CN100336359C

CN100336359C - Method for deciding over-ring flow overrun on elastic group ring

Info

Publication number: CN100336359C
Application number: CNB2004100804752A
Authority: CN
Inventors: 游泳
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2004-10-10
Filing date: 2004-10-10
Publication date: 2007-09-05
Anticipated expiration: 2024-10-10
Also published as: CN1758623A

Abstract

The present invention discloses a method for judging the overrun of an over ring flow on a resilient packet ring. A token bucket is arranged on a detecting point, and tokens in the token bucket are added according to a fair rate period; according to a detected blocking point, the package length of over ring packages dynamically decreases, and the tokens in the token bucket are compared with a preset threshold so as to judge whether the over ring flow currently passing the blocking point overruns or not. The method of the present invention is adopted, and the fullness of the token bucket is utilized to judge whether the over ring flow passing the blocking point exceeds a fair rate published by the blocking point or not so as to avoid detail loss caused by low-pass filtering and enhance judging accuracy; thereby, the division of a blocking region is accurate so as to ensure the full utilization of bandwidth and the fairness of an RPR ring.

Description

A kind of method of judging on Resilient Packet Ring that circulation transfinited

Technical field

The present invention relates to Resilient Packet Ring (RPR:Resilient Packet Ring), particularly judge the method whether circulation surpasses the fair rate of choke point issue of crossing on the Resilient Packet Ring by the choke point.

Background technology

Resilient Packet Ring (RPR) technology proposed in 2000; it is a kind of novel mac-layer protocol that data service transmits of on loop configuration, optimizing; it utilizes the advantage of ring structure; supporting protocol by the MAC layer solves the problem in the professional transmission of grouping such as bandwidth sharing, protection, QOS guarantee; because wherein, the low priority traffice bandwidth is controlled by internal algorithm; have self-adjusting characteristic, therefore be called Resilient Packet Ring.

RPR MAC can adapt to multiple physical layer, can transmit multiple business types such as data, speech, image effectively.It has merged the characteristics such as economy, flexibility, extensibility of ethernet technology; absorbed the advantage of the quick protection of 50ms of SDH looped network simultaneously; and have that network topology is found automatically, loop bandwidth is shared, fair allocat, strict business classification technical advantages such as (COS), target is that effectively metropolitan area network solution is provided under the prerequisite that does not reduce network performance and reliability more economically.

The important feature of RPR is by fair algorithm, can be between each node the fair allocat bandwidth, and make full use of line bandwidth.Fair algorithm is based on to the detection of choke point and the distribution of choke point bandwidth.On the RPR ring, the priority of crossing the business of ring is higher than the local ring business that goes up, if encircle on the fair algorithm of the node permission local service, but causes local service can not go up ring because of crossing the professional too much occupied bandwidth of ring, this node just enters blocked state so, is called the choke point.The choke point will send a speed indication according to the situation upstream nodes that this point blocks, and it is professional to require upstream node to send ring by this speed, and to remove the blocked state of this point, this speed is called fair rate.Node on the RPR ring is periodically gone up the frame that other node sends set form to ring, points out the congestion situations on the current ring and allows the each point transmitted traffic, is called fairness frame; The cycle that sends fairness frame is called the fair cycle.Comprised in the fairness frame that the address of current choke point, current choke point are apart from the distance of this point, the information such as fair rate of choke point issue.

According to the congestion situations and the service traffics of each node, a RPR ring can be divided into a plurality of zones, different fair rates is arranged on different zones, thereby reach the effect that makes full use of loop bandwidth, and a such zone is called blocks the territory.As shown in fig. 1, after the S6 node blocks, send fair rate 10 to upstream node; Node S5 adjust this point to go up the ring service traffics be 10, and detect to send through the flow of this point by S6 and be (10+4+3+2)=19, greater than the fair rate of choke point S6 issue, so S5 is to S4 forwarding fair rate 10 by upstream node; The upward ring service traffics that S4 adjusts this point are 10, and detect upstream node and send the flow that arrives S6 by this point and be (2+3+4)＜10, less than the fair rate of choke point S6 issue, and S4 does not block, so no longer transmit fair rate 10, and upstream send FULL_RATE.S6-S4 becomes an obstruction territory like this, and wherein S6 is the head that blocks the territory, and S4 is the tail that blocks the territory.Blocking the detailed rules of dividing in the territory can be referring to RPR technical standard " IEEE Draft P802.17 D3.3 ".

Can see from top description, block the territory, make those nodes not controlled by the fair rate of S6 issue, can make full use of bandwidth with the independent of service that causes S6 to block by dividing.Block for dividing the territory, the RPR node must be judged and crosses circulation whether greater than the fair rate of choke point issue by the choke point.Because it is what the RPR rim bearing carried is data service, has the characteristics of business burst, professional at short notice by the linear speed transmission, so can't directly compare with instantaneous service traffics and fair rate.Usually the method that adopts is that the fair rate of choke point issue and the circulation of crossing by the choke point are carried out low-pass filtering, the value after the low-pass filtering relatively, and detailed description can be with reference to RPR technical standard " IEEE Draft P802.17 D3.3 ".But low-pass filtering filters out a large amount of details, causes the precision of judgement to reduce greatly.Under both more approaching situations, judge by accident easily especially, thereby cause the mistake of blocking the territory to divide, thereby may cause two kinds of consequences, a kind of is to be continued to extend back in the obstruction territory, causes the waste of bandwidth; A kind of is to finish to block the territory in advance, makes the node traffic of back uncontrolled, causes the blocked state of choke point to finish, thereby has destroyed the fairness of RPR ring.

Summary of the invention

Purpose of the present invention is exactly circulation is crossed in the choke point to judge that precision is not high, the shortcoming of easy erroneous judgement in order to overcome in the prior art, proposes a kind of on Resilient Packet Ring the employing token bucket judged the method that circulation transfinites.

A kind of method of judging on Resilient Packet Ring that circulation transfinited comprises the following steps:

Step 1, create a token bucket, be used for deposits tokens at test point;

Step 2, judge whether to have arrived a fair cycle, if then continue, otherwise execution in step 11;

Step 3, judge whether the distance between choke point and the test point changes, if then continue, otherwise execution in step five;

Step 4, empty the token in the token bucket;

Step 5, whether judge token in the token bucket less than pre-set threshold, if then continue, otherwise execution in step seven;

Step 6, current by the choke point cross circulation more than or equal to current fair rate, the circulation sign that transfinites was set; Execution in step eight;

Step 7, current by the choke point cross circulation less than current fair rate, removed the circulation sign that transfinites;

Step 8, the fair rate of issuing by the choke point increase the interior token number of token bucket;

Step 9, judge whether overflow of token bucket,, otherwise return execution in step two if then continue;

Step 10, the token number in the token bucket is changed to " the maximum byte number that sends in threshold value+one fair intraperiod line road "; Return execution in step two;

Step 11, judge whether to detect one by the choke point cross the ring bag, if then continue, otherwise return execution in step two;

Step 12, according to the long token number that reduces in the token bucket of detected bag;

Step 13, judge whether underflow of token bucket, if return execution in step two after then emptying token in the token bucket; Otherwise directly return execution in step two.

Adopt method of the present invention, utilize the sky of token bucket completely to judge the fair rate that whether surpasses the choke point issue by the circulation excessively of choke point, avoid the loss in detail that causes because of low-pass filtering, improved the accuracy of judging, thereby make the division of blocking the territory more accurate, guaranteed the fairness of encircling with RPR that makes full use of of bandwidth.

Description of drawings

Fig. 1 divides the schematic diagram that blocks the territory on the Resilient Packet Ring;

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

Embodiment

Further specify implementation process of the present invention 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, in conjunction with specific embodiments, the method that the present invention proposes comprises the following steps:

The first step: set up a token bucket at test point, be used for deposits tokens.The definition of the token bucket described in the present invention (token bucket) meets among the ietf rfc3290 description and the definition to token bucket.In one embodiment of the invention, token bucket uses 15 counter to realize that the value of counter is represented token number, the corresponding byte of each token, and test point is crossed ring bag Statistics Division on the RPR ring.

Second step: arrived a fair cycle? in this example, a fair cycle is 100 microseconds.If changed for the 3rd step over to.Otherwise changed for the 11 step over to.

Does the 3rd step: the choke point change apart from the distance of test point? in this example, the distance of choke point can be represented with the TTL that carries in the fair bag that receives, if the TTL in this fair bag that receives is different with last time, thinks that the choke point changes.If changed for the 4th step over to, otherwise changed for the 5th step over to.

The 4th step: the token in the token bucket is emptied, be about to counter O reset, this step is for fear of change the judgement that makes the mistake because of the choke point.

The 5th step: compare with token number in the token bucket and pre-set threshold, threshold setting is 0x2000 in this example, changes for the 6th step over to if token number is lower than threshold value, otherwise changes for the 7th step over to.The setting of threshold value is relevant with line bandwidth, can be set to be slightly larger than line bandwidth.

The 6th step: judge that current mistake circulation by the choke point more than or equal to current fair rate, was provided with the circulation sign that transfinites.Changed for the 8th step after finishing over to.

The 7th step: judge that current mistake circulation by the choke point less than current fair rate, removed the circulation sign that transfinites.

The 8th step: the token increase in the token bucket once, added value is the current fair rate of receiving.

The 9th step: token bucket generation overflow? whether promptly make the addition hour counter overflows.If changed for the tenth step over to, otherwise changed for second step over to.

The tenth step: token number is reduced to (the maximum byte number that sends in threshold value+one a fair intraperiod line road).In this example, threshold value is 0x2000, and a fair intraperiod line road maximum transmission byte number is 0x1D40.This step is in order to improve the response speed to Added Business.Changed for second step after finishing over to.

The 11 step: detect a ring of crossing and wrap by the choke point? if changeed for the 12 step, otherwise changeed for second step.

The 12 step: according to token number in the long minimizing of the bag token bucket.In this example, directly deduct the byte number of bag with the value of counter.Changed for the 13 step after finishing over to.

The 13 step: token bucket generation underflow? whether the hour counter that promptly subtracts overflows.If changeed for the 14 step.Otherwise changeed for second step.

The 14 step: the token in the token bucket is emptied, be about to counter O reset.Changed for second step over to.

Claims

1, a kind of method of judging on Resilient Packet Ring that circulation transfinited is characterized in that comprising the following steps:

Step 1, create a token bucket, be used for deposits tokens at test point;

Step 4, empty the token in the token bucket;

2, method according to claim 1 is characterized in that: the test point in the described step 1 is crossed ring bag Statistics Division on Resilient Packet Ring.

3, method according to claim 1 is characterized in that: the token bucket in the described step 1 realizes that with counter the value of counter is represented token number, the corresponding byte of each token.

4, method according to claim 1 is characterized in that: test point can be represented with the TTL that carries in the fair bag that receives to the distance of choke point in the described step 3.

5, method according to claim 1 is characterized in that: pre-set threshold is set at and is slightly larger than line bandwidth in the described step 5.