border reference that detection messages repeats situation.

(8) rear portion detection window Tail Detection Window in detection window back, center, is used for a border reference of the out of order of detection messages and the situation of repetition.

(9) out of order alarm Misorder Alarm, the alarm of sending after the out of order generation in the present invention, if message drops in the detection window of rear portion, is then sent out of order alarm, drops on and does not then send this alarm in the detection window of center.

(10) repeat to alarm Duplication Alarm, the alarm that repeats the back takes place and send, in the present invention, if message drops in anterior duplicate detection window, center detection window and the rear portion detection window, all to send and repeat alarm, but can close unwanted alarm by switch.

(11) comprehensive out-of-sequence alarm General Misorder Alarm, out of order alarm and repeat alarm and all belong to comprehensive out-of-sequence alarm, if but message falls into detection window, according to circumstances send out of order alarm or repeat to alarm or do not send alarm, and no longer send comprehensive out-of-sequence alarm, if and a message does not fall into any one detection window, then send comprehensive out-of-sequence alarm, each window is as shown in table 1:

Table 1

…	0	1	2	3	4	5		7	8		10	11				…
…	0	1	2	3	4	5		7	8		10	11				…				N/A		Anterior duplicate detection window width Wf=4				Center detection window width Wc=6, SID_o=5						Rear portion detection window width Wt=4				N/A

。

(12) not out of order recently message SID Latest non-misordered SID, expression comprises that this SID and former SID do not take place out of order, it is positioned at the leftmost side of center detection window all the time, is three benchmark that detection window moves, and is defined as SID_o in the realization program.

Now according to shown in the table 1, to suppose and receive a message, its sequence number is expressed as SID_x, then:

If SID_x==6 is illustrated in the out of order tolerance limit, do not send any alarm, and window can slide to the right, SID_o is updated to 8.

If SID_x==9 is illustrated in the out of order tolerance limit, do not send any alarm;

If SID_x==12, expression has out of order generation, sends out of order alarm;

If SID_x==2 or 5 or 11 are all represented to repeat to take place, if corresponding switch opens is then sent and repeated alarm, the repetition alarm switch of three windows can be defined as WfDupAlm respectively, WcDupAlm, WtDupAlm;

If SID_x==20 then falls into outside three windows, send comprehensive out-of-sequence alarm.

Based on above-mentioned each basic conception, will describe realizing out of order and implementation method duplicate detection among the present invention below.

Corresponding out of order and duplicate detection must be carried out between two communication point, can detect unidirectional out of orderly in one-way (unidirectional) mode, also can detect two-way out of order in two-way (two-way) mode.Which kind of mode no matter, the message that sends in testing process all must have sequence number, and sequence number circulates from 0 to MAX (maximum), and typical case is MAX=2^32-1, specifically can make sequence number take the 32bits of message.

For the one-way mode, send point and send the message that has continuous SID, receive message and implement out of order and duplicate detection by the opposite end.Specifically can in the ETH-CC function, realize, even comprise SID in the transmission message of ETH-CC, specifically as shown in Figure 1.

For the two-way mode, send point and send the message that has continuous SID, after the opposite end receives message, with the simple loopback of message, take back SID, implement out of order detection, specifically can in the ETH-TEST function, realize by sending point, in ETH-TEST, have the Transaction ID (sending sign) that can be used as SID, utilized this sign promptly can realize corresponding out of order and duplicate detection.

Need to prove that the out of order and duplicate detection function among the present invention must realize on the MEP (maintenance group end points) of same ME Level (maintenance entity layer).

At last, according to the difference of applied environment, out of order and duplicate detection can be implemented as different scales, such as adopting following three kinds of realization scales:

(1) the full realization: Wf＞=1, Wc＞=2, Wt＞=1 promptly is provided with anterior duplicate detection window, center detection window and rear portion detection window simultaneously;

When utilizing three detection windows to detect out of order and repeating, if the sequence number of message that receives surpasses the scope of three detection windows, then think a kind of more serious out-of-sequence, need report a comprehensive out-of-sequence alarm to get final product, but fall within three detection windows, then can segment alarm type, specifically can be divided into following several situation:

Because hypothesis SID_o be the SID of out of order message not recently, therefore forwardly in the duplicate detection window, the message that expression has been received, if current message is received the message of anterior duplicate detection window again, expression repeats to take place, and then can report and repeat to alarm;

The center detection window is thought the out of order tolerance of receiving terminal, suppose that promptly receiving terminal has certain out of order disposal ability, fall into the center window if receive sequence number of message, even entanglement to some extent before and after the sid value, do not alarm yet, but may repeat in the window of center yet, if the message collisions of message of receiving and buffer memory, then expression repeats to take place, and can report and repeat alarm;

The rear portion detection window represents that receiving terminal is flagrant out of order, and message falls into this window, if do not repeat, then reports out of order alarm.

(2) typical case realizes: Wf==0, and Wc＞2, Wt==0 promptly only is provided with the center detection window;

(3) Minimal Realization: Wf==0, Wc==2, Wt==0 the center detection window promptly only is set, and the width of center detection window is set to 2.

That is to say, can (Wt) the out of order and duplicate detection of one of group expression realizes for Wf, Wc, Wc＞=2 wherein, Wf＞=0, Wt＞=0 with one.Above-mentioned three kinds of realization scales just are used as configuration mode commonly used, obviously also can use other combinations as required in actual application.

In the out of order of reality and duplicate detection process, the realization of various realization scale correspondences is out of order specifically to be comprised with the duplicate detection function operations

(1) configuration process of parameter

Particularly, dispose Wf, Wc, three parameter values of Wt exactly, determine detection window width, and configuration WfDupAlm, WcDupAlm, WtDupAlm determines whether to allow to repeat alarm;

(2) startup that resets

Particularly, be exactly used variable in the initialize routine, the SID_o value that must provide in the time of startup can be set to the sid value of current message;

(3) executable operations

Particularly, exactly make functional module carry out with receiving frame rhythm, require to provide the SID_x of present frame, carrying out each time all to have a feedback, repeats alarm, out of order alarm, comprehensive out-of-sequence alarm or does not alarm; And after comprehensive out-of-sequence alarm took place, measuring ability must reset and restart, and promptly resets SID_o, is set to the sid value of next message.

To describe the realization of the present invention of previously described three kinds of different scales respectively with concrete application example below.

(1) the full realization

Under this scale, at first need to be defined as follows variable:

Wf, Wc and Wt: integer is respectively applied for the width of representing anterior duplicate detection window, center detection window and rear portion detection window;

WfDupAlm, WcDupAlm and WtDupAlm:Bool (boolean) type is respectively applied for the repetition alarm switch of representing three window correspondences;

SID_o: integer, be used to represent recently the not SID of out of order message, maximum is MAX;

SID_x: integer, be used to represent the current SID that receives message, maximum is MAX;

Lx: signed integer, expression SID_x is with respect to the distance of anterior duplicate detection window left margin, and bit wide surpasses SID_o and SID_x;

Wx: signed integer, expression SID_x is the distance of SID_o with respect to center detection window left margin, bit wide surpasses SID_o and SID_x;

B[Wc+Wt]; Bit array is used to represent bit sequence, covers center detection window and rear portion detection window, be B[0], B[1] ... B[Wc+Wt-1], each position is represented to begin backward SID from SID_o, if B[i]==0, the message of SID_o+i is not received in expression, if B[i]==1, the message of SID_o+i has been received in expression, when out of order and duplicate detection function on, B[0] be initialized as 1, other bit are initialized as 0.In running, if from B[0] begin to occur continuous " 1 ", the expression window can slide backward, and makes B sequence integral body move to left, the right zero padding moves to B[1 always]==1, can upgrade SID_o according to the distance that moves then; Specifically as shown in table 2:

Table 2

N/A		The location map sequence, on the throne is 1, otherwise is 0									N/A
												1	0	1	1	0	1	1	0	0	0
		…	0	1	2	3	4	5	7	8		1	0	1	1	0	1	1	0	0	0	10	11	…
N/A	Anterior duplicate detection window width Wf=4	…	0	1	2	3	4	5	7	8	Center detection window width Wc=6, SID_o=5			Rear portion detection window width Wt=4				N/A				10	11	…

Cnt: the temporary variable that is used to count, calculate the distance of B displacement, promptly the distance that need slide of window is used to upgrade SID_o.

In specific implementation process of the present invention, at first, program start, allocation window width W f, Wc and Wt, deploy switch variable WfDupAlm, WcDupAlm and WtDupAlm, configuration SID_o is the SID of current message, zero clearing B sequence makes B[0]=1;

Secondly, based on above-mentioned each parameter, whenever receive a message, obtain after the SID_x, will enter program branches according to the currency of SID_o, B sequence, corresponding processing procedure is specific as follows:

If described SID_x falls into anterior duplicate detection window, and repeat alarm switch and open, then output repeats alarm;

If described SID_x falls into the center detection window, if B[Wx]==1, this message has been received in expression, opens if repeat alarm switch, output repeats alarm; If B[Wx]==0, then make B[Wx]==1, represent that this position received message, detect B[1] whether be 1, if be 1, then the B sequence is done and is shifted left, until B[1]==0 till, and the distance C nt (inferior numerical value that promptly moves to left) that moves to left of record, and utilize its renewal SID_o;

When described SID_x falls into the rear portion detection window, if B[Wx]==1, this message has been received in expression, opens if repeat alarm switch, output repeats alarm; If B[Wx]==0, then modern B[Wx]==1, represent that this position received message, export out of order alarm then;

If described SID_x falls into outside three detection windows, then export comprehensive out-of-sequence alarm, at next message constantly, and reset routine, i.e. zero clearing B sequence, SID_o is set to the SID of this message, and makes B[0]==1.

Using the B sequence is for simplifying the operation and saving memory space, so that realize in chip.In order to implement out of order and duplicate detection, sid value that must the buffer memory some, anterior detection window does not need buffer memory, and directly relatively SID_o and SID_x get final product, and the SID of center detection window and rear portion detection window then needs buffer memory.And direct buffer memory SID wasting space too, such as sid value 32 bits, center detection window width 6, rear portion detection window width 4 then needs 32* (6+4)=320 bit.Owing to stipulated that SID increases progressively, therefore can the not out of order recently message SID_o of buffer memory, corresponding B[0]=1, if received SID_o+2, then at B[2] be recorded as 1, receive SID_o+3, then at B[3] be recorded as 1, because SID_o+1 does not still receive B[1] still be 0, so B sequence correspondence the difference of follow-up SID to SID_o, this caching method only needs 32 bits of SID_o, 32 bits of SID_x, 10 bits of B sequence, 74 bits just altogether.

In addition, the B sequence is handled easily also, still is example with above-mentioned, and current B sequence is B[0-9]={ 1,0,1,1,0,0,0,0,0,0} is if received SID_o+1 now, B[1 then]=1, B[0-9 now]={ 1,1,1,1,0,0,0,0,0,0} has satisfied the window sliding condition, very simple toward moving to left 3 and mend 0 on the right side and get final product, and SID_o also is updated to SID_o+3, B becomes B[0-9 after being shifted]={ 1,0,0,0,0,0,0,0,0,0}.Shifting function also is very easy to realize in chip.

In implementation procedure, calculate the skew of SID_x with respect to SID_o, to represent with signed number Lx and Wx, the bit wide that guarantees Lx and Wx surpasses SID, and this can be avoided overflowing the problem that causes in calculating, upgrades SID_o in addition and may have and overflow, directly ignore and get final product, it is very convenient to realize ignoring the addition and subtraction that overflows in chip, in whole procedure, avoids using division and modular arithmetic.

Detailed process can adopt following pseudo-code to realize:

If BEGIN/* begin */Lx=SID_x-SID_o+Wf/* calculate SID_x to duplicate detection window left margin apart from */IF Lx＜0 THEN/* Lx less than 0; If then */Lx=Lx+MAX+1/* */the END/*IF that overflows that adjusts the SID plus-minus finishes */IF Lx＜Wf THEN/* and has fallen into anterior detection window */IF WfDupAlm not Off THEN/* and allow switch to export this alarm; Then */Duplication Alarm/* output repeat alarm */END ELSE/* otherwise; Be not to fall into anterior detection window */Wx=Lx-Wf/* to calculate SID_x and fallen into center or rear portion detection window */IF B[Wx to SID_o apart from */IF Wx＜Wc+Wt THEN/*]=message of=1 this position of THEN/* received; Repeating */IF Wx＜Wc THEN IF WcDupAlm not Off THEN/* allows outputting alarm */Duplication Alarm/* output repetition alarm */END ELSE IF WtDupAlm not Off THEN/* to allow outputting alarm */Duplication Alarm/* output to repeat alarm */END END ELSE/* otherwise B[Wx]==0; Expression take place to repeat */B[Wx]=1 IF Wx＞=Wc THEN/* fallen into rear portion detection window */Misorder Alarm/* and exported out of order alarm */ELSE/* and fallen into anterior detection window */Cnt=0/* zero clearing; Begin to calculate need move to left apart from */WHILE B[1]==1 THEN/* is until B[1]==0 withdraw from */B＜＜the 1/*B sequence moves to left; The right zero padding */Cnt++/* counter adds 1*/END WHILE IF SID_o＜=MAX-Cnt THEN/* to be upgraded SID_o*/SID_o=SID_o+Cnt/* and not to need to adjust and overflow */ELSE SID_o=SID_o+Cnt-MAX-1/* and adjust and overflow */END END/* and fall into center or rear window, do not have reprocessing finish */END/* fall into center or rear window */ELSE/* fall into the out-of-sequence alarm * of * outside three detection windows/General Misorder Alarm/* output integrated/END/*Wx processing finish */END/*Lx processing finish this secondary program of */END/* carry out finish */

(2) typical case realizes

Be defined as follows variable:

Wc: integer is used to represent the width of center detection window;

The WcDupAlm:Bool type is used for expression and repeats alarm switch;

SID_o: integer is used to represent be recently the SID of out of order message;

SID_x: integer is used to represent the current SID that receives message;

B[Wc]: be used to represent bit sequence, B[0], B[1] ... B[Wc-1], each position is represented to begin backward SID from SID_o, if B[i]==0, the message of SID_o+i is not received in expression, if B[i]==1, the message of SID_o+i has been received in expression, when out of order and duplicate detection function on, B[0] be initialized as 1, other bit are initialized as 0.In running, if from B[0] begin to occur continuous " 1 ", the expression window can slide backward, and makes B sequence integral body move to left, the right zero padding moves to B[1 always]==1, can upgrade SID_o according to the distance that moves then;

The present invention in the specific implementation process, at first, program start, allocation window width W c, deploy switch variable WcDupAlm, the configuration SID_o be the SID of current message, zero clearing B sequence makes B[0]=1.

SID_x falls into the center detection window, if B[Wx]==1, this message has been received in expression, opens greatly if repeat alarm switch, output repeats alarm; If B[Wx]==0, then make B[Wx]==1, represent that this position received message, detect B[1] whether be 1, if be 1, then the B sequence is done and is shifted left, until B[1]==0 till, and the distance C nt that moves to left of record upgrades SID_o with it;

SID_x falls into outside the detection window of center, exports comprehensive out-of-sequence alarm, at next message constantly, reset routine, i.e. zero clearing B sequence, SID_o is set to the SID of this message, and makes B[0]==1.

Equally, using the B sequence is for simplifying the operation and saving memory space, so that realize in chip.In order to implement out of order and duplicate detection, the sid value of necessary buffer memory some, direct buffer memory SID is wasting space too, adopts buffer memory SID_o and SID_x, middle value is used relative position, and whether on the throne the expression gets final product, and therefore uses a bit sequence to shine upon relative position.In addition, the B sequence can be used the left shift operation of right zero padding in operating process, also is very easy to realize in chip.

In implementation procedure, calculate the skew of SID_x with respect to SID_o, to represent with signed number Lx and Wx, the bit wide that guarantees Wx surpasses SID, and this can be avoided overflowing the problem that causes in calculating, upgrades SID_o in addition and may have and overflow, directly ignore and get final product, it is very convenient to realize ignoring the addition and subtraction that overflows in chip, in whole procedure, avoids using division and modular arithmetic.

In the typical case realizes, Wf=0, Wc＞2, Wt=0, degenerated anterior duplicate detection window and rear portion detection window also no longer include special out of order alarm, have only alarm of repeating and comprehensive out-of-sequence alarm.

Concrete detection is achieved as follows:

If BEGIN/* begin */Wx=SID_x-SID_o/* calculate SID_x to SID_o apart from */IF Wx＜0 THEN/* Wx less than 0; Then */Wx=Wx+MAX+1/* */the END/*IF that overflows that adjusts the SID plus-minus finishes */IF Wx＜Wc THEN/* and has fallen into Spot detection window */IF B[Wx]=message of=1 this position of THEN/* received; Repeating */IF WcDupAlm not Off THEN/* allows outputting alarm */Duplication Alarm/* output to repeat alarm */END ELSE B[Wx]=1 Cnt=0/* zero clearing; Begin to calculate need move to left apart from */WHILE B[1]==1 THEN/* is until B[1]==0 withdraw from */B＜＜the 1/*B sequence moves to left, the right zero padding */Cnt++/* counter add 1*/END WHILE IF SID_o＜=MAX-Cnt THEN/* upgrade SID_o*/SID_o=SID_o+Cnt/* do not need to adjust overflow */ELSE SID_o=SID_o+Cnt-MAX-1/* adjust overflow */END END ELSE/* fall into the out-of-sequence alarm * of * outside the detection window of center/General Misorder Alarm/* output integrated/END/*Wx processing finish this secondary program of */END/* carry out finish */

(3) Minimal Realization

In Minimal Realization, Wf=0, Wc=2, Wt=0, three windows have all been degenerated, and alarm is also no longer distinguished out of order alarm and is repeated alarm, and has only comprehensive out-of-sequence alarm, at this moment the realization of Jian Ceing is simple and effective, and simplification is described as: whether the SID_x that receives after the detection equals SID_o+1, if equate, represent not out-of-sequence, otherwise represent out-of-sequencely, overflow, do not consider to overflow part if having.

Implementation concrete under this scale implementation is as follows:

BEGIN

IF SID_x！＝SID_o+1 THEN

General Misorder alarm

END

When realization is of the present invention in the ETH-CC of Ethernet OAM, can carry out conventional OAM monitoring, specifically detect out-of-sequence situation by acceptance point.When realization is of the present invention in ETH-TEST (ethernet test), then can also initiate out-of-sequence testing process, to carry out corresponding comprehensive out-of-sequence detection by administrative staff.

In sum, Mathematical Modeling based on the sequence of message detection window provided by the invention, clearly defined and do not had out of order, repetition and the comprehensive out-of-sequence problem that connects in the message switching network, be applicable to the OAM field of message switching network of adopting as bearer network, for example, the detection of the out of order and replication problem in the network is carried out in the OAM field that is used for carrier-class ether metropolitan area network.

That is to say, in the carrier-class Ethernet, utilize the present invention can detect out of order, repetition or comprehensively out-of-sequence easily, and OAM is provided alarm, and, because realization mechanism provided by the invention has short and sweet advantage, thereby is easier to realize in chip.

The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.

Claims

1. A method for detecting out-of-sequence and repetition of messages in a connectionless message switching network, characterized in that it comprises:

A. The sequence number information of the setting message is carried in the connectionless packet switching network message used for detection;

B. At the receiving end, perform out-of-sequence and duplicate detection of messages in the connectionless packet switching network according to the sequence number information carried in the received connectionless packet switching network packets.

2. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 1, wherein said step A comprises:

The digital information that is set to change regularly is carried in the packet of the connectionless packet switching network used for detection as the sequence number of the packet.

3. The method for detecting out-of-sequence and duplication of messages in a connectionless packet switching network according to claim 1, wherein said connectionless packet switching network packets include:

Ethernet detection packets in the process of Ethernet operation management and maintenance.

4. The method for detecting out-of-order and repetition in the connectionless packet switching network according to claim 1, characterized in that, the method further comprises:

C. Set a central detection window, the central detection window is a border reference defined by the serial number of the message, which is used to detect disorder and repetition of the message.

5. The method for detecting out-of-sequence and duplication in a connectionless switching network according to claim 4, wherein said step C further comprises:

Setting the front portion repeat detection window and the rear portion detection window, wherein, the front portion repeat detection window is located in front of the central detection window, and is used as a boundary reference for detecting repeated messages, and the rear portion detection window is located behind the central detection window, Boundary reference for detecting duplicate and out-of-sequence packets.

6. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 4 or 5, wherein said step B comprises:

When a received message is received, the sequence number information in the message is obtained by parsing, and the out-of-sequence and duplicate detection of the message is performed according to the message sequence number information in the central detection window.

7. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 6, wherein said step B comprises:

B1. Determine the serial number of the received message;

B2. Determine the serial number of the non-disordered message according to the position of the central detection window, and the serial number of the non-disordered message means that no disorder occurs in the messages received before the serial number;

B3. According to the interval value between the serial number of the received message and the serial number of the unordered message, the width of the central detection window, and the serial number of the received message, the disordered and repeated detection of the message is performed.

8. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 7, wherein said step B3 further comprises:

Packet out-of-sequence and duplicate detection are also performed according to the information of the front duplicate detection window and the rear detection window.

9. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 8, wherein said step B3 comprises:

When the serial number of the received message is within the central detection window, it is determined that there is no out-of-order, otherwise it is determined that out-of-order occurs;

When the sequence number of the received message is identical to the sequence number of the received message in the central detection window, the front portion of the repeated detection window and the rear portion of the detection window, then it is determined that repetition occurs; otherwise, it is determined that there is no repetition;

When the sequence number of the received message is not within the central detection window, the front duplicate detection window and the rear detection window, it is determined that a comprehensive out-of-sequence occurs.

10. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 7, wherein when only the central detection window is set, said step B3 includes:

When the serial number of the received message is within the central detection window, it is determined that there is no out-of-order, otherwise, it is determined that there is out-of-order;

When the serial number of the received message is the same as the serial number of the received message in the central detection window, it is determined that there is duplication; otherwise, it is determined that there is no duplication.

11. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 10, characterized in that, when only the center detection window is set, and the width of the center detection window is 2, said step B3 includes:

When the sequence number of the received message is the sequence number of the current non-disordered message plus one, it is determined that there is no comprehensive disorder, otherwise it is determined that the comprehensive disorder occurs.

12. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 7, wherein said step B3 further comprises:

Set corresponding alarm switches for out-of-order and repeated detections. When the alarm switch is turned off, no alarm will be reported, otherwise an alarm will be reported.

13. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 7, wherein said step B3 further comprises:

Set the corresponding bit sequence for the center detection window, which is used to identify whether the message corresponding to each serial number in the center detection window has been received, perform out-of-order and repeated detection according to the bit sequence, and/or perform center detection according to the bit sequence Window sliding handling.

14. The method for detecting out-of-sequence and duplication of messages in a connectionless message switching network according to claim 7, wherein said step B3 further comprises:

When the starting point of the window sliding direction in the center detection window starts to receive unordered packets continuously, the center detection window is slid, and the position of the starting point of the window sliding direction is updated.