JPH0897858A - Data transfer system - Google Patents

Abstract

PURPOSE: To reduce the number of packets transmitted to a network and to reduce the loads of the network. CONSTITUTION: A specified address S in common to all terminals to be fetched as a present address, an identifier I for dividing plural data and an end identifier E for informing the end of the packet are stipulated. The plural data A to C for which transmission is requested are combined in a data part while holding the identifiers I there between regardless of termination destination addresses by a packet combining part 12. The specified address S is placed at a destination address, the end identifier E is placed at the end and a combined packet 4 is formed and transferred to the transmission line 3 of the network by a packet transmission part 13. The transferred combined packet 4 is fetched from a packet reception part 14 to a combined packet judgement part 15 and a packet disassemblying part 16 successively takes out the plural data A-C and sends only the data provided with its own termination destination address through a data fetching part 18 to an upper layer 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer system for collectively forming a plurality of data into one packet and transferring it to a transmission line in a network in which three or more terminals are connected to one transmission line. In particular, the present invention relates to a data transfer method capable of reducing the number of packets on the transmission path and reducing the load on the network.

[0002]

2. Description of the Related Art Conventionally, in this type of data transfer system, a technique of collectively concatenating a plurality of packets having the same destination to form one packet is disclosed in, for example, Japanese Patent Laid-Open No. 1-17.
It is described in Japanese Patent No. 5431.

In this method, as shown in FIG. 5, in the terminal 7, two packets 201, 20 requested to be transmitted from the upper layer having the same destination address (LCNa) are transmitted.
Two packets are concatenated to form one packet 203, and this one packet 203 is sent to the network via the transmission path 8.

Next, it is assumed that the packet format is composed of a header including a destination address (LCN) and a cyclic redundancy code (CRC) and data, as shown in FIG. The short packet 201 is LC
The short packet 202 is composed of a header composed of Na and CRCa and data a, and the short packet 202 is composed of a header composed of LCNa and CRCb and data b.

The destination addresses of the short packets 201 and 202 are both LCNa and are the same.
3 also has the same destination address as LCNa. The CRC of the connected packet 203 is the recalculated CRCab.
In the data, the data a and the data b are linked into one data according to the generation order.

[0006]

In the above-mentioned conventional data transfer method, a packet in which a plurality of data are concatenated has one destination address, and this destination address is set to the destination address of all the data included in the concatenated packet. I am doing it.
That is, since one packet is formed by concatenating a plurality of packets of the same destination requested to be transmitted, the number of packets to be sent out on the network can be reduced.

However, in this configuration, when the number of terminals connected to the same network increases, the number of packets also increases, the load on the network increases, and the overhead such as retransmission increases due to the competition for the use of the transmission path. There is a problem.

An object of the present invention is to provide a data transfer system capable of reducing the load on the network by further reducing the number of packets sent to the network.

[0009]

According to the data transfer method of the present invention, a plurality of data are collectively formed into one packet in a network in which three or more terminals are connected to one transmission path. In the data transfer method of transferring to a road, the packet has a special address that can be commonly received by each of the plurality of terminals in a predetermined address part, and identifies a boundary of the plurality of data between the plurality of data. Has a possible identifier.

Further, the packet receiving unit of each of the plurality of terminals determines the special address contained in the predetermined address portion of the received packet and takes in the packet internally, and the identifier from the taken packet. It is provided with a decomposing means for decomposing each data by using it, and a taking-in means for referring to a destination address included in the decomposed data and taking in only data having a predetermined address.

Further, the packet transmission unit of each of the plurality of terminals inserts the identifier into a plurality of data to be transmitted and combines them within a predetermined maximum length to form one packet, and a combining unit for the packet. It is provided with a sending means for adding the special address to a predetermined address part, and adding an end identifier to the end and sending out to the transmission path.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a functional block diagram showing an embodiment of the present invention. In the data transfer method shown in FIG. 1, the terminal transmitting / receiving unit 1, which is the physical layer, collectively collects the data A to C, which have different destination addresses and are passed from the upper layer 2, in a batch.
Formed into one combined packet 4 and network transmission line 3
It is assumed that the data has been transmitted to the user, and this point is different from FIG.

As shown in FIG. 1, in the combined packet 4, in order to distinguish the data A to C, the data A to C are arranged in the transmission request order with the identifier I interposed therebetween, and the special address S is placed at the head, and , The tail identifier E having a flag indicating the tail is placed at the tail. Further, the data A, B, and C are internally stored in the destination address a, b, a
And the destination address a is the own address of the destination terminal. The special address S is set with an address code that allows each terminal to receive a call other than its own address. For example, for the special address S, the oldest number or the like can be used.

First, the configuration of the terminal transmitting / receiving unit 1 will be described with reference to FIG. The terminal transmitting / receiving unit 1 includes a transmission buffer 11 having a data storage area 19, a packet combining unit 12, and a packet transmitting unit 13 as transmitting units, and a packet receiving unit 14, a combined packet determination unit 15, and packets as receiving units. It has a disassembling unit 16, a data discarding unit 17, and a data capturing unit 18.

In the transmission section, the transmission buffer 11 sequentially receives the data A to C received from the upper layer 2 in the data storage area 1.
9 is stored and accumulated. Upon receiving the packet transmittable notification from the packet transmitting unit 13, the packet combining unit 12 takes out the data A to C accumulated in the data storage area 19 of the transmission buffer 11 and, as shown in FIG. The identifier I is inserted to form a combined packet 4 having a length within the maximum length that can be transmitted to the transmission line 3, and the combined packet 4 is transmitted to the packet transmission unit 13. The packet transmitter 13 adds the special address S and the last identifier E as shown to the received combined data to form a combined packet 4 and sends it to the transmission line 3.

On the other hand, in the receiving unit, the packet receiving unit 1
4 takes in the transfer packet on the transmission path 3 and transfers it to the combined packet determination unit 15. The combined packet determination unit 15
The destination address of the captured packet is checked, and if it is its own address or the special address S, the captured packet is sent to the packet disassembly unit 16. Packet decomposition unit 16
Decomposes the received combined packet into respective data.

As described above, since the data includes the destination address, in the case of the combined packet 4, the data A having the destination address a which is its own address among the decomposed data A, B and C. , C are sent to the data fetching unit 18 and fetched by the data fetching unit 18 in the upper layer 2. On the other hand, data B having an address b other than itself is
It is sent to the data discarding unit 17, and is discarded by the data discarding unit 17.

Next, with reference to FIG. 1 and FIG. 2, the packet transmission procedure of the terminal transmitting / receiving unit 1 will be described.

First, the data A to C which have received the transmission request from the upper layer 2 are sequentially stored and accumulated in the data storage area 19 of the transmission buffer 11 (step 101). Send buffer 11
Informs the packet transmitter 13 via the packet combiner 12 that there is a transmission request. Packet transmitter 13
Waits for the transmission line 3 of the network to become free, and when the transmission line 3 becomes free and becomes usable (YES in step 102), informs the packet coupling unit 12 of this availability.

The packet combiner 12 includes a data storage area 1
9 has a plurality of data (YES in step 103), and
If the total number of bits of these data exceeds the maximum length of one packet (YES in step 104), one packet of data is retrieved from the data storage area 19 (step 105).
And form a combined packet as shown in FIG. 1 (procedure 1
06, 107), and the data is sent to the transmission line 3 via the packet transmission unit 13 (procedure 108).

If the procedure 103 is "NO" and the data is independent, the conventional procedure of forming and transmitting a packet of independent data is performed. If step 104 is “NO” and a plurality of data fits within one packet length, step 105
Are omitted and deleted, and the process proceeds to step 106.

In step 106, the fetched data A to B and B to B as shown in the combined packet 4 in FIG.
An identifier I for distinguishing data is inserted between the Cs and combined into one. In step 107, the special address S that has the function of taking in the same as its own address at any terminal
Is inserted at a predetermined position at the beginning of the data combined in step 106, and an end identifier E for notifying the end is added to the end.

Next, the packet receiving procedure of the terminal transmitting / receiving unit 1 will be described with reference to FIGS. Here, FIG. 1 which is the same as the above-mentioned transmission procedure is used, but description will be given assuming that the own address of the terminal transmission / reception unit 1 is “a”.

The packet receiving unit 14 takes in the packet on the transmission path 3 and transfers it to the combined packet determination unit 15, and the received packet is stored and accumulated in the combined packet determination unit 15 (procedure 131). The combined packet determination unit 15 collates the destination address of the accumulated packets with its own address and the special address S (procedure 132), and determines that the destination address of the accumulated packet is not the own address (“NO” in procedure 133) and the special address S. If yes (YES in step 134), the packet taken in is determined to be the combined packet 4, and the packet decomposition unit 1
Send to 6. Combined packet 4 with special address S
Can determine the tail by the tail identifier E.

The packet disassembling unit 1 which has received the combined packet 4
In 6, the received data A, B, C of the combined packet 4 is decomposed by the identifier I (procedure 135), and first, the data A is taken out as the first data (procedure 136). Next, when the destination address a included in the data A is referred to by the own address a and it is determined that the data A is an incoming call to itself (YES in step 137), the data A is acquired by the data capturing unit. It is taken in via 18 and the upper layer 2 (procedure 138).

Next, since the identifier A, not the last identifier E, follows the data A (NO in step 139), the next data, data B, is taken out (step 140) and the procedure 1
Returning to the incoming call determination procedure of 37. The data B has the incoming address b and is not the incoming call of the own terminal, and the procedure 137 is “NO”.
In the case of, the taken-out data B is sent from the packet disassembling unit 16 to the data discarding unit 17, and is discarded by the data discarding unit 17 (procedure 141).

After discarding the data B, the packet disassembling unit 16 takes out the data C following the identifier I by the procedure from the procedure 139, and the procedure returns to the procedure 139. Step 13
If 9 is "YES" and the last identifier E appears, the processing procedure of this packet ends.

As a result of the step 132, the step 133 is "YE".
If the address is "S" and the address is his / her own address, the normal reception procedure (step 142) is performed, and the procedure ends.
Is "NO" and it is not the special address S, the received and accumulated packet is discarded (procedure 143), and the procedure ends.

First, it was explained that the number is the oldest number as the special address S, but a character string which is not permitted by the conventional usage may be adopted at the beginning of the address. For example, as shown in FIG. 4, the own address of the terminal A is "0".
000 ... 01 "and the own address of terminal B is" 0000 ... 0 "
2 ”and the own address of each terminal are different,
When the common special address S is set to "$ 000 ... 0F", all terminals handle the destination addresses $ 000 ... 0F as their own addresses.

That is, in each of the terminals A and B, the destination address $
A packet having 000 ... 0F is judged to be a combined packet arriving to itself and handled. In this case, for example, the leading code $ of the destination address is prohibited to be used as a system. The means for doing so will be adopted for all terminals.

In the above, the functional blocks are shown in FIG.
Although the main procedure is illustrated and described in FIGS. 2 and 3, functional block separation / merging and parallel operation / post-replacement operation of the procedure may be allowed as long as the above functions are not hindered. That is, the above description does not limit the present invention.

[0033]

As described above, according to the present invention, the special address S common to all the terminals to be taken in as its own address, the identifier I for distinguishing each data A to C, and the end of the packet are notified. A special address S is placed in the destination address as a packet to be transferred to the transmission line of the network in which the last identifier E is defined, and a plurality of data requested to be transmitted in the data part sandwiches the identifier I regardless of the destination address. Combined, the tail identifier E is placed at the end, and the combined packet to be formed is obtained.

By transmitting and receiving this combined packet, the number of packets sent to the network is reduced,
It is possible to obtain a data transfer method that can reduce the load on the network.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart showing an example of a transmission part of FIG.

FIG. 3 is a flowchart showing an embodiment of the receiving part of FIG.

FIG. 4 is an explanatory diagram showing an example of a special address of the present invention.

FIG. 5 is an explanatory diagram showing an example of conventional packet transfer.

[Explanation of symbols]

 1 Terminal Transmitter / Receiver (Physical Layer) 2 Upper Layer 3 Transmission Line 4 Combined Packet 11 Transmitter Buffer 12 Packet Combiner 13 Packet Transmitter 14 Packet Receiver 15 Combined Packet Judger 16 Packet Disassembler 17 Data Discarder 18 Data Capturer 19 data storage area

Claims (4)

[Claims] 1. In a data transfer method for collectively forming a plurality of data into one packet and transferring the packet to the transmission line in a network in which three or more terminals are connected to one transmission line, the packet is A data transfer having a special address that can be commonly received by each of the plurality of terminals in a predetermined address part, and an identifier that can identify a boundary of the plurality of data between the plurality of data. method. 2. The packet receiving unit of each of the plurality of terminals according to claim 1, further comprising: a determining unit that determines the special address included in a predetermined address portion of the received packet and captures the packet internally. It is characterized by further comprising: a decomposing means for decomposing each data from the packet using the identifier, and a retrieving means for referring only to a destination address included in the decomposed data and taking in only data having a predetermined address. And data transfer method. 3. The combination according to claim 1, wherein the packet transmission unit of each of the plurality of terminals inserts the identifier between a plurality of data to be transmitted and combines them within a predetermined maximum length to form one packet. And a sending means for adding the special address to a predetermined address part of the packet and for adding an end identifier indicating the end to the end and sending out to the transmission path. Transfer method. 4. The specific address according to claim 1, wherein the special address has a specific bit that is not normally permitted at the beginning of an address number, and the receiving unit of each of the terminals has the specific address included in a predetermined address unit of a received packet. A data transfer system comprising a determination means for permitting a bit to pass through, determining the special address, and fetching the received packet inside.