JP2016165034A - Synchronous network, communication device, synchronization method, and synchronization program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synchronous network system, synchronization method and synchronization program capable of achieving selection of a clock signal having high quality.SOLUTION: A communication device according to the invention is a communication device to be used in a synchronous network system composed of a plurality of communication devices which synchronize with a synchronous clock to operate, and includes information setting means for writing a HOP number in a prescribed area of a packet that notifies of a quality state of the synchronous clock, information operation means for writing a value obtained by counting up or counting down the HOP number in a prescribed area of a packet that notifies of a quality state of a synchronous clock arriving from another communication device, and selection instruction means for instructing to select a synchronous clock on the basis of information of the prescribed area of the packet that notifies of the quality state of the synchronous clock.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a synchronous network system, a communication device, a synchronization method, and a synchronization program in which a plurality of communication devices operate in synchronization with a synchronous clock signal, and more particularly to a clock signal selection method used for synchronization.

  As the communication network speeds up, high-quality clock signal synchronization is required between communication devices. As a CLK synchronization method between a plurality of communication apparatuses, there is Synchronous Ethernet (hereinafter referred to as Sync-E) defined in ITU-T Recommendations G.8260 to 8265 (Ethernet and Ethernet are registered trademarks). Hereinafter, a network communication apparatus that performs synchronization using Synchronous Ethernet will be described as an example.

  In Sync-E, as a method for selecting a clock signal to be synchronized from a plurality of input clock signals, a PL mode (Priority Level Mode) for determining priority for each port and a QL mode (QL mode for determining quality information of the clock signal) Quality Level Mode).

  The synchronization source selection method in the normal QL mode is determined only by the CLK synchronization quality information (SSM: Synchronous Status Message) set at the synchronization source. In addition, there is a technique for preventing a timing loop based on information on a synchronization path and a master station (Patent Document 1).

  Patent Document 2 relates to a synchronous network, and relates to selection of a synchronous clock used for relay transmission. In Patent Document 2, when a clock signal is received from the same direction based on information on the SSM, the clock unique name, and the number of relays of each of a plurality of input clock signals, a clock signal with a smaller number of relays is selected. It has been proposed to enable. In Patent Document 2, when there are clock signals with the same clock supply source and the same number of relays, it is possible to select a clock signal with a high priority set in advance in the transmission device. Proposed. As a result, a higher quality clock signal can be selected from a plurality of input clock signals.

JP 2004-032175 A JP-A-11-122207

  According to Patent Document 1 and Patent Document 2, a high-quality clock signal can be selected from a plurality of input clock signals. However, a more preferable and effective clock signal selection method is required.

  An object of the present invention is to provide a synchronization network system, a synchronization method, and a synchronization program that can realize selection of a high-quality clock signal.

In order to achieve the above object, a synchronous network system according to the present invention is a synchronous network system comprising a plurality of communication devices operating in synchronization with a synchronous clock,
One communication device
A clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, and a control unit,
The control unit includes an information setting unit that writes the number of HOPs in a predetermined area of the packet that notifies the quality state of the synchronous clock, and a predetermined area of the packet that notifies the quality state of the synchronous clock received from another communication device. A selection instruction for instructing the clock selection unit to select a synchronization clock based on information operation means for writing a value obtained by counting up or counting down the number of HOPs and information on a predetermined area of a packet for notifying the quality state of the synchronization clock Means.

A communication apparatus according to the present invention is a communication apparatus used in a synchronous network system including a plurality of communication apparatuses that operate in synchronization with a synchronous clock,
Information setting means for writing the number of HOPs in a predetermined area of the packet notifying the quality state of the synchronous clock, and counting up the number of HOPs for the predetermined area of the packet notifying the quality state of the synchronous clock received from another communication device Alternatively, it includes information operation means for writing the counted down value, and selection instruction means for instructing selection of the synchronization clock based on information on a predetermined area of the packet notifying the quality state of the synchronization clock.

A synchronization method according to the present invention is a synchronization method of a synchronous network system in which a plurality of communication devices operate in synchronization with a synchronization clock,
One communication device has a clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, and a control unit,
The control unit
Write the number of HOPs in a predetermined area of the packet that reports the quality state of the synchronous clock
Write a value obtained by counting up or counting down the number of HOPs to a predetermined area of a packet notifying the quality state of a synchronous clock received from another communication device,
Based on the information in a predetermined area of the packet for notifying the quality state of the synchronous clock, the selection of the synchronous clock used for the synchronization is instructed.

A synchronization program according to the present invention is a synchronization program for a synchronized network system in which a plurality of communication devices operate in synchronization with a synchronization clock,
One communication device
A process of writing the number of HOPs in a predetermined area of a packet notifying the quality state of the synchronous clock;
A process of writing a value obtained by counting up or counting down the number of HOPs to a predetermined area of a packet notifying the quality state of a synchronous clock received from another communication device;
And a process for instructing selection of a synchronous clock to be used for the synchronization based on information on a predetermined area of the packet for notifying the quality state of the synchronous clock.

  According to the present invention, it is possible to select a high-quality synchronous clock with a small amount of jitter and a phase difference between apparatuses, and a synchronous network system can be configured.

It is a block diagram which shows the control part of the communication apparatus by embodiment of the highest level concept of this invention. It is a block diagram which shows the communication apparatus of embodiment of this invention. It is a figure which shows the multiplexing position of the number of HOP and apparatus ID information. It is a block diagram about the CLK selection method using the number of HOPs. It is a block diagram about the CLK selection method using apparatus ID information. (A) is a block diagram which shows an example of a communication apparatus, (b) is explanatory drawing about the synchronous CLK selection pattern of the communication apparatus of (a).

  Preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram illustrating a control unit of a communication device according to an embodiment of the highest concept of the present invention. FIG. 1 shows a control unit for one communication apparatus used in a synchronous network system. The control unit 4 in FIG. 1 includes an information setting unit 1, an information operation unit 2, and a selection instruction unit 3. The information setting unit 1 writes the number of HOPs in a predetermined area of a packet that notifies the quality state of the synchronous clock. The information operating means 2 writes a value obtained by counting up or counting down the number of HOPs in a predetermined area of a packet notifying the quality state of the synchronous clock received from another communication device. The selection instructing unit 3 instructs the selection of the synchronous clock based on the information of the predetermined area of the packet that notifies the quality state of the synchronous clock.

  According to the communication apparatus according to the present embodiment, a value obtained by counting up or counting down the number of HOPs is written in a predetermined area of a packet notifying the quality state of a synchronous clock received from another communication apparatus. As a result, it is possible to select a high-quality synchronous clock with a small amount of jitter and a phase difference between apparatuses, and a synchronous network system can be configured. Hereinafter, the present invention will be described with reference to more specific embodiments.

[First Embodiment]
First, a synchronous network system, a communication device, a synchronization method, and a synchronization program according to the first embodiment of the present invention will be described. FIG. 2 is a block diagram showing a communication apparatus according to the embodiment of the present invention. FIG. 3 is a diagram illustrating the multiplexing position of the number of HOPs and device ID information. FIG. 4 is a configuration diagram of the CLK selection method using the number of HOPs. FIG. 5 is a block diagram of a CLK selection method using device ID information. FIG. 6A is a block diagram illustrating an example of a communication device, and FIG. 6B is an explanatory diagram of a synchronous CLK selection pattern of the communication device of FIG.

[Description of configuration]
The synchronous network system of this embodiment is a synchronous network system in which a plurality of communication devices operate in synchronization with a synchronous clock. FIG. 2 shows a communication apparatus 100 to which the present invention is applied. As illustrated in FIG. 2, the communication device 100 according to the present embodiment includes a CLK selection unit 102 as an example of a clock selection unit, and a main signal control unit 105 as an example of a control unit. The main signal control unit 105 includes information setting means, information operation means, and selection instruction means as shown in FIG. The information setting means writes the number of HOPs in a predetermined area of the packet that notifies the quality state of the synchronous clock. The information operation means writes a value obtained by counting up the number of HOPs in a predetermined area of a packet notifying the quality state of the synchronous clock received from another communication device. The selection instruction unit instructs the CLK selection unit 102 to select a synchronization clock based on information on a predetermined area of the packet that notifies the quality state of the synchronization clock.

  As an example of a predetermined region of the packet for notifying the quality state of the synchronous clock, in the present embodiment, a region that can be used by a user in an ESMC (Ethernet Synchronization Messaging Channel) packet is used.

  The communication apparatus 100 in FIG. 2 further includes PHYs 101, 104, and 106 as physical layer devices and an oscillator 103.

  The communication apparatus 100 in FIG. 2 shows an example of the minimum number of ports 3 required for explanation, but the same effect can be obtained even if the number of ports further increases. The components of the communication device 100 will be described below. The communication devices 200, 300, 400, 500, 600, 700, 800 in FIG. 4 and the communication devices 10, 20, 30, and 40 in FIG. 5 are communication devices having the same configuration as the communication device 100. .

  The communication apparatus 100 includes a PHY 101, a PHY 104, a PHY 106, a CLK selection unit 102, an oscillator 103, and a main signal control unit 105.

  The communication device 100 operates in a mode of either a master device that is a supply source of the synchronous CLK or a slave device that is synchronized with CLK from an external device. In the master device, an internal circuit operates with the internal CLK 109 as a reference CLK. When transmitting to an external device, each PHY is sent as synchronized electrical signals 115, 116, 117 by operating with the internal CLK 109. The slave device operates in synchronization with one of the CLKs 107, 108, and 118 extracted from the electrical signals 115, 116, and 117 received from the outside of the device.

  Next, the operation of each component will be described.

(PHY)
Since the PHYs 101, 104, and 106 have the same configuration, the PHY 101 will be described. The PHY 101 converts an electrical signal 116 input from the outside of the apparatus into a logic signal 111 and sends it to the main signal control unit 105. Similarly, it has a function of converting the logic signal 111 received from the main signal control unit 105 into an electric signal 116 and sending it out of the apparatus. It has a function of extracting CLK from the input electrical signal 116 and sending it to the CLK selection unit 102 as extracted CLK 107. These operations are performed in synchronization with the device CLK112 received from the CLK selector 102.

(CLK selection part)
The CLK selection unit 102 selects one of the extracted CLKs 107, 108, and 118 by the control signal 114 from the main signal control unit 105, and generates a CLK synchronized with the selected CLK. Further, according to the master / slave device setting included in the control signal 114, the CLK synchronized with the selected CLK is transmitted as the device CLK112 in the case of the slave device setting. In the case of the master device setting, CLK synchronized with the internal CLK 109 input from the oscillator 103 is transmitted as the device CLK 112.

(Main signal controller)
The main signal control unit 105 has a switch function of selecting and sending the path of the received logic signals 110, 111, and 113. In addition, the function of reading the quality level, the number of HOPs, and the device ID from the received ESMC packets of the logical signals 110, 111, and 113, determining the CLK to be selected from the information, and sending it to the CLK selector 102 as the control signal 114 Have The selection of CLK is determined based on the information of three elements of Quality Level, the number of HOPs, and the device ID information read based on the selection elements set by the user.

  When Quality Level is a selection element of CLK, CLK having a high Quality Level is selected. When the number of HOPs is used as a selection element for CLK, the CLK having the smaller number of HOPs is selected. When the device ID information is a selection element of CLK, the read device ID information matches the device ID information desired to be selected.

  In the case where the comparison result is the same level, a predetermined system may be selected or set so as to hold the selected state. Further, the number of HOPs is counted up to indicate that it has passed through its own device, that is, a value obtained by incrementing the count is written in the HOP number column in a predetermined area of the packet for notifying the quality state of the synchronous clock. In the case of master device setting, an optional Quality Level, device ID information, and the number of HOPs are written and an ESMC packet is transmitted. These operations are executed in synchronization with the device CLK112 sent from the CLK selector 102.

(Oscillator)
When the communication device 100 is set as a master device serving as a supply source of the synchronous CLK, the oscillator 103 generates a reference CLK and sends out an internal CLK 109 for device operation.

  Next, the position where the number of HOPs and device ID information in the present invention are multiplexed will be described with reference to FIG.

  The packet format shown in FIG. 3 is an ESMC format defined by ITU-T G.8264. This ESMC format has an extended area called Data and Padding. The extension area Data and Padding includes an area QL TLV and an area ESMC PDU extensions. The embodiment of the present invention uses an example in which information on the number of HOPs and device IDs is multiplexed using this extended area. By using the extended area of ESMC, it can be used in Ethernet. It should be noted that the same effect can be obtained by using other areas for storage.

[Description of operation]
The CLK selection method according to the present embodiment will be described with reference to FIGS. As the CLK selection method, a method using the number of HOPs as a selection element and a method using device ID information will be described. First, a CLK selection method using the number of HOPs as a selection element will be described with reference to FIG.

  The synchronous network system of FIG. 4 includes a communication device 200 set as a master device and communication devices 300, 400, 500, 600, 700, and 800 set as slave devices. A case is shown in which a communication device 800 set as a slave device is synchronized through two clockwise and counterclockwise paths from the communication device 200 set as one master device.

  Communication device 200 is set as a master, and CLK is selected by communication device 800. The communication device 200 set as the master device transmits a packet with the number of HOPs set to zero. In the case of a counterclockwise route, the packet sent out with the HOP number 0 by the communication device 200 is written with the value counted up as the HOP number 1 by the communication device 300 and the HOP number 2 by the communication device 400. To reach.

  Similarly, in the case of the clockwise route, the packet sent from the communication device 200 is written with a value counted up as the HOP number 1 in the communication device 500, the HOP number 2 in the communication device 600, and the HOP number 3 in the communication device 700, The communication device 800 is reached. The HOP number information received by the communication device 800 is compared with the HOP number information by the clock selection unit, and the CLK received from the port with the smaller HOP number is selected. Since the number of HOPs of the signal received from the communication device 400 side is small this time, the CLK extracted from the main signal on the communication device 400 side is selected. With the above operation, it is possible to select the CLK of the route having a small number of HOPs.

  A second CLK selection method using apparatus ID information as a selection element will be described with reference to FIG. FIG. 5 shows a CLK selection method when the same SSM master exists in a plurality of networks.

  The synchronous network system of FIG. 5 includes a communication device 10 set as a master device in the network A and a communication device 20 set as a master device in the network B. The synchronous network system of FIG. 5 includes a communication device set as a slave device in the network A and a communication device set as a slave device in the network B.

  Communication devices 10 and 20 are set as masters, and CLK is selected by communication device 30 set as a slave device. The communication devices 10 and 20 transmit the packets with device ID information “10” and “20”. The communication device 30 sets “device ID = 10” as the selection condition of CLK so as to synchronize with the communication device 10.

  The communication device 30 compares the received device ID information with the set device ID information of the selected CLK. Since the device ID information “20” received from the communication device 20 side is different from the set device ID information “10”, it is not adopted as a synchronization clock. Since the device ID information “10” received from the communication device 10 side matches the set device ID information “10”, it is selected as a synchronous clock.

  With the above operation, even when the same SSM master exists in a plurality of synchronous network systems, the CLK of the intended master device can be selected.

  Next, the synchronization source selection result when the number of HOPs and the device ID information are used as selection elements will be described with reference to FIG.

  The communication device 40 in FIG. 6 is a slave-set communication device having the same configuration as the communication device 100 in FIG. 2, and the input / output units connected to the PHY are displayed as Port 1 and Port 2.

  It is assumed that the information received from the Port1 side is set as A, the information received from the Port2 side is set as B, and the synchronized device ID information set in the communication device 40 is set as C.

(When the number of HOP is used as the synchronization selection method)
When A> B, since B has a smaller number of HOPs, the communication device 40 selects the Port 2 side as the synchronization CLK.
In the case of A <B, since the number of HOPs is smaller in A, the communication device 40 selects the Port 1 side as the synchronization CLK.
When A = B, the synchronization source is selected according to the priority set in the communication device 40.

  Here, the priority set in the communication device 40 is a setting determined in advance when the CLK selection by the selection element cannot be performed. For example, the priority order of the ports and the setting of holding the selection system, etc. It is.

(When device ID information is selected as the synchronization selection method)
When C ≠ A and C ≠ B, there is no matching device ID information, so the internal CLK is used without synchronization.
When C = A and C ≠ B, the communication device 40 selects the Port 1 side as the synchronization CLK.
When C = B and C ≠ A, the communication device 40 selects the Port 2 side as the synchronization CLK.
When C = A and C = B, the synchronization source is selected from the matched devices according to the priority set in the communication device 40.

[Description of effects]
According to the present embodiment, by using the number of HOPs as a selection reference for the synchronous CLK, it is possible to select a high-quality synchronous CLK with a small amount of jitter and a phase difference between apparatuses. The reason is that there is a possibility that the jitter amount and the phase difference increase every time the device is crossed. This is because a high-quality synchronous CLK with little phase difference can be selected.

  Furthermore, according to the present embodiment, the intended synchronization source CLK information can be selected by using the device ID information as the selection reference of the synchronization CLK. The reason is that since synchronization is performed using the device ID information, it is possible to determine the synchronization source even if the devices come through a plurality of devices or have the same SSM.

[Second Embodiment]
Next, a synchronous network system, a communication device, a synchronization method, and a synchronization program according to the second embodiment of the present invention will be described. In the first embodiment, the number of HOPs is counted up to indicate that it has passed through its own device, that is, a value obtained by incrementing the count is written in the HOP number column of a predetermined area of the packet that notifies the quality state of the synchronous clock. ,explained. This embodiment provides a different counting method.

  The configurations of the synchronous network system and the communication device according to the second embodiment of the present invention are substantially the same as those of the first embodiment, and thus detailed description thereof is omitted.

  In the present embodiment, the number of HOPs is counted down to indicate that it has passed through its own device, that is, a value obtained by decrementing the count by -1 is written in the HOP number field of a predetermined area of the packet that notifies the quality state of the synchronous clock. In other words, every time it passes through the apparatus, the number of HOPs is decremented by -1 and written in a predetermined area of the packet for notifying the quality state of the synchronous clock.

  According to the present embodiment, it is possible to limit the maximum number of HOPs, and it is possible to exclude a low-quality synchronization CLK from the synchronization source candidates. For example, when the received HOP number information is 0, the main signal control unit of the communication apparatus is provided with a function that does not synchronize with the signal transmission source. In addition, the main signal control unit has a function of reading information on the number of HOPs of the received logic signal, and writing by counting −1 to the number of HOPs.

  From the number of HOPs set by the communication device set as the master device, a value counted down every time the communication device is passed is written. When the number of HOPs in a predetermined area of a packet notifying the quality state of the synchronous clock received by a certain communication device becomes 0, the operation can be performed such as not synchronizing with the transmission source of the signal. As a result, it is possible to remove the low-quality synchronization CLK from the synchronization source candidates.

  As mentioned above, although preferable embodiment and the Example of this invention were described, this invention is not limited to this. For example, it is conceivable to provide a method for selecting the combination of Quality Level, the number of HOPs, and device ID information as a method for selecting the synchronous CLK in the CLK selection unit 102 in FIG. It is also conceivable to provide a function for setting the priority order of each element in the CLK selection unit 102 in FIG. As a result, even when the determination cannot be made with one determination element, a high-quality synchronous CLK can be selected using another determination element. It goes without saying that various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention.

A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.
(Appendix 1) A communication device used in a synchronous network system including a plurality of communication devices operating in synchronization with a synchronous clock,
A clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, an information setting unit that writes the number of HOPs in a predetermined area of a packet that notifies the quality state of the synchronization clock, and another communication device Based on information operating means for writing a value obtained by counting up or counting down the number of HOPs in a predetermined area of the packet notifying the quality state of the synchronous clock, and information on the predetermined area of the packet notifying the quality state of the synchronous clock And a selection instruction means for instructing the clock selection section to select a synchronous clock.
(Appendix 2) A synchronous network system in which a plurality of communication devices operate in synchronization with a synchronous clock,
One communication device
A clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, and a control unit,
The control unit includes an information setting unit that writes the number of HOPs in a predetermined area of a packet that notifies the quality state of the synchronous clock, and a predetermined area of the packet that notifies the quality state of the synchronous clock received from another communication device. An information operation means for writing a value obtained by counting up or counting down the number of HOPs, and a selection instruction for instructing the clock selection section to select a synchronization clock based on information on a predetermined area of a packet for notifying the quality state of the synchronization clock A synchronization network system.
(Supplementary note 3) The synchronous network system according to supplementary note 2, wherein the information operation means of the communication device writes device identification information in a predetermined area of a packet notifying the quality state of the synchronous clock.
(Appendix 4) The communication device has a plurality of ports,
The control unit instructs the clock selection unit to select a synchronization clock based on information on a predetermined region of the packet that notifies the quality state of the synchronization clock and information on the plurality of ports that have received the packet. The synchronous network system according to appendix 2 or appendix 3.
(Supplementary Note 5) Information related to the number of HOPs written in a predetermined area of the packet for notifying the quality state of the synchronous clock is written in a format that counts up every time it passes through the communication device, and information related to the number of HOPs 5. The synchronous network system according to any one of appendix 2 to appendix 4, which instructs the clock selection unit to make selection impossible when a predetermined value or more is reached.
(Supplementary Note 6) Information related to the number of HOPs written in a predetermined area of the packet for notifying the quality state of the synchronous clock is written in a form that counts down every time it passes through the communication device, and information related to the number of HOPs is predetermined. 5. The synchronous network system according to any one of appendix 2 to appendix 4, which instructs the clock selection unit to make a selection impossible when the value is less than or equal to a value.
(Supplementary note 7) A communication device used in a synchronous network system including a plurality of communication devices operating in synchronization with a synchronous clock,
A clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, an information setting unit that writes the number of HOPs in a predetermined area of a packet that notifies the quality state of the synchronization clock, and another communication device Based on information operation means for writing a value obtained by counting up or counting down the number of HOPs to a predetermined area of a packet notifying the quality state of the synchronous clock, and information on the predetermined area of the packet notifying the quality state of the synchronous clock And a selection instruction means for instructing the clock selection section to select a synchronous clock.
(Supplementary note 8) The communication device according to supplementary note 7, wherein the information operation means of the communication device writes device identification information in a predetermined area of a packet notifying the quality state of the synchronous clock.
(Appendix 9) Having multiple ports
The control unit instructs the clock selection unit to select a synchronization clock based on information on a predetermined region of the packet that notifies the quality state of the synchronization clock and information on the plurality of ports that have received the packet. The communication apparatus according to appendix 7 or appendix 8.
(Supplementary Note 10) Information related to the number of HOPs written in a predetermined area of the packet for notifying the quality state of the synchronous clock is written in a format that counts up each time it passes through the communication device, and information related to the number of HOPs The communication device according to any one of appendix 7 to appendix 9, which instructs the clock selection unit to make selection impossible when the value exceeds a predetermined value.
(Supplementary Note 11) Information related to the number of HOPs written in a predetermined area of the packet for notifying the quality state of the synchronous clock is written in a form that counts down every time it passes through the communication device, and information related to the number of HOPs is predetermined. The communication device according to any one of appendix 7 to appendix 9, which instructs the clock selection unit to make a selection impossible when the value is equal to or less than the value.
(Supplementary note 12) A synchronization method of a synchronous network system in which a plurality of communication devices operate in synchronization with a synchronous clock,
One communication device
A clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, and a control unit,
The controller is
Write the number of HOPs in a predetermined area of the packet that reports the quality status of the synchronous clock,
Write a value obtained by counting up or counting down the number of HOPs to a predetermined area of a packet notifying the quality state of a synchronous clock received from another communication device,
A synchronization method for a synchronous network system, instructing selection of a synchronization clock to be used for the synchronization based on information on a predetermined area of a packet that notifies the quality state of the synchronization clock.
(Supplementary note 13) A synchronization program for a synchronous network system in which a plurality of communication devices operate in synchronization with a synchronous clock,
One communication device
A process of writing the number of HOPs in a predetermined area of a packet notifying the quality state of the synchronous clock;
A process of writing a value obtained by counting up or counting down the number of HOPs to a predetermined area of a packet notifying the quality state of a synchronous clock received from another communication device;
A synchronization program for a synchronization network system, which executes a process of instructing selection of a synchronization clock to be used for synchronization based on information on a predetermined region of a packet that notifies the quality state of the synchronization clock.

DESCRIPTION OF SYMBOLS 1 Information setting means 2 Information operation means 3 Selection instruction | indication means 4 Control part 10, 20, 30, 40 Communication apparatus 100,200,300,400,500,600,700,800 Communication apparatus 101,104,106 PHY
102 CLK selection unit 103 Oscillator 105 Main signal control unit 107, 108, 118 Extraction CLK
109 Internal CLK
110, 111, 113 Logic signal 112 Device CLK
114 Control signal 115, 116, 117 Electrical signal

Claims (10)

A communication device used in a synchronous network system including a plurality of communication devices operating in synchronization with a synchronous clock,
Information setting means for writing the number of HOPs in a predetermined area of the packet notifying the quality state of the synchronous clock, and counting up the number of HOPs for the predetermined area of the packet notifying the quality state of the synchronous clock received from another communication device Alternatively, a communication apparatus comprising information operation means for writing a counted down value and selection instruction means for instructing selection of a synchronization clock based on information on a predetermined area of a packet notifying the quality state of the synchronization clock. A synchronous network system in which a plurality of communication devices operate in synchronization with a synchronous clock,
One communication device
A clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, and a control unit,
The control unit includes an information setting unit that writes the number of HOPs in a predetermined area of a packet that notifies the quality state of the synchronous clock, and a predetermined area of the packet that notifies the quality state of the synchronous clock received from another communication device. An information operation means for writing a value obtained by counting up or counting down the number of HOPs, and a selection instruction for instructing the clock selection section to select a synchronization clock based on information on a predetermined area of a packet for notifying the quality state of the synchronization clock A synchronization network system.   The synchronous network system according to claim 2, wherein the information operation means of the communication device writes device identification information in a predetermined area of a packet notifying the quality state of the synchronous clock. The communication device has a plurality of ports,
The control unit instructs the clock selection unit to select a synchronization clock based on information on a predetermined region of the packet that notifies the quality state of the synchronization clock and information on the plurality of ports that have received the packet. The synchronous network system according to claim 2 or 3.   Information related to the number of HOPs written in a predetermined area of the packet notifying the quality state of the synchronous clock is written in a format that counts up every time it passes through the communication device, and the information related to the number of HOPs exceeds a predetermined value. The synchronous network system according to any one of claims 2 to 4, wherein when it becomes, the clock selection unit is instructed to make selection impossible.   Information related to the number of HOPs written in a predetermined area of the packet for notifying the quality state of the synchronous clock is written in a format that counts down each time the packet passes through the communication device, and the information related to the number of HOPs becomes a predetermined value or less. The synchronous network system according to any one of claims 2 to 4, wherein when it is selected, the clock selection unit is instructed to disable selection. A communication device used in a synchronous network system including a plurality of communication devices operating in synchronization with a synchronous clock,
A clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, an information setting unit that writes the number of HOPs in a predetermined area of a packet that notifies the quality state of the synchronization clock, and another communication device Based on information operation means for writing a value obtained by counting up or counting down the number of HOPs to a predetermined area of a packet notifying the quality state of the synchronous clock, and information on the predetermined area of the packet notifying the quality state of the synchronous clock And a selection instruction means for instructing the clock selection section to select a synchronous clock.   The communication apparatus according to claim 7, wherein the information operation unit of the communication apparatus writes apparatus identification information in a predetermined area of a packet notifying the quality state of the synchronous clock. A synchronization method of a synchronous network system in which a plurality of communication devices operate in synchronization with a synchronous clock,
One communication device
A clock selection unit that selects one synchronization signal from a plurality of synchronization clocks according to an instruction, and a control unit,
The controller is
Write the number of HOPs in a predetermined area of the packet that reports the quality status of the synchronous clock,
Write a value obtained by counting up or counting down the number of HOPs to a predetermined area of a packet notifying the quality state of a synchronous clock received from another communication device,
A synchronization method for instructing selection of a synchronization clock to be used for the synchronization based on information on a predetermined region of a packet for notifying the quality state of the synchronization clock. A synchronization program for a synchronous network system in which a plurality of communication devices operate in synchronization with a synchronous clock,
One communication device
A process of writing the number of HOPs in a predetermined area of a packet notifying the quality state of the synchronous clock;
A process of writing a value obtained by counting up or counting down the number of HOPs to a predetermined area of a packet notifying the quality state of a synchronous clock received from another communication device;
And a process for instructing selection of a synchronization clock to be used for synchronization based on information on a predetermined area of a packet notifying the quality state of the synchronization clock.

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