CN1224961A - Communication method and communication apparatus - Google Patents

Abstract

The communication method and communication apparatus are capable of generating a data having a identifier representing an identifier of a transmitting end point and a receiving end point of a logical communication channel, data representing an address corresponding to the identifier of the transmitting and receiving end point of the logical communication channel, data representing an IP address corresponding to an address of the transmitting and receivingend point of the logical communication channel; and are capable of transmitting the packet thus generated. The inventive arrangements allow the initially established logical communication channel to remain intact and available even if a computing entity is moved from one computer to another.

Description

Communication means and communicator

The present invention relates to a kind of communication means and communicator.Especially, the present invention relates to a kind of communication means and communicator, the end points that TCP connects utilizes them, if if when the resident computer of an end points mobile between the computer or this connection is reorientated, can keep TCP to connect in the internet.

In computer network, use the reliable communication between the agreement assurance computer such as TCP (transmission control protocol).As shown in Figure 7, before communication between the computer, TCP sets up logical channel (being referred to as TCP connects) between computer.TCP plays a part connection type agreement highly reliably.For keeping its reliable operation, TCP handles and resembles sequence control, affirmation, window control and the such operation of current control.

TCP transfers data to IP (Internet protocol) with the unit of the section of being called.As shown in Figure 8, each section is made up of TCP title section and application section.At TCP title section, the port numbers of the transmission sources that source port number (16 bit) expression is used by TCP, the port numbers of the transmission destination that destination slogan (16 bit) expression is also used by TCP.

Above-mentioned section position in the data flow that sequence number (32 bit) indicates to transmit.When setting up one when connecting, initialization sequence number.Then, every generation one data transfer, this sequence number then adds.Even order does not send IP datagram (datagram), also can reappear original data stream according to the sequence number that is comprised.If by a repeating sequences number proof, found to have repeated to receive identical section, just abandoned the section of this repetition.

Returning the affirmation number (32 bit) of transmission sources, is that normal nearest section the sequence number that receives adds 1, that is, and and the sequence number of the section that next time will receive.Whether the affirmation that the check of this source receives is number consistent with the sequence number of the section that will send next time.If two numbers unanimities just confirm that communication is normal.

May take place (to repeat to transmit overtime) for some reason and send data or confirm number in transporting, to lose and make in preset time affirmation no show in the cycle.In this case, just carry out the repetition transmission process.

Data-bias (4 bit) expression is the size of the TCP title section of unit with four eight bit groups (32 bit).Therefore, data-bias is represented the starting position of data in this section.If do not comprise option, just will be worth 5 and be set to this data-bias.

Code bit (6 bit) is made up of six following bit control marks, and each mark is represented state: the serious anxious data of handling appear in URG (urgent mark) expression.The urgent pointer that will be described by the back is represented the position of these data.ACK (affirmation mark) expression is current just to be used and is confirming number.PSH (release mark), when PSH was set, the data that just require to receive handed over to application layer at once.RST (reset flag) expression is forced to disconnect.SYN (sync mark) when setting up one when connecting, uses SYN initialization sequence number.Connection of FIN (finishing mark) expression is finished.

Window (16 bit) is expressed as the slow middle size of distinguishing that window control provides.The function of window control is to allow a plurality of sections of transmissions continuously in the size of a buffering area, and need not wait for confirmation of receipt number.When omitting the affirmation processing, just can finish transfer of data more efficiently.If can not receive data for some reason, just window size can be changed so that carry out suitable current control.

Check and whether data that (16 bit) is used for verifying transmission (corrupt) transporting to be mixed up.The position of urgent pointer (16 bit) expression data to be processed when above-mentioned URG mark is set.

Connect by a pair of endpoint identifier (EndPointID) definition of T CP, as follows, an expression local endpoint, another represents remote endpoint.

TCP?connection={EndPointID_local,EndPointID_remote}

Each endpoint identifier as follows, as to come definition of T CP to be connected by the combination of IP address and port numbers.

EndPointID={IPaddr,port}

Connect by four following sign definition of T CP like this:

TCP?connection={Ipaddr_local,port_local,Ipaddr_remote,port_remote}

Routinely, if the end points that TCP connects moves to another computer from a computer, because the IP address modification can not keep this connection.Equally, if the resident computer of an end points that TCP connects is being reorientated on the internet, same variation owing to the IP address can not keep this TCP to connect.

Therefore, an object of the present invention is to provide a kind of communication means and communicator, the end points that TCP connects utilizes them, even can also can keep the TCP connection reorientating on the internet with transparent mode moves and an end points of this connection is resident computer between computer.

For realizing the present invention, according to a first aspect of the invention, a kind of communication means is provided, may further comprise the steps: produce bag with a title, this title comprises the data of identifier of the transmission end points of presentation logic communication channel at least, the data of the identifier of the reception end points of presentation logic communication channel, expression is corresponding to the data of the address of the identifier of the transmission end points of logical channel, expression is corresponding to the data of the address of the identifier of the reception end points of logical channel, expression is corresponding to the data of the IP address of the address of the transmission end points of logical channel and the expression data corresponding to the IP address of the address of the reception end points of logical channel; With the bag that sends by described generation step generation.

According to a second aspect of the invention, a kind of communicator is provided, comprise: generation device, be used to produce bag with a title, this title comprises the data of identifier of the transmission end points of presentation logic communication channel at least, the data of the identifier of the reception end points of presentation logic communication channel, expression is corresponding to the data of the address of the identifier of the transmission end points of logical channel, expression is corresponding to the data of the address of the identifier of the reception end points of logical channel, expression is corresponding to the data of the IP address of the address of the transmission end points of logical channel and the expression data corresponding to the IP address of the address of the reception end points of logical channel; Dispensing device is used to send the bag that is produced by described generation device.

As mentioned above, communication means of being invented and communicator can produce a bag, this bag comprises the data of identifier of the transmission end points of presentation logic communication channel at least, the data of the identifier of the reception end points of presentation logic communication channel, expression is corresponding to the data of the address of the identifier of the transmission end points of logical channel, expression is corresponding to the data of the address of the identifier of the reception end points of logical channel, expression is corresponding to the data of the IP address of the address of the transmission end points of logical channel and the expression data corresponding to the IP address of the address of the reception end points of logical channel; And can send the bag of such generation.

Fig. 1 is the schematic diagram that the typical case of the network of expression communicator employing of the present invention forms;

Fig. 2 is the schematic diagram of the typical packet header of VIP use;

Fig. 3 is the schematic diagram of the typical packet header of VTCP use;

Fig. 4 is a picture group of the relation between expression communication foundation and the packet header;

Fig. 5 is the block diagram of typical internal router 100;

Fig. 6 is the block diagram of computer 24 and 25;

Fig. 7 is the schematic diagram by the correlation technique TCP connection of its end points definition; With

Fig. 8 is the schematic diagram of the form of correlation technique TCP section.

The VTCP (virtual TCP) that is used by communicator according to the present invention is described below to be connected.VIP (virtual IP protocol) clearly distinguishes the tick lables (address) of computer (being also referred to as main frame) and their identifier.It is the communication of transparent (be called and move the transparency) that these characteristics are used for realizing moving.

Can be defined as by using the ability of a computer of constant identifier and another compunication, with the location independent of the latter on network moving the transparency.These characteristics allow TCP to be connected computer before reorientating on the network and remain unchanged afterwards intuitively.Because the IP address has the characteristics of the dual sign that comprises address and identifier, mobile transparent communication is being inapplicable on the internet.

Especially, replenishing under the situation of IP address (tick lables), realize moving the transparency by the VIP address that is introduced into as the identifier that is exclusively used in each master computer (suitable hereinafter place is called main frame).

The VIP address has identical form with the IP address and can not distinguish each other in essence.Relation between these two kinds of addresses is similar to the relation that exists between the virtual address of virtual storage system under the operating system and the physical address.

The ultrahigh speed buffer that be called AMT (address mapping table, address mapping table) of use in the VIP layer can efficiently be transformed to corresponding IP address with any VIP address.In the following description, each data unit of formation AMT is called as an AMT item.The AMT item is by a VIP address, an IP address, and a version number and other control informations are formed.

The VIP address (corresponding to the transmission hostid of Fig. 2) and IP address (corresponding to the transmission host address of Fig. 2) that comprise sending computer by the title of the bag of mobile computer (for example, have among Fig. 1 produce and the mobile host 24 of dispensing device) transmission.When computer specific on the suitable network (receiving computer) is wrapped in one of mobile computer transmission, be included in the packet header and represent the VIP address and the IP address of sending computer, the router that is sent by contracted affreightment reads and is finally read by the computer that receives bag.Set up the AMT item based on the address of reading like this.

Just, because wrapping in the network of mobile computer transmission forwards, the AMT item is in principle along the expansion of bag route.

Under distributed computing environment, computational entity (process, object, the agency, or the like) can handle mobile between computer like that by image data.As under the situation of communication mode, whenever next computational entity (computing entity) must rebulid the TCP connection when a computer moves to another at TCP.In this case, if the end points that TCP connects is transparent mobile just more convenient between computer.Equally, if the TCP connection keeps motionless also more convenient when the resident computer of an end points that connects is reorientated in the internet.

Connect characteristics above realizing by in correlation technique TCP sets up, introducing VTCP (virtual TCP).As follows, comprise all that by each end points the end points definition VTCP of a pair of identifier " VEndPointID " and " VEndPointAddr " is connected.

VTCP?connection?end?point={VEndPointID,VEndPointAddr}

VTCP connection endpoint identifier VEndPointID is defined as follows:

VEndPointID={VIPaddr,vport}

Here, the VIP address that " VIPaddr " expression produces the computer of VTCP connection end point, the port numbers that " vport " (virtual port number) expression is worked when producing the VTCP connection end point.Even the VTCP connection end point moves to different computers, VIP address and virtual port number also remain unchanged.When computer was reorientated in the internet, it is constant that the VIP address of given computer keeps.

Each TCP connection end point address (VEndPointAddr) is defined as follows:

VEndPointAddr={VIPaddr,port}

Here, VIPaddr and port represent the VIP address and the port numbers of the current resident computer of VTCP connection end point respectively.When producing a VTCP connection end point, determine that at this some the VTCP connection endpoint identifier also remains unchanged afterwards.When connection end point is mobile between computer, VTCP connection end point address change.

Connect by the VTCP of four sign definition shown in following.End points transparent moving between computer that these allow VTCP to connect, and this connection is remained unchanged with available.

VTCP?connection={VEndPointID_local,VEndPointID_remote}

={VIPaddr_local,vport_local,

VIPaddr_remote,vport_remote}

Fig. 3 represents a typical packet header form.IP title in the packet header comprises source IP address,, sends the address of the computer of above-mentioned bag that is; With purpose IP address, that is, receive the address of the computer of the bag that sends.The VTCP address head is being followed in IP title back, comprises the identifier of two end points that VTCP connects, that is, and and VTCP connection end point address, source and purpose VTCP connection end point address.Be VTCP ID title after the VTCP address head, comprise source VTCP connection endpoint identifier and purpose VTCP connection endpoint identifier.

With reference now to Fig. 4, describes when computer and in network, to reorientate time institute's occurrence.Here supposition is set up a VTCP and is connected { VEndPoint_A, VEndPoint_B} shown in the component (a) of Fig. 4 between VTCP connection end point VEndPoint_A on the computer A and the VTCP connection end point VEndPoint_B on the computer B.Also suppose to connect identical mode and set up the VTCP connection with TCP.

VEndPointID_A=VEndPointAddr_A={VIPaddr_A,port_A}

VEndPointID_B=VEndPointAddr_B={VIPaddr_B,port_B}

Here, the port numbers of the VIP address of " VIPaddr_A " expression computer A and " port_A " expression distribution when computer A produces " VEndPoint_A ".This is equally applicable to " VIPaddr_B " and " port_B ".In this case, the title of bag of delivering to " VEndPoint_B " from " VEndPoint_A " is shown in Fig. 4 (b).Just, in packet header, the IP address (IPaddr_A) of computer A is set at source IP address, and the IP address (IPaddr_B) of computer B is set at purpose IP address.In following the VTCP address head of packet header, the VIP address (VIPaddr_A) and the port numbers (port_A) of computer A are set at VTCP connection end point address, source, and VIP address (VIPad_B) and the port numbers (port_B) of computer B are set at purpose IP address.In following the VTCP ID title of VTCP address head, the VIP address (VIPaddr_A) and the port numbers (port_A) of computer A are set at source VTCP connection endpoint identifier, and VIP address (VIPaddr_B) and the port numbers (port_B) of computer B are set at purpose VTCP connection endpoint identifier.

The title of bag of delivering to " VEndPoint_A " from " VEndPoint_B " is shown in Fig. 4 (c).Especially, in packet header, the IP address (IPaddr_B) of computer B is set at source IP address, and the IP address (IPaddr_A) of computer A is set at purpose IP address.In following the VTCP address head of packet header, VIP address (VIPaddr_B) and the port numbers (port_B) of computer B are set at VTCP connection end point address, source, and the VIP address (VIPaddr_A) and the port numbers (port_A) of computer A are set at purpose IP address.In following the VTCP ID title of VTCP address head, VIP address (VIPaddr_B) and the port numbers (port_B) of computer B are set at source VTCP connection endpoint identifier, and the VIP address (VIPaddr_A) and the port numbers (port_A) of computer A are set at purpose VTCP connection endpoint identifier.

Suppose that shown in Fig. 4 (d), VTCP connection end point " VEndPoint_ B " moves to computer C from computer B.When the processing of the VTCP connection end point " VEndPoint_B " on the B that uses a computer moved on the computer C, such moving took place intuitively.When VTCP connection end point " VEndPoint_B " when computer B moves to computer C, the identifier " VEndPointID_B " of VTCP connection end point " VEndPoint_B " remains unchanged, but that " VEndPointAddr_B " changes is as follows:

VEndPointAddr_B={VIP_C,port_C}

Here, the VIP address of " VIP_C " expression computer C, and the port numbers of computer C is distributed in " port_C " expression.

VTCP connection end point " VEndPoint_B " is then address " VEndPointAddr_B " the notice end points " VEndPoint_A " that changes.This notice offers end points " VEndPoint_A " about connecting corresponding following information:

VEndPointID_B={VIP_B,portB}

VEndPointAddr_B={VIP_C,port_C}

Therefore, the title that sends to the bag of " VEndPoint_B " from " VEndPoint_A " becomes shown in Fig. 4 (e), and the title of the bag of " VEndPoint_A " that sends from " VEndPoint_B " is shown in Fig. 4 (f).Although the identifier of end points " VEndPoint_B " remains unchanged, the address change of " VEndPoint_B ".Simultaneously, the IP address of the resident computer of end points " VEndPoint_B " has also changed.

Now supposition is as Fig. 4 (g) shown in, and computer C reorientates at wide area network, and the VIP address of computer C remains unchanged and its IP address modification is " IPaddr_D ".In this case, VIP allows the IP address of computer C to deliver to computer A.Computer A receives about connecting corresponding following information:

VIP?address?of?computer?C=VIPaddr_C

IP?address?of?computer?C=IPaddr_D

The result is, the title that sends to the bag of end points " VEndPoint_B " from end points " VEndPoint_A " becomes shown in the component (g) as Fig. 4, and IPaddr_D is changed into from " IPaddr_C " (Fig. 4 (e)) in purpose IP address.The title of bag that sends to end points " VEndPoint_A " from end points " VEndPoint_B " is shown in Fig. 4 (i), and source IP address is changed into " IPaddr_D " from " IPaddr_C " (Fig. 4 (f)).As mentioned above, only change the IP address of " VEndPoint_B " resident computer.

Fig. 5 represents the typical structure by the employed internal router of network (router) 100 of the present invention's employing.Receive a bag by network interface 31a to one of 31c (dispensing device), and by passing on to one of 31c by sending the definite network interface 31a of network interface determining unit 32 (generation devices).Use routing table 33 determine to wrap-pass on network interface.Router one 00 also has the table of a contact VIP address and IP address.

As shown in Figure 6, each computer such as mobile host 24 and main frame 25 comprises table (VTCP ID address table) 43 intuitively, and the identifier of VTCP connection end point and their address are interrelated; Table (AMT) 42 interrelates the VIP address of computer and their IP address; Routing table 41; With network interface 44.

In the superincumbent foundation, the computer A of Fig. 4 is corresponding to the master computer 25 of Fig. 1, and the computer C of Fig. 4 is corresponding to the mobile host (MH) 24 of Fig. 1, and the computer B of Fig. 4 is corresponding to another master computer on the wide area network 23 of Fig. 1.

Suppose that the TCP connection end point that resides among the computer B moves to computer C.In this case, the TCP connection end point of reorientating uses internal router 100, with the address notification of the TCP connection end point on the computer C to the TCP connection end point on the computer A.This notice makes computer A and internal router 100 understand the correspondence between the address of the identifier of the TCP connection end point on the computer C and this end points.

Then, bag can conversion between TCP connection end point on the computer A and the TCP connection end point on the computer C.In this manner, when such as a process, an object or an agency's and so on computational entity (promptly, TCP connection end point in the top example) when a computer moves to another computer, can use the logical channel (TCP in the top situation connects) of initial foundation continuously unchangeably.

As shown in Figure 1, if computer C (mobile host 24) moves to wide area network 23 from local area network (LAN) 21,, then just change the IP address of computer C in wide area network 23 if perhaps computer C reorientates.IP address that computer C changes and the correspondence between its VIP address send to computer A (main frame 25) from computer C in a bag.This bag permission internal router 100 and computer A reserved address are to the correspondence of address.Subsequently, computer A and C can be between them the conversion bag.

As mentioned above, no matter when a computational item moves to different computers, can reorientate logical channel simultaneously.This just allows to use unchangeably continuously the initial logical channel of setting up.When a resident computer of computational entity is reorientated, also can use logical channel primitively unchangeably in wide area network.

Although the embodiment above the present invention is used for wherein sending and receiving according to virtual internet protocol the network of bag, this is not to limit the present invention.The present invention also can be used for the network based on other agreements.

With the above, can produce bag according to communication means of the present invention and communicator with title, this title comprises the data of identifier of the transmission end points of presentation logic communication channel at least, the data of the identifier of the reception end points of presentation logic communication channel, expression is corresponding to the data of the address of the identifier of the transmission end points of logical channel, expression is corresponding to the data of the address of the identifier of the reception end points of logical channel, expression is corresponding to the data of the IP address of the address of the transmission end points of logical channel and the expression data corresponding to the IP address of the address of the reception end points of logical channel; And can send the bag of such generation.Even a computational entity moves to another computer from a computer, perhaps the resident computer of computational entity is reorientated in network, and the solution of the present invention also allows the initial logical channel of setting up to be kept perfectly and be available.

Claims (3)

1. communication means comprises step:

Generation has the data of the identifier of the transmission end points that comprises the presentation logic communication channel at least, the data of identifier of representing the reception end points of described logical channel, expression is corresponding to the data of the address of the identifier of the described transmission end points of described logical channel, expression is corresponding to the data of the address of the identifier of the described reception end points of described logical channel, expression is corresponding to the data of the IP address of the address of the described transmission end points of described logical channel and the expression bag corresponding to the title of the data of the IP address of the address of the described reception end points of described logical channel; With

The described bag that transmission is produced by described generation step.

2. communication means according to claim 1, wherein said logical channel are that TCP connects.

3. communicator comprises:

Generation device, be used to produce the data of identifier with the transmission end points that comprises the presentation logic communication channel at least, the data of identifier of representing the reception end points of described logical channel, expression is corresponding to the data of the address of the identifier of the described transmission end points of described logical channel, expression is corresponding to the data of the address of the identifier of the described reception end points of described logical channel, expression is corresponding to the data of the IP address of the address of the described transmission end points of described logical channel and the expression bag corresponding to the title of the data of the IP address of the address of the described reception end points of described logical channel; With

Dispensing device is used to send the described bag that is produced by described generation device.

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