JP2007180887A - Packet probe system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To normally continue operation without causing a downstream device to detect an erroneous network fault even when a fault or a power interruption occurs in a packet probe. <P>SOLUTION: Switches SW1 and SW2 of a switch part 11 are changed over to a probe side when probe processing is executed, and are changed over to a through side when probe processing is not executed. A switch changing-over control part 12 performs switch changing-over control of the switch part 11. A dummy light emission control part 13 causes dummy light to be emitted toward a succeeding-stage transmission line L2 only during a switch changing-over operation when switches SW1 and SW2 are changed over to the through side together. A probe processing part 21 receives a packet which has passed the switch SW1 changed over to the probe side, and performs probe processing, and discards the packet when discriminating that the packet is an incorrect packet, and when discriminating that the packet is a normal packet, transmits the normal packet to the switch DW2 changed over to the probe side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a packet probe system, and more particularly to a packet probe system that performs packet transmission by performing a probe process for analyzing a packet.

  Currently, various services such as Web and e-mail are provided for IP networks, and communication networks such as the Internet / intranet have become widespread. While such network technology advances, communication networks are always at risk due to access by malicious packets infected with viruses.

  FIG. 14 is a diagram illustrating a state of a network through which illegal packets flow. The network 100 includes L3 (layer 3) switches 101 and 102 and terminals t1 to t11. The L3 switches 101 and 102 are connected to each other, and the L3 switch 101 and the terminals t1 to t4 are connected. Further, the L3 switch 102 and the terminals t5 to t8 are connected, and the terminal t7 and the terminals t9 to t11 are connected. The transmission path connecting each device is an optical transmission path.

  Here, it is assumed that a packet (optical packet) is multicast and an illegal packet is output from the terminal t4. When an illegal packet flows from the L3 switch 101 to the L3 switch 102, the L3 switch 102 multicasts the illegal packet toward the IP addresses of all terminals connected to the L3 switch 101, so that the terminals t5 to t8 are illegal packets. Will be infected with a virus.

  In addition, since the terminals t9 to t11 are connected to the terminal t7, when the terminal t7 multicasts an illegal packet to the terminals t9 to t11, the terminals t9 to t11 are infected with the virus, and the damage is expanded. become.

  Therefore, packet probes have been developed in order to prevent such damage caused by illegal packets. A packet probe is a function that analyzes packets and blocks virus infection caused by malicious packets (generally, devices and software that inspect and measure signals and traffic that flow on the network are called probes). .

  FIG. 15 is a diagram showing a network having a packet probe. In the network 100a, a packet probe device 110 is arranged between the L3 switches 101 and 102 described above with reference to FIG.

  The packet probe apparatus 110 includes an optical switch 111 that switches the optical transmission path to either the probe side or the through side (original transmission path side), and a probe apparatus 112 that performs packet analysis.

  Here, the packet that has flowed through the L3 switch 101 flows to the probe device 112 when the optical switch 111 switches to the probe side. After converting the received packet into an electrical signal, the probe device 112 analyzes the received packet. If the probe device 112 determines that the packet is an illegal packet, the probe device 112 discards the packet and transmits it to the optical switch 111 if it is a normal packet. The optical switch 111 receives the packet transmitted from the probe device 112 and transmits it to the L3 switch 102 side.

As a conventional technique for packet probes, it has an optical switch and a fault detection unit. When a line fault is detected, the optical path is switched, and in order not to detect an input interruption on the subsequent stage side, auxiliary light that is weaker than the main signal is continuously emitted. A technique to be used has been proposed (for example, Patent Document 1).
JP 2002-014293 A (paragraph numbers [0012] to [0016], FIG. 1)

  If a failure occurs in the optical switch 111 or the probe device 112 in the packet probe device 110, packet transmission to downstream devices (terminals t5 to t11, etc.) is blocked. In such a case, the optical switch 111 It is necessary to switch from the probe side to the through side.

  In addition, when the power of the optical switch 111 is cut off, the power supply for switching the switch as described above cannot be performed. Therefore, normally, the non-latch (Non-Latch) that automatically switches to the default side when the power supply is stopped. ) Type optical switch is used.

  FIG. 16 is a diagram illustrating a difference in operation of the optical switch. The latch-type optical switch 111a is of a type that maintains the switching state at the time when the power is cut off. The non-latch type optical switch 111b is a type that switches to the default side when the power is cut off.

  Therefore, if a non-launch type is used for the optical switch 111 and is set to the through side as a default, packet transmission will not be interrupted even when the optical switch 111 is powered off. The switching time of the non-latch type optical switch 111b is about 10 to 20 msec.

  On the other hand, when packet transmission is interrupted on the network, each component device in the network assumes that the link has been disconnected as a network failure and detects a link disconnection. The time from when the optical signal can no longer be received until the link is considered to be broken is about 100 μsec.

  Here, considering the case where the optical switch 111 is powered off, when the power is cut off, the non-latching optical switch 111 is switched to the through side, but the switch switching time is 10 to 20 msec. The reception device (here, the L3 switch 102) detects a link disconnection, which is much longer than 100 μsec.

  That is, since the optical switch 111 is configured by a physical switch such as MEMS, the switch switching speed is much slower than the signal processing speed, so that the L3 switch 102 is faster than the physical switch switching operation. Failure detection is executed, and although no failure has occurred in the original packet transmission path, it is erroneously recognized that a link break has occurred.

  In addition, in the IP network, when a link break is detected, it is determined that the transmission path is broken or a transmission side device is abnormal, and a route switching protocol (routing protocol) is determined based on the routing information in the routing table held by the devices in the network. ) Will operate, and as a result, it will switch to another route.

  FIG. 17 is a diagram illustrating a state of switching to another route by detecting link breakage. Even if the optical switch 111 is turned off and the switch is switched to the through side, the L3 switch 102 detects that the link is broken from the state in which the packet is not received during switch switching. Since the L3 switch 101 does not receive a response from the L3 switch 102, another route (L3 switch 101 → L3 switch 103 → L3 switch 104 → L3 switch 102) is selected and packet transmission is performed on the other route. become.

  In addition, once another route is established, it takes time until the routing table is updated again even if the original route is restored, so it takes a considerable amount of time to return to the original state. The state where the packet does not pass through the probe device 112 continues for a while, and there is a problem that the illegal packet cannot be detected.

  On the other hand, in the above-described conventional technique (Japanese Patent Laid-Open No. 2002-014293), DC light weaker than the main signal is continuously emitted so as not to detect an input interruption at the time of switching, but DC light is always emitted. Therefore, even if an abnormality occurs in the optical switch, there is a disadvantage that the downstream device cannot detect the abnormality.

  The present invention has been made in view of such points, and even if a packet probe fails or power is cut off, the operation of packet transmission continues normally without detecting an erroneous network failure in the downstream device. An object of the present invention is to provide a packet probe system.

  In the present invention, in order to solve the above-described problem, as shown in FIG. 1, a switch that switches to the probe side when a received packet is switched from the upstream transmission line L1 to the downstream transmission line L2 or when probe processing is performed. Unit 11, switch switching control unit 12 that performs switch switching control of switch unit 11, and light source 13 a that emits dummy light, and when switch unit 11 is switched to the through side, from the probe side to the through side Only during the switch switching operation, the optical switch unit 10 configured to emit dummy light toward the rear transmission line L2, and the probe processing of the packet transmitted from the optical switch unit 10 are performed. And a probe unit 20 including a probe processing unit 21 for performing the packet probe. System 1 is provided.

  Here, the switch unit 11 switches the reception packet to the probe side when performing the switching on the through side for flowing the received packet from the front-stage transmission path L1 to the rear-stage transmission path L2, or the probe processing. The switch switching control unit 12 performs switch switching control of the switch unit 11. The dummy light emission control unit 13 includes a light source 13a that emits dummy light. When the switch unit 11 is switched to the through side, the dummy light emission control unit 13 enters the downstream transmission line L2 only during the switch switching operation from the probe side to the through side. A dummy light is emitted. The probe processing unit 21 performs a probe process on the packet transmitted from the optical switch unit 10.

  The packet probe system of the present invention includes an optical switch unit that performs switching on the through side that causes a received packet to flow from a preceding transmission line to a subsequent transmission line, or performs switching to the probe side when a packet is probed, and packet probe processing. In the optical switch unit, when the switch is switched from the probe side to the through side, dummy light is directed toward the subsequent transmission path only during the switch switching operation from the probe side to the through side. It was set as the structure made to light-emit. As a result, light interruption during switch switching can be eliminated, and packet transmission operation can be continued normally without erroneous network failure detection in the downstream apparatus on the downstream transmission path side.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a principle diagram of a packet probe system. The packet probe system 1 is composed of an optical switch unit 10 and a probe unit 20, and is a system that performs a probe process for analyzing a packet (optical packet) and relays the packet.

  The optical switch unit 10 includes a switch unit 11, a switch switching control unit 12, a dummy light emission control unit 13, an operation state monitoring unit 14, and a coupler Cp. The switch unit 11 includes a first switch (switch SW1) and a first switch. 2 switches (switch SW2).

  The switch SW1 switches the packet flowing through the preceding transmission line L1 to the through side or the probe side. The switch SW2 switches the packet that has passed through the switch SW1 through to the through side in order to transmit it to the subsequent transmission line L2, or receives the probe-processed packet and transmits it to the subsequent transmission line L2. Switch to the side.

  In the switch unit 11, when the probe process is executed, both the switches SW1 and SW2 are switched to the probe side, and when the probe process is not executed, both the switches SW1 and SW2 are switched to the through side. The switch switching control unit 12 performs switch switching control of the switch unit 11 based on an external signal.

  The dummy light emission control unit 13 includes a light source (LD: Laser Diode) 13a that emits dummy light. When both the switch SW1 and the switch SW2 are switched to the through side, the switch is switched from the probe side to the through side. Only during the operation, dummy light is emitted toward the subsequent transmission line L2 via the coupler Cp. The operation state monitoring unit 14 monitors the operation state of the probe processing unit 21 and notifies the monitoring result to the switch switching control unit 12 and the dummy light emission control unit 13.

  The probe unit 20 includes a probe processing unit 21. The probe processing unit 21 receives a packet that has passed through the switch SW1 that has been switched to the probe side, and performs probe processing. At this time, if it is determined as an illegal packet, it is discarded, and if it is a normal packet, the normal packet is transmitted to the switch SW2 switched to the probe side.

Next, the switching operation will be described with reference to FIGS. In the following description, only components necessary for explaining the operation are shown in the drawings.
FIG. 2 is a diagram showing a state of probe side switching. In the packet probe system 1, the probe unit 20 probes the packet that has flowed from the upstream transmission line L1, discards the illegal packet, and sends only normal packets to the downstream transmission line L2. Accordingly, during normal operation, the switches SW1 and SW2 are both switched to the probe side.

  Since the packet flowing through the transmission path is an optical packet, the probe processing unit 21 once converts the received probe target packet into an electrical signal, and then determines whether the packet is an illegal packet or a normal packet. In addition, in the case of an illegal packet, it has a function of not only discarding but also analyzing the illegal packet, analyzing the transmission source, and notifying the operator of the analysis result. The probe-processed packet is converted again into an optical packet and transmitted to the optical switch unit 10.

  FIG. 3 is a diagram illustrating a state of through-side switching. In the probe unit 20, when the probe processing cannot be performed normally (failure of the probe processing unit 21, power failure of the probe unit 20, or poor connection between the optical switch unit 10 and the probe unit 20) or the optical switch unit 10 is powered In the case of disconnection or the like, the packet probe system 1 has failed, and therefore the communication path of the original network has not failed. Therefore, in such a case, the switches SW1 and SW2 are switched to the through side so that the unnecessary link breakage is not detected on the downstream device side on the downstream transmission line L2, and the downstream transmission line from the upstream transmission line L1. Pass the packet in the through direction to L2.

Next, emission control of dummy light when the switches SW1 and SW2 are switched from the probe side to the through side when the optical switch unit 10 is powered off will be described.
FIG. 4 is a diagram illustrating the emission of dummy light when the optical switch unit 10 is powered off. The dummy light emission control unit 13 includes an LD 13a and a power supply unit 13b. A rechargeable battery or a large-capacity capacitor is used for the power supply unit 13b. When the optical switch unit 10 is turned off, power is supplied to the LD 13a to emit dummy light.

  Since the switch unit 11 uses the non-latch type switch described above with reference to FIG. 16, when the optical switch unit 10 is powered off, the switches SW1 and SW2 are automatically switched to the through side which is the default state. When the optical switch unit 10 is powered off, the power supply unit 13b autonomously drives and supplies power to the LD 13a for a certain time (time required for the switches SW1 and SW2 to switch from the probe side to the through side).

  The LD 13a drives the LD 13a by power supply from the rechargeable battery or charge discharge of the capacitor capacity. The LD 13a is directed toward the rear transmission line L2 (downstream on the rear transmission line L2 only during the switch switching operation when the power is cut off). Dummy light is emitted (towards the device).

  The transition to the link disconnection in the downstream device (IP device) is determined not by looking at the contents of the packet but by looking only at the optical level. Therefore, the switches SW1 and SW2 are switched from the probe side to the through side. By transmitting the dummy light to the downstream device while the switch is on, the disconnection of the link can be prevented from being detected even if the switching time of the switches SW1 and SW2 is long (for example, a maximum of 20 msec). Note that after the switch is switched, the light is turned off to prevent interference with the main signal.

  In addition, since the link break detection in the downstream device is not based on the contents of the optical signal but is determined based on the presence or absence of the received light, there is no particular limitation on the optical output level or wavelength of the LD 13a, and the main signal and The same wavelength band or another wavelength band may be used. In addition, an inexpensive LED (Light Emitting Diode) may be used as the light source instead of the LD.

  The dummy light is input to the post-stage transmission line L2 via the coupler Cp. However, if the dummy light is set to a wavelength different from that of the actual signal light, the WDM (Wavelength Division Multiplex) having a small multiplexing loss as the coupler Cp. A coupler can be used (if there is a margin in the light level and the loss is not a concern, a normal fused coupler may be used as the coupler Cp).

  Next, light emission control of dummy light when the optical switch unit 10 fails will be described. Assuming that the packet probe system 1 is also regarded as a part of the transmission line, it is necessary to treat a system failure as a transmission line break. Therefore, when the optical switch unit 10 breaks down, it is desirable to cause the downstream station to detect a disconnection promptly and switch to another route, rather than emitting dummy light more than necessary and maintaining the current route. For this reason, the dummy light is forcibly shut down, the link disconnection is surely detected on the downstream side, and the route is switched to another route by the routing protocol.

Next, emission control of dummy light when the switches SW1 and SW2 are switched from the probe side to the through side when a failure occurs in the probe processing unit 21 will be described.
FIG. 5 is a diagram illustrating the emission of dummy light when a failure occurs in the probe processing unit 21. The operation state monitoring unit 14 monitors the operation state of the probe processing unit 21 and notifies the monitoring result to the switch switching control unit 12 and the dummy light emission control unit 13.

  Based on the monitoring result, the switch switching control unit 12 switches the switches SW1 and SW2 to the probe side when recognizing normal operation of the probe processing, and switches to the through side when recognizing abnormal operation of the probe processing.

  Also, the dummy light emission control unit 13 does not emit dummy light when recognizing normal operation of the probe process based on the monitoring result, and only during switch switching operation when recognizing abnormal operation of the probe process. The dummy light is emitted (in the figure, the dummy light emission control is performed based on the external signal transmitted from the operation state monitoring unit 14, but the switch status information from the switch unit 11 and the switch switching control unit 12 is used. Based on this, the emission control of dummy light may be performed).

  Here, the LD 13a is turned on only during the switching operation of the switches SW1 and SW2 and is turned off after the switch is switched to prevent interference with the actual signal. However, when the packet loss occurs, the IP packet is FCS ( Since it has a packet retransmission protocol such as an error detection function using (Frame Check Sequence), it is not necessary to strictly control the timing of turning on / off the LD 13a.

  In other words, as long as the link disconnection is not detected, light may be emitted after the start of switching control of the switches SW1 and SW2, or it may be turned off after the switches SW1 and SW2 are switched and packets begin to communicate.

  FIG. 6 is a diagram illustrating a timing chart of dummy light emission. Respective waveform timings in reference signs A to E shown in FIG. 5 are shown. A is a signal indicating the operating state of the probe processing unit 21, and is “L” when the power is cut off (failure). B is a signal indicating an external signal output from the operation state monitoring unit 14 (“L” is normal, “H” is abnormal). C indicates the LD output, D indicates the output of the switch SW2, and E indicates the output of the optical switch unit 10.

  At timing T1, the probe processing unit 21 powers off (A). At timing T2, when an external signal (failure occurrence notification) is notified from the operation state monitoring unit 14 to the switch switching control unit 12 and the dummy light emission control unit 13 (B), the switches SW1 and SW2 are switched from the probe side to the through side. Start switching to.

  Note that the output (D) of the switch SW2 is indefinite from the timing T1 when the probe power is turned off to the timing T4 when the through switching is completed. Further, the switch switching time from the probe side to the through side is from the timing T2 at which the abnormality is detected to the timing T4 at which the through switching is completed.

  Further, the output (E) of the optical switch unit 10 is indefinite from the probe power-off timing T1 to the dummy light emission start timing T3. Smaller than.

  At timing T3, the LD 13a emits light before the link break is detected with a delay of several tens of microseconds from the occurrence of the power cut of the probe processing unit 21 (C). The output (E) from the optical switch unit 10 becomes dummy light.

  At timing T4, the switches SW1 and SW2 complete the switching operation from the probe side to the through side (the switching transition time is about 20 msec at the maximum) (D). Further, the output (E) of the optical switch unit 10 outputs the packet and the dummy light simultaneously from the timing T4 to the timing T5 when the dummy light is turned off.

At timing T5, the output of dummy light stops (C). The output (E) from the optical switch unit 10 is only the packet that has flowed from the preceding transmission line L1.
As described above, if the disconnection time of the time Ta is shorter than the link disconnection detection time, the dummy light may be emitted after the time Ta has elapsed after the packet output from the optical switch unit 10 is disconnected. If a packet regeneration protocol is activated before a link break is detected when a received packet error is detected, the dummy light may be turned off after the time Tb has elapsed from the state where the packet and the LD light are output simultaneously.

  Note that the light emission control of the LD 13a can be started immediately after receiving the abnormality information from the probe processing unit 21. In addition, when the lights are turned off, the switch SW1 and SW2 can be used to check the status information of the switching state and confirm that the switching has been made to the through side. Can also be used to automatically turn off the lights.

  Next, emission control of dummy light when the switches SW1 and SW2 are switched from the probe side to the through side when the inter-unit connection between the optical switch unit 10 and the probe unit 20 is poor will be described.

  FIG. 7 is a diagram showing the emission of dummy light when an inter-unit connection failure occurs. In the connection between the optical switch unit 10 and the probe unit 20, it is assumed that a connection failure has occurred at the connection point J1 from the switch SW1 toward the probe processing unit 21.

  In this case, the probe processing unit 21 cannot receive a packet from the switch SW1 switched to the probe side, and recognizes that the packet cannot be received. Then, it is determined that there is a connection failure at the connection point J1 between the optical switch unit 10 and the probe unit 20.

  The operation state monitoring unit 14 receives the determination result in the probe processing unit 21 and notifies the switch switching control unit 12 and the dummy light emission control unit 13. When the switch switching control unit 12 recognizes a connection failure between the units, it switches both the switches SW1 and SW2 to the through side. When the dummy light emission control unit 13 recognizes a connection failure between the units, the dummy light emission control unit 13 performs light emission control of the LD 13a so that the dummy light is emitted toward the subsequent transmission line L2 only during the switch switching operation.

  FIG. 8 is a diagram illustrating the emission of dummy light when a connection failure between units occurs. In the connection between the optical switch unit 10 and the probe unit 20, it is assumed that a connection failure occurs at the connection point J2 from the probe processing unit 21 toward the switch SW2.

  The operation state monitoring unit 14 monitors whether the normal packet after the probe processing can be received by the switch SW2 switched to the probe side with respect to the path P in which the packet goes from the probe processing unit 21 to the switch SW2. Yes. If reception is impossible, it is determined that there is a connection failure between the optical switch unit 10 and the probe unit 20, and the determination result is notified to the switch switching control unit 12 and the dummy light emission control unit 13.

  When the switch switching control unit 12 recognizes a connection failure between the units, it switches both the switches SW1 and SW2 to the through side. When the dummy light emission control unit 13 recognizes a connection failure between the units, the dummy light emission control unit 13 performs light emission control of the LD 13a so that the dummy light is emitted toward the subsequent transmission line L2 only during the switch switching operation.

Next, control of the drive current supplied to the LD 13a will be described. FIG. 9 is a diagram showing a drive current supplied to the LD 13a. The vertical axis represents the light emission output of the LD 13a, and the horizontal axis represents the drive current.
The dummy light emission control unit 13 causes the LD 13a to pass a drive current that does not exceed the drive threshold Ith during normal operation to the LD 13a, and emits dummy light (when the probe unit 20 is abnormal, a switch switching operation is performed). ), A drive current Ia exceeding the drive threshold value Ith is passed. By controlling the drive current in this way, it is possible to speed up the emission start of dummy light. During normal operation, the LD 13a emits light slightly with a drive current that does not exceed the drive threshold value Ith. However, since the output power is very small, the main signal light is not affected.

  Next, the state of the switch when a transmission line break occurs will be described. FIG. 10 is a diagram illustrating a switch state when a transmission line disconnection occurs. In the packet probe system 1, during normal operation, the switches SW1 and SW2 are switched to the probe side. Therefore, even when a disconnection occurs in the front transmission line L1 or the rear transmission line L2, the switches SW1 and SW2 remain switched to the probe side in preparation for recovery (the switches SW1 and SW2 are normally on the probe side). After all, it is not necessary to specifically recognize whether or not a transmission path failure has occurred, and it is sufficient to maintain the switch state as it is).

  It is also possible to perform switch switching control by monitoring the transmission line abnormality with the operation state monitoring unit 14. The operation state monitoring unit 14 monitors the input unit of the switch SW1 to monitor the occurrence or restoration of the disconnection of the upstream transmission line L1. Further, by monitoring the output part of the coupler Cp, occurrence or restoration of the disconnection of the rear transmission line L2 is monitored. Based on these monitoring results, switch switching control may be performed (monitoring from the occurrence of transmission line disconnection to recovery, and during this time, switches SW1 and SW2 are switched to the probe side).

  Next, various controls performed in the packet probe system 1 and the location where a failure has occurred will be described. FIG. 11 is a diagram showing a table in which various controls performed in the packet probe system and failure locations are summarized.

  Table 2 describes switch switching control, dummy light emission control, and route change control based on a routing protocol as various types of control performed in the packet probe system, and power failure (optical switch unit 10, probe unit 20) as a failure occurrence location. ), Device failure (optical switch unit 10, probe unit 20), transmission line break (front transmission line L1, rear transmission line L2), and inter-unit connection failure (connection part J1, connection part J2).

  Looking at the table 2 in the vertical direction, for example, in various control states when the optical switch unit 10 fails, switch switching control is not possible, dummy light emission control is shut down, and path change control is switched to another path. It has become. Further, in various control states when the inter-unit connection portion J1 is defective, the switch switching control switches the switches SW1 and SW2 to the through side, the dummy light emission control emits light only during the switch switching operation, and the path change control is maintained as it is. It has become.

  When viewing the table 2 in the horizontal direction, for example, at a fault occurrence location in dummy light emission control, if the power is cut off, the probe unit 20 is faulty, or the connection between units is poor, the dummy light emission and light are emitted during the switch switching operation. When the switch unit 10 is faulty or the transmission path is cut off, it is shut down.

  Next, a modification of the packet probe system 1 will be described. FIG. 12 is a diagram showing the configuration of the packet probe system. The packet probe system 1-1 of the modified example includes an optical switch unit 10-1 and a probe unit 20, and has a timer 13c in the dummy light emission control unit 13-1. This is the only difference in configuration, and the other configuration is the same as in FIG.

  When the switches SW1 and SW2 are switched from the probe side to the through side due to a failure of the probe unit 20 or the like, the dummy light emission control unit 13 in FIG. 1 causes the LD 13a to emit light only during the switch switching operation. When the probe processing or the switching function does not operate normally, the control unit 13-1 continues to emit dummy light for a certain time set in the timer 13c.

  As described above, when there is no abnormality in the transmission line such as the front transmission line L1 and the rear transmission line L2 and it can be clearly recognized that there is some trouble on the packet probe system side, Since there is a possibility that a fault that has occurred will be recovered in a short time, it is possible to keep the LD 13a lit and maintain the path so that the downstream device does not detect a link break.

  However, since it is not preferable to maintain the route for a long time in an abnormal state, the timer setting time of the timer 13c is, for example, about several tens of seconds, the route is maintained by dummy light only within the set time, and after the time is up, dummy light is Shut down and let the routing protocol change route.

  Next, an optical switch device 30 that generalizes the optical switch unit 10 will be described. FIG. 13 is a diagram illustrating the configuration of the optical switch device 30. The optical switch device 30 includes a switch 31, a switch switching control unit 32, and a dummy light emission control unit 33.

  The switch 31 switches the optical signal that has flowed through the upstream transmission line L1 to the downstream transmission line L2 or the other path L3. The switch switching control unit 32 performs switch switching control of the switch 31. The dummy light emission control unit 33 includes a light source 33a that emits dummy light. When the switch 31 is switched from the other path L3 to the rear transmission line L2, only the switch switching operation is performed toward the rear transmission line L2. Dummy light is emitted.

  Further, the dummy light emission control unit 33, when the switching function in the unit fails (the switch status is always notified to the dummy light emission control unit 33, so that normal / abnormal switching can always be recognized). The downstream device side on the downstream transmission line L2 detects a network failure and shuts down the emission of the dummy light so as to switch to another transmission line based on the routing protocol.

  As described above, according to the present invention, even when the probe unit 20 breaks down or the power is cut off, the switches SW1 and SW2 can be switched to the through side without causing the downstream device to detect a broken link. In addition, when the optical switch unit 10 fails, it can be switched to another path with certainty. Therefore, it is possible to perform routing path switching control using only the normality / abnormality of devices and transmission paths existing in the network as judgment materials regardless of the transition time of optical switch switching.

(Supplementary note 1) In a packet probe system for performing packet transmission by performing a probe process for analyzing a packet,
Through-side switching for flowing received packets from the front-stage transmission path to the rear-stage transmission path, or a switch section that switches to the probe side when probing, a switch switching control section that performs switch switching control of the switch section, and dummy light When the switch unit is switched to the through side, the dummy light emission for emitting the dummy light toward the subsequent transmission path only during the switch switching operation from the probe side to the through side. An optical switch unit comprising a control unit;
A probe unit including a probe processing unit that performs probe processing of a packet transmitted from the optical switch unit;
A packet probe system comprising:

  (Supplementary Note 2) When the switching function of the optical switch unit fails, the dummy light emission control unit detects the network failure on the downstream device side on the subsequent transmission line and switches to another transmission line. The packet probe system as set forth in appendix 1, wherein the light emission is shut down.

  (Additional remark 3) The said switch part transmits the packet which passed through the said front stage transmission line to the through side or the probe side, and the packet which passed the said 1st switch through through the said back stage transmission A second switch that switches to the through side for transmission to the path or receives a packet after probe processing and switches to the probe side for transmission to the subsequent transmission path, and performs probe processing When the probe processing is not performed, both the first switch and the second switch are switched to the probe side, and when the probe process is not executed, both the first switch and the second switch are switched to the through side. The packet probe system according to supplementary note 1, which is characterized.

  (Supplementary Note 4) When the optical switch unit is powered off, the first switch and the second switch are both switched to the through side as a default state, and the dummy light emission control unit is 4. The packet probe system according to appendix 3, wherein the dummy light is emitted only during a switch switching operation when the power is cut off by being driven by a charge discharge of a rechargeable battery or a capacitor capacity.

  (Supplementary Note 5) The optical switch unit includes an operation state monitoring unit that monitors an operation state of the probe processing unit and notifies a monitoring result to the switch switching control unit and the dummy light emission control unit. The unit switches the first switch and the second switch to the probe side when recognizing the normal operation of the probe process based on the monitoring result, and recognizes the abnormal operation of the probe process, When the first switch and the second switch are switched to the through side, and the dummy light emission control unit recognizes the normal operation of the probe processing based on the monitoring result, the dummy light emission control unit emits the dummy light. If the abnormal operation of the probe process is recognized, the dummy light is emitted only during the switch switching operation. Robe system.

  (Additional remark 6) When the said probe process part cannot receive a packet from the said 1st switch switched to the probe side, it discriminate | determines that there is a connection defect between the said optical switch unit and the said probe unit, The operation state monitoring unit receives a determination result and notifies the switch switching control unit and the dummy light emission control unit, and the switch switching control unit recognizes a connection failure between units and the first switch And switching the second switch to the through side, and the dummy light emission control unit emits the dummy light only during the switch switching operation when recognizing a connection failure between the units. Packet probe system.

  (Additional remark 7) The said operation state monitoring part monitors whether the normal packet after a probe process can be received with the said 2nd switch switched to the probe side, and when it cannot receive, it is said optical switch unit When it is determined that there is a connection failure with the probe unit, the determination result is notified to the switch switching control unit and the dummy light emission control unit, and the switch switching control unit recognizes a connection failure between units. The first switch and the second switch are both switched to the through side, and the dummy light emission control unit, when recognizing a connection failure between the units, emits the dummy light only during the switch switching operation. The packet probe system according to appendix 5, which is a feature.

  (Supplementary Note 8) The dummy light emission control unit allows a drive current that does not exceed a drive threshold value to flow to the light source during normal operation, and causes a drive current that exceeds the drive threshold value to flow when the dummy light is emitted. Thus, the packet probe system according to appendix 1, wherein the emission start of the dummy light is accelerated.

(Supplementary Note 9) In a packet probe system for performing packet transmission by performing a probe process for analyzing a packet,
Through-side switching for flowing received packets from the front-stage transmission path to the rear-stage transmission path, or a switch section that switches to the probe side when probing, a switch switching control section that performs switch switching control of the switch section, and dummy light And a dummy light emission control unit that emits the dummy light to the subsequent transmission path only for a predetermined time when the probe processing or the switching function does not operate normally. Unit,
A probe unit including a probe processing unit that performs probe processing of a packet transmitted from the optical switch unit;
A packet probe system comprising:

(Additional remark 10) In the optical switch apparatus which switches an optical path,
A switch that switches the optical signal that has flown through the previous transmission line to the subsequent transmission line or another path;
A switch switching control unit that performs switch switching control of the switch;
A dummy light emission that includes a light source that emits dummy light and emits the dummy light toward the subsequent transmission path only during switch switching when the switch is switched from the other path to the subsequent transmission path. A control unit;
An optical switch device comprising:

It is a principle diagram of a packet probe system. It is a figure which shows the state of probe side switching. It is a figure which shows the state of through side switching. It is a figure which shows light emission of the dummy light when an optical switch unit is a power failure. It is a figure which shows light emission of the dummy light when a failure generate | occur | produces in a probe process part. It is a figure which shows the timing chart of dummy light emission. It is a figure which shows light emission of the dummy light when the connection defect between units generate | occur | produces. It is a figure which shows light emission of the dummy light when the connection defect between units generate | occur | produces. It is a figure which shows the drive current supplied to LD. It is a figure which shows a switch state when a transmission-path interruption | blocking generate | occur | produced. It is a figure which shows the table which put together the various control performed by a packet probe system, and a failure location. It is a figure which shows the structure of a packet probe system. It is a figure which shows the structure of an optical switch apparatus. It is a figure which shows the mode of the network through which an unauthorized packet flows. It is a figure which shows the network which has a packet probe. It is a figure which shows the difference in operation | movement of an optical switch. It is a figure which shows the switching state to another path | route by link disconnection detection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Packet probe system 10 Optical switch unit 11 Switch part SW1 1st switch SW2 2nd switch 12 Switch switching control part 13 Dummy light emission control part 13a Light source 14 Operation state monitoring part 20 Probe unit 21 Probe processing part Cp Coupler L1 Previous stage Transmission line L2 Rear transmission line

Claims (5)

In a packet probe system that performs packet processing by performing probe processing to analyze packets,
Through-side switching for flowing received packets from the front-stage transmission path to the rear-stage transmission path, or a switch section that switches to the probe side when probing, a switch switching control section that performs switch switching control of the switch section, and dummy light When the switch unit is switched to the through side, the dummy light emission for emitting the dummy light toward the subsequent transmission path only during the switch switching operation from the probe side to the through side. An optical switch unit comprising a control unit;
A probe unit including a probe processing unit that performs probe processing of a packet transmitted from the optical switch unit;
A packet probe system comprising:   The dummy light emission control unit shuts down the emission of the dummy light so that when the switching function of the optical switch unit fails, the downstream device side on the downstream transmission line detects a network failure and switches to another transmission line. The packet probe system according to claim 1, wherein:   The switch unit transmits a packet that has passed through the upstream transmission path to the through side or the probe side, and a packet that has passed through the first switch through the downstream transmission path to the downstream transmission path. A second switch that switches to the through side or receives a packet after probe processing and switches to the probe side for transmission to the subsequent transmission path, and when the probe processing is executed Both the first switch and the second switch are switched to the probe side, and when the probe process is not executed, both the first switch and the second switch are switched to the through side. Item 1. The packet probe system according to Item 1.   When the optical switch unit is powered off, the first switch and the second switch are both switched to the through side as a default state, and the dummy light emission control unit is a rechargeable battery or a capacitor. 4. The packet probe system according to claim 3, wherein the dummy light is emitted only during a switch switching operation when the power is cut off by driving the capacitor by charge discharge.   The optical switch unit includes an operation state monitoring unit that monitors an operation state of the probe processing unit and notifies a monitoring result to the switch switching control unit and the dummy light emission control unit, and the switch switching control unit includes: When the normal operation of the probe process is recognized based on the monitoring result, the first switch and the second switch are switched to the probe side, and when the abnormal operation of the probe process is recognized, the first switch When the switch and the second switch are switched to the through side and the dummy light emission control unit recognizes the normal operation of the probe process based on the monitoring result, the dummy light is not emitted and the probe process is not performed. 4. The packet probe system according to claim 3, wherein when the abnormal operation is recognized, the dummy light is emitted only during the switch switching operation. Temu.

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