JPH01227544A - Repeater - Google Patents

Abstract

PURPOSE:To speedily find out the fault of a repeater by returning a response packet to contain confirmation information indicating that a relay packet to a segment is normally transmitted to the transmission source of the packet when the packet to the self-destination is recognized. CONSTITUTION:When the packet inputted to a receiving circuit 18 is a test packet to the repeater and it is the correct packet, the response packet composed of a called address, a self-address, transmission completion information to a called segment, etc., is prepared by an identification responding circuit 20. The packet is transmitted through an interface 16 from a transmission circuit 22 in a condition in which the relay packet inputted from a segment 13 from a receiving circuit 19 does not exist and, simultaneously, a carrier does not exist in a segment 12, and the response packet is returned to a station to transmit the test packet. From the transmission completion information, etc., of the response packet to be returned in such a way, whether the repeater is normally operated or not is decided.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a repeater used for relaying a trunk line of a local area network.

(Prior Art) Conventionally, repeaters used in local area networks (hereinafter referred to as LAN) relay packets flowing through the coaxial trunk line, so packet collisions between two segments connected by the repeater may occur. It can be realized by having the function of detecting and transmitting the data to both segments, and the function of receiving, reproducing and transmitting the data bit string, so it is composed of a relatively simple circuit. In a LAN where segment 1 and segment 2 are connected by repeater 3 as shown in Fig. 2,
A packet from station 4 is transmitted to segment 2 via repeater 3 and received by the intended station 6 or station 7. Similarly, a packet from station 6 in segment 2 is transmitted to segment 1 via repeater 3 and received by station 4 or station 5.

For this reason, if a failure occurs in the repeater 3 installed between two segments 2, segment 1 and segment 2
It becomes impossible to send packets between To investigate the location of this failure, first, when there is no problem in communication within each of segments 1 and 2, the failure is checked at each station, and then the failure between segments is checked.

(Problems to be Solved by the Invention) For this reason, when the number of stations in each segment 1 and 2 is large, there may be a delay in discovering a fault in the repeater. This can be achieved by the relay having the function to detect packet collisions and the function to send and receive data, so even if it does not have the function to detect failure occurrence, it can function as a relay. It is something. For this reason, there has been a demand for repeaters to have a function that allows them to easily detect the occurrence of a fault.

This invention was made in view of the above points, so
It is an object of the present invention to provide a repeater that can easily detect the occurrence of a fault.

[Structure of the Invention] (Means for Solving the Problems) This invention provides a repeater used for relaying the main line of a local area network, by having a function of identifying the data frame of an input packet. , recognizes a test packet addressed to itself, and upon identifying this packet, generates a response packet containing confirmation information indicating that the transmission of the relay packet is being performed normally, and sends it back to the source of the test packet. This monitors the operation of the repeater.

(Function) In the repeater used in the LAN configured in this way, the test packet addressed to itself is sent to l! ! When this is detected, a response packet containing information indicating that transmission to the segment is being performed normally is sent back to the source of the test packet.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a repeater according to an embodiment of the present invention. A repeater 11 shown in the figure is for relaying between a segment 12 and a segment 13. Transceivers 14.15 are provided in the trunk lines of the segments 12.13, respectively, and are connected to interfaces 16.17 of the repeater 11, respectively. The interface 16.17 receives data from signals from the transceiver 14.15.

Detects carrier sense and II sudden detection signals, and outputs transmission data to transceiver 14.15. The interface 16.17 outputs the input received data to the receiving circuit 18.19, and the receiving circuit 18.19 classifies the data into data to be relayed and self-addressed data which is a test packet. The identification response circuit 20.21 is connected to the receiving circuit 18.19.
It determines whether it has correctly received the classified data addressed to itself, and generates a response packet.

The transmitting circuits 22 and 23 control the transmission of packets to be relayed or response packets generated by the above-mentioned identification response circuits 20 and 21.

The operation of the repeater configured in this way will be explained.

Here, the station connected to segment 12 (
(not shown) transmits a test packet addressed to the repeater 11 and monitors the operating state of the repeater 11. Here, in order to configure the repeater with a relatively simple circuit, the test packets are limited to those that can be confirmed by the repeater to be addressed to itself and to be normal packets.

First, a packet inputted from the segment 12 via the transceiver 14 and the interface 16 is inputted to a receiving circuit 18 that monitors the packet.

Then, the receiving circuit 18 classifies whether the data is relay data to be transmitted to the segment 13 or self-addressed data such as a test packet. If the input packet does not have its own address, it is determined to be relay data and is sent to the transmission circuit 23. and,
It is output to the transceiver 15 via the interface 17 and sent to the segment 13.

Furthermore, if the packet input to the receiving circuit 18 is a test packet for this repeater, it is recognized as a packet addressed to itself. After receiving the packet, if the packet is correct, a test packet reception signal and the other party's address are output to the identification response circuit 20. If the received bucket is incorrect, it will be invalid.

When the test packet is received in this manner, the identification response circuit 20 generates a response packet consisting of the destination address, the own address, transmission completion information to the destination segment, and the like. The transmission completion information in the response packet generated by the identification response circuit 20 and 21 is based on the 802 committee of the Institute of Electrical and Electronic Engineers (IEEE).
This is for performing the SQF test specified in 02.3. This is because the transmission completion information for each segment is exchanged between the identification response circuits 20 and 21, so that when the segment 12 and the repeater 11 are tested, it can be determined whether the transmission to the segment 13 is being performed normally. is possible.

The response packet generated in the identification response circuit 20 is transmitted from the transmission circuit 22 to the segment 1 from the reception circuit 19.
There is no relay packet input from segment 3, and segment 1
2 is transmitted via the interface 16 when there is no carrier present. If a data collision occurs due to this transmission, the transmission is restarted after a certain period of time. Thus - a response packet is sent back to the station that sent the test packet.

Based on the transmission completion information of the response packet returned in this manner, it is determined whether the repeater is operating normally.

In this way, the repeater is equipped with a function to receive packets addressed to itself, and when it receives a test packet from a segment, it generates a response packet containing information indicating that the transmission is being performed normally. By sending this response packet back to the station that sent the test packet, it becomes possible to monitor the operation of the repeater. Therefore, it becomes possible to easily discover the occurrence of a fault in a repeater.

[Effects of the Invention] As described above, according to the present invention, a repeater used for relaying the main line of a local area network is provided with a function of recognizing data frames of input packets, and is capable of recognizing packets addressed to itself. In this case, the operation of the repeater can be easily monitored by sending back a response packet containing confirmation information indicating that the transmission of the relay packet to the segment is being performed normally to the source of this packet. This makes it possible to quickly discover repeater failures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the structure of a repeater according to an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a structure in which the repeater is used in a LAN. 11...Repeater, 12.13...Segment, 14
．． 15... Transceiver, 16.17... Interface, 18.19... Receiving circuit, 20.21...
-Identification response circuit, 22.23...transmission circuit.

Claims (1)

[Claims] A repeater used for relaying the main line of a local area network has an identification means for identifying the data frame of an input packet, and an identification means for correctly transmitting the relay packet when the identification means recognizes a packet addressed to the local station. 1. A repeater comprising: generating means for generating a response packet including confirmation information indicating that the packet is being sent; and return means for transmitting the response packet back to the source of the packet addressed to the local station.