Abstract:
This invention provides an improved data transferring method performed in a communication network comprising a management system M 1  and a plurality of nodes K 1 –K 3 . Since the management system M 1  collectively manages the algorithm information that indicates algorithm possessed in each node, if the fist node does not have algorithm needed for processing a certain packet, the first node can find the second node having the algorithm by inquiring the network management element M 1 . In addition, the first node can transfer the certain packet to the second node to process the certain packet by using the algorithm.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to a network management method applied to a communications network system, such as a public telephone network and a data communication network. 
   2. Description of the Related Art 
   In general, a conventional communication network system comprises a plurality of nodes each having a switching function and terminal equipments (TEs). The system further comprises a network management system to monitor traffic status of network communications and to manage establishment of roundabout routes. The network management system is then connected to each node via a control line, and the management of the network communication is performed via the control lines. For that reason, it is unavoidable to increase the number of control lines and control information in proportion to the number of nodes. Accordingly, the increase in the control information is a burden to the network management system, and the total traffic on the conventional communication network system also increases. 
   Furthermore, it is feared that the conventional communication network system can not accept new communication technology or cope with new communication service. For example, it has been developed that a node executes a program appended to a received user packet to assist transferring operations. If the program commands that the node makes a plurality of replicas of the user packet and transfers the replicas to a plurality of nodes respectively, the network management system can not manage traffic congestion on the conventional communication network system. As a result, the whole communication on the communication network system would become unusable. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to provide an improved network management method to avoid the increase in the traffic due to transferring a protocol itself. 
   It is another object of the present invention to provide an improved communication network system to manage the traffic congestion due to a large number of replicas excessively generated by executing the particular program. 
   In order to achieve the above object of the present invention, a network management method performed in a communication network system comprising a plurality of nodes and a network management system, the method comprising steps of:
     (a) selecting at least one network control item to be collected from each node at the network management system,   (b) sending, from the network management system to a first node, a user packet appending a control program that commands a node to provide, to the control program, information corresponding to the network control item,   (c) storing a first network control item of the first node in the control program based on executing the control program,   (d) transferring the user packet from the first node to a second node,   (e) storing a second network control item of the second node in the control program based on executing the control program,   (f) returning the user packet from the second node to the network management system, and   (g) managing the first and second nodes based on the first and second network control items.   

   Furthermore, in order to achieve another object of the present invention, a network management method performed in a communication network system comprising at a plurality of nodes and a network management system, the method comprising steps of:
     (a) identifying and recording, at each of the plurality of nodes, header information in response to reception of a user packet,   (b) reporting, to the network management system from a first node, reception information when the first node receives same user packets having the same header information more than a predetermined number of times,   (c) giving notice of discard of a succeed user packet having the same header information from the network management system to each nodes, and   (d) discarding, at each node, the succeed user packet having the same header information according to the notice of discard form the network management system.   

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred form of the present invention is illustrated in the accompanying drawings in which: 
       FIG. 1  is a simplified block diagram of a communication network system in accordance with the first embodiment of the invention; 
       FIG. 2  is a simplified block diagram of a node according to the first embodiment of the invention; 
       FIG. 3  is a simplified block diagram of a network management system in accordance with the first embodiment of the invention; 
       FIG. 4  is a simplified block diagram of a node according to the second embodiment of the invention; and 
       FIG. 5  is a simplified block diagram of a network management system in accordance with the second embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A. First Embodiment of the Invention 
   The first embodiment of the present invention will be described below with reference to a preferred embodiment in conjunction with the accompanying drawings. 
     FIG. 1  shows a communications network system comprising nodes K 1 –K 3  and a network management system M 1 . Each of the nodes K 1 –k 3  is equipped with a switching function, for example a switching system or a router, and accommodates terminal equipment (TE). Accordingly, when a packet is input to a node, the node transfers it to the addressed terminal equipment (TE) by performing optimum algorithm as a transferring function. In  FIG. 1 , the node K 1  is connected to the nodes K 2  and K 3  via transmission lines T 1  and T 2  respectively, and the node K 2  is connected to the node K 3  via a transmission line T 3 . The management system M 1  is connected to the nodes K 1 –K 3  via control lines C 1 –C 3  respectively. 
     FIG. 2  shows a simplified block diagram of the nodes K 1 –K 3 . As shown in  FIG. 2 , each of the nodes K 1 –K 3  comprises a program operating unit P 1 , a network management library L 1 , an operating system OS 1 , a program transferring hardware PH 1 , a data transferring software DS 1 , and a data transferring hardware DH 1 . The program operating unit P 1 , the network management library L 1 , the operating system OS 1  and the data transferring software DS 1  are generally realized by software. The program transferring hardware PH 1  and the data transferring hardware PH 1  comprise a central processing unit (CPU), a memory and an I/O interface. In addition, the program transferring hardware PH 1  is a device for transmitting/receiving a control program that is transferred to each node and is executed by each node. The operation of the control program will be described later. The data transferring hardware DH 1  is also a device for transmitting/receiving packets. 
   The functions of the program-operating unit P 1 , the network management library L 1  and the data transferring software DS 1  are generally performed by application software. However, all or a part of the functions may be performed as a function of the operating system OS 1  instead of the application software. Here it is assumed that the application software (the network management library L 1 , the operating system OS 1  and the data transferring software DS 1 ) is performed under the command of the operation system. Also, the data transferring software DS 1  has a function of transferring user packets to destination addresses. The program-operating unit P 1  has functions to execute the control program and other programs, which are transferred from the network management system M 1  or other nodes. The network management library L 1  provides functions to store and manage information regarding network topology and status of each node. In this case, as the information for the network management library L 1 , the rate of operation of a central processing element (CPU) and transferring speed of user packets can be obtained by transferring and executing the control program CP among the corresponding nodes. Here the rate of operation of the CPU is indicative of congestion rate or congestion status of each node to process user packets. 
     FIG. 3  shows a simplified block diagram of the management system M 1 , which comprises a network information controller NC 1 , a control program generator CP 1  and a control program transferring hardware CH 1 . The network information controller NC 1  and the control program generator CP 1  are generally realized by software, and the control program transferring hardware CH 1  comprises a central processing unit (CPU), a memory and an I/O interface. Although the network information controller NC 1  and the control program generator CP 1  are generally performed by application software, all or a part of the functions may be performed by an operating system instead of the application software. When the network management system M 1  selects network control items necessary for control of the communication network system, the control program generator CP 1  functions to generates a control program CP that commands to collect the network control items from each node. The control program generator CP 1  also generates a user packet appending to the generated control program. The network information controller NC 1  functions to store and manage the network control items provided by each node during the control program CP is transferred to each node in turn. 
   Next, an outline of a network management method according to this embodiment will be described below. In the conventional network management method, a network management system has communicated with each node to collect information necessary for management of a network system. However, in a network management method according to the first embodiment of the invention, when a network administrator selects the network control items necessary for management of a network system for network communication, the control program generator CP 1  generates the control program CP to collect the network control items from each node. The control program CP is appended to a user packet, and then the user packet is transferred to all nodes or predetermined nodes in turn by the control program transferring hardware CH 1 . Consequently, a burden imposed to the network management system M 1  can be lightened even if the number of nodes increases in the communication network system, because the network management system M 1  need not to send the control program to each node. Further, the traffic for collecting the network control items from each node may be reduced to a minimum. 
   In this embodiment, for example, it is assumed that the user packet appending to the control program CP is first transferred to the node K 1 . As shown in  FIG. 1 , the control program CP is sent from the network management system M 1  to the node K 1  via the control line C 1 . In the node K 1 , the control program CP is then received at program transferring hardware PH 1  and is provided to the program-operating unit P 1  by way of the operating system OS 1 . In the program-operating unit P 1 , the control program CP is executed. If the control program CP commands to collect network control items, i.e. the rate of operation of a central processing element (CPU) and transferring speed of user packets, the network control items are obtained by accessing the network management library L 1  of the node K 1 . When completing the operation of the control program CP, the network control items are accumulated in the control program CP. Alternatively, the network control items can be accumulated in a predetermined portion of the user packet that is appending to the control program CP. 
   Next, the control program CP is transferred to a predetermined node (i.e. the node K 3 ) via transmission line T 2  by providing a next destination address according to a routing table in a network management library L 1  of the node K 1 . The node K 3  receives and executes the control program CP, and then network control items of the node K 3  are accumulated in the control program CP like the above-mentioned operation of the node K 1 . The control program CP is further transferred to a predetermined next node (i.e. the node K 2 ) via transmission line T 3  by providing a next destination address according to a routing table in a network management library L 1  of the node K 3 . The node K 2  also receives and performs the control program CP, and network control items of the node K 2  are accumulated in the control program CP. This operation is repeatedly performed until the control program CP is transferred to all nodes or predetermined nodes. In this embodiment, the control program CP is finally transferred to the network management system M 1  after the node K 2  executes the control program CP. That is, the control program CP makes the rounds of the nodes K 1 –K 3  in turn and then returns to the network management system M 1 . The control program CP thus provides the network control items obtained from each of the nodes K 1 –K 3  to the network information controller NC 1  of the network management system M 1 . 
   With regard to the transferring the control program CP among nodes according to the routing table in the network management library L 1 , transferring information stored in the routing table can be obtained in a well-known transferring technique. For example, the corresponding two nodes communicates mutually or the corresponding two nodes inquire the transferring information of the network management system M 1 . 
   According to the first embodiment of the invention, a burden imposed to the network management system M 1  can be lightened, since the network management system M 1  need not to communicate with each node to collect the network control items. Also, as a result of the control program CP is transferred to each node and each node executes the control program CP, the total traffic in the communication network system can be reduced abundantly. 
   In this embodiment, it has been described that the network management library L 1  of each node has a function of collecting the network control items by executing the received control program CP. Further, it can be realized that the network management library L 1  functions to set up the network libraries by executing the control program CP. For example, the network management library L 1  of each node has functions to detect and solve congestion of the traffic as a congestion control operation, and the network management library L 1  performs the congestion control operation in response to reception of the control program CP. 
   As mentioned above, by reason of the control program CP performs not only collecting the network control items of each node but also setting up the network library, the network management system M 1  can rapidly control each node in response to condition of the communication network system. 
   B. Second Embodiment of the Invention 
   The second embodiment of the invention will be described below. Since a communication network system according to the second embodiment is the same as that of the first embodiment as shown in  FIG. 1 , accordingly the explanation will be omitted here. 
     FIG. 4  shows a block diagram of nodes K 1 –K 3  according to the second embodiment of the present invention. As shown, each of the nodes K 1 –K 3  comprises a packet-observing element PS 2 , a packet-processing element PP 2 , an operating unit E 2  and a packet transferring hardware DH 2 . In general, the packet-observing element PS 2 , the packet-processing element PP 2  and the operating unit E 2  are realized by software, and the packet transferring hardware DH 2  comprises a central processing element (CPU), a memory and I/O interface. The packer-observing element PS 2  identifies and records header information of a received packet. In addition, if packets having the same header information are received more than a predetermined number of times (i.e. five times), the packer-observing element PS 2  reports the reception to the network management system M 1  via a control line. Incidentally, after confirming the reception of the five packets and reporting the reception to the network management system M 1 , the packet-processing element PP 2  immediately discards succeed packets having the same header information. Further, if one node reports the reception information of the five packets having the same header information to the network management system M 1 , the network management system M 1  then gives notice to other nodes. As a result, the packet-processing element PP 2  of each node immediately discards the packets having the same header. In such case, the reception information and the notice include header information of the same user packet in order to identify, at each node, received user packets as a user packet to be discarded. 
   With regard to the reception of the same header, each node can regard as the same header when all or a particular portion of header of the former packet is the same as that of the later one. For example, as the particular portion, a destination address, a destination port number of the destination node, a source address or a source port number of the source node can be utilized. 
   Here the function of the packet-observing element PS 2  is generally realized by application software. However, all or a part of the function can be realized by an operating system. The operating unit E 2  provides a desirable environment where the functions of the packet-observing element PS 2  and the packet-processing element PP 2  can be performed. In general, the function of the operating unit E 2  is realized by the operation system. However, all or a part of the function can be performed by application software. The operating unit E 2  also provides a function of transmitting and receiving packets between the operating unit E 2  and the packet transferring hardware DH. 
     FIG. 5  shows a block diagram of the network management system M 1  according to the second embodiment of the present invention, which comprises a network control element NMF 2 , a packet information collecting element PC 2  and a packet transferring hardware CH 2 . The network control element NMF 2  and the packet information collecting element PC 2  are generally realized by software, and the packet transferring hardware CH 2  comprises a central processing element (CPU), a memory and I/O interface. The network control element NMF 2  has functions necessary for managing the communication network system and the functions are generally realized by application software. However, all or a part of the functions can be performed by an operating system. When one node reports the reception of five packets having the same header to the network management system M 1 , the network control element NMF 2  also has a function to provide a control signal including the its header information and a discarding order to each node. As a result, each node immediately discards specific packets that are indicated to header information in response to the control signal. The header information is collected by the packet-processing element PP 2  of the node that receives the five packets having the same header information and then is sent to the network control element NMF 2  of the network management system M 1 . 
   The data transferring operation performed on the communication network system will be described below. In this embodiment, it is assumed that each node has a program that commands to duplicate a received packet and to transfer the duplicated packets to a plurality of nodes, and the node K 1  first receives the received packet. In such case, the packet-observing element PS 2  of the node K 1  identifies and records header information of the packet, which indicates two destination addresses for transferring two different nodes (i.e. the nodes K 2  and K 3 ). The packet is duplicated and then is transferred to the nodes K 2  and K 3  respectively. The node K 2  duplicates the received packet and transfers them to two different nodes. Similarly, the node K 3  duplicates the received packet and transfers them to two different nodes. If repeating these operations, each node is congested with processing a large number of the duplicated packets. However, as mentioned above, when one node receives the duplicated packets five times, the node reports the reception of the five duplicated packets the to the network management system M 1 . In response to the report from the one node, the network management system M 1  gives notice to other nodes such that the packet-observing element PS 2  of each node discards the duplicated packet having the same header. As a result, each node can discard the duplicated packets without duplicating and transferring the duplicated packet based on the notice from the network management system M 1 . 
   As mentioned above, according to the second embodiment of the invention, it is possible to avoid an occurrence of congestion on the communication network system due to a function of duplicating a received packet and transferring them to different nodes. 
   In the second embodiment, one node reports the reception of the five duplicated packets to the network management system M 1 , however it can be realized that the one node directly report the reception to other nodes such that other nodes discards the duplicated packets. 
   The invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the appended claims is intended to cover all such changes and modifications as fall within the true spirit of the invention.