Abstract:
In a network in which GMPLS-implemented nodes and GMPLS-not-implemented nodes coexist, the GMPLS-implemented nodes cannot control the GMPLS-not-implemented nodes. To solve this, the GMPLS-implemented nodes suspend GMPLS control when the GMPLS control is started, and transmit a GMPLS control start message to a monitoring/control device. The monitoring/control device determines whether GMPLS-not-implemented nodes exist on a GMPLS control target LSP, when they exist, performs all settings necessary for the GMPLS-not-implemented nodes, and then transmits a GMPLS control suspension release message to resume the GMPLS control.

Description:
CLAIM OF PRIORITY 
       [0001]    The present application claims priority from Japanese patent application serial no. 2006-143758, filed on May 24, 2006, the content of which is hereby incorporated by reference into this application. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a path setting method, node devices, and a monitoring/control device in an optical transmission system used in a backbone network intended for international or domestic coverage, or urban areas, local networks, and the like. More particularly, it relates to an efficient path setting method, node devices, and a monitoring/control device in a state in which GMPLS (Generalized Multi-Protocol Label Switching)-implemented nodes and GMPLS-not-implemented nodes coexist. 
         [0003]    Recently, in transmission devices, research and development of inter-node mutual control technology has been briskly made. As inter-node mutual control technology, GMPLS technology is available as technology for opening a communication route by use of a label in a communication network including transmission devices and the like. The GMLS technology, which is described in non-patent document 1 (RFC3945), is expected as means for achieving efficient network management to provide for diversified devices on networks such as routers, time division multiplexers, and OXC (Optical Cross-Connect)/PXC (Photonic Cross-Connect) as a result of the emergence of diversified services and an increase in transmission capacity. 
         [0004]    With GMPLS, by a signaling protocol such as GMPLS RSVP-TE (ReSerVation Protocol-Traffic Engineering), and a routing protocol such as OSPF-TE (Traffic Engineering Extensions to OSPF (Open Shortest Path First)), LSP (Label Switched Path) can be opened by use of a label on a communication network including a packet switch such as a router, a time division multiplexer such as SONET (Synchronous Optical Network)/SDH (Synchronous Digital Hierarchy), and a wavelength switch such as OXC/PXC. The GMPLS RSVP-TE is described in non-patent document 2 (RFC3437), and the OSPF-TE is described in non-patent document 3 (RFC3630). 
         [0005]    As part of a current communication network, a monitoring/control device such as NMS (Network Management System) that uses protocols such as SNMP (Simple Network Management Protocol) and TL1 (Transaction Language 1) exists as a device that centrally manages the communication network. 
         [0006]    A study is underway of technology for coherently opening LSP to a destination client through a core network including SONET/SDH and OXC/PXC by use of user control protocols such as O-UNI (Optical-User Network Interface), OIF-UNI-01.0 R2, and GMPLS UNI, and GMPLS in a transmitting client device. The OIF-UNI-01.0 R2 is described in non-patent document 4, and GMPLS UNI is described in non-patent document 5. 
         [0007]    As transmission capacity increases, main signals accommodated in a transmission device become higher in communication speed and larger in capacity. Therefore, time from failure occurrence to recovery is required to be as short as possible in communication networks. 
         [0008]    With technology described in non-patent document 6, GMPLS RSVP-TE is extended, and when failure is detected in an end point node of LSP, or failure information is notified to an end point node by a Notify message, LSP failure recovery is enabled by switching to a backup route. As technology for switching to a usable backup route, 1+1 unidirectional protection, 1+1 bidirectional protection, 1:1 protection, 1:N protection, and Re-routing are available. 
         [0009]    [Non-patent Reference 1] E. Mannie, “Generalized Multi-Protocol Label Switching (GMPLS) Architecture”, [online], October 2004, IETF, retrieved on Apr. 20, 2006, Internet &lt;URL:http://www.ietf.org/rfc/rfc3945.txt?number=3945&gt; 
         [0010]    [Non-patent Reference 2] L. Berger, “Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions”, [online], January 2003, IETF, retrieved on Apr. 20, 2006, Internet &lt;URL:http://www.ietf.org/rfc/rfc3473.txt?number=3473&gt; 
         [0011]    [Non-patent Reference 3] D. Katz and two others, “Traffic Engineering (TE) Extensions to OSPF Version 2”, [online], September 2003, IETF, retrieved on Apr. 20, 2006, Internet &lt;URL:http://www.ietf.org/rfc/rfc3630.txt?number=3630&gt; 
         [0012]    [Non-patent Reference 4] “User Network Interface (UNI) 1.0 Signaling Specification, Release 2”, [online], Feb. 27, 2004, OIF, retrieved on Apr. 20, 2006, Internet &lt;URL:http://www.oiforum.com/public/documents/OIF-UNI-01.0-R 2-Common.pdf&gt; 
         [0013]    [Non-patent Reference 5] G. Swallow and three others, “Generalized Multiprotocol Label Switching (GMPLS) User-Network Interface (UNI): Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Support for the Overlay Model”, [online], October 2005, IETF, retrieved on Apr. 20, 2006, Internet &lt;URL:http://www.ietf.org/rfc/rfc4208.txt?number=4208&gt; 
         [0014]    [Non-patent Reference 6] J. P. Lang and two others, “RSVP-TE Extensions in support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS)-based Recovery draft-ietf-ccamp-gmpls-recovery-e2e-signaling-03.txt”, [online], April 2005, IETF, retrieved on Apr. 21, 2006, Internet &lt;URL:http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-recovery-e2e-signaling-03.txt&gt; 
       SUMMARY OF THE INVENTION 
       [0015]    Since GMPLS-not-implemented nodes not implementing GMPLS functions exist in existing communication networks, a communication network may be built in which GMPLS-not-implemented nodes and GMPLS-implemented nodes coexist. 
         [0016]    In a communication network in which GMPLS-implemented nodes and GMPLS-not-implemented nodes coexist, since the GMPLS-not-implemented nodes cannot be recognized from the GMPLS-implemented nodes, control by GMPLS cannot be performed. Therefore, in order to quickly and efficiently utilize resources by controlling, by GMPLS, LSP through which the GMPLS-not-implemented nodes also pass, all settings necessary for the GMPLS-not-implemented nodes must have been completed. To effectively utilize resources, it is necessary to perform settings for the GMPLS-not-implemented nodes upon the occurrence of abrupt and dynamic reservation and allocation of resources by GMPLS. 
         [0017]    Since, in GMPLS, depending on its utilization form, resources are reserved and allocated abruptly and dynamically, the present technology has difficulty in completing in advance all settings necessary for GMPLS-not-implemented nodes. Furthermore, the present technology has difficulty in performing settings for GMPLS-not-implemented nodes upon the occurrence of reservation and allocation of resources by GMPLS. 
         [0018]    With the technology described in the Non-patent Reference 1, even after switching to a backup route for failure recovery, when GMPLS-not-implemented nodes exist in the backup route, or when settings for GMPLS-not-implemented nodes are not completed, a failure state continues despite LSP after the switching. As a result, failure recovery cannot be performed. 
         [0019]    When reservation and allocation of resources occur abruptly or dynamically in GMPLS, the present invention determines by a monitoring/control device whether GMPLS-not-implemented nodes exist on a route, when the GMPLS-not-implemented nodes exist, suspends processing by GMPLS, automatically determines settings necessary for the GMPLS-not-implemented nodes, completes the settings for them, then resumes the processing by GMPLS, thereby solving the above problem. This is described below more specifically. 
         [0020]    First, each node is provided with a communication interface with the monitoring/control device, and the monitoring/control device acquires device configuration information and network configuration information of each node via the communication interface. The monitoring/control device stores the acquired device configuration information in a device configuration information database. By consulting the device configuration information database, the monitoring/control device controls a communication network including communication devices that do not implement GMPLS, and communication devices that implement GMPLS. 
         [0021]    Second, the GMPLS-implemented nodes have a function to send a GMPLS control message to the monitoring/control device. The GMPLS control message tells the monitoring/control device that an event requiring dynamic reservation and allocation of resources have occurred in the GMPLS-implemented nodes. When detecting the event, the monitoring/control device determines whether to perform presetting. 
         [0022]    Third, the monitoring/control device has a GMPLS routing calculation function, and when detecting an event requiring dynamic reservation and allocation of resources, calculates a route selected in the GMPLS-implemented nodes. The monitoring/control device determines whether GMPLS-not-implemented nodes exist on the route selected by GMPLS, and when they exist on the route, performs settings necessary for GMPLS processing such as data switch setting, for all GMPLS-not-implemented nodes that exist on the route. 
         [0023]    By any one of the above-described means, at least one of problems below is solved. 
         [0024]    First, since all settings necessary in advance for GMPLS-not-implemented nodes can be completed, during LSP opening by GMPLS, obstructions to main signal conduction due to the GMPLS-not-implemented nodes can be removed. 
         [0025]    Second, since all settings necessary in advance for GMPLS-not-implemented nodes can be completed, during switching to a backup route by GMPLS, obstructions to GMPLS failure recovery due to communication equipment not implementing GMPLS can be removed. 
         [0026]    Third, since the monitoring/control device centrally manages device configuration and network configuration information, loads on a GMPLS processing function part within the GMPLS-implemented nodes can be reduced. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]      FIG. 1  is a block diagram of a communication network; 
           [0028]      FIG. 2  is a block diagram for explaining a core network; 
           [0029]      FIG. 3  is a block diagram of a GMPLS-implemented node; 
           [0030]      FIG. 4  is a block diagram of a GMPLS-not-implemented node; 
           [0031]      FIG. 5  is a block diagram of monitoring/control device; 
           [0032]      FIG. 6  is a transition diagram for explaining device configuration notification processing; 
           [0033]      FIG. 7  is a table for explaining a device configuration database; 
           [0034]      FIG. 8  is a transition diagram for explaining network configuration notification processing; 
           [0035]      FIG. 9  is a table for explaining a network configuration database; 
           [0036]      FIG. 10  is a transition diagram explaining GMPLS processing start notification; 
           [0037]      FIG. 11  is a flowchart showing presetting processing of a monitoring/control device for GMPLS-not-implemented nodes; and 
           [0038]      FIG. 12  is a transition diagram for explaining presetting processing for GMPLS-not-implemented nodes. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0039]    Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. It is understood that identical reference numbers are assigned to substantially identical members, and duplicate descriptions are avoided.  FIG. 1  is a block diagram of a communication network.  FIG. 2  is a block diagram for explaining a core network.  FIG. 3  is a block diagram of a GMPLS-implemented node.  FIG. 4  is a block diagram of a GMPLS-not-implemented node.  FIG. 5  is a block diagram of monitoring/control device.  FIG. 6  is a transition diagram for explaining device configuration notification processing.  FIG. 7  is a table for explaining a device configuration database.  FIG. 8  is a transition diagram for explaining network configuration notification processing.  FIG. 9  is a table for explaining a network configuration database.  FIG. 10  is a transition diagram explaining GMPLS processing start notification.  FIG. 11  is a flowchart showing presetting processing of a monitoring/control device for GMPLS-not-implemented nodes.  FIG. 12  is a transition diagram for explaining presetting processing for GMPLS-not-implemented nodes. 
         [0040]    First, a communication network to embody the present invention is described using  FIG. 1 . 
         [0041]    A communication network  710  shown in  FIG. 1  constitutes a core network  701  by nodes  100 - 1  to  100 - 5  such as router, layer 2 switch, layer 3 switch, WDM (Wavelength Division Multiplexing), SONET/SDH, and OXC/PXC. The nodes are connected with client devices  110 - 1  to  110 - 4  such as router, layer 2 switch, layer 3 switch, and SONET/SDH. User control protocols  600 - 1  and  600 - 2  may be installed as programs in the client devices  110 . As the user control protocols, protocols such as RSVP-TE, GMPLS-UNI, and O-UNI are available. 
         [0042]    Programs in this embodiment may be executed as required by hardware processing such as FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), and network processor. 
         [0043]    The following describes a core network. The core network  701  shown in  FIG. 2  includes GMPLS-implemented nodes  230 , a GMPLS-not-implemented node  231 , a monitoring/control device  251 , and control signal lines  252  for connecting the nodes and the monitoring/control device. The GMPLS-implemented nodes  230  are provided with GMPLS  610 , thereby enabling GMPLS-based mutual control between the nodes. 
         [0044]    In  FIG. 2 , an active LSP (Label Switched Path)  200 - 1  is opened by GMPLS on a main signal of the GMPLS-implemented nodes  230 - 1 ,  230 - 2 , and  230 - 3 . When a failure occurs on the active LSP  200 - 1 , switching occurs to a backup LSP  200 - 2  on a main signal of the GMPLS-implemented nodes  230 - 1  and  230 - 4 , a GMPLS-not-implemented node  231 , and the GMPLS-implemented node  230 - 3 . The backup LSP  200 - 2  may be opened before a failure occurs. In this specification, nodes implementing the GMPLS protocol are referred to as “GMPLS-implemented nodes”, nodes not implementing the GMPLS protocol are referred to as “GMPLS-not-implemented nodes”, and the two types of nodes are referred to simply as “nodes” when they are not differentiated for description. The monitoring/control device shown in  FIG. 2  may monitor and control the client devices. The control signal line  252  may be wireless. 
         [0045]    The following describes the hardware configuration of GMPLS-implemented nodes with reference to  FIG. 3 . The GMPLS-implemented nodes  230  include a central processing unit (CPU)  310 - 1 , an internal communication line  390 - 1  such as bus, an external communication interface  350 - 1 , a GMPLS communication interface  360 - 1 , a device configuration information database  320 - 1 , a network configuration information database  321 - 1 , a main signal interface  340 - 1 , a data switch  380 - 1 , and a main storage device  370 - 1 . 
         [0046]    The main storage device  370 - 1 , which is a rewritable semiconductor memory such as RAM (Random Access Memory), stores a program  601 - 1  executed by the CPU  310 - 1  and the GMPLS protocol  610 . The main storage device  370 - 1  may store the device configuration information database  320 - 1  or the network configuration information database  321 - 1 . 
         [0047]    The device configuration information database  320 - 1  or the network configuration information database  321 - 1  may be stored on secondary storage devices such as hard disks. As the secondary storages, rewritable nonvolatile semiconductor memories such as Flash ROM (Read Only Memory), Compact Flash, SSFDC (Solid State Floppy Disk Card), and SD memory card (Secure Digital memory card) may be used. 
         [0048]    Two or more of the main signal interface  340 - 1  may be provided if necessary. The main signal interface  340 - 1  employs a signal system such as Ethernet stipulated by IEEE 802.3, 802.3z, 802.3ae, and the like, SONET/SDH stipulated by “International Telecommunication Union Telecommunication Standardization Sector” (ITU-T) G.707 and G.783, and OTN (Optical Transport Network) stipulated by ITU-T G.709 and the like. The main signal interface  340 - 1  is connected with other adjacent nodes, and used for the exchange of user data. The main signal interface  340 - 1  is further connected with the client devices, and used to exchange user data with the client devices. The data switch  380 - 1  is selected from an electrical switch, an optical switch of MEMS (Micro Electro Mechanical Systems) system, an optical switch of PLC (Planar Lightwave Circuit) system, a time division multiplex switch, an ADD/DROP switch, and the like, and switches main signals for connection. 
         [0049]    The GMPLS communication interface  360 - 1  is connected with other adjacent GMPLS-implemented nodes. Via the GMPLS communication interface, control signals such as routing protocols and signaling protocols, and data such as device configuration information are exchanged. The GMPLS communication interface  360 - 1  may use the same interface as a main signal interface according to the requirements of GMPLS. 
         [0050]    The external communication interface  350 - 1  is connected with the monitoring/control device  251 . The external communication interface  350 - 1  exchanges data such as network configuration information and device configuration information with the monitoring/control device  251  by use of protocols such as SNMP, HDLC (High-level Data Link Control procedure), and TL1. 
         [0051]    The GMPLS protocol  610  and the program  601 - 1  are stored in the main storage device  370 - 1 , and processing stipulated in GMPLS by the GMPLS protocol is performed by the CPU  310 - 1 . By executing the program  601 - 1 , in the core network shown in  FIG. 2 , device configuration information is transferred from the nodes to the monitoring/control device (described later using  FIG. 6 ), and network configuration information is transferred from the nodes to the monitoring/control device (described later using  FIG. 8 ). Furthermore, by transferring a GMPLS control start message from the GMPLS-implemented nodes to the monitoring/control device by processing of  FIG. 10  (described later using  FIG. 10 ), presetting processing for the GMPLS-not-implemented node is performed in the monitoring/control device (described using  FIG. 11 ) The program on the main storage may perform other than the above-described processing as required. 
         [0052]    The following describes the hardware configuration of a GMPLS-not-implemented node with reference to  FIG. 4 . The GMPLS-not-implemented nodes  231  includes a central processing unit (CPU)  310 - 2 , an internal communication line  390 - 2  such as bus, an external communication interface  350 - 2 , a device configuration information database  320 - 2 , a network configuration information database  321 - 2 , a main signal interface  340 - 2 , a data switch  380 - 2 , and a main storage device  370 - 2 . 
         [0053]    The main storage device  370 - 2 , which is a rewritable semiconductor memory such as RAM, stores a program  601 - 2  executed by the CPU  310 - 2 . The main storage device  370 - 2  may store the device configuration information database  320 - 2  or the network configuration information database  321 - 2 . 
         [0054]    The device configuration information database  320 - 2  or the network configuration information database  321 - 2  may be stored on secondary storage devices such as hard disks. As the secondary storage devices, rewritable nonvolatile semiconductor memories such as Flash ROM, Compact Flash, SSFDC, and SD memory card may be used. 
         [0055]    Like the GMPLS-implemented nodes  230 , two or more of the main signal interface  340 - 2  may be provided if necessary. The main signal interface  340 - 2  employs a signal system such as Ethernet, SONET/SDH, and OTN. The main signal interface  340 - 2  is connected with other adjacent nodes, and used for the exchange of user data. The main signal interface  340 - 2  is further connected with the client devices, and used to exchange user data with the client devices. The data switch  380 - 2  is selected from an electrical switch, an optical switch of MEMS system, an optical switch of PLC system, a time division multiplex switch, an ADD/DROP switch, and the like, and switches main signals for connection. 
         [0056]    Like GMPLS-implemented nodes  230 , the external communication interface  350 - 2  is connected with the monitoring/control device  251 . The external communication interface  350 - 2  exchanges data such as network configuration information and device configuration information with the monitoring/control device  251  by use of protocols such as SNMP, HDLC, and TL1. 
         [0057]    The main storage device  370 - 2  stores the program  601 - 2 . With the CPU  310 - 2  executing the program, in the core network shown in  FIG. 2 , device configuration information is transferred from the nodes to the monitoring/control device, and network configuration information is transferred from the nodes to the monitoring/control device. By a command from the monitoring/control device  251 , the CPU  310 - 2  performs presetting processing for path switching. The program on the main storage device may perform other than the above-described processing as required. 
         [0058]    The following describes the hardware configuration of the monitoring/control device with reference to  FIG. 5 . The monitoring/control device  251  include a central processing unit (CPU)  310 - 3 , an internal communication line  390 - 3  such as bus, an external communication interface  350 - 3 , a device configuration information database  320 - 3 , a network configuration information database  321 - 3 , and a main storage device  370 - 3 . 
         [0059]    The external communication interface  350 - 3  is connected with the nodes, and exchanges data such as network configuration information and device configuration information with the monitoring/control device  251  with them by use of protocols such as SNMP, HDLC, and TL1. 
         [0060]    The main storage device  370 - 3  stores a program  601 - 3 . With the CPU  310 - 3  executing the program  601 - 3 , in the core network shown in  FIG. 2 , device configuration information and network configuration information on all nodes in the core network are acquired to create the device configuration information database  320 - 3  and the network configuration information database  321 - 3 . The program  601 - 3  on the main storage device  370 - 3  may instruct the CPU  310 - 3  to perform other than the above-described processing as required. 
         [0061]    The device configuration information database  320 - 3  and the network configuration information database  321 - 3  may be stored on secondary storage devices such as hard disks. They may be stored on the main storage device  370 - 3 . As the secondary storage devices, rewritable nonvolatile semiconductor memories such as Flash ROM, Compact Flash, SSFDC, and an SD memory card may be used. 
         [0062]    With reference to  FIG. 6 , device configuration notification processing between a node and the monitoring/control device is described. The node  100  updates the device configuration database  320 - 1  or  320 - 2  when a change occurs in the device configuration of the main signal interface, the data switch, and the like as a result of operations by the operator (T 601 ). The node  100  that have performed the updating processing transmits a device configuration notification message to the monitoring/control device  251  via the control signal line (T 602 ). The device configuration notification message contains change contents of the device configuration. The monitoring/control device  251  executes a program stored in the main storage device  370 - 3  according to the received device configuration notification message, thereby updating the device configuration information database  320 - 3  (T 603 ). The monitoring/control device  251  notifies the node  100  of the completion of updating of the device configuration information database by use of a device configuration notification confirmation message (T 604 ). The node  100  that have received the device configuration notification confirmation message detect that synchronization with the device configuration information database in the nodes is completed by the updating of the device configuration information database in the monitoring/control device. The device configuration notification confirmation message may have contents indicating a request to retransmit the device configuration notification message, depending on an updating result of the device configuration information database in the monitoring/control device. When the device configuration information database in the monitoring/control device is unsuccessfully updated, the device configuration notification confirmation message may contain contents indicating the cause of failure. The device configuration notification processing may be repeatedly performed during automatic updating or in other cases, or may be performed once by the judgment of the operator. 
         [0063]    Furthermore, the nodes  100  hold a value (node identifier) capable of uniquely identifying a node such as IP address, node ID, and node name, information (interface information) about the GMPLS communication interface  360 , external communication interface  350 , main signal interface  340 , and data switch  380 , an interface type, and an installation position. When the nodes  100  are GMPLS-implemented nodes, they further hold information indicating a GMPLS-implemented node. 
         [0064]    The interface type uses a value capable of uniquely identifying information about which of the GMPLS communication interface  360 , external communication interface  350 , main signal interface  340 , and data switch  380 . When the interface is the main signal interface  340 , an identifier capable of uniquely identifying an interface connected with the client devices and an interface connected with the nodes is used. 
         [0065]    When the interface type is the GMPLS communication interface  360  or external communication interface  350 , the nodes  100  hold information such as an IP address and a subnet mask as interface information. When the interface type is the main signal interface  340 , the nodes  100  hold information about frame formats such as Ethernet, OTN, and SONET/SDH, communication speed information of a main signal, and wave-length information of the main signal as interface information. When the type is the data switch  380 , the nodes  100  hold information indicating the switching capability of the data switch, and information indicating the type of the data switch such as MEMS and an electrical switch as interface information. 
         [0066]    The installation position held in the nodes is information capable of uniquely identifying the positions in which the respective interfaces are installed, such as a frame number, a unit number, and a slot position. 
         [0067]    The nodes  100  transfer these pieces of information to the monitoring/control device  251  via the control line by use of the device configuration notification message. Thus, the device configuration database shown in  FIG. 7  is constructed in the monitoring/control device  251 . In  FIG. 7 , the device configuration database  320 - 3  includes node identifies  330 , interface information  331 , interface type  332 , installation position  333 , and GMPLS  334  indicating whether a node concerned is a GMPLS node (Yes) or not (-). When the nodes  100  are GMPLS-not-implemented nodes, since information indicating GMPLS-implemented nodes is not contained in the device configuration notification message, “-” is set in the GMPLS  334 . 
         [0068]    With reference to  FIG. 8 , network configuration notification processing between a node and the monitoring/control device is described. When a change occurs in the network configuration as a result of operations by the operator, the node  100  updates the network configuration database  321 - 1  or  321 - 2  (T 801 ). The node  100  that have performed the updating processing transmits a network configuration notification message to the monitoring/control device  251  via the control signal line (T 802 ). The network configuration notification message contains change contents of the device configuration. The monitoring/control device  251  executes a program stored in the main storage device  370 - 3  according to the received network configuration notification message, thereby updating the network configuration information database  321 - 3  (T 803 ). The monitoring/control device  251  notifies the node  100  of the completion of updating of the network configuration information database by use of a network configuration notification confirmation message (T 804 ). The node  100  that have received the network configuration notification confirmation message detects that synchronization with the network configuration information database in the node is completed by the updating of the network configuration information database in the monitoring/control device. The network configuration notification confirmation message may have contents indicating a request to retransmit the network configuration notification message, depending on an updating result of the network configuration information database in the monitoring/control device. When the network configuration information database in the monitoring/control device is unsuccessfully updated, the network configuration notification confirmation message may contain contents indicating the cause of failure. The network configuration notification processing may be repeatedly performed during automatic updating or in other cases, or may be performed once by the judgment of the operator. 
         [0069]    The nodes  100  collect information on the network configuration by use of a routing protocol such as OSPF-TE. Information on the network configuration may be manually set by the operator. As a result, the nodes  100  hold a value (node identifier) capable of uniquely identifying a node such as IP address, node ID, and node name, node identifiers of adjacent nodes, and protocol information as information about means by which the network configuration information is acquired. When the nodes  100  are GMPLS-implemented nodes, the nodes  100  further hold GMPLS adjacent relation information indicating whether to form a GMPLS adjacent relation. The GMPLS adjacent relation is formed only between GMPLS-implemented nodes. GMPLS-not-implemented nodes cannot form a GMPLS adjacent relation because they do not implement GMPLS. The nodes  100  hold main signal adjacent information indicating whether main signal interfaces are connected with each other. The GMPLS adjacent relation and the main signal adjacent information may be collected using OSPF-TE and LMP (Link Management Protocol), or may be manually set by the operator. By use of a dynamic routing protocol such as OSPF-TE, information about nodes not in adjacent relation can be collected. 
         [0070]    The nodes  100  transfer these pieces of information to the monitoring/control device  251  via the control line by use of the network configuration notification message. Thus, the monitoring/control device  251  constructs the network configuration database  321 - 3 . 
         [0071]    In  FIG. 9 , the network configuration database  321 - 3  includes node identifiers  1   321 , and for each of the node identifiers  1   321 , a node identifier  2   322  adjacent to the node identifiers, a protocol  323 , GMPLS adjacent  324 , and main signal adjacent  325 . The GMPLS adjacent  324  is set to “Yes” when both a node of node identifier  1  and a node of node identifier  2  are GMPLS-implemented nodes and the main signal adjacent is “Yes”. 
         [0072]    The following describes GMPLS processing start notification with reference to  FIG. 10 . The GMPLS-implemented node  230  monitors the occurrence of LSP opening processing, LSP deletion processing, and LSP switching processing by GMPLS. When processing by GMPLS is started on the occurrence of these events, the GMPLS-implemented node  230  performs GMPLS control suspension processing (T 901 ). Next, the GMPLS-implemented node  230  transmits a GMPLS control start message to the monitoring/control device  251  (T 902 ). In this case, the GMPLS control start message contains the type of switching processing such as 1+1 path protection in the LSP switching processing and information about a backup route. When an intermediate route is specified in the LSP opening processing, information about the intermediate route may be contained. Furthermore, in the case of LSP deletion processing, the GMPLS control start notification message may contain information such as path ID and a path name capable of uniquely identifying LSP to be deleted. 
         [0073]    GMPLS control may time out because of GMPLS control suspension processing during a series of processings. By transmitting a message indicating that GMPLS control is suspended and processing in the monitoring/control device is in progress to other GMPLS-implemented nodes, processing failure due to time-out can be prevented. 
         [0074]    On receiving the GMPLS control start message, the monitoring/control device  251  performs presetting processing for communication equipment on a backup route (T 903 ). On completion of the presetting, the monitoring/control device  251  transmits a GMPLS control suspension release message to the GMPLS-implemented node  230  (T 904 ). 
         [0075]    On receiving the GMPLS control suspension release message, the GMPLS-implemented node  230  releases the control suspension by GMPLS (T 905 ), and performs processing stipulated in GMPLS. The processing of  FIG. 10  is usually repeatedly performed. 
         [0076]    The following describes in detail presetting processing for the GMPLS-not-implemented node  231  on a backup route with reference to  FIG. 11 . The presetting processing is detailed contents of T 903  of  FIG. 10 . When receiving the GMPLS control start message (S 301 ), the monitoring/control device  251  performs routing calculation on LSP after GMPLS control, based on information contained in the GMPLS control start message (S 302 ). The monitoring/control device  251  determines whether presetting for the GMPLS-not-implemented node is necessary, by determining whether the GMPLS-not-implemented node exists in the LSP route (S 303 ). When determining from backup routing calculation that a GMPLS-not-implemented node exists on a backup route and presetting is necessary, the monitoring/control device  251  performs data switch presetting necessary for the GMPLS-not-implemented node (S 304 ). The monitoring/control device  251  terminates the processing when no GMPLS-not-implemented node exists on the backup route in Step  303  (transitions to T 904  of  FIG. 10 ). 
         [0077]    With reference to  FIG. 12 , the following describes the operation of a GMPLS-implemented node, the monitoring/control device, and a GMPLS-not-implemented node when the GMPLS-not-implemented node exists on a switching route. In  FIG. 12 , when starting GMPLS processing, the GMPLS-implemented node  230  performs GMPLS control suspension (T 701 ). The GMPLS-implemented node  230  transmits a GMPLS control start message to the monitoring/control device  251  (T 702 ). 
         [0078]    On receiving the GMPLS control start message, the monitoring/control device  251  performs LSP routing calculation (T 703 ). The monitoring/control device  251  transmits setting information such as data switch cross-connect connection setting information and main signal interface light-emitting control information that are required to conduct a main signal, to the GMPLS-not-implemented node  231  that exists on the switching route by use of a node setting request message (T 704 ) On receiving the node setting request message, the GMPLS-not-implemented node  231  interprets the received message, and performs node control processing requested from the monitoring/control device  251  (T 705 ). After completion of the node control processing, the GMPLS-not-implemented node  231  transmits a node setting completion message to the monitoring/control device  251  (T 706 ). The node setting completion message may contain contents indicating that the requested setting is completed in the GMPLS-not-implemented node  231 , or contents indicating the cause of setting failure if so. 
         [0079]    On receiving the node setting completion message, the monitoring/control device  251  transmits a GMPLS control suspension release message to the GMPLS-implemented node  230  (T 707 ). 
         [0080]    After receiving the GMPLS control suspension release message, the GMPLS-implemented node  230  releases the control suspension by GMPLS (T 708 ) and resume the GMPLS control. 
         [0081]    Although, in the above-described embodiment, the number of GMPLS-not-implemented nodes on the backup route of the core network is one, when there are plural GMPLS-not-implemented nodes on the backup route, necessary data switch setting is performed for all GMPLS-not-implemented nodes on the backup route. 
         [0082]    Although inter-node mutual control technology is described above using GMPLS as an example, the present invention is not limited to GMPLS. Specifically, in the above-described embodiments, even in a network that employs inter-node mutual control technology other than GMPLS, and user control protocols other than RSVP-TE and O-UNI, if a monitoring/control device exists in the network and the above-described control method or devices are used, even when nodes that implement an inter-node mutual control protocol, and nodes that do not implement it coexist, control can be performed through cooperation between them. 
         [0083]    According to the present invention, in a communication network in which GMPLS-implemented nodes and GMPLS-not-implemented nodes coexist, GMPLS-based efficient LSP opening processing including GMPLS-not-implemented nodes is enabled by cooperatively operating them. Moreover, even when GMPLS-not-implementing equipment exists, GMPLS-based efficient failure recovery including GMPLS-not-implemented nodes is enabled.