JPS61214044A - Data transfer system for remote ipl - Google Patents

Abstract

PURPOSE:To segment accurately only the latest packet in the packet input mode of a superposed data transfer sequence by attaining discrimination between the sequence numbers and the head and end packets. CONSTITUTION:When file server 2 receives 13 the initial program load IPL start request packet of a personal computer 1, an acceptance part 14 gives information to a request part 15 for the assembly of a packet. Here an STX code showing the head packet is written to the control field of the packet and a sequence number and a redundant code are set and transmitted 17. While the codes and sequence numbers showing the intermediate packets are set to the second and subsequent packets together with an ETX code set to the final packet respectively. The control part 7 of the computer 1 neglects the reception of packets before the packet of the STX code is received. Then a check part 11 checks the received 10 packets and stores them in the prescribed addresses of a RAM 19 as long as the codes of these packets are correct. The part 11 receives the final packet of the ETX code and decides the end of a remote IPL to finish the IPL control.

Description

[Detailed Description of the Invention] [(Already required)] When data is transferred between multiple computers connected via a packet switching network during remote 1-IPL, the sending side transfers data to each of the first, middle, and last packets. Add the code that identifies - to Bakeso 1~.

Send continuously without receiving an acknowledgment. On the other hand, on the receiving side,
The first, middle, and last packet identification codes are identified to select only valid received packets.

[Industrial application field]

TECHNICAL FIELD The present invention relates to a computer network system, and in particular to an initial program flow, ie, IPL (IPL), between computers in a network.
The present invention relates to a data transfer method using packets that is useful when performing program loading.

[Prior Art and Problems to be Solved by the Invention] FIG. 2 shows the configuration of a computer file Zaha type network, which is an example of a computer network system to which the present invention is directed. In the figure, 21 to 24 are computers.

25 is a file, and 26 is a packet switching network.

The computer 24 is a file server (hereinafter referred to as a file server) that manages all data in the network in a file 25 and transfers data in the file 25 in packets in response to requests from other computers 21 to 23.

Since the computers 21 to 23 do not have a file function, their programs also need to be IPLed from the file server, and when they are started up, the IPL is sent to the file server.
A request is made to have a predetermined program transferred in data packets.

Computers connected to such a network are
IPL is remote IP 1. , is called. Performed from other combination calls within the network.

During remote 1-TPL, a simple data transfer procedure is adopted because the operating system (O8) and network software are not loaded on the computer.

The procedure shown in FIG. 3(a) continuously transfers data errors (.) from the file server to the computer.

When the computer detects a transfer error, it notifies the operator and performs the remote 1-1 PL again, and is often applied in high-quality LAN systems with one transmission path.

However, in this procedure, if the operator (knee→〕') mistakenly issues the IPI, then the T P l-indication again.

As shown in FIG. 3(b), some of the packets sent with the previous I P +- instruction are transferred to the later T
The problem is that the packet will be mistakenly received as the first packet sent with the PL instruction, and as shown in FIG. 3(c),
A packet destination address or transmission path error occurs,
There is a problem in that if a packet is missing, it cannot be detected.

[Means for solving problems]

The present invention manages packets by sequence numbers during remote 1-IPL, and also manages packets by sequence numbers.

The final packet is identified and continuous transfer is performed without receiving an acknowledgment from the receiving computer.

FIG. 4 is an explanatory diagram of a data transfer procedure showing the principle of the present invention. As shown in the figure, when a computer makes an IPL request to a file server, the file server transmits a program to a series of data packets with sequence numbers 1, 2, . ...n, redundant code, and the beginning.

A code identifying the intermediate and final packets is added and transmitted.

On the other hand, when a computer receives packets, it validates only the packets between the first packet and the last packet. As a result, if other packets have been received before the first packet is received, they are discarded. Also, packets between the first packet and the last packet are checked for transmission path errors using sequence numbers and redundancy codes.

[Effect]

According to the present invention, if remote! The packets sent from the server are identified as having been received by the computer before the first packet of the packets sent in response to the second remote IPL request, and are all discarded.

Further, as in the example of FIG. 3 (c+), if a packet is not received due to a transmission path error, or if a data error occurs, each is detected by a missing sequence number or a redundant code.

〔Example〕

FIG. 5 shows the configuration of an embodiment of a packet format used during remote IPL according to the present invention.

In fig.

F: Flag sequence DA: Called DTE address SA: Calling DTE address C: Control field STX code...First packet ETX code...Final code NUL I, code...Intermediate code N sequence number CRC: Represents redundancy code (block check sequence). That is, in the present invention, remote IP L
The C, N, and CRC fields shown in the figure are sometimes used to control packet transfer through a simple procedure.

FIG. 1 shows the configuration of an embodiment system that executes remote TPL using the packet format shown in FIG.

In the figure, 1 is a personal computer, 2 is a file server, 3 is a file, 4 and 5 are DTE (data line terminal equipment), 6 is a data line, 7 is a remote lPL control unit,
8 is an IPL request section, 9 is a packet transmitter, 10 is a packet receiver, 11 is a check section 212 is an error notification section, 1
3 is a packet receiving section.

14 is an IPL request reception unit, 15 is a packet assembly and transmission request unit, 16 is a file management unit, 17 is a packet transmission unit, 1
8 is a ROM, and 19 is a RAM.

Next, the operation of the embodiment system of FIG. 1 will be explained based on the data transfer procedure of FIG. 4.

■ On PC 1, the operator can
When an instruction to start P L is given, the I P L program stored in ROM 1B starts execution. This IP
The functionality of the L program is illustrated by a remote IPL control 7.

■ The IPL request unit 8 of the remote +-rPL control unit 7.

An IPL start request packet is sent to the file server 2 via the packet transmitter 9.

■ In the file server 2, the packet receiving unit 13
When the PL start request packet is received, the IPL request reception section 14 accepts it, starts the file management section 16, and causes the requested program to be extracted from the file 3. The IPL request reception unit 14 further notifies the packet assembly and transmission request unit 15 to assemble the packets, and at this time inputs the STX code indicating the beginning of the series of packets to the control field C (see FIG. 5) of the bucket machine 1-. Then, the sequence number N and redundancy code CRC are set, and the packet transmitter 17 transmits the first packet.

(2) For the second and subsequent packets, the file server 2 sets a NULL code indicating that it is an intermediate packet in the control field of the packet, attaches a corresponding sequence number, and transmits the packet. And in the final packet.

Set the ETX code and send.

■ On the other hand, the remote I of PC 1 that issued the IPL request
The PL control unit 7 waits until it receives the packet with the STX code set. Ignore any other packets received. The checking unit 11 checks the packet received by the packet receiving unit 10 and checks whether the STX code is set and the CRC
If the packet is correct, the packet is received and stored at a predetermined address in RAMI9.

■ From then on, when the remote controller 1 to the IPL controller 7 receive an intermediate packet, the checker 11 checks the sequence number and C
The RC is checked, and if it is correct, it is stored in the RAM 19.

■ The check unit 11 of the remote IPL control unit 7 is ETX.
If the final packet with the code set is received and the sequence number and CRC are normal.

(Remote) Determines that IPL has ended, and ends IPL control.

After this, the IPLed program is executed from its entry point.

■ If a packet dropout or other error is detected in the above ■, ■, ■, the error notification section 12 displays the error and remotely informs the operator (user).
Make L request again.

This re-request for remote IPL causes file server 2 to
When the PC 1 again sends a series of packets for remote IPL starting from the first packet, when the checking unit 11 identifies the first PC, it discards the packets received so far (data in the RAM 19) and assigns a new sequence number. The packet is received according to the following.

It should be noted that the present invention is not limited to the computer file server type network of the above-described embodiment, but can be similarly applied to remote IPL in computer network/node work.

〔Effect of the invention〕

According to the present invention, a computer that has made a remote IPL request to a remote computer (for example, a file server) can identify the first packet and the last packet in addition to the sequence number.
Even if packets of duplicate data transfer sequences are input, only the packets of the latest data transfer sequence can be reliably extracted.

Furthermore, since checks are made possible using sequence numbers and redundancy codes (CRC), reliable remote control 1 to IPL can be performed using the IPL program.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a system according to one embodiment of the present invention;
The figure is a configuration diagram of a computer-Fairsach-type computer software, Figure 3 (al is a sequence diagram showing the data transfer procedure in the conventional remote control 1-IPL, Figure 3 (b) and Fig. 3 fcl is a similar sequence diagram in the case of re-IPI- and packet dropout, respectively, Fig. 4M is a sequence diagram of the data transfer procedure according to the method of the present invention, and Fig. 5 is a sequence diagram of the data transfer procedure in one embodiment of the method of the present invention. 1 is an explanatory diagram of the format. In FIG. 1, 1 is a personal computer, 2 is a file server,
3 is a file, 6 is a data line, 8 is an IPL request section, 9
17 represents a packet receiving unit, 10 and 13 a packet receiving unit, 11 a checking unit, 14 an IPL request receiving unit, 15 a packet assembly transmission requesting unit, and 16 a file management unit.

Claims (1)

[Claims] In a network system in which multiple computers are connected to a packet-switched network, the sending computer adds codes that identify the first, middle, and last packets to the packets to be transferred, along with sequence numbers and redundancy codes. Continuous transfer is performed without receiving a response, and when the receiving computer receives the first packet, if it has received other packets by then, it discards them, and the sequence number continues from the first packet until the last packet is received. and a data transfer method characterized by carrying out a transmission path error check using a redundant code.