JP2005072851A - Computer network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a computer network system capable of reducing the load on a server by simplifying protocol between a switch and the server in TCP connection of Ethernet (R). <P>SOLUTION: The system comprises a server 1 that operates with the assumption that only a normal confirmation packet is returned from the other party, client computers 3-6 that operate based on the protocol of TCP/IP, and a switching hub 2 that transmits a confirmation packet indicating error to the server 1 instead of transmitting the confirmation packet to the server 1 if the confirmation packet which indicates that data are normally transmitted from the server 1 to any one of the client computers 3-6 is transmitted to the client computer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a computer network system using TCP (Transmission Control Protocol) / IP (Internet Protocol). In particular, the present invention relates to a computer network system in which a server and a plurality of clients are connected by an Ethernet (registered trademark) and a switching hub and can transmit and receive data by TCP / IP.

  In recent years, the majority of computer networks are composed of Ethernet (registered trademark) and a switching hub, and many of the protocols running on the network are realized by reliable connections using TCP / IP. An example of a system using TCP / IP has already been shown (for example, Patent Document 1). TCP establishes a connection between two points of a computer by a method called a three-way connection, and performs data transmission / reception control and error management for each connection. As for packets to be transmitted / received, an acknowledgment packet (ACK) is always issued from the transmitting side or the receiving side, and even if a plurality of transmitted packets are missing, detection is possible, and the data in the packet itself Can be detected by checking the checksum attached to each packet. For these erroneous packets, a retransmission request for the corresponding packet is issued from the reception side to the transmission side. In this way, TCP / IP focuses on providing high-quality communication regardless of collision and physical quality on the route, rather than performance. However, in the case of a server or the like, data must be exchanged with a plurality of clients, the protocol of TCP itself becomes heavy, and it is a problem that the processing inside the server and the performance of the network itself are degraded.

Japanese Patent Laid-Open No. 09-261274 (FIG. 1)

  It is an object of the present invention to provide a computer network system that reduces the load on a server by simplifying a protocol between a switch and a server in an Ethernet (registered trademark) TCP connection.

  The computer network system of the present invention includes a server that operates on the assumption that only a normal confirmation packet is returned from the other party, a client computer that operates based on a TCP / IP protocol, and the server to the client computer. And a switching hub that does not send the confirmation packet to the server when the confirmation packet indicating that the data has been transmitted normally is transmitted from the client computer.

  The computer network system of the present invention can improve performance by reducing interrupts from a network of computers connected by 1: N such as a server without impairing the TCP protocol for transmitting and receiving high-quality data.

  The best mode for carrying out the present invention will be described.

  The best mode of the present invention includes a server 1 that operates on the premise that only a normal confirmation packet is returned from the other party, client computers 3 to 6 that operate based on the TCP / IP protocol, and the server 1 When a confirmation packet indicating that data has been normally transmitted to any one of the client computers 3 to 6 is transmitted from the client computer, this confirmation packet is not sent to the server 1 but indicates an error. The confirmation packet includes the switching hub 2 that transmits to the server 1.

  Next, examples of the present invention will be described.

  Referring to FIG. 1, in one embodiment of the present invention, a server 1 that operates on the premise that only a normal confirmation packet is returned from the other party, and client computers 3 to 6 that operate based on the TCP / IP protocol. When a confirmation packet indicating that data is normally transmitted from the server 1 to any one of the client computers 3 to 6 is transmitted from the client computer, the confirmation packet is transmitted to the server 1. The confirmation packet indicating an error without sending includes a switching hub 2 that sends it to the server 1.

  FIG. 2 shows a general TCP header frame. In the figure, the vertical direction represents a word, and the horizontal direction represents a bit width of 32 bits. N1 in the first word indicates the port number on the packet start point side, and N2 indicates the port number on the reception side. N3 in the second word is a sequence number that is appropriately given on the start point side, and N4 in the third word is an ACK number that is generated when an ACK is further returned to the received packet. The left side of the fourth word is a flag bit, indicating that A is ACK, S is SYN, and F is FIN. WIN represents a window size and represents a usable remaining buffer size on the receiving side.

  Next, the configuration of the switching hub, which is a feature of the present invention, will be described with reference to FIG. Reference numeral 14 denotes e-support on the server side, and 15 to 18 denote e-support on the client side. Reference numeral 13 denotes a crossbar switch that switches on-line between any two ports mounted on a normal switching hub. A control unit 10 reaps the confirmation packet ACK sent from the client in the case of data transmission as seen from the server side. A sequence number + capacity is sent as a confirmation packet ACK number from the client. The control unit 10 checks whether or not this ACK number is skipped and detects whether or not there is an error. If an error is detected, the server is notified.

  Further, the WIN of the confirmation packet ACK is monitored, and when the remaining buffer size on the client side is insufficient, the packet buffer 11 is made to save the temporary transmission packet. Thus, normally, the client notifies the server of the receivable capacity, and the server that has received the notification needs to adjust the transmission capacity. This packet buffer can alleviate the need to make such adjustments to the server. A packet selection unit 12 arbitrates data from the packet buffer 11 and data from the server-side e-support 14 by the control unit 10. In the case of data transmission as seen from the server side, the control unit 10 operates as a normal switching hub. In the case of a protocol other than TCP / IP, it operates as a normal hub.

  Next, the operation of the first embodiment will be described in comparison with the prior art.

  FIG. 3 and FIG. 4 show time tables showing how packets are transmitted and received by the TCP protocol. In FIG. 1, 3000 octets of data are transferred from the server 1 to the client computer 3 in response to a request from the client computer 3. It is assumed that Assuming that one packet is 1000 octets, a total of three packets of data are transferred from the server to the client.

  In the case of the conventional TCP communication shown in FIG. 3, a total of five ACKs are transmitted from the client to the server after the connection is first established and then disconnected.

  In the case of TCP communication using the switching hub of the present invention shown in FIG. 4, since three data reception ACK packets are pruned, only two confirmation packet ACKs are transmitted to the server side. At this time, the server needs to operate on the assumption that only a normal confirmation packet ACK is returned from the partner. If an error occurs during communication, only the error confirmation packet ACK is transmitted by the switch, so that a rewinding loss occurs but communication reliability is not impaired.

It is a figure which shows the structure of this invention. It is a figure which shows the header frame of TCP used for this invention. It is a figure for demonstrating the operation | movement of the conventional TCP communication. It is a figure for demonstrating the operation | movement of TCP communication in embodiment of this invention. It is a figure which shows the structure of the switching pub which is the characteristics of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Server 2 ... Switching hub 3 ... Client computer 4 ... Client computer 5 ... Client computer 6 ... Client computer 10 ... Control part 11 ... Packet Buffer 12 ... Packet selection unit 13 ... Crossbar switch 14 ... Server side e-support 15 ... Client side e-support 16 ... Client-side e-support 17 ... Client-side e-support Support 18 ... e-support on the client side

Claims (1)

A server that operates on the premise that only normal confirmation packets are returned from the other party,
A client computer operating based on the TCP / IP protocol;
And a switching hub that does not send the confirmation packet to the server when the confirmation packet indicating that the data has been normally transmitted from the server to the client computer is transmitted from the client computer. Computer network system.

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