JPH06243063A - Optical link state monitoring device - Google Patents

Abstract

PURPOSE:To recognize the normality/abnormality of an optical link by monitoring an idle signal turning back at an optical transceiver on the reception port of an optical concentrator. CONSTITUTION:Turn-back circuits for idle signal (an idle signal discrimination part 22 and a switch 23 forming a turn-back loop by the detection signal of the discrimination part 22), which turn back and transmit the idle signal at the time of receiving the idle signal from the optical concentrator 1 are provided for the optical transceiver 2. A link monitor circuit 11 monitoring the idle signal which turns back at the optical transceiver 2 and received, is provided in the optical concentrator 1. The state of the link can be recognized by monitoring only with the reception port of the optical concentrator 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical link status monitor for monitoring the status of an optical link between an optical concentrator (optical concentrator) and an optical transceiver.

[0002]

2. Description of the Related Art A link abnormality detecting means between an optical concentrator (optical concentrator) and an optical transceiver is used to detect an optical concentrator and an optical concentrator when a signal path by the optical link is in an idle state (no packet). Idle signals are sent from both transmission ports of the transceiver, and the idle signals are monitored at the reception ports of both the optical concentrator and the optical transceiver. If both receive the idle signals correctly, it is determined that the link is normal. It was The configuration and operation of the conventional optical link status monitoring mechanism at this time will be described with reference to FIG.

In FIG. 3, an optical concentrator 31 and an optical transceiver 32 are provided with optical fiber cables 34 and 3.
When the state of the optical link forming the signal path is discriminated by 4, when the optical link is in the idle state, the idle signal is transmitted / received to / from each other.

That is, the optical concentrator 31 sends out an idle signal of a specific frequency from the transmission port (PS) when the optical link is in an idle state (state with no packets). The idle signal output from the transmission port (PS) of the optical concentrator 31 is the optical fiber cable 34.
Is received by the receiving port (PR) of the optical transceiver 32 via the. The optical transceiver 32 displays the status display section 32a according to the reception state of the idle signal on the reception port (PR).
The normal / abnormal status of the optical link is displayed on.

Further, the optical transceiver 32 sends an idle signal from the transmission port (PS) when the optical link becomes idle. The transmission port (P
The idle signal output from S) is received by the receiving port (PR) of the optical concentrator 31 via the optical fiber cable 35. The optical concentrator 31 displays the status of the optical link on the status display section 31a according to the reception status of the idle signal on the reception port (PR).

As described above, conventionally, when the optical link becomes idle, the idle signals are transmitted from the transmission ports (PS) of both the optical concentrator 31 and the optical transceiver 32, and the optical concentrator 31 and the optical transceiver 32 are transmitted. The idle signal was monitored at both receiving ports (PR), and when both received the idle signal correctly, it was determined that the link was normal.

[0007]

As described above, in the conventional optical link state monitoring mechanism, when the optical link is in the idle state, the idle signals are transmitted from the transmission ports of both the optical concentrator and the optical transceiver. However, the idle signal is monitored at each of the receiving ports of both the optical concentrator and the optical transceiver, and it is determined that the link is normal when both receive the idle signal correctly.

Therefore, conventionally, the state of the link can be recognized only by monitoring the idle signals by both the optical concentrator and the optical transceiver, which are coupled by the optical cable at a relatively large distance, and therefore, the link state can be recognized. There is a problem that the state of the optical link cannot be easily recognized. Further, both the optical concentrator and the optical transceiver must be provided with an idle signal transmitting means of a specific frequency and a link monitor circuit, which causes a problem that the system configuration becomes complicated.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide an optical link state monitoring device which can recognize the state of a link by a monitor having only a receiving port of an optical concentrator, which can easily recognize the state of the optical link and can simplify the system configuration.

[0010]

According to the present invention, as shown in FIG. 1, when an optical transceiver 2 connected to an optical concentrator 1 via optical fiber cables 4 and 5 receives an idle signal from the optical concentrator 1. An idle signal loopback circuit (the idle signal discriminating unit 22 and a switch 23 that forms a loopback loop based on the detection signal of the discriminating unit 22) for transmitting the same signal by looping back is provided, and the optical concentrator 1 is looped back to receive the optical transceiver 2. The link monitor circuit 11 for monitoring the idle signal is provided so that the status of the link can be recognized by the monitor of only the receiving port of the optical concentrator 1.

[0011]

When the optical link becomes idle, the optical concentrator 1 sends an idle signal. In the optical transceiver 2, the switch 23 is turned on in accordance with the idle signal detection output of the idle signal determination section 22 to form a loop loop, and the idle signal received at the reception port (PR) is output to the transmission port (PS). The link monitor circuit 11 of the optical concentrator 1 monitors the idle signal on the reception port (PR) where the optical transceiver 2 is folded back, and recognizes the state (normal / abnormal) of the link.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a network configuration including an optical link status monitoring mechanism according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an optical concentrator that relays received data to another port, and immediately outputs an idle signal of a specific frequency from each transmission port (PS) in an idle state.

The optical concentrator 1 includes a link monitor circuit 11 for monitoring an idle signal received by folding back the optical transceiver 2, and an LED driver 12 for displaying the status (normal / abnormal) of the link obtained by the link monitor circuit 11. , And a status display unit (LED) 13 and the like are provided. The status display unit (LED) 13 is configured to display the normal / abnormal state of the link in color (for example, green when normal and red when abnormal), or a configuration that emits light only when abnormal. Good.

Reference numeral 2 denotes an optical transceiver (FTR) which serves as an interface between the optical link and the terminal 5.
An E / O converter 24 that converts an electric signal received from the optical signal into an optical signal and outputs the optical signal to a transmission port (PS), and an optical signal received from the reception port (PR) is converted into an electric signal and the terminal 5
It is configured by including an O / E converter 21 for delivering to the.

Further, in the optical transceiver 2, an idle signal discriminating section 22 for detecting an idle signal on the receiving port (PR), and a loop loop between the optical fiber cables 4 and 5 according to the detection signal of the idle signal discriminating section 22. A loop forming switch 23 for forming is provided. Reference numeral 3 is a terminal for transmitting and receiving various data via the optical concentrator 1 and the optical transceiver 2.

Numerals 4 and 5 are optical fiber cables serving as a signal path between the optical concentrator 1 and the optical transceiver 2, and among them, numeral 4 is an optical fiber cable for transmitting data and idle signals from the optical concentrator 1 to the optical transceiver 2. Reference numeral 5 is an optical fiber cable for transmitting data and idle signals from the optical transceiver 2 to the optical concentrator 1. FIG. 2 is a flow chart showing the procedure for detecting a link abnormality in the above embodiment.

In FIG. 2, S1 is a step of judging an idle state (state in which there is no packet) associated with the end of data transmission / reception. S2 is a processing step of the optical concentrator 1 which immediately transmits an idle signal from each transmission port (PS) upon determination of the end of transmission / reception.

S3 is a processing step of the optical transceiver 2 for detecting the idle signal transmitted from the optical concentrator 1 on the receiving port (PR), and is realized by the operation of the idle signal discriminating section 22. S4 is the receiving port (PR)
This is a processing step of the optical transceiver 2 that loops back the idle signal received in step 1 to the transmission port (PS), and is realized by turning on the loop forming switch 23.

S5 is a processing step of the optical concentrator 1 which judges the normal / abnormal state of the optical link from the reception state of the idle signal returned from the optical transceiver 2, and is realized by the operation of the link monitor circuit 11. The operation of the embodiment of the present invention will now be described with reference to FIGS.

When the transmission / reception of data ends and the idle state (the state where there is no packet) is entered, the optical concentrator 1 immediately sends an idle signal to all the transmission ports (PS, P).
S, ...) is transmitted (steps S1 and S2 in FIG. 2).

The idle signals on the respective transmission ports (PS, PS, ...) Are the optical fiber cables 4 provided corresponding to the transmission ports when the link is in a normal state.
It is received by the receiving port (PR, PR, ...) Of each optical transceiver 2, 2 ,.

Idle signal discrimination section 2 of optical transceiver 2
2 detects an idle signal on the receive port (PR),
The loop forming switch 23 is switch-on controlled by the detection signal, and the loop forming switch 23 forms a loopback loop between the receiving port (PR) and the transmitting port (PS). The idle signal received by the receiving port (PR) is sent to the transmitting port (PS) via the loop loop by the switch 23 (steps S3 and S4 in FIG. 2).

The link monitor circuit 11 of the optical concentrator 1 recognizes on the receiving port (PR) whether or not an idle signal is returned from the optical transceiver 2 (step S5 in FIG. 2).

At this time, if the idle signal is correctly received on the receiving port (PR), [optical concentrator 1
Transmission port (PS) → optical fiber cable 4 → optical transceiver 2 reception port (PR) → optical transceiver 2 transmission port (PS) → optical fiber cable 5 → optical concentrator 1 reception port (PR)] Link is normal). Also, optical concentrator 1
When the idle signal does not appear on the receiving port (PR) of the above, it is determined that the above path is abnormal (link abnormality).

The link determination result is displayed on the status display section (LED) 13. The display form of the link determination result at this time is such that each normal / abnormal state of the link is displayed in color (for example, green when normal, red when abnormal), or lit only when abnormal (LED emission) ) May be used. Thus, in the idle state, the normal / abnormal state of the optical link can be confirmed simply by monitoring the reception port (PR) of the optical concentrator 1.

The above-described optical link state monitoring mechanism of the present invention can be applied not only to the network based on the optical link connection as shown in the above-mentioned embodiment but also to other STAR type LAN which transmits an idle signal during idle.

[0028]

As described in detail above, according to the present invention, the optical concentrator can recognize the link status (normal / abnormal) only by monitoring the idle signal on the receiving port (PR). Thus, the state of the optical link can be easily recognized and the system configuration can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an optical link state monitoring mechanism according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of a link monitor in the above embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional optical link status monitoring mechanism.

[Explanation of symbols]

1 ... Optical concentrator, 2 ... Optical transceiver (FT
R), 3 ... Terminal, 4, 5 ... Optical fiber cable, 11
... Link monitor circuit, 12 ... LED driver, 13 ... Status display section (LED), 21 ... O / E converter, 22
... Idle signal discrimination unit, 23 ... Loop forming switch, 2
4 ... E / O converter, PR ... reception port, PS ... transmission port.

Claims (2)

[Claims] 1. A mechanism for monitoring the state of an optical link between an optical concentrator and an optical transceiver, wherein an idle signal loopback circuit that loops back and transmits the idle signal to the optical transceiver when the idle signal is received from the optical concentrator. And an optical link condition monitoring device, wherein the optical concentrator includes a link monitor circuit for monitoring an idle signal received by returning the optical transceiver. 2. The optical link status monitoring device according to claim 1, wherein the optical concentrator is provided with a status display section for displaying a status of the link according to a reception status of an idle signal returned from the optical transceiver.