JP2003333043A - Network control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a network control method which allows control data to be communicated via the transmission lines of a network. <P>SOLUTION: In a network has a media converter 1 installed between transmission lines, having different physical media for relaying data communications, the converter 1 is capable of interconverting signals in the different physical media, and control data of the media converter 1 are transferred over the transmission lines in a spread spectrum communication system. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network management method including a media converter operating in a physical layer, and more particularly to a network management method capable of communicating management data via a transmission line of a network. is there.

[0002]

2. Description of the Related Art Ethernet (registered trademark), which has been developed as a method suitable for regional data communication, is recently being used for wide area data communication. In parallel with this, the communication speed of Ethernet is increasing. As a result, the communication speed is 100Mbps or more.
It has also been conceived to construct a WAN with 00M Ethernet or giga Ethernet of 1 Gbps or more.

In Ethernet, a plurality of types of physical media are defined. For example, 10BASE-T10 is a physical medium that uses a twisted pair and has a communication speed of 10 Mbps, and BASE-FL is a physical medium that uses an optical fiber and has a communication speed of 10 Mbps. In order to relay data communication between transmission paths of different physical media, it is necessary to install a relay device capable of mutually converting signals according to the physical media.

For example, a communication distance of 100 m using a twisted pair wire
LANs using 100BASE-TX as a physical medium, 100BA with an optical fiber and a communication distance of 2km
When the WAN is constructed by connecting with SE-FX, the signals of both physical media are mutually converted by the relay device.

In the conventional relay device, a physical layer interface for each transmission line is provided in each port, and a relay circuit such as a bridge circuit or a switch circuit that operates above the data link layer is provided between each physical layer interface. To be

[0006] As a method for managing the state of the network, an in-band management method in which management data is communicated in the same band as the band used by the user and an out-of-band management method in which a band different from the band used by the user is used. There is. In the in-band management method, for example, a management station on a network uses SNMP to communicate management data with a relay circuit. In the out-of-band management method, for example, a transmission line different from the transmission line for data communication is connected to the management port of the relay circuit to take out the management data.

[0007]

A relay circuit such as a bridge circuit incorporated in a conventional relay device has a drawback of being expensive. In addition, the bridge circuit has a drawback that there is a limitation in the frame length due to the buffer capacity. In order to solve these drawbacks, the present applicant envisions installing a media converter operating in the physical layer as a relay device between transmission lines.

The media converter does not include a relay circuit for processing so-called frames (frames such as IP frames processed in the data link layer and above), and only performs mutual conversion of signals according to physical media on both sides of input and output. Regarding the signal logic, the bit string (bit stream) input from one transmission line is converted to the bit string as it is or only the code format is converted and output to the other transmission line. Therefore, by installing the media converter instead of the conventional relay device, the restriction on the frame length is eliminated and the cost is reduced.

However, since the media converter does not process the frame, it cannot communicate from the management station to the media converter itself using SNMP. That is,
In-band management method cannot be implemented. On the other hand, if an out-of-band management method is used, it is difficult to manage a large number of media converters that are remote in the WAN.

Therefore, an object of the present invention is to solve the above problems and provide a network management method capable of communicating management data via a transmission line of a network.

[0011]

In order to achieve the above object, the present invention relays data communication by installing a media converter capable of mutually converting signals of both physical media between transmission paths having different physical media. In the network
Management data of the media converter is communicated via the transmission line by a spread spectrum communication system.

By amplitude-modulating the signal strength of the communication data at a speed sufficiently slower than the communication speed of the data communication and with a minute amplitude change that does not interfere with the data communication,
The management data may be sent to the transmission path.

The device for transmitting the management data, after first-order-modulating the management data having a speed sufficiently slower than the amplitude modulation speed by PSK, has a P change speed equal to the amplitude modulation speed.
It is also possible to perform spread modulation with an N series and perform the amplitude modulation with this spread modulated wave.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

Media converter 1 in this embodiment
As shown in FIG. 1, two optical transceivers 2 and 3 for mutually converting 1000BASE-LH as a short-distance giga Ethernet and 1000BASE-SX as a long-distance giga Ethernet, and management data. It is assumed to have a CPU 4 to be created. 5 is
It is an 8B / 10B code converter. The physical media on both sides may be the same. In the present invention, a transmission / reception circuit described later with reference to FIG. 3 is added to this media converter 1.

As shown in FIG. 2, the media converter includes a stand-alone media converter 22 installed in the house and having one port to which the terminal 21 is connected, and a plurality of ports installed in the station. The individual media converter 22 and the terminal 21 are connected by a short-distance physical medium, and the individual media converter 22 and the collective media converter 23 are connected at a plurality of locations. It is connected by a long-distance physical medium, and further, the collective media converter 23 and another network (not shown) are also connected by an appropriate physical medium. The management station that manages each media converter is provided on a network (not shown). Each of the media converters 22 and 23 has a CP
Equipped with U.

In the transmission / reception circuit shown in FIG. 3, the left side is the management data transmission side apparatus, and the right side is the management data reception side apparatus. In the description below, the media converter 1 is the transmission side device and the management station is the reception side device. Needless to say, the media converter 1 is also provided with a receiving circuit similar to that on the right side, but it is omitted here.

The transmission side device has a primary modulator 31 for modulating the management data from the CPU by PSK (phase modulation),
It has a PN sequence generator 32 that generates a PN sequence at a speed much higher than the speed of the management data, and a secondary modulator (spreader) 33 that spread-modulates the primary modulation signal with the PN sequence. The signal (spread signal) can be superimposed on the communication data (amplitude modulation) and sent from the optical transceiver 34 to the transmission path.

The receiving side device includes a low-pass filter 36 for extracting a superposition component (amplitude modulation component) from the communication data received by the optical transceiver 35 from the transmission line, and a PN sequence generator for generating the same PN sequence as the transmitting side device. 32, and a despreader 37 that despreads the extracted signal with a PN sequence,
It has a bandpass filter 38 for removing out-of-band noise and a demodulator (detector) 39 for reproducing management data by PSK demodulating the despread signal.

A known M-sequence generator may be used as the PN sequence generator 32. The M-sequence generator feeds back the output taken from an appropriate tap to the output of the final stage of the shift register having a large number of bits to the input of the first stage while taking the exclusive OR.

The operation of the circuit shown in FIG. 3 will be described below.

Among the spread spectrum communication systems (SS communication systems), the direct sequence (DS) system is a system for carrying out spread modulation by multiplying a PN sequence by a digital signal which is primary-modulated by PSK modulation. A spread signal in which the power components are distributed over the range is obtained. In the present invention, the management data is PSK modulated by the primary modulator 31, the primary modulation signal is spread and modulated by the spreader 33 by the PN sequence, and the spread signal is superposed on the communication data by the optical transceiver 34. A small amplitude change is given to the signal strength of (the average output level of a plurality of bits).

As shown in FIG. 4, the average level of communication data changes in amplitude above and below the signal strength (specified value) according to the communication standard of data communication. The magnitude of the amplitude change is
By setting it to about 1 dB to 0.1 dB with respect to the specified value, an error does not occur in data communication. If the communication data speed is 1.25 Gbps, the amplitude change speed is about 1/10 or less, for example, 125
Kbps. Therefore, during the period in which there are a plurality of data bit values 1 or 0 in the communication data, there is one logic 1 or 0 represented by the amplitude change of the average level.

The changing speed of the PN series is also set to be approximately the same as the changing speed of the amplitude. One bit of the PN sequence shown in FIG. 5 corresponds to the period of logic 1 or logic 0 in FIG. The speed of the management data is slower. For example, if the cycle of the PN sequence is 1000 bits, 1 bit of the management data is P
Since it is represented using N bits of 1000 bits, the speed of the management data is 1.25 Kbps.

As a result, the optical transceiver 3 of the receiving side device
In the communication data received at 5, there is no obvious change that can be seen as superposition of the management data, and of course, there is no problem in data communication. However, in the present invention, the minute amplitude change in the signal strength of the communication data is extracted by the low-pass filter 36, and this extracted signal is despreader 3
Since the despreading is performed by the PN sequence at 7, the interference wave in the narrow band with high power is eliminated and the primary modulation signal is reproduced. Management data is obtained by detecting the reproduced signal with the wave detector 39. Further, in the present invention, since the PN sequence consisting of a large number of bit pulses has a huge redundancy of representing 1/0 of 1 bit of the management data, even if some bit pulses are damaged, the management data can be Can be demodulated correctly.

According to the present invention, the management data of the media converter is communicated through the same transmission line as the data communication by the spread spectrum communication method, so that the media converter does not have the ability to process the frame of the data communication. Regardless, the CPU can send and receive management data, and the media converters distributed on the WAN can be managed online from a remote management device in the same manner as the in-band management method. .

In the above embodiment, the signal intensity of the communication data is amplitude-modulated by the spread signal, but the spreader 33
May be connected to the VCXO to finely modulate the frequency of communication data to the extent that it does not interfere with data communication.

[0028]

The present invention exhibits the following excellent effects.

(1) Since management data is communicated via a transmission line, remote management is possible. Since the management data is communicated by the spread spectrum communication method, it does not affect the communication data communicated on the same transmission line, and the media converter operating in the physical layer can transmit and receive.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a media converter showing an embodiment of the present invention.

FIG. 2 is a block diagram of a WAN using the media converter of the present invention.

FIG. 3 is a configuration diagram of a transmission / reception circuit of a media converter of the present invention.

FIG. 4 is a diagram of a waveform of communication data and a waveform of its amplitude change according to the present invention.

FIG. 5 is a diagram of a management data waveform and a PN series waveform according to the present invention.

[Explanation of symbols]

1 Media converter 2,3,34,35 optical transceiver 4 CPU 22 Stand-alone media converter 23 Collective Media Converter 31 Primary modulator (Phase modulator) 32 PN sequence generator 33 Secondary modulator (spreader) 36 low pass filter 37 Despreader 39 Demodulator (detector)

Claims (3)

[Claims] 1. In a network that relays data communication by installing a media converter capable of mutually converting signals of both physical media between transmission paths having different physical media, management data of the media converter is spread spectrum communication method. A network management method characterized in that communication is performed via the transmission path. 2. The management data is sent to the transmission line by amplitude-modulating the signal strength of the communication data at a speed sufficiently slower than the communication speed of the data communication and by a small amplitude change that does not interfere with the data communication. The network management method according to claim 1, further comprising: 3. An apparatus for transmitting management data, after primary-modulating management data having a speed sufficiently slower than the amplitude modulation speed by PSK, spread-modulating with a PN sequence having a change speed equivalent to the amplitude modulation speed, The network management method according to claim 2, wherein the amplitude modulation is performed by the spread modulation wave.