CN102325146A - Universal data exchange (UDX) protocol stack, and UDX-protocol-based data transmission system and method - Google Patents

Abstract

The invention discloses a universal data exchange (UDX) protocol stack, a UDX-protocol-based data transmission system and a UDX-protocol-based data transmission method. The protocol stack comprises a link layer, a network layer, a transport layer and an application layer, wherein the transport layer adopts a UDX protocol which can coexist with a transmission control protocol (TCP) and a UDP-based data transfer (UDT) protocol. The transmission system comprises an application server, a workstation, a personal computer, a mobile terminal, a terminal monitor and a digital signal processing (DSP) camera which access the world wide web, wherein the application server, the workstation, the personal computer and the like are connected with the world wide web by using the UDX protocol; and the application server, the workstation, the personal computer, the mobile terminal, the terminal monitor and the digital signal processing camera all can transmit data with one another by utilizing the UDX protocol by the world wide web. By the protocol stack, the system and the method, packet loss rates in a wired network and a wireless network can be effectively decreased, transmission efficiency can be improved, response can be quickened, the utilization rate of a channel can be increased and network performance can be improved.

Description

The UDX protocol stack, based on the data transmission system and the method for UDX agreement

Technical field

The present invention relates to communication and internet data transmission technology, relate in particular to a kind of conventional data exchange (UDX, Universal Data eXchange) protocol stack, based on the data transmission system and the method for UDX agreement.

Background technology

Communication and the Internet etc. need carry out the occasion of transfer of data; Commonly used to transmission control protocol (TCP), based on the reliable transport protocol (UDT of UDP; UDP-based Data Transfer Protocol); It can be used in wired, wireless communication field, between the personal computer (PC) or handheld terminal, mobile communication equipment carry out data communication through wired or wireless network.As, at portable terminal and PC, carry out exchanges data between PC and the PC.But to be based upon congested be on the basis of Network Packet Loss reason to congestion control mechanism in the TCP communication protocol that legacy network uses; And the friendly that realizes for the different TCP of compatibility, so the packet loss of link that this mechanism can not adapt to is wired, high bit-error, high latency cause in the wireless network and quicken to wait slowly situation.

With traditional Transmission Control Protocol is example, owing to its developing history and realize that principle has its congenital and posteriori reason, can not satisfy existing demand in the plurality of applications field.For with early stage TCP1.1 edition compatibility, on algorithm, employing be conservative algorithm, increase on the algorithm at overtime re-transmission and send window and be tending towards conservative, make efficient that certain loss arranged.On the other hand, also there are some defectives in algorithm on re-transmission policy, and resume speed is relatively slow.And TCP mainly is that under error rate condition with higher, performance sharply descends to the wired network design.

Summary of the invention

In view of this; Main purpose of the present invention is to provide a kind of UDX protocol stack, based on the data transmission system and the method for UDX agreement; Packet loss in, the wireless network wired with effective reduction improves efficiency of transmission and response speed, improves the utilance and the network performance of channel.

For achieving the above object, technical scheme of the present invention is achieved in that

A kind of conventional data exchange UDX protocol stack comprises link layer, network layer, transport layer and application layer; Its transport layer adopts the UDX agreement, and this UDX agreement can coexist as transport layer with Transmission Control Protocol, UDT agreement.

Wherein, said UDX agreement seal assembling structure be divided into UDX connect among packet header, the UDX subcontract, four kinds of UDX general data bag and UDX response packets; Wherein:

Said UDX connects packet header; Length is 39 bytes, data length that comprise that the connect hours of maximized window number, 2 bytes of ten thousand net address SOCKADDR, 2 bytes of UDX packet header, 20 bytes of 10 bytes stabs, whether 1 server refuses flag bit, carries in 7 connection procedures during the connection of state, 4 bytes and the data of carrying when connecting;

Subcontract among the said UDX, comprise the UDX packet header of 10 bytes, 64 destination address DEST and data source;

Said UDX general data bag comprises UDX packet header and data field two parts of 10 bytes;

Said UDX response packet comprises the UDX packet header of 10 bytes, 8 ack number and the ack data of 8 bytes.

Wherein, said UDX packet header comprises 1 P2P flag bit, 1 first transfer registered symbol position, 1 second transfer registered symbol position, subcontracts flag bit in 1,4 UDX that keep position, 16 bit checks and position and 7 bytes wraps.

Further, said UDX bag comprises that it is 0 sign, 4 bag type indicating bits and channel position position, 2 seat that 16 transmitting time, 32 bag sequence number, 1 are effectively calculated RTT flag bit, 1 ack occupy-place number.

A kind of data transmission system based on the UDX agreement comprises the application server, work station, personal computer, portable terminal, terminal monitor and the Digital Signal Processing DSP camera that insert the World Wide Web (WWW); Said application server, work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera use the UDX agreement to connect the World Wide Web (WWW) respectively; Said application server, work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera all can utilize the UDX agreement transmitting data each other through the World Wide Web (WWW).

Wherein, said work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera all insert the World Wide Web (WWW) through the UDX module of self.

Wherein, in the UDX module of work station and personal computer, comprise applied logic submodule and communicator module.

Wherein, in the portable terminal the UDX module in, comprise JAVA/C++ and use submodule and communicator module.

Wherein, in terminal monitor and the DSP camera, comprise image processing submodule and communicator module.

A kind of data transmission method based on the UDX agreement comprises the steps:

A, transmitting terminal connect bag through the UDX agreement and carry out three-way handshake with receiving terminal, set up communication link;

B, transmitting terminal send data through UDX general data bag to said receiving terminal;

After C, receiving terminal are received said UDX general data bag, send response packet, and return transmitting time and calculate two-way time to said receiving terminal;

After D, transmitting terminal receive response packet, if said packet receives successfully, by the application layer resolution data, and by the receiving terminal verification of data integrity.

UDX protocol stack provided by the present invention, based on the data transmission system and the method for UDX agreement, have the following advantages:

Adopt the data transmission system of this UDX agreement; Can be under the environment of high latency, high packet loss; Compare with quasi-protocol with Transmission Control Protocol or other, still can keep higher efficiency of transmission, packet loss still less and preferable real-time, thereby can effectively utilize the existing network bandwidth; In the unit interval, can transmit more valid data, improve throughput.

Description of drawings

Fig. 1 is the data transmission system sketch map that the present invention is based on the UDX agreement;

Figure 1A is the structural representation of UDX module in work station, the personal computer;

Figure 1B is the structural representation of UDX module in the portable terminal;

Fig. 1 C is the structural representation of UDX module in watch-dog, the DSP camera;

Fig. 2 A is that the UDX of said UDX agreement connects packet header (39 bytes+excessive data) structural representation;

Fig. 2 B is UDX transfer packet header (18 byte) structural representation of said UDX agreement;

Fig. 2 C is the UDX general data pack arrangement sketch map of said UDX agreement;

Fig. 2 D is UDX response packet (18 bytes+extra sack position, the distance to go) structural representation of said UDX agreement;

Fig. 3 is at the process sketch map that utilizes the UDX agreement to establish a communications link and communicate by letter between PC background control end and mobile terminal device;

The process sketch map that Fig. 3 A utilizes the UDX agreement to establish a communications link and communicate between PC background control end and mobile terminal device for the present invention;

Fig. 3 B carries out audio transmission for network application Transmission Control Protocol shown in Fig. 3 A process with and the corresponding situation sketch map of bandwidth availability ratio;

Fig. 3 C carries out audio transmission for network application UDX agreement shown in Fig. 3 A process with and the corresponding situation sketch map of bandwidth availability ratio;

Fig. 4 utilizes Transmission Control Protocol and UDX agreement to carry out the effect comparison sketch map of transfer of data under the equal conditions;

Fig. 5 utilizes UDT agreement and UDX agreement to carry out the effect comparison sketch map of transfer of data under the equal conditions.

Embodiment

Below in conjunction with accompanying drawing and embodiments of the invention method of the present invention is done further detailed explanation.

Fig. 1 is the data transmission system sketch map that the present invention is based on the UDX agreement, and is as shown in Figure 1, mainly comprises application server, work station, personal computer, portable terminal, terminal monitor and Digital Signal Processing (DSP) camera that inserts the World Wide Web (WWW); Wherein:

Said application server, work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera use the UDX agreement to connect the World Wide Web (WWW) respectively; Said application server, work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera all can utilize the UDX agreement transmitting data each other through the World Wide Web (WWW).

Said work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera all insert the World Wide Web (WWW) through the UDX module of self.

In the UDX module of work station and personal computer, comprise applied logic submodule and communicator module.Said work station, personal computer all can utilize the UDX agreement to carry out transfer of data through this applied logic submodule and communicator module and other work station, personal computer and portable terminal, terminal monitor or DSP camera.

In the portable terminal the UDX module in, comprise JAVA/C++ and use submodule and communicator module.Said portable terminal can be used submodule and communicator module and other portable terminal, work station, personal computer, terminal monitor or DSP camera through this JAVA/C++ and utilize the UDX agreement to carry out transfer of data.

In terminal monitor and the DSP camera, comprise image processing submodule and communicator module.Said terminal monitor or DSP camera can utilize the UDX agreement to carry out transfer of data through this image processing submodule and communicator module and other DSP camera, terminal monitor, portable terminal, work station or personal computer.

UDX agreement of the present invention is based on standard C ++ the protocol stack of language development, have cross-platform, the existing main flow platform of support, and like WIN, Linux, Mac, IOS etc., and 32/64 compatibility.Can conveniently be applied in the various communication products, can be integrated in Digital Signal Processing (DSP) chip, or curable in hardware, form that also can pure software is applied in the transfer of data occasion of diverse network.

This UDX agreement owing to adopt general development language, is utilized other ancillary technique, and flexible Application on different platforms can greatly make things convenient for the carrying out of R&D work, practices thrift R&D costs and also shortens product development cycle.

As, on personal computer, can be compiled into win32 dynamic base or static library and supply application layer transfer.On mobile device, on the android operating system like google, utilize JAVA to call the NDK interface, indirect call UDX.SO file comprises the apple system, easily the value of moving.Simultaneously also support DSP equipment, the UDX agreement also provides C interface, in DSP, also can use like this, thereby make protocol interconnection, the seamless connection of system, performance maximum function.

Here, said UDX agreement, similar ICP/IP protocol.Its protocol stack is divided into four layers of application layer (Application), transport layer (Transport), network layer (Network) and link layers (Link).In this UDX protocol stack, this UDX agreement can coexist as transport layer with Transmission Control Protocol, udp protocol and UDT agreement.Introduce the packet structure of this UDX agreement below.

Fig. 2 A～Fig. 2 D be respectively the UDX agreement the connection bag, in subcontract, general data bag and response packet encapsulating structure sketch map.

Shown in Fig. 2 A; UDX connects packet header; Comprise 39 bytes (1 byte=8) and excessive data, this connection packet header includes UDX packet header (10 byte), SOCKADDR (i.e. ten thousand net address, 20 bytes), maximized window number (2 byte), connect hours and stabs the data that whether (2 byte), server refuse state (7) in flag bit (1), the connection procedure, the data length (4 byte) that carries when connecting and carry when connecting.Wherein, UDX packet header (10 byte) further comprise P2P flag bit (1), transfer registered symbol 1 (1), transfer registered symbol 2 (1), in subcontract (1), keep position (4), verification and (16) wrap (7 byte) with UDX.Said UDX bag further comprises transmitting time (16), bag sequence number (32), effectively calculates RTT flag bit (1), ack occupy-place number is 0 sign (1), bag type (4) and subchannel sequence number (2).

Shown in Fig. 2 B, subcontract (18 bytes+data field) among the UDX, comprise UDX packet header (10 byte), DEST (64 of destination addresses) and data field three parts.Wherein, the UDX header part is identical with UDX connection packet header.

Shown in Fig. 2 C, UDX general data bag comprises UDX packet header (10 byte) and data field two parts.Wherein, the UDX header part is identical with UDX connection packet header.

Shown in Fig. 2 D, UDX response packet (18 bytes+extra sack position, distance to go) comprises UDX packet header (10 byte), ack number (8) and ack data (length is according to ack number * 8), and these ack data are claimed distance to go again.Wherein, the UDX header part is identical with UDX connection packet header.

The process sketch map that Fig. 3 utilizes the UDX agreement to establish a communications link and communicate between PC background control end and mobile terminal device for the present invention, as shown in Figure 3, to suppose to carry out speech talkback with PC background control end and mobile terminal device, this process comprises:

1) after portable terminal (transmitting terminal, client) carries out three-way handshake through connection bag in the UDX agreement and PC (receiving terminal, server end), sets up data link.

After connection is set up successfully, just can carry out active data and communicate by letter.Portable terminal transmits the general data bag of username and password through the UDX agreement; General data is that with the difference that is connected bag it has only UDX packet header, and then is exactly data field (being used to carry data), and the sequence number in each bag is since 0; 32 no symbol sequence numbers increase; After using up,, can Infinite Cyclic use sequence number so again since 0.The recipient after receiving normal packet, will send response packet, and sequence number is also arranged in the response packet, and the passback transmitting time, so that transmit leg calculates two-way time.

Transmit leg is received response packet, successfully returns application layer if the expression of sequence number coupling receives, the application layer resolution data, and after the integrality of PC side's verification msg, communication process is just accomplished.

Here, PC receives username and password, after verification is passed through, can carry out the business datum exchange.This process lasts till to connect always breaks off.

After portable terminal collects the microphone voice, adopt the compression of AMR arrowband, call the UDX interface and transmit; The PC square tube is crossed the UDX callback interface and is received data, decompress(ion), and calling system multimedia API carries out playback; PC speech principle is also similar, and gather PC side, and compression sends to portable terminal through the UDX interface; Portable terminal decoding, and playback, intercommunication function comes to this and has realized like this.Use the benefit of UDX to be, it can effectively utilize wireless network, and than other agreement of transmission, voice quality can be more clear, because the packet of the retransmits lost that it can be complete, if data-bag lost will make speech data produce noise.

2) connect disconnection: it is thin disconnection that the UDX agreement adopts, or cries dangerous disconnection, sends four packet of disconnects to far-end, and this locality is broken off immediately.

Packet of disconnect has only a UDX packet header, and just " bag type " is the UDX_BROKEN sign; Because the UDX agreement realizes in application layer; And often to use half be to break off, and half is in application layer when closing, and can not wait for whether this packet of disconnect has issued the other side so must withdraw from once.If but the other side can not receive disconnection message, also can the wait timeout automatic disconnection, thereby can not cause the waste of resource.

Utilize TCP or UDX agreement to be applied as example (shown in Fig. 3 A) with portable terminal (suppose insert WCDMA network), personal computer below, the difference of Transmission Control Protocol and UDX agreement further introduced through what World Wide Web (WWW) and application flow media server carried out audio transmission:

Fig. 3 B carries out audio transmission for network application Transmission Control Protocol shown in Fig. 3 A process with and the corresponding situation sketch map of bandwidth availability ratio, as can be seen from the figure and since the realization of Transmission Control Protocol former comprehend cause of short duration broadband not make full use of; This generally is when packet loss, to take place, and general cable network does not have so serious, even if packet loss also can recover very soon; But at wireless environment, this phenomenon of packet loss is more frequent, and this defective of TCP; It is not suitable for wireless; Or the high latency network use, resemble this type of audio frequency and video especially, the application that real-time and throughput are had relatively high expectations.Because Transmission Control Protocol book velocity of wave motion transmits, and greatly reduces bandwidth availability ratio.As shown in the figure, the uploading rate of this portable terminal is about 8KB, and downloading rate is about 15～25KB.

Fig. 3 C carries out audio transmission for network application UDX agreement shown in Fig. 3 A process with and the corresponding situation sketch map of bandwidth availability ratio, as can be seen from the figure owing to taked series of improving measures among the realization principle of UDX agreement and the present invention; Can make full use of bandwidth, improve response speed, even packet loss takes place; The quick retransmission algorithm of UDX agreement; Also can recover network traffics very soon, thereby save unnecessary retransmission, save operation cost and user's expense indirectly.So the UDX agreement is fit to resemble this type of audio frequency and video, the application that real-time and throughput are had relatively high expectations very much.

Sliding window protocol has been adopted in the realization of the UDX agreement among the present invention, still, is having more differently with the Traditional TCP protocol algorithm aspect its concrete control, and control thought is also different.

UDX agreement control thought mainly is through measuring two ends RTT two-way time, and the conversion channel capacity carries out congested control through the control transmitted traffic.Wherein, compare, the following difference arranged with other agreements such as traditional T CP, UDT agreements:

The first, bandwidth estimation algorithm.

To the assessment of bandwidth, prediction when detecting maximum send window, is with reference to RENO algorithm, packet loss detection.But in this process; UDX has also detected the response rate of ACK, when occurring showing that fluctuation has appearred in present network when the ACK reply frequency changes (rate of change K>0.35), can predict to have reached congested critical; This has point image VEGAS the same; Can predict in advance that appearance is congested, UDX adjustment at this moment starts threshold values slowly, gets into congestion avoidance phase in advance.

In conjunction with the SACK algorithm, each ACK association has been with a plurality of response packets, thereby has accurately realized the selectivity re-transmission.Reduced unnecessary retransmission.With traditional ACK difference be, association has been with more ACK, and has designed new ACK structure, increase compression ACK method, thereby the reply data amount is also fewer.

In congestion avoidance phase, through calculating DIFF=minrtt* (wnd/minrtt-wnd/rtt) < avgbew*0.35f.Shift to an earlier date predict congestion, this difference is at avgbew, and this value is to reply through ACK to calculate, and near actual value, thereby has avoided the calculated value of traditional VEGAS inaccurate (general inaccurate occurring in is because the hardware speed limit of gateway).

The packet loss detection algorithm, each transmission is wrapped and has been write down, time and the maximum of sending last time send sequence number, when receiving ACK and current corresponding amount compare, can know accurately that which bag needs re-transmission, and needn't wait until overtime arrival.Thereby can respond fast to retransmit and save the time.

Fast quick-recovery continuously returns to previous send window when receiving two new ACK immediately when UDX joins, and has reduced and has recovered to open to disappear.

In conjunction with WEST WOOD, through the statistical calculated flow rate, through the formula of RTT/WND=BEW, theory of computation send window and actual window compare, thereby improve stability, make to send to be stabilized in actual bandwidth.

The second, fast retransmit.

The ACK design of UDX agreement is exactly the SACK agreement in fact, but realizes that gimmick is to be different from SACK; SACK is that the head and the tail sequence number is right, and UDX is a start sequence number, and the relative sequence number of back is formed; Can hold so more ACK. when transmit leg is received any one ACK, just can confirm accurately which the bag lost; At this moment can retransmit at once, and need not wait until and retransmit again after overtime, thus the throughput that improved real-time and indirect raising.

Three, the last improvement of AIDM.

The startup stage of slow and the TCP class be W +=1, congestion avoidance phase be W +=1/W;

The UDX agreement has also adopted different methods for designing on window management.Saturation condition, just an optimum state have wherein been introduced.And the 1.25 times transmission speeds of actual transmission speed when being this optimum state.Can guarantee higher striving property unexpectedly like this.

Among the UDX, the unit of tolerance is a present flow rate, and the core concept of control window is the increment of control flow.When increment level off to actual flow=5% when fluctuation, think that flow is maximum; At this moment get into saturation condition, when UDX gets into saturation condition, change the Congestion Avoidance aero mode over to; Window does not increase on the contrary and can reduce; Reach a dynamically flat horizontal stroke, make transmission speed, all-the-time stable is on a level.

Difference is in addition, and window is controlled and is, traditional TCP is weekly that the phase increasing degree is 1 to the maximum, and UDX is the growth of ACK driving window, is not limited in changing value in the RTT, so its acceleration may surpass 1 in a RTT.

UDX has carried out the automatic adaptive algorithm of RTT to various network; Introduced the notion of self-defining " theoretical delivery "; The stream reason of it and the actual data computation of receiving compares, and can proofread and correct window during less than actual flow when theoretical delivery, makes it remain on the window size of present flow rate; Flow is more steady like this, deviation can not occur.Have only the stationarity of flow could let other parameter meaningful, otherwise flow control becomes empty talk, this also is the shortcoming of other algorithm.

When packet loss control: UDX whenever receives a packet loss signal, can adjust, adopt sstresh=wnd*a congestion window, wnd +=b; A wherein, b (can bear) is the UDX empirical value, concrete parameter can be adjusted.

Calculate a packet loss in conjunction with packet loss control: UDX in per 100 ACK meeting of arrival, to A, B adjusts according to packet loss, so more can combine the real network situation that window is adjusted.In order to pursue maximal rate, UDX is suitable permission packet loss, to guarantee the maximum throughput of data.

Four, optimize on the algorithm.

Different and other algorithm on the re-transmission policy, overtime re-transmission is to be driven by ACK, rather than only relies on timer, data retransmission increases real-time so faster.Because the characteristic of UDP, UDX is the time-out time that adopts 1.5 times of calculating at present.Time-out time is RTT+4*|dRTT|, if calculate time-out time by the exponential backoff algorithm of traditional T CP, at packet loss and the big network that postpones, performance can sharply descend.

UDX mainly retransmits when occurring in the ACK arrival, owing to receive ACK, explains that network is normal, and at this moment retransmission data is reliably more than blindly relying on timer to retransmit.The UDX timer only can be sent out a retransmitted packet at every turn, when network recovery, will rely on ACK to send out retransmitted packet fast again.When start quickening, UDX through theoretical delivery as a reference, when the theoretical delivery that calculates, in that < during 1/>MINRTT, UDX ignores packet loss, can accelerate to actual maximum bandwidth faster like this

Five, to wireless adjustment.

Wireless network key property and cable network still are apparent in view.Be characterized in that fluctuation is big, instability of flow, packet loss are unfixing, receive the effect of signals of environment fully.In view of this characteristic, some improvement of UDX still relatively are fit to this environment, than other algorithm, anti-packet loss and interference are arranged more.Such as, ACK design and quick re-transmission etc. have improved throughput and response time.

Six, friendly.

The relative TCP of UDX is disagreeableness fully, and general UDX and TCP move simultaneously, the shared flow of TCP basic half less than.Have more the property seized than other algorithm.This main cause still is because the algorithm characteristics of UDX agreement determines.UDX is more accurate in overtime re-transmission, when causing others algorithm also not have enough time to recover window, more utilizes bandwidth thereby UDX has returned to best window.

Eventually the above, through above several improvement, at high latency network and wireless network, network transmission performance, real-time has had bigger raising, fills and part utilizes network.

Because the These characteristics of UDX agreement is so using the UDX agreement can be at high latency; Under the environment of high packet loss, with quasi-protocol higher efficiency of transmission is arranged than traditional TCP or other, packet loss still less; Better real-time property; Can effectively utilize existing band width in physical, thereby can transmit more valid data, improve throughput.

Need benly be: this UDX protocol application on wireless communication field, is had more obviously raising to real-time.As, in 3G network, use Transmission Control Protocol, suppose that network delay is 300 milliseconds, a general instruction needs 800 milliseconds to 1 second time back and forth at least, if in the place of poor signal, then needs the more time.Usually only need about 700 milliseconds time and use the UDX agreement.It is thus clear that the UDX agreement can improve the real-time of network response really.Can also obviously improve the throughput of network with the UDX agreement, please refer to Fig. 5.

Fig. 4 utilizes Transmission Control Protocol and UDX agreement to carry out the effect comparison sketch map of transfer of data under the equal conditions.As shown in the figure, the network that with the bandwidth is 2M is as test environment, revises through the WANemv2.2 simulation softward to postpone and packet loss, and the time delay of supposing this link is that 500ms, packet loss are 15%.

We can see both throughput difference on same link through traffic monitoring software, and TCP is because packet loss is decayed with the formula window that reduces by half, and speed descends gradually.And UDX remains unchanged on throughput always, maintain about 210KB flow the transmission, on throughput, under this test case, the raising about 53% is arranged.It is thus clear that the UDX agreement can obviously improve the throughput of data.

Fig. 5 is for utilizing UDT agreement and UDX agreement to carry out the effect comparison sketch map of transfer of data under the equal conditions, and is as shown in the figure, in control desk, connects the server simulation transmission data of public network with the client that adopts the UDT4.6 version; We write down it and send valid data speed, and the output information of appclient is done simple modification, and first row of output are real-time speeds; Last row are number of dropped packets, and secondary series is to send sum, behind statistics and the input form; Compare, the UDT4.6 version at transmission speed at peak, the beginning about 140KB; Average speed is at 87.47KB/s, and packet loss is 38.4%.

Window client to adopt the UDX agreement is a testing tool, and the real time data that shows from the interface is processed figure side by side with average data, from figure, finds out; Adopting the client average speed of UDX agreement is 187.9KB, obviously much larger than the client of UDT agreement, and shows in the testing tool that packet loss is 12%; Also, see that from flow software both flow diagram differences are that UDT begins to give out a contract for a project very violent again much smaller than the UDT agreement; Flow-rate ratio is higher, lowers then, and can not keep at once.The latter adopts the UDX agreement, and flow is relatively stable, and intensive, full.

Postpone with 500ms below, 15% packet loss link is an example:

Because the overtime calculating of TCP is to adopt exponential backoff algorithm, its overtime precision is a rough grade, causes huge error; And UDX adopts accurate SACK to confirm retransmission packet, and overtime also be adopt calculate accurately time-out time CURRENT_RTT+4 * | DRTT|, and limit maximum be AVG_RTT+_ _ min (400ms; 0.2f*CURRENT_RTT), more can be accurately heavily defeated, at the packet loss environment; Wireless environment postpones with 500ms, and 15% packet loss link is an example; On response speed, we respond the 3K test data with the echo mode is example to UDX than TCP, does complete test and measures for 10 times; The UDX average response time is 522MS, and the TCP response time is on average wanted fast 754-522=232ms in its response speed of 754ms., and response speed has the raising about 34%.It is thus clear that, adopt the UDX agreement, can obviously improve response speed.

The above is merely preferred embodiment of the present invention, is not to be used to limit protection scope of the present invention.

Claims (10)

1. a conventional data exchange UDX protocol stack comprises link layer, network layer, transport layer and application layer; It is characterized in that its transport layer adopts the UDX agreement, this UDX agreement can coexist as transport layer with Transmission Control Protocol, UDT agreement.

2. UDX protocol stack according to claim 1 is characterized in that, said UDX agreement seal assembling structure be divided into UDX connect among packet header, the UDX subcontract, four kinds of UDX general data bag and UDX response packets; Wherein:

Said UDX connects packet header; Length is 39 bytes, data length that comprise that the connect hours of maximized window number, 2 bytes of ten thousand net address SOCKADDR, 2 bytes of UDX packet header, 20 bytes of 10 bytes stabs, whether 1 server refuses flag bit, carries in 7 connection procedures during the connection of state, 4 bytes and the data of carrying when connecting;

Subcontract among the said UDX, comprise the UDX packet header of 10 bytes, 64 destination address DEST and data source;

Said UDX general data bag comprises UDX packet header and data field two parts of 10 bytes;

Said UDX response packet comprises the UDX packet header of 10 bytes, 8 ack number and the ack data of 8 bytes.

3. UDX protocol stack according to claim 2; It is characterized in that; Said UDX packet header comprises 1 P2P flag bit, 1 first transfer registered symbol position, 1 second transfer registered symbol position, subcontracts flag bit in 1,4 UDX that keep position, 16 bit checks and position and 7 bytes wraps.

4. UDX protocol stack according to claim 3; It is characterized in that; Said UDX bag comprises that it is 0 sign, 4 bag type indicating bits and channel position position, 2 seat that 16 transmitting time, 32 bag sequence number, 1 are effectively calculated RTT flag bit, 1 ack occupy-place number.

5. the data transmission system based on the UDX agreement comprises the application server, work station, personal computer, portable terminal, terminal monitor and the Digital Signal Processing DSP camera that insert the World Wide Web (WWW); It is characterized in that said application server, work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera use the UDX agreement to connect the World Wide Web (WWW) respectively; Said application server, work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera all can utilize the UDX agreement transmitting data each other through the World Wide Web (WWW).

6. the data transmission system based on the UDX agreement according to claim 5 is characterized in that, said work station, personal computer, portable terminal, terminal monitor, Digital Signal Processing camera all insert the World Wide Web (WWW) through the UDX module of self.

7. according to claim 5 or 6 described data transmission systems, it is characterized in that, in the UDX module of work station and personal computer, comprise applied logic submodule and communicator module based on the UDX agreement.

8. according to claim 5 or 6 described data transmission systems, it is characterized in that based on the UDX agreement, in the portable terminal the UDX module in, comprise JAVA/C++ and use submodule and communicator module.

9. according to claim 5 or 6 described data transmission systems, it is characterized in that, in terminal monitor and the DSP camera, comprise image processing submodule and communicator module based on the UDX agreement.

10. the data transmission method based on the UDX agreement is characterized in that, comprises the steps:

A, transmitting terminal connect bag through the UDX agreement and carry out three-way handshake with receiving terminal, set up communication link;

B, transmitting terminal send data through UDX general data bag to said receiving terminal;

After C, receiving terminal are received said UDX general data bag, send response packet, and return transmitting time and calculate two-way time to said receiving terminal;

After D, transmitting terminal receive response packet, if said packet receives successfully, by the application layer resolution data, and by the receiving terminal verification of data integrity.

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