JP2001197083A - Path network operating method, path network, and node device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a path network, a path network operating method, and a node device which are sufficiently adaptive to abrupt variation in traffic by actualizing an increase in path bandwidth at a high speed. SOLUTION: The path network which allows a communication between nodes by using more than one active path and more than one standby path is placed in operation by transmitting a path signal from a transmission node to a reception node through the active and standby paths and temporarily diverting a standby path to an active path to increase the bandwidth of the active paths when a request to increase the bandwidth is made in the path network. For automatic path diversion the transmission node and reception node divert the standby path to the active path by using automatic path diversion information included in a path overhead.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a path network for performing communication between nodes using at least one working path and at least one protection path. The present invention relates to a path network and a path network operation method that can be handled when the communication is performed, and a node device of a transmission node and a reception node.

[0002]

2. Description of the Related Art Conventionally, in a path network in which communication is performed by using a working path and a protection path and the paths are managed by a network management system, a request for an increase in a bandwidth due to an increase in traffic or due to administrative reasons. In the case where there is a problem, the network management system searches for a free space in both the working path and the backup path, and if there is a free space, opens the path to increase the bandwidth.

[0003] The path network is a feature of SDH (Synchronous Digital Hierarchy) that incorporates a layered transmission network (three layers) in a frame structure, and is defined together with a line network and a medium network. This is a network that is not conscious of the line and the transmission medium, is generally shared by various services, and is an operation unit of the transmission line network. Also,
The optical path is an operation unit for each wavelength in the transmission path network.

Generally, in a path network, the working path and the protection path are used to transmit the same signal between the same nodes via different paths, and the protection path can be used when the working path fails. It has become.

FIGS. 1 and 2 are conventional path network configuration diagrams showing an initial state before a change in the number of paths and a state after the change.
5 is an operation flowchart illustrating a path number changing method of the network management system.

In FIGS. 1 and 2, 1 to 5 are nodes (nodes A to E), 6 is a network management system (OpS), a solid line is a working path, a dotted line is a backup path, and a dashed line is a network management communication path. . FIG. 1 shows an initial state in a normal operation state, in which two working paths are connected from the node 1 to the node 5 via the nodes 2 and 3. In such an initial state, when the traffic between the node 1 and the node 5 increases, or when the construction is performed between the node 1 and the node 5 or the like, it becomes necessary to manage the bandwidth. Increase demand occurs. The network management system 6 refers to the configuration information of the network to search whether or not each of the requested working path and the protection path has a free space. If there is a free space, the node through which the path passes (here, Nodes 1, 2, 3, 5)
To the pass opening instruction. The path opening instruction is transmitted via a dashed line network management communication path. Nodes (nodes 1, 2, 3, and 5) that have received the path opening instruction open the path as instructed, thereby increasing the bandwidth.

As shown in FIG. 3, according to the method of changing the number of paths of the network management system, when a new path allocation request is received (step 71), the network management system 6 switches between the nodes 1 and 2 and between the nodes 2 and 3. While the path calculation for calculating the traffic between the nodes 3 and 5 and the current working path currently being used are saved and confirmed, while searching for an empty path to secure resources (step 72). ,
If there is a vacancy, the path is set by transmitting a path opening instruction (path setting instruction) to a node through which the path passes (steps 73 to 75).

As shown by the three solid lines in FIG. 2, after the bandwidth is increased, the number of working paths is increased by one, and a path opening instruction is transmitted from the network management system 6 to the protection node 4. Then, the third backup path 3 is opened (see three dotted lines in FIG. 2).

[0009]

However, when a new path is allocated via the network management system, it takes a long time to search for a free resource in the network. It is extremely difficult to set a new path.

Accordingly, an object of the present invention is to solve these conventional problems and realize a path network and a path network operation capable of sufficiently responding to sudden traffic fluctuations by realizing an increase in path bandwidth at high speed. A method and a node device are provided.

[0011]

To achieve the above object, the present invention is a method for operating a path network for performing communication between nodes using at least one working path and at least one protection path, Transmitting a path signal from the transmitting node to the receiving node via the working path and the protection path, and temporarily using the protection path to increase the bandwidth of the working path when a bandwidth increase request occurs in the path network. Diverting the path to a path.

Further, the present invention is a path network for performing communication between nodes, wherein the transmitting node transmits a path signal, the receiving node receives a path signal, and transmits a path signal between the transmitting node and the receiving node. And a transmitting node and a receiving node, when a bandwidth increase request is generated in the path network, a temporary protection path for increasing the bandwidth of the working path. A path network characterized by having a function of diverting to a working path.

Further, the present invention is a node device functioning as a transmitting node in a path network for performing communication between nodes using at least one working path and at least one protection path, wherein each path generation unit converts a client signal into a client signal. Transmit a path signal obtained by adding path overhead, the path overhead includes automatic path diversion information used to divert the protection path to the working path, when a bandwidth increase request occurs in the path network, A plurality of path generators for temporarily diverting the backup path to the working path by using the automatic path diversion information included in the path overhead to increase the bandwidth of the working path; A plurality of multiplexing units for transmitting the multiplexed path signal through each path, and a path signal transmitted by the path generation unit. Providing a node device and having a switch unit for switching the duplex unit.

Further, the present invention is a node device functioning as a receiving node in a path network for performing communication between nodes using at least one working path and at least one backup path, wherein each path terminating unit is connected to a transmitting node by a transmitting node. Terminates the path overhead added to the received path signal, the path overhead includes automatic path diversion information used to divert the backup path to the working path, and when a bandwidth increase request occurs in the path network. A plurality of path terminating units for temporarily diverting the backup path to the working path using the automatic path diversion information included in the path overhead in order to increase the bandwidth of the working path; A plurality of demultiplexing units for demultiplexing the multiplexed path signal transmitted through the path into path signals for each path, and a path termination for each path obtained by the demultiplexing unit. Providing a node apparatus characterized by having the a switch section for switching the parts.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a path network and a path network operating method according to the present invention will be described in detail with reference to FIGS.

In short, in most cases, a backup path corresponding to the working path is prepared in the path network, and therefore, according to the present invention, when there is a request for increasing the bandwidth, the protection path is temporarily used as the working path. By using as a path and searching for and securing network resources not used in the network management system during that time, it is possible to cope with a request to increase the bandwidth as a result of a sudden traffic change.

4 to 7 show a path network according to an embodiment of the present invention. FIG. 4 shows an initial state, FIG. 5 shows a state after the number of automatic paths is changed, and FIG. FIG. 7 shows a state in which a backup path has been added, and FIG. 7 shows a state after priority byte reallocation.

4 to 7, 10 to 14 are nodes (A to E), and 15 is a network management system (Op).
S), the solid line indicates the working path, the dotted line indicates the backup path, and the dashed line indicates the network management communication path.

In the initial state of FIG. 4, two working paths are connected between the node 10 and the node 14 from the node 10 to the node 1.
1, is set to the node 14 via the node 12. On the other hand, two backup paths are connected from node 10 to node 1
3 is set in the node 14. The network management system 15 is connected to all nodes by network management communication paths. In this state, the protection signals flowing through the two protection paths are equivalent to the working signals flowing through the two protection paths.

In the state of FIG. 4, it is assumed that a request for a new path allocation has been made. Such a request for a new path assignment is issued by a traffic monitoring function of a router outside the path network of FIG. 4 or an operator, and is detected by a control unit (not shown) provided in the node. And node 1
0 and the node 14 automatically convert the backup path to the working path, and use the backup path 2
One of the book paths is used as the current path. FIG. 5 shows the state up to this point. In addition to the two active nodes coupled to the node 14 via the node 10 and the nodes 11 and 12, the node 1
One working line and one spare line connected to the node 14 via 0 and the node 13 are set. In such a state, only the protection signal corresponding to the working signal flowing through the working path having the highest priority flows through the protection path. For example, a backup signal flowing through the backup path coupled to the node 14 via the node 10 and the node 13 is transmitted to the upper one of the working paths coupled to the node 14 via the node 10 and the nodes 11 and 12. It can be equivalent to a working signal flowing through a book.

In the state shown in FIG. 5, it is assumed that two new backup paths are subsequently allocated by the network management system 15. FIG. 6 shows the state at this time. That is, in addition to the setting of one newly assigned spare to the current two connected to the node 14 via the node 10 and the nodes 11 and 12, the node 14 via the node 10 and the node 13 is set. One newly assigned spare is set to one working and one spare that are combined. In this state, the protection signals flowing through the three protection paths are equivalent to the working signals flowing through the three protection paths again.

Finally, the network management system 15 replaces the working path and the protection path and rearranges the working path and the protection path, so that three working paths are transferred from the node 10 to the node 14 via the nodes 11 and 12. The three backup paths are connected to the node 14 from the node 10 via the node 13. FIG. 7 shows a state after the rearrangement. This rearrangement is realized by reallocation of priority bytes as described later.

FIG. 8 is a flowchart of an automatic path diversion method according to an embodiment of the present invention.

When a request for allocating a new path occurs due to factors such as an increase in traffic (step 81), the spare band is automatically diverted to the working between the nodes 10 and 14 (step 82). The management system 15 calculates a route to secure free resources in the network (step 83), allocates a new path, and sets a path at each node by transmitting a path setting command (steps 84 to 86). Then, according to the request of the network management system 15, the priority byte of the path is reallocated, and the working path and the protection path are rearranged (steps 87 and 88). After the required bandwidth in the path network decreases,
The network management system 15 can also request to release a part of the working path and the protection path by transmitting a path release command, thereby reducing the bandwidth of the working path and the protection path (steps 89 and 90).

The rearrangement of the working path and the protection path as shown in FIG. 7 and the reassignment of the priority byte in step 88 are optional, and may be omitted if not necessary. The release of the path in step 90 is also optional, and may be omitted if not necessary.

If the steps in FIG. 8 correspond to FIGS. 4 to 7, the state (initial state) before the new path assignment request (step 81) corresponds to FIG. The state after FIG. 5 corresponds to FIG. 5, the state after resource securing and path setting execution (steps 83, 84 to 86) corresponds to FIG. 6, and the state after priority byte reassignment (step 88). 7 is supported.

FIG. 9 is a signal sequence chart for automatic band conversion, FIG. 10 is a diagram showing a definition example of an automatic band conversion byte (automatic path diversion byte), and FIG. 11 is a diagram showing a definition example of a priority byte. .

In FIG. 10, 4 bits (bits 1 to 4) indicate the definition of the automatic bandwidth diversion byte. '000
"0" indicates a normal state, "0001" indicates a backup path diversion request requesting that a backup path be converted to a working path,
'0011' is a backup path diversion reverse request from the node which received the backup path diversion request to request the requesting node to flow a signal to the diversion band, '0100' is a standby state of the backup path diversion and waiting for change,
'0101' is for replying with the same content as' 0100 ',' 0110 'is for changing priority byte,' 0
111 'defines the same content as'0110' for reply.

In FIG. 11, the first bit is used to distinguish between the working path and the protection path, and seven bits below the second bit indicate the priority from 0 to 127.

In the above-described path diversion method, the priority byte is used as follows. That is, priorities are given to the working path and the protection path in advance, and when the protection path is diverted to the working path, the protection path having the highest priority is diverted. For example, in FIG. 4, priority numbers 1 and 2 are assigned to the upper and lower ones of the two working paths, respectively, and priority number 1 is assigned to the upper and lower ones of the two backup paths, respectively. And No. 2 are given. When the backup path is diverted to the working path, the protection path having the first priority is diverted to the working path as shown in FIG. When the number of paths is reduced by reducing the required bandwidth, the paths with lower priorities are discarded. When the paths are rearranged by reallocation of the priority bytes, the first bit of the priority bytes of the paths to be replaced is changed.

A sequence operation for automatic path conversion will be described with reference to FIG.

In the case where a backup path is automatically diverted to a working path between nodes, according to the present invention, an automatic path diversion byte and a priority byte are defined in the overhead part of the path, and the diversion is performed by exchanging them. It is possible to do.

First, the node A transmits a backup path diversion request 91 by using the downstream traveling route. The node E that has received the backup path diversion request 91 diverts the backup band to the current use (92), secures an output terminal on the receiving side, connects its input to the path where the backup path diversion request 91 was issued, and A path diversion reverse request 93 is returned. Node A that has received the backup path diversion reverse request 93 transmits a signal to the diversion path (94), and the backup path diversion completion 95
To the node E.

As described above, the automatic path diversion information used to divert the backup path to the working path and the priority information indicating the priority of the path are transmitted and received while being included in the path overhead.

FIGS. 12 to 15 are explanatory diagrams relating to the node configuration and the path setting of the nodes A and E.

FIG. 12 shows a node configuration when two working paths and two protection paths are used as shown in FIG. 4, and FIG. 13 shows a node configuration in a process of transition from the state of FIG. 4 to the state of FIG. FIG. 14 shows a node configuration when three working paths and one protection path are used as shown in FIG.
Reference numeral 5 denotes a node configuration after setting three working paths and three protection paths as shown in FIG.

12 to 15, in the configuration of the node A, reference numerals 20 to 23 denote a path generation unit, 24 denotes an optical switch unit,
Reference numerals 5 to 28 denote a wavelength multiplexing unit and 30 in the configuration of the node E.
33 to 33 are wavelength separation units, 34 is an optical switch unit, and 35 to 38.
Is a path terminator. Although not explicitly shown in FIGS. 12 to 15, each node is provided with a control unit that controls the operation of each component described above. Also, here
A case where a signal is transmitted from the node A to the node E will be described, but a description of a signal in the opposite direction is omitted.

The path generators 20 to 23 and the path terminators 35 to
The exchange of the path overhead is performed between the P.38 and the P.38. Here, the overhead is an area for transferring operation and maintenance information secured in a transmission frame with a margin so that network operation can be advanced. S
DH defines an overhead area of about 10%. As described above, the path overhead of the present invention includes the automatic path diversion information used for diverting the backup path to the working path and the priority information indicating the priority of the path.

The node A on the transmitting side in FIG. 12 includes a path generation unit 20 to 23, an optical switch unit 24, and a wavelength multiplexing unit 25 to 2
8 When a client signal is input to the path generation units 20 to 23, the path generation units 20 to 23 add a path overhead to the client signal to generate a path signal. The path overhead includes the above-described automatic path diversion information and information indicating the priority of the path. The optical switch unit 24 sets a desired route for the working path and protection path signals from the path generation units 20 to 23.

For example, the working path from the path generating section is sent to the wavelength multiplexing section 25 via the optical switch section 24, and the wavelength multiplexing section 25 multiplexes a plurality of working paths and transmits the multiplexed path to the transmission line. . The backup path is sent to the wavelength multiplexing unit 26 via the optical switch unit 24, and after being multiplexed by the wavelength multiplexing unit 26, is transmitted to the transmission path.

On the receiving side, in most cases, two paths from different transmission lines including the working path and the protection path are guided to a predetermined one of the path terminating units 35 to 38. Path termination part 35-3
8 is output as a client signal. In the figure, the solid path represents the working path, and the alternate long and short dash line represents the backup path.

FIG. 12 shows the initial state.
Two working paths and two protection paths are set between the node and the node E. The two working paths are transmitted and received through a transmission line connecting the transmission-side wavelength multiplexing unit 25 and the reception-side wavelength separation unit 30, and the two protection paths connect the transmission-side wavelength multiplexing unit 26 and the reception-side wavelength separation unit 31. It is transmitted and received through a transmission path.

FIG. 13 shows a state after a band change request has occurred and the receiving node E has changed the connection of the backup path connected to the path terminating unit 35 to the path terminating unit 37. That is, when the control unit (not shown) of the node A detects the band change request, the control unit controls the node A to transmit the protection path diversion request through the downlink transmission path. On the other hand, the node E controls the output terminal on the receiving side, that is, the path termination unit 37, by the control unit.
Node A that has received the diversion request
Is controlled so as to connect to the wavelength separation unit 31 via the optical switch unit 34 in order to connect to the path to. A backup path diversion reverse request is returned to node A via this path.

In FIG. 14, after the reverse request is sent from the node E to the node A, the transmission side node A connects the backup path of the path generation unit 20 up to now as the working path of the path generation unit 22 by its control unit. Controlled to change. Then, after receiving the reverse request, the node A transmits a signal to the diversion path via the path generation unit 22, the optical switch unit 24, and the wavelength multiplexing unit 26 by the control unit, and notifies the node E of the completion of the diversion of the protection path. Is controlled to be notified. In this way, in FIG. 14, two working paths are connected on the transmission line connecting the transmission-side wavelength multiplexing unit 25 and the reception-side wavelength separation unit 30 to the transmission-side wavelength multiplexing unit 26 and the reception-side wavelength separation unit 31. Are connected to one working path and one protection path.

In FIG. 15, in the network management system, a new backup path is set, and the path between the transmission side path generation unit 20 and the reception side path termination unit 35 and the transmission side path generation unit 22 and the reception side path termination unit 37 are set. Set a backup path to. That is, the backup path newly set in the transmission side path generation unit 20 is connected from the wavelength multiplexing unit 26 through the optical switch unit 24 to the reception side wavelength separation unit 31 via the transmission line, It is connected to the termination part 35.
The backup path newly set in the transmission-side path generation unit 22 is connected to the reception-side wavelength separation unit 30 from the wavelength multiplexing unit 25 via the optical switch unit 24 via the transmission line, and further transmitted through the optical switch unit 34. It is connected to the path termination unit 37.

Thus, the transmission path connecting the transmission-side wavelength multiplexing unit 25 and the reception-side wavelength separation unit 30 has two working paths and one protection path, and the transmission-side wavelength multiplexing unit 26 and the reception-side wavelength separation unit. One working path and two protection paths are set on the transmission paths connecting the units 31 respectively.

Referring to FIG. 12 to FIG.
23 to 23, when a path signal is generated by adding a path overhead to a client signal, a request for diverting a backup path to a working path, a reverse request, diverting completion and waiting for change during the path overhead, or An automatic path diversion byte indicating that the priority byte is being changed, and a priority byte indicating the distinction and priority between the working path and the backup path are defined.

The operation of the path terminating units 35 to 38 is to terminate the path overhead received from the transmitting node, and to restore the client signal, the automatic path diversion byte and priority byte in the path overhead are restored. Recognize each, if the received signal is a backup path diversion request, secure the output end of the receiving side and connect the input to the path where the backup path diversion request was,
A backup path diversion reverse request is returned to the transmitting node.

FIG. 16 shows an example of a frame configuration of an optical path signal that can be used in the path generation unit and the path termination unit in the node configurations shown in FIGS.

SDH (Synchronous Digital Hierarchy) is used as a new broadband communication technology represented by the broadband ISDN, and the multiplexing unit which is the basis of SDH is STM (Syn).
chronous Transport Modul
e) is used. Basic unit (level 1) is STM
-1 (155.52 Mbit / s), but also ST
M-4 (622.08 Mbit / s), STM-16 (2.488
G bits / second) and the like. In FIG. 16, S
An example in the case of using a TM-1 frame is shown.

An STM frame is formed by a (section) overhead and a payload. Here, the (section) overhead is an area for transmitting a signal used for managing the network. In the present invention, the automatic path diversion information and the path priority information are defined here. The payload is an area for transmitting the data of the user.

The path network is a network that is generally shared by various services without being aware of the line and the transmission medium, and serves as an operation unit of the transmission path network. In the SDH, a transmission system portion of a transmission medium network layer is defined as a section, and a path of a path network layer is defined as a virtual container.

The wavelength multiplexing technique not only increases the capacity of the transmission path, but also uses the conventional transmission node (cross-connect, A
DM (Add / Drop Multiplexer))
At the time position in the TDM frame or the ATM
(AsynchronousTransfer Mod
e: Asynchronous transfer method), it is possible to use the wavelength for path identification and path routing performed by the cell header. As described above, a lightwave network system using an optical path that is wavelength-multiplexed in a transmission path and identified and routed by a node at a wavelength is expected as a next-generation network technology.

FIG. 17 shows a configuration example of an optical path generation device and an optical path termination device that can be used as a path generation unit and a path termination unit in the node configurations of FIGS.

As shown in FIG. 17, the optical path generation device 40
The switch 49 switches the client signal between the working signal and the backup signal in accordance with the switching command from the control unit 60, the overhead adding unit 43 that adds overhead to the working signal input from the switch 49, and the input from the overhead adding unit 43. The E / O converter 41 converts the electrical signal of the working signal into an optical path signal, and transmits the obtained optical path signal to the working optical path, and an overhead for adding an overhead to the backup signal input from the switch 49. E / E for converting the electrical signal of the backup signal input from the providing unit 44 and the overhead signal from the overhead providing unit 44 into an optical path signal, and transmitting the obtained optical path signal to the backup optical path.
And an O conversion unit 42.

The overhead giving unit 43 (44) writes the value of the priority byte into the overhead according to the command from the control unit 60.
And an automatic path diversion information writing unit 46 (48) for writing the value of the automatic path diversion byte into the overhead according to a command from the control unit 60.

As shown in FIG. 17, the optical path terminating device 50 includes an O / E converter 51 for converting an optical path signal received from the working optical path into an electric signal of the working signal, and an O / E converter. An overhead separating unit 53 for separating the overhead from the working signal input from the working signal 51; and an O for converting the optical path signal received from the protection optical path into an electrical signal of the protection signal.
/ E conversion section 52, an overhead separation section 54 for separating overhead from the spare signal input from O / E conversion section 52, and a switching command from control section 60,
A switch 59 for switching the working signal and the backup signal input from the overhead separation units 53 and 54 into client signals.

The overhead separating unit 53 (54) reads the value of the priority byte from the overhead and transfers it to the control unit 60.
And an automatic path diversion information reading unit 56 (58) for reading the value of the automatic path diversion byte from the overhead and transferring it to the control unit 60.

The control unit 60 controls the optical path generation device 40 and the optical path termination device 50. When performing the automatic path diversion, the optical path generation device 40 and the optical path terminating device 50 are controlled to realize the automatic path diversion based on the automatic path diversion byte and the priority byte.

In the optical path generation device 40 shown in FIG. 17, a signal to be transmitted is first input to the overhead adding units 43 and 44 via the switch 49. Overhead giving unit 4
In 3 (44), the priority order writing unit 45 (47) writes the priority order information into the overhead, and the automatic path diversion information writing unit 46 (48) writes the automatic path diversion information into the overhead. The signal to which the overhead is added by the overhead adding unit 43 (44) is sent to the E / O conversion unit 41 (4).
In 2), the electric signal is converted into an optical signal and output as an optical path signal.

The signals transmitted through the working and protection optical paths are subjected to termination processing in the optical path terminating device 50. First, the optical path signal is converted into an electric signal in the O / E conversion unit 51 (52), and the overhead is separated from the obtained electric signal in the overhead separation unit 53 (54). In the overhead separating section 53 (54), the priority information is read by the priority information reading section 55 (57), and the automatic path diversion information is read by the automatic path diversion information reading section 56 (58). The priority information and the automatic path diversion information read from the overhead are transferred to the control unit 60, where the information is interpreted and an appropriate operation is performed based on the priority information and the automatic path diversion information. When writing the priority order information and the automatic path diversion information into the overhead, the control unit 60 sends a command to each writing unit.

Incidentally, the nodes in the path network generally have a configuration having both the above-described configuration of the transmitting node and the configuration of the receiving node, and can function as both a transmitting node and a receiving node.

[0063]

As described above, according to the present invention,
By temporarily using the protection path prepared along with the working path in the path network as the working path, the effect of being able to sufficiently cope with a request to increase the bandwidth as a result of a sudden traffic fluctuation is obtained. is there.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an existing path network in an initial state before changing the number of paths.

FIG. 2 is a diagram showing a configuration of a conventional path network in a state after a change in the number of paths.

FIG. 3 is a flowchart showing a conventional path number changing procedure in a conventional path network.

FIG. 4 is a diagram showing a configuration in an initial state of a path network according to the present invention.

FIG. 5 is a diagram illustrating a configuration of the path network according to the present invention in a state after automatic path diversion.

FIG. 6 is a diagram showing a configuration of the path network according to the present invention in a state where backup paths are added.

FIG. 7 is a diagram showing a configuration of a path network according to the present invention in a state after priority byte reassignment.

FIG. 8 is a flowchart showing an automatic path diversion procedure in the path network of the present invention.

FIG. 9 is a signal sequence chart of an automatic path diversion procedure in the path network of the present invention.

FIG. 10 is a diagram showing a definition example of an automatic path diversion byte used in the path network of the present invention.

FIG. 11 is a diagram showing a definition example of priority bytes used in the path network of the present invention.

FIG. 12 is a block diagram showing an example of a node configuration of the path network of the present invention in the state shown in FIG. 4;

FIG. 13 is a block diagram showing an example of a node configuration in a state where the path network of the present invention transits from the state of FIG. 4 to the state of FIG. 5;

FIG. 14 is a block diagram showing an example of a node configuration of the path network of the present invention in the state shown in FIG. 5;

FIG. 15 is a block diagram showing a node configuration example of the path network of the present invention in the state shown in FIG. 6;

FIG. 16 is a diagram showing an example of a frame configuration of an optical path signal that can be used in a path generation unit and a path termination unit in the node configurations of FIGS. 12 to 15;

FIG. 17 is a diagram showing a configuration example of an optical path generation device and an optical path termination device that can be used in the node configurations of FIGS. 12 to 15;

[Explanation of symbols]

 10-14 Node 15 Network management system 20-23 Path generation unit 24, 34 Optical switch unit 25-28 Wavelength multiplexing unit 30-33 Wavelength separation unit 35-38 Path termination unit 40 Optical path Generating devices 41, 42 E / O converters 43, 44 Overhead assigning units 45, 47 Priority writing units 46, 48 ... Automatic path diversion information writing units 49, 59 Switch 50 Optical path terminating device 51 52, O / E converter 53, 54 overhead separator 55, 57 priority reader 56, 58 automatic path diversion information reader 60 controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04M 3/00 H04L 11/20 C H04Q 11/04 H04Q 11/04 M

Claims (26)

[Claims] 1. A method of operating a path network for performing communication between nodes using at least one working path and at least one protection path, comprising: a path from a transmitting node to a receiving node via the working path and the protection path. Transmitting a signal; and, when a bandwidth increase request is generated in the path network, temporarily diverting a backup path to the working path to increase the bandwidth of the working path. Network operation method. 2. In the transmitting step, a transmitting node transmits a path signal obtained by adding a path overhead to a client signal, and the path overhead is an automatic path used for diverting a protection path to a working path. The path network operation according to claim 1, further comprising diversion information, wherein, in the diversion step, the transmitting node and the receiving node divert the backup path to the working path using the automatic path diversion information included in the path overhead. Method. 3. The method according to claim 1, wherein the diverting step further comprises: at the transmitting node, receiving a path signal having path overhead including automatic path diversion information indicating a backup path diversion request for requesting diversion of the backup path to the working path. In the receiving node, in response to the backup path diversion request, the receiving end secures an output terminal on the receiving side, and connects the input of the output terminal to the path where the backup path diversion request is received, to the diversion path. Returning a path signal having a path overhead including automatic path diversion information indicating a backup path diversion reverse request for requesting transmission of a signal to the transmission node, at the transmission node, in response to the protection path diversion reverse request, Sends a path signal with path overhead including automatic path diversion information indicating backup path diversion completion notification to the receiving node via the diversion path 3. The path network operating method according to claim 2, further comprising the step of: 4. After the diversion step, adding a backup path to increase the bandwidth of the backup path, and after the adding step, all the working paths connect the transmitting node and the receiving node to the first node. Reordering the working path and the protection path such that all the protection paths connect the transmitting node and the receiving node via the second path. Item 7. The path network operation method according to Item 1. 5. The method according to claim 1, wherein the diverting step further comprises a step of assigning priorities between the working path and the protection path in advance so that the protection path having the highest priority is diverted to the working path. 5. The path network operating method according to claim 4, wherein the working path and the protection path are rearranged by reassigning the priority order between the working path and the protection path. 6. In the transmitting step, the transmitting node transmits a path signal obtained by adding path overhead to the client signal through each of the working path and the protection path, and is transmitted through each path. The path overhead given to the path signal includes priority information indicating the priority of each path, and in the diversion step, the transmitting node and the receiving node pass the path given to the path signal transmitted through each path. 6. The path network operation method according to claim 5, wherein the protection path is diverted to the working path using the priority information included in the overhead. 7. The method according to claim 1, further comprising the step of releasing a part of the working path and the protection path to reduce the bandwidth of the working path and the protection path when the required bandwidth in the path network decreases. 2. The path network operation method according to 1. 8. A path network for communicating between nodes, comprising: a transmitting node transmitting a path signal; a receiving node receiving a path signal; and at least one transmitting a path signal between the transmitting node and the receiving node. And the transmitting node and the receiving node temporarily change the protection path to increase the bandwidth of the working path when a bandwidth increase request occurs in the path network. A path network having a function of diverting to a network. 9. The transmission node has a path generation unit for transmitting a path signal obtained by adding a path overhead to a client signal, wherein the path overhead is an automatic path used for diverting a backup path to a working path. The path receiving unit includes path diverting information, and the receiving node has a path terminating unit for terminating path overhead, and the path generating unit and the path terminating unit use the automatic path diverting information included in the path overhead to generate a backup path. 9. The path network according to claim 8, wherein the path is diverted to the working path. 10. A path generation unit for transmitting, to a receiving node, a path signal having path overhead including automatic path diversion information indicating a backup path diversion request for requesting diversion of a protection path to a working path. In response to the backup path diversion request, the receiving node secures an output terminal on the receiving side, connects the input of the output terminal to the path where the backup path diversion request is received, and connects to the diversion path. A path terminating unit that returns a path signal having a path overhead including an automatic path diversion information indicating a backup path diversion reverse request for requesting signal transmission to a transmission node; In response to the path diversion reverse request, a path signal having a path overhead including automatic path diversion information indicating a backup path diversion completion notification is transmitted to the receiving node via the diversion path. Path network as claimed in claim 9, wherein. 11. After diverting a protection path to a working path, a protection path is added to increase the bandwidth of the protection path, and after adding the protection path, all working paths connect the transmitting node and the receiving node. The network management system further includes a network management system that rearranges the working path and the protection path so that the protection path is connected via one path and all protection paths connect the transmitting node and the reception node via the second path. Claim 8
The described path network. 12. The network management system assigns priorities between the working path and the protection path in advance so that the transmitting node and the receiving node divert the protection path with the highest priority to the working path. 12. The path network according to claim 11, wherein the working path and the protection path are rearranged by reassigning the priority order between the protection paths. 13. The transmission node has a path generation unit that transmits a path signal obtained by adding a path overhead to a client signal through each of a working path and a protection path, and transmits the path signal through each path. The path overhead added to the path signal includes priority information indicating the priority of each path, and the receiving node has a path termination unit that performs termination processing on the path overhead. 13. The path network according to claim 12, wherein the path termination unit diverts the backup path to the working path using the priority information included in the path overhead given to the path signal transmitted via each path. 14. The transmitting node and the receiving node,
9. The path network according to claim 8, further comprising a function of releasing a part of the working path and the protection path to reduce the bandwidths of the working path and the protection path when the required bandwidth in the path network decreases. . 15. A node device functioning as a transmitting node in a path network for performing communication between nodes using at least one working path and at least one protection path, wherein each path generation unit adds a path overhead to a client signal. The path overhead includes the automatic path diversion information used for diverting the protection path to the working path, and when the bandwidth increase request is generated in the path network, the path overhead is transmitted. A plurality of path generation units for temporarily diverting a backup path to a working path by using automatic path diversion information included in path overhead to increase bandwidth, and each multiplexing unit via each path Multiplex the path signal to be transmitted, and transmit the multiplexed path signal via each path,
A node device, comprising: a plurality of multiplexing units; and a switch unit that switches a path signal transmitted by the path generation unit to the multiplexing unit. 16. When diverting a backup path to a working path,
The path generation unit transmits a path signal having a path overhead including automatic path diversion information indicating a backup path diversion request for requesting diversion of the backup path to the working path to the receiving node, and the transmitting node diverts the protection path. Upon receiving a path signal having path overhead including automatic path diversion information indicating a backup path diversion reverse request for requesting transmission of a signal to the diversion path, returned from the receiving node in response to the request, the path generation is performed. The unit transmits a path signal having a path overhead including automatic path diversion information indicating a backup path diversion completion notification to the receiving node via the diversion path in response to the backup path diversion reverse request. Item 16. The node device according to item 15. 17. Each path generation unit adds a path overhead including priority information indicating a priority of each path to a path signal transmitted via each path, and the transmitting node and the receiving node determine each path. 16. The node device according to claim 15, wherein the protection path is diverted to the working path by using the priority information included in the path overhead added to the path signal transmitted via the node. 18. A node device functioning as a receiving node in a path network for performing communication between nodes using at least one working path and at least one backup path, wherein each path termination unit receives a path received from a transmitting node. Terminates the path overhead added to the signal, the path overhead includes automatic path diversion information used for diverting the protection path to the working path, and when a bandwidth increase request occurs in the path network, the working path A plurality of path terminating units for temporarily diverting the backup path to the working path using the automatic path diversion information included in the path overhead to increase the bandwidth of the A plurality of separation units for separating the transmitted multiplexed path signals into path signals for each path, and switching the path signals for each path obtained by the separation unit to a path termination unit. And a switch unit for switching. 19. When diverting a backup path to a working path,
When the receiving node receives from the transmitting node a path signal having a path overhead including automatic path diversion information indicating a protection path diversion request requesting diversion of the protection path to the working path, the path termination unit diverts the protection path. In response to the request, the receiving end secures an output end, connects the input of the output end to the path where the backup path diversion request was received, and issues a backup path diversion reverse request for requesting transmission of a signal to the diversion path. The path signal having the path overhead including the automatic path diversion information is returned to the transmitting node, and in response to the backup path diversion reverse request, the path signal including the automatic path diversion information indicating the backup path diversion completion notification is provided. 19. The node device according to claim 18, wherein the path signal is received from the transmitting node to the receiving node via the diversion path. 20. Each path terminator performs a termination process on path overhead including priority information indicating the priority of each path, which is added to a path signal transmitted via each path, and 19. The method as claimed in claim 18, wherein the receiving node uses the priority information included in the path overhead added to the path signal transmitted via each path to divert the backup path to the working path. Node device. 21. A path generation unit for generating a path signal by adding a path overhead to a client signal in a path network for performing communication using one or more working paths and one or more backup paths between the same pair of locations. A switch unit for changing a route of a signal, a transmitting node including a multiplexing unit for multiplexing a plurality of path signals, and a separating unit for separating a signal multiplexed by the multiplexing unit of the transmitting node. A switch unit for changing the path of the path signal separated by the separation unit;
A path termination unit for terminating the path overhead and restoring a client signal, wherein the path overhead is an automatic path diversion information used for diverting a backup path to a working path and priority of the path. A path network having priority information indicating a rank. 22. The path network according to claim 21, wherein said path signal is an optical path signal. 23. A path switching method for automatically switching a protection path to a working path between nodes, wherein the first node requests the transfer of the protection path to the working path via a communication path. A request is transmitted to the second node. When the second node receives the backup path diversion request, the second node secures an output unit on the receiving side, and connects the input to the path where the backup path diversion request was issued. The first node returns a backup path diversion reverse request to the first node. When the first node receives the backup path diversion reverse request, the first node transmits a signal to the diversion path to notify the standby path diversion completion to the second path. A path switching method characterized by notifying a node. 24. The path switching method according to claim 23, wherein the working path and the protection path are optical paths. 25. A path generation device of a transmission node for performing communication using one or more working paths and one or more protection paths between the same pair of locations, wherein the path signal is generated by adding a path overhead to a client signal. In the path overhead, during the path overhead, a request for diverting the backup path to the working path, a reverse request, completion of diverting and waiting for change, or an automatic path diverting byte indicating that the priority byte is being changed; A path generation device for defining a priority byte indicating a priority. 26. A path terminating device of a receiving node for performing communication using one or more working paths and one or more backup paths between the same pair of terminals, wherein the path terminating device terminates a path overhead received from the transmitting node and outputs a client signal. When restoring, the automatic path diversion byte and the priority byte in the path overhead are respectively recognized, and when the received signal is a backup path diversion request, the output end of the receiving side is secured and the input and the A path termination device that connects to a path for which a backup path diversion request has been made and returns a backup path diversion reverse request to a transmission node.