CN1747454A - Method for adjusting service access time and decreasing service to achieve burst - Google Patents

Abstract

A method for controlling the service access time interval to decrease the service arrival bursts includes such steps as sending a service request from a user to network, queuing for waiting access, setting up a next service access time by network boundary router according to access interval, allowing a service access, and updating the access interval according to the arrival interval of current request and the current access interval.

Description

The control service access time interval is reduced the professional method that arrives burstiness

Technical field

The present invention relates to a kind of professional method that arrives burstiness that reduces, especially a kind of by the professional method that arrives burstiness of control service access time interval reduction, belong to communication technical field.

Background technology

The main business of Internet is data service at present.Data service does not have strict requirement to the service quality (Quality of Service is hereinafter to be referred as QoS) of network.Along with the appearance of speech and real-time multimedia business, customer service is more and more higher to the qos requirement of network.Qos requirement mainly comprises the professional available bandwidth that transmits, time-delay, packet loss etc.Be the key of network research how for various access service provide QoS to guarantee always.

Existing QoS guarantees that mechanism generally all consists of the following components: traffic shaping (traffic shaping), admittance control (calladmission control), resource reservation (resource reservation), packet scheduling (Packet Scheduling), state upgrade (stateupdating), QoS route (QoS routing) etc.They are interrelated, and mutual restriction is finished the task that QoS guarantees jointly.

In order to satisfy the qos requirement of customer service, QoS guarantees the machine-processed operating position that will constantly understand current network resources, on this basis, and in conjunction with certain optimization aim, for the service selection optimum or be available transmission path at least, and guarantee that network has higher utilance.The operating position of Internet resources is expressed by node state.Node state commonly used has available bandwidth, time-delay and the delay jitter etc. of routing node.Node state is dynamic change in the network.This gives the QoS assurance mechanism of carrying out work according to node state, brings difficulty as state update mechanism, admission control mechanism and QoS routing mechanism.

According to our achievement in research, node state steadily is the primary condition that realizes that QoS guarantees.Node state is meant that steadily node state has stationarity in short-term in time.Can think just that at two next state reproducting periods node state is similar to a stochastic variable stably, its statistical property is approximate constant as average, variance and probability distribution.All QoS guarantee that the design of mechanism (traffic shaping, admittance control, resource reservation, packet scheduling, state renewal, QoS route etc.) all should be around making steadily this basic premise of node state.

Each node state is jiggly in the existing Packet Based Network, thereby makes network utilization low, and QoS realizes difficulty.Cause the jiggly factor of node state a lot, the sudden of business arranged, admit control, state renewal, QoS routing mechanism imperfection or the like, need study one by one.The conclusion that network research is at present generally acknowledged is: the burstiness of Network is low more, and node state is steady more.Therefore must before the transmission beginning,, adopt certain control and treatment mechanism, change professional statistical nature, make it help the stable and professional transmission of network state according to the requirement of Network Transmission.This process is called Network and handles.The burstiness that reduces Network is one of important goal of Network processing.

The sudden of Network mainly is made up of two parts, the professional burstiness that arrives and the burstiness of business data flow.The professional burstiness that arrives is meant the burst degree that arrives the professional number of network in the unit interval; The burstiness of business data flow is meant the burst degree of single or convergence service data flow traffic in the unit interval.The burstiness that not only will reduce the business data flow flow is handled in Network, also will reduce the professional burstiness that arrives, and could reduce the burstiness of Network so better.

The method that Network is at present handled mainly is after business arrives network, adopts the burstiness of some shaping algorithms reduction business data flows, as (r b) leaks the bucket shaping algorithm.(r b) is defined as, and in the section t, the flow of obeying the Business Stream of this kind model is not more than rt+b at any time, and wherein, r is the Mean Speed of Business Stream, and b be the degree of depth of bucket, the length of buffering area just, and after it has determined shaping, the burstiness of business.Because this class shaping algorithm is after business enters network, adopt for effectively transmitting, we classify as passive shaping algorithm with them.The shaping of passive shaping algorithm is to liking professional discharge characteristic, as the burstiness of business data flow.It need consume Internet resources such as buffering area, bandwidth.Passive shaping algorithm has been obtained lot of research in network theory research.Also how nobody research before the service access network, handled the application process of business, reduces the professional burstiness that arrives but up to the present.

For IP phone, the such business of the network teleconference, its access procedure can be divided into professional application process and professional transmission course, as shown in Figure 1.Professional application process is initiated by the user, comprises dialing, connects, operation such as wait for that the other side replys.This process is the negotiation process of user (people) and network, consumption of network resources not substantially, and can tolerate certain time-delay and delay jitter.As the dialing procedure of IP phone, can tolerate the 1-2 time-delay wait of second at least.After application process finished, business just really was access in network, began transmission.Professional transmission course is had relatively high expectations to time-delay, is 30～60ms such as the delay requirement of IP phone, and the delay requirement of video conference is 40～90ms.

Before the service access network, the application process of business is handled, be called the professional pre-treatment of arrival.Behind the service access network, the discharge characteristic of business is handled, be called the arrival Business Processing.The tolerable application time-delay of user is far longer than transmission delay for a second level time-delay, and this provides bigger time and space for arriving professional pre-treatment.We can in a planned way adjust user's the application stand-by period, such as allowing the user wait 1-2 to converse second, utilize the time interval of the business of adjusting access network during this period of time more again, thereby reduce the burstiness that Network arrives.This process can not exert an influence to the time-delay characteristics of transmission course, can not take Internet resources yet.

The present invention proposes a kind of shaping algorithm that can be used for arriving professional pre-treatment.By the service access time interval is controlled, reduce the professional burstiness that arrives.Because this algorithm is before the service access network, initiatively to adjusting at interval the turn-on time of business.Therefore, it is classified as initiatively shaping algorithm.Different with passive shaping algorithm, the shaping of this class shaping algorithm arrives the burstiness of network to liking professional arrival characteristic as business.It belongs to the professional pre-treatment of arrival.The shaping methods that the present invention relates to and the relation of method for processing business are as shown in Figure 2.

Summary of the invention the objective of the invention is to propose a kind of active shaping algorithm that can be used for arriving professional pre-treatment.It adjusts the time interval of service access network by professional application process is handled, and reduces the professional burstiness that arrives network.This shaping methods is suitable for IP phone, video conference like this, and transmission delay is required height, but to the insensitive business of the time-delay of application process.Processing procedure of the present invention does not take Internet resources, and does not influence the time-delay characteristics of professional transmission, and the burstiness tool that reduces Network is had certain effect.

The invention is characterized in that described method contains following steps successively:

Step 1: user (people) sends professional application by modes such as manual or automatic dialing to network, waits access then;

Step 2: the network boundary router is set the access moment of this customer service by following step;

Step 2.1 initialization, establish:

The moment that user's business application arrives is respectively O, t _A1, Λ, t _An-1, t _An, n=1,2,3 Λ, wherein t _An＞t _An-1

After the active shaping, the moment of service access is respectively t ' _A0, t ' _A1, Λ, t ' _An-1, t ' _An, t ' wherein _An＞t ' _An-1

T _A0Be initial interval turn-on time, T _A1, Λ, T _Am-1, T _Am, m=1,2,3K is the interval of upgrading successively turn-on time;

Order: initial time is 0, n=0, m=0

After H business applied for before step 2.2 border router was received, calculate the mean value of this H professional arrival interval, as initial interval turn-on time, promptly

$T_{a0}=\frac{t_{\mathrm{aH}}}{H},$ H is a set point;

Step 2.3 is at t _AH ⁺Constantly, described border router is the customer service access network of first application, and with T _A0Be at interval, be provided with and insert constantly,, arrive up to next professional application, wherein the customer service that waiting access network successively;

$t_{a1}^{\′}={t_{\mathrm{aH}}}^{+};$

After next professional application of step 2.4 arrived, described border router upgraded service access at interval by following formula:

T _Am=T _Am-1+ K (t _AH+m-t _AH+m-1-T _Am-1), wherein K is a set point, in 0＜K＜1 value, promptly exists

(t _AH+m-t _AH+m-1)＞T _Am-1The time, T _Am＞T _Am-1,

(t _AH+m-t _AH+m-1)＜T _Am-1The time, T _Am＜T _Am-1

Step 2.5 is provided with at interval with new access and inserts constantly, inserts the customer service of waiting in line successively;

Step 2.6 repeating step 2.4,2.5, the moment renewal that arrives in each professional application inserts at interval, makes the burstiness of service access burstiness at interval less than the application arrival interval.

The control service access time interval that the present invention proposes is reduced the professional method that arrives burstiness, has following advantage:

1, handles by application process, reduce the professional burstiness that arrives network business.

2, before business arrives network, adopt initiatively shaping methods, initiatively adjust professional access at interval.

3, before the service access network, by setting professional access constantly, the access interval that control is professional.

3, process object of the present invention is to transmission delay requirement height, but to the insensitive business of the time-delay of application process, as the application stand-by period of phone, video conference etc.

4, application process can have long processing time-delay;

5, the processing of application process does not take Internet resources (bandwidth and memory);

6, the processing of application process time-delay does not influence the time-delay characteristics of professional transmission;

Description of drawings

The professional arrival of Fig. 1 handles and business arrives pre-treatment.

Fig. 2 is shaping methods and passive shaping methods initiatively.

Fig. 3. workflow diagram of the present invention.

Fig. 4. service access of the present invention definite method flow diagram constantly.

Embodiment

The control service access time interval that the present invention proposes is reduced the professional method that arrives burstiness, can be used for the network boundary router to the networking telephone, the access that Web conference etc. are professional.Its workflow as shown in Figure 3, at first user (people) sends professional application by manual or dial mode automatically to network, waits in line service access then.The network boundary router is according to certain algorithm, for traffic set inserts constantly.When access arrives constantly, just insert a business.And the access of definite next business constantly.Inserting under the control constantly, customer service is by queuing order access network successively.The present invention is by the time interval that the control service access is set to the service access moment, thus the professional burstiness that arrives of reduction.Wherein, insert establishing method constantly as shown in Figure 4.

When beginning at first, apply for that number is set to 0, initial time also is set to 0.After this whenever receive a customer service application, an application counter adds 1.When the application number equals H (H can set in advance according to actual conditions), insert first business and insert initial value at interval according to preceding H the professional interval calculation time of advent.Setting next according to this value inserts constantly.Constantly detection has or not the new business application to arrive, if there is not new business application to arrive, just constantly is provided with at interval according to this and inserts the moment.If there is the new business application to arrive, just adopt certain algorithm, upgrade and insert at interval, and after a last access finishes constantly, with new access next is set at interval and inserts constantly.So move in circles.

Insert the calculating and the renewal of initial value at interval and can adopt following algorithm:

If the moment that professional application arrives be 0, t _A1, Λ, t _An-1, t _An, n=1,2,3 Λ, t _An＞t _An-1, through after the shaping initiatively, the moment of service access be t ' _A0, t ' _A1, Λ, t ' _An-1, t ' _An, t ' _An＞t ' _An-1, T _A0Be initial interval turn-on time.T _A1, Λ, T _Am-1, T _Am, m=1,2, the turn-on time that 3K upgrades successively after.H professional average arrival interval in the past, as initial turn-on time at interval, promptly

$T_{a0}=\frac{t_{\mathrm{aH}}}{H},$

At t _AH ⁺Constantly begin, with the service access network of first application.Simultaneously, with T _A0For at interval, set next and insert constantly.Therefore, the access of first business equals H professional due in constantly, that is:

$t_{a1}^{\′}={t_{\mathrm{aH}}}^{+},$

Before H+1 professional application arrives, i.e. t _AH+1Constantly, with T _A0Insert constantly for being provided with at interval.

After H+1 professional application arrives, calculate new service access at interval by following formula:

T _A1=T _A0+ K (t _AH+1-t _AH-T _A0), 0＜K＜1 wherein.

From t _AH+1 ⁺After, with T _A1Be the interval access service, up to next one application, t _AH+2Arrive.

So continue, work as t _AH+mAfter the arrival, new service access is spaced apart:

T _am＝T _am-1+K(t _aH+m-t _aH+m-1-T _am-1)

From t _AH+mAfter the arrival, i.e. t _AH+m ⁺After, with T _AmInsert constantly for being provided with at interval, arrive up to next professional application.

Claims (1)

1, a kind of by the professional method that arrives burstiness of control service access time interval reduction, it is characterized in that described method contains following steps successively:

Step 1: the user sends professional application by modes such as manual or automatic dialing to network, waits access then;

Step 2: the network boundary router is set the access moment of this customer service by following step;

Step 2.1 initialization, establish:

The moment that user's business application arrives is respectively 0, t _A1, Λ, t _An-1, t _{An, n}=1,2,3 Λ, wherein t _An＞t _An-1

After the active shaping, the moment of service access is respectively t _A0', t _A1', Λ, t _An-1', t _An', t wherein _An'＞t _An-1';

T _A0Be initial interval turn-on time, T _A1, Λ, T _Am-1, T _Am, m=1,2,3K is the interval of upgrading successively turn-on time;

Order: initial time is 0, n=0, m=0

After H business applied for before step 2.2 border router was received, calculate the mean value of this H professional arrival interval, as initial interval turn-on time, promptly

$T_{a0}=\frac{t_{\mathrm{aH}}}{H}$ H is a set point;

Step 2.3 is at t _AH ⁺Constantly, described border router is the customer service access network of first application, and with T _A0Be at interval, be provided with and insert constantly,, arrive up to next professional application, wherein the customer service that waiting access network successively;

t _a1′＝t _aH ⁺；

After next professional application of step 2.4 arrived, described border router upgraded service access at interval by following formula:

T _Am=T _Am-1+K (t _AH+m-t _AH+m-1-T _Am-1), wherein K is a set point, in 0＜K＜1 value, promptly exists

(t _AH+m-t _AH+m-1)＞T _Am-1The time, T _Am＞T _Am-1,

(t _AH+m-t _AH+m-1)＜T _Am-1The time, T _Am＜T _Am-1

Step 2.5 is provided with at interval with new access and inserts constantly, inserts the customer service of waiting in line successively;

Step 2.6 repeating step 2.4,2.5, the moment renewal that arrives in each professional application inserts at interval, makes the burstiness of service access burstiness at interval less than the application arrival interval.

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