CN102710464B - Fine-grained single-flow delay detection method based on reference delay insertion structure - Google Patents

Abstract

The invention provides a fine-grained single-flow delay detection method based on a reference delay insertion structure, and the method comprises the following steps of setting a reference packet generator at a transmission end; setting a delay estimator at a receiving end; and periodically injecting a reference packet with a timestamp from the transmission end into a data stream by utilizing the reference packet generator, delaying the reference packet in the transmission process, receiving the reference packet delay sample by utilizing the receiving end, and collecting the reference packet delay sample and performing the delay detection by utilizing the delay estimator. By setting the reference packet, as long as the transmission time of the reference packet is close enough to the transmission time of the data packet, the delay property of the data packet can be deduced after observing the reference packet, and thus the delay estimation error can be reduced. In addition, compared with the scheme that a great amount of data packet timestamps are required to collect from multiple terminals, the detection result can be directly acquired on the receiving end, and the timestamps of all conventional data packets on the transmission end are not required, so that the architecture is convenient to implement, the cost performance is high, and wide popularization and application can be favored.

Description

Based on the fine granularity single current rank method of testing delay with reference to delay insert structure

Technical field

The present invention relates to technical field of computer multimedia, particularly a kind of based on the fine granularity single current rank method of testing delay with reference to delay insert structure.

Background technology

At present, the Internet is applied to many new fields gradually, such as algorithm transaction and high performance computation, and these applications are very strict to the requirement postponed, and reach Microsecond grade.But Virtual network operator is now short of fine-grained testing tool to locate and revise those Network Abnormals causing SLA to break rules and postpone spike very much.Researcher is had to propose a kind of extendible delay detection scheme being LDA recently, but it can only carry out delay to aggregated flow and detect, and also can show obviously difference because even if not homogeneous turbulence transmits on the same link, therefore when getting rid of the failure and special of application layer, we need the delay of single stream to detect.Also have a kind of detection scheme that postpones to be detection technique based on active probe, this detection technique is mainly used in end-to-end system, can not detect the delay issue of router, and high precision test equipment expensive in addition also cannot be widely used in current network.

Summary of the invention

The present invention is intended at least solve the technical problem existed in prior art, especially innovatively proposes a kind of based on the fine granularity single current rank method of testing delay with reference to delay insert structure.

In order to realize above-mentioned purpose of the present invention, the invention provides a kind of based on the fine granularity single current rank method of testing delay with reference to delay insert structure, it comprises the steps:

S1: set up with reference to generator package at transmitting terminal;

S2: set up delay estimator at receiving terminal;

S3: the reference bag with timestamp is periodically injected into data flow from transmitting terminal with reference to generator package, postpone with reference to wrapping in transmitting procedure, receiving terminal receives with reference to packet delay sample, and delay estimation device is collected with reference to packet delay sample and carried out delay and detects.

The present invention is relative to the concrete time delay directly measuring each packet in single current, by arranging one with reference to bag, only need ensure that it is enough close with the time of Packet Generation, carry out observing the later lag characteristic just can inferring packet to it, this method reduces delay estimation error.In addition, collect compared with the scheme of mass data bag timestamp with needs from multi-endpoint, testing result of the present invention directly obtains at receiving terminal, do not need the timestamp of all routine data bags of transmitting terminal, this framework is convenient to implement, and cost performance is high, is conducive to applying widely.

Additional aspect of the present invention and advantage will part provide in the following description, and part will become obvious from the following description, or be recognized by practice of the present invention.

Accompanying drawing explanation

Above-mentioned and/or additional aspect of the present invention and advantage will become obvious and easy understand from accompanying drawing below combining to the description of embodiment, wherein:

Fig. 1 the present invention is based on the flow chart with reference to the fine granularity single current rank method of testing delay postponing insert structure.

Embodiment

Be described below in detail embodiments of the invention, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has element that is identical or similar functions from start to finish.Being exemplary below by the embodiment be described with reference to the drawings, only for explaining the present invention, and can not limitation of the present invention being interpreted as.

The invention provides a kind of based on the fine granularity single current rank method of testing delay with reference to delay insert structure, as shown in Figure 1, it comprises the steps:

S1: set up with reference to generator package at transmitting terminal;

S2: set up delay estimator at receiving terminal;

S3: the reference bag with timestamp is periodically injected into data flow from transmitting terminal with reference to generator package, postpone with reference to wrapping in transmitting procedure, receiving terminal receives with reference to packet delay sample, and delay estimation device is collected with reference to packet delay sample and carried out delay and detects.

In the present embodiment, the step of the transient state location of measurement operation diversity and time delay can also be had before step S1, the method of the transient state location of this measurement operation diversity and time delay is: the trace in use real router is as beasurement base, analyze SANJ, the average delay of this Four types packet of CHIC, WEB468 and WEB700.Particularly, in order to more in depth catch the Delay Variation of each group packet, calculate their respective average delays, in the present embodiment, analyzing the method for packet is: be packet grouping according to the 2 yuan of characteristics comprising source address and destination address, calculates average retardation, and computer capacity factor R, definition R be often organize average retardation value from one of percentage to percent ninety-nine quantile, be divided into 100 parts by length of delay, the introducing of R can obtain most delay coverage.

Time average is divided into the time slot of fixed intervals, for each group packet k, time slot i, records the number n of now packet _{i, k}with average latency d _{i, k}.So, in i time slot, the overall average time delay of packet is:

$\stackrel{\‾}{d}=\frac{{\mathrm{\Σ}}_k{n}_{i,k}{d}_{i,k}}{{\mathrm{\Σ}}_k{n}_{i,k}}---\left(1\right)$

The overall average time delay of kth group packet is:

$D_k=\frac{{\mathrm{\Σ}}_i{n}_{i,k}{d}_{i,k}}{{\mathrm{\Σ}}_i{n}_{i,k}}---\left(2\right)$

At D _kdefinition in, Ke Yiyong replace d _{i, k}, namely adopt by the number n of packet _{i, k}for weight weighted average time delay as k group packet each time Yanzhong feature, just can obtain a quite accurately approximation, the average delay obtained after replacement is local average time delay:

$D_k=\frac{{\mathrm{\Σ}}_i{n}_{i,k}\stackrel{\‾}{d}}{{\mathrm{\Σ}}_i{n}_{i,k}}=\frac{{\mathrm{\Σ}}_{i,j}{n}_{i,k}{n}_{i,j}{d}_{i,j}/{\mathrm{\Σ}}_l{n}_{i,l}}{{\mathrm{\Σ}}_i{n}_{i,k}}---\left(3\right)$

Utilize this method of measurement, when the packet of two streams transmits in typical delay burst duration, when particularly transmitting within the almost identical time, the delay performance of the packet of these two streams shows consistency closely.Therefore, router can produce a reference stream on a certain bar link, to provide the basic settings that reference stream postpones to detect.Then, the delay of stream is specified arbitrarily can be obtained by the packet measuring the reference stream around it.So just enormously simplify the complexity of detection, data are detected for the reference stream not corresponding to homogeneous turbulence and all obtains from same reference stream.

Particularly, queueing delay can by one-tenth continuous function when Packet Generation, transmitting terminal obtains postponing time dependent function, and the delay that normal packet stands can be estimated by certain some delay sample, and these delay samples are from a large amount of delay samples in reference bag.Therefore, insert error to be controlled by the number changing the reference point inserted in delay curve.

In the preferred embodiment of the present invention, based on the concrete steps with reference to the fine granularity single current rank method of testing delay postponing insert structure be:

One is set up with reference to generator package, at the delay estimator that receiving terminal sets up to be made up of counter at transmitting terminal.With reference to generator package, the reference bag with timestamp is periodically expelled to data flow from the transmitting terminal of router, these are with reference to the queuing time that bag experiences and general data bag is similar or other effects, postpone in transmitting procedure, therefore relative delay sample can be provided at receiving terminal with reference to bag, receiving terminal receives with reference to packet delay sample, and delay estimation device is collected these delay samples and they sent to single current counter and carries out delay detection.

In the present embodiment, the method produced with reference to bag with reference to generator package is: the condition 1 produced with reference to bag sends one with reference to bag after often sending n normal packet, the condition 2 produced with reference to bag is send one with reference to bag every the time interval of τ, when condition 1 meets or condition 2 meets, send with reference to bag according to the send mode of the condition met.Namely, when some in two conditions meets, just send according to its send mode.In the present embodiment, can also dynamically monitor with reference to the producing level wrapped to determine to inject the speed with reference to bag.A kind of like this strategy sent with reference to bag is all better than the mode of fixed packet number and set time transmission.According to the effect that the utilance with reference to bag can obtain, reduce the transmission rate with reference to bag when high utilization rate, make raising with reference to the transmission rate of bag at poor efficiency.

In the present embodiment, the delay to obtain them is wrapped in process mixing reference in the normal packet by receiving terminal.This structure does not require that receiving terminal is that stream all in network safeguards counter, as long as and they can the feature of sub-fraction subflow in maintenance data stream.In the present embodiment, the method of estimator of being delayed is maintenance three kinds of counters, in these three kinds of counter kinds, the number of delay sample in this data group of a kind of counter records, a delay summation in this data group of counter records suffered by all packets, the quadratic sum of another each packet delay of counter records.The setting of this mixing make counter along with receiving data stream more new data, therefore, in the present embodiment, adopt high-speed SRAM to be applied to these counters.

In delay estimator, further comprises an interpolation buffering area, this interpolation buffer records two with reference to bag between arrive the relevant information of all bags.Arranging this interpolation buffering area is because be the function that is independent variable with two with reference to the delay data of sample data bag between bag to the delayed data of each packet.This buffering area does not need to store packet completely, only stream number need be stored, corresponding timestamp and byte counter, the size of this interpolation buffering area can set statically according to reference stream generator, the number upper limit of the buffers packet between two probes arrival can be calculated thus, and it is set to the size of interpolation buffering area.Such as, in time average generator scene, for given link capacity, just can calculate at most that it can send how many bags within the τ time, this just can as the size of interpolation buffer.

The existence of interpolation buffering area makes it possible to wrap with reference to bag and right reference the time delay estimating it by the left of some packets, but it makes storage organization become more complicated.In another kind of preferred implementation of the present invention, the time delay of this packet estimated as a reference by the reference bag arrived before adopting certain packet, this does not need interpolation buffering area, and only need record with reference to wrapping the delay experienced, this can obtain with a counter easily.

In the present embodiment, the delay estimator of employing is RLI estimator, in this RLI estimator, and order be i-th reference bag, j=1,2 ... n, for time of reception stamp is positioned at with between normal bag.Order represent the timestamp of receiving terminal, represent receiving terminal pair byte count value, τ _land τ _rrepresent a _land a _rtime of reception stamp, b be with reference to bag size, l _cfor link capacity.So, then jth with reference to the delay estimation of bag for:

Wherein, d _lfor reference bag delay, d _rfor reference bag delay.

On the right of the equal sign of formula (4), Section 3 is different the done compensation of seasonal effect in time series to causing with the size with reference to bag because of normal packet.In the present embodiment, when no matter when a new reference bag arrives, a _land a _rupgrade, Delay Estima-tion thereafter just can by calculating at once.

Delay Estima-tion result out after, several single current counters of design can do following renewal:

c(f _k)=c(f _k)+1

m(f _k)=m(f _k)+d _j（5）

$v\left(f_k\right)=v\left(f_k\right)+{\tilde{d}}_j^2$

Wherein, f _kfor the kth in the single current that receives is with reference to bag, k is positive integer.

When a certain bar stream stops, if represent with reference to the last number of bag respectively, the value of average and variance, so the average of this stream and variance can calculate respectively as follows:

$E\left[d_{\mathrm{fk}}\right]=\tilde{m}\left(f_k\right)/\tilde{c}\left(f_k\right)$

$\mathrm{Var}\left[d_{\mathrm{fk}}\right]=\frac{\tilde{v}\left(f_k\right)}{\tilde{c}{\left(f_k\right)}^2}-E{\left[d_{\mathrm{fk}}\right]}^2---\left(6\right)$

Wherein d _fkwhat represent is the stochastic variable that this stream packets postpones, and these values all can export after completing calculating together with stream record.

Above RLI estimator requires to store packet in interpolation buffering area, until the next arrival with reference to bag, this provides for improved the complexity of system.Therefore, in the preferred implementation that the present invention is other, adopt RLI-L estimator, this estimator does not need two, the left and right delay sample of interpolation buffering area to carry out valuation simultaneously, and only needs left delay sample.Postponing for d for all _land d _rreference bag with between to be commonly surrounded by:

In present embodiment is converged, RLI-L estimator and RLI estimator have identical data refresh mode, and therefore not to repeat here.

The present invention is relative to the concrete time delay directly measuring each packet in single current, by arranging one with reference to bag, only need ensure that it is enough close with the time of Packet Generation, carry out observing the later lag characteristic just can inferring packet to it, this method reduces delay estimation error.In addition, collects compared with the scheme of mass data bag timestamp with needs from multi-endpoint, testing result of the present invention directly in receiving terminal acquisition, does not need the timestamp of all routine data bags of transmitting terminal.This framework is convenient to implement, and cost performance is high, is conducive to applying widely.

In the description of this specification, specific features, structure, material or feature that the description of reference term " embodiment ", " some embodiments ", " example ", " concrete example " or " some examples " etc. means to describe in conjunction with this embodiment or example are contained at least one embodiment of the present invention or example.In this manual, identical embodiment or example are not necessarily referred to the schematic representation of above-mentioned term.And the specific features of description, structure, material or feature can combine in an appropriate manner in any one or more embodiment or example.

Although illustrate and describe embodiments of the invention, those having ordinary skill in the art will appreciate that: can carry out multiple change, amendment, replacement and modification to these embodiments when not departing from principle of the present invention and aim, scope of the present invention is by claim and equivalents thereof.

Claims (4)

1., based on reference to the fine granularity single current rank method of testing delay postponing insert structure, it is characterized in that, comprise the steps:

S1: set up with reference to generator package at transmitting terminal, wherein, before step S1, also there are following steps: the transient state location measuring operation diversity and time delay, and the method measuring the transient state location of operation diversity and time delay is: the trace in use real router is as beasurement base, analyze SANJ, CHIC, the average delay of this Four types packet of WEB468 and WEB700, and analyze the method for packet and be: be packet grouping according to the 2 yuan of characteristics comprising source address and destination address, calculate average retardation, and computer capacity factor R is often organize the quantile of average delay value from 1 to 99, time average is divided into the time slot of fixed interval (FI), for each group packet k, time slot i, record the number n of now packet _i,kwith average latency d _i,k, so, in i gap, the overall average time delay of packet is: the overall average time delay of kth group packet is: $D_k=\frac{{\mathrm{\Σ}}_i{n}_{i,k}\stackrel{\‾}{d}}{{\mathrm{\Σ}}_i{n}_{i,k}}=\frac{{\mathrm{\Σ}}_{i,j}{n}_{i,k}{n}_{i,j}{d}_{i,j}/{\mathrm{\Σ}}_l{n}_{i,l}}{{\mathrm{\Σ}}_i{n}_{i,k}};$

S2: set up delay estimation device at receiving terminal;

S3: the reference bag with timestamp is periodically injected into data flow from transmitting terminal with reference to generator package, postpone with reference to wrapping in transmitting procedure, receiving terminal receives with reference to packet delay sample, and delay estimation device is collected with reference to packet delay sample and carried out delay and detects.

2. as claimed in claim 1 based on the fine granularity single current rank method of testing delay with reference to delay insert structure, it is characterized in that, the method produced with reference to bag is: the condition 1 produced with reference to bag sends one with reference to bag after often sending n normal packet, the condition 2 produced with reference to bag is send one with reference to bag every the time interval of τ, when the some conditions in condition 1 or condition 2 meet, send with reference to bag according to the send mode of the condition met.

3. as claimed in claim 1 based on the fine granularity single current rank method of testing delay with reference to delay insert structure, it is characterized in that, the method of estimator of being delayed is: safeguard three kinds of counters, the number of delay sample in described counter records data group, the quadratic sum of the delay summation in described data group suffered by all packets and the delay of each packet.

4. as claimed in claim 1 based on reference to the fine granularity single current rank method of testing delay postponing insert structure, it is characterized in that, the method that delay estimator carries out postponing to detect is:

Delay estimator makes be i-th reference bag, j=1,2 ... n is that time of reception stamp is positioned at with between normal bag, order represent the timestamp of receiving terminal, represent receiving terminal pair byte count value, τ _land τ _rrepresent a _land a _rtime of reception stamp, b be with reference to bag size, l _cfor link capacity, then the delay estimation of a jth reference bag for:

Wherein, d _lfor reference bag delay, d _rfor reference bag delay;

When no matter when a new reference data bag arrives, a _land a _rto upgrade, Delay Estima-tion thereafter calculates successively at once.