Network control method and apparatus therefor

A control method for reconfiguration of a network comprising a plurality of TDMs, each comprising a memory to store connection relationships between subscriber circuits connected to said TDMs and trunk circuits connecting said TDMs to each other, one of said TDMs being connected to a network controller which stores first parameters characteristic of said trunk circuits and second parameters characteristic of said subscriber circuits,

• said control method comprising the steps of:
• detecting a failure in one or more of said trunk circuits;
• calculating evaluation indexes responsive to the first parameters, the second parameters and physical status information relating to said trunk circuit in which said failure has occurred;
• determining network configuration data to be supplied to said TDMs on the basis of said evaluation indexes;
• and
• distributing frames having said network reconfiguration data from said network controller to each of said TDMs so that each TDM changes the relationships in its memory according to the distributed reconfiguration data.

In a packet exchange system which comprises a plurality of packet exchangers and packet terminals connected by trunk circuits, wherein a sending terminal inserts route information in a route information field of a transmitted packet to show the route to a destination terminal, and wherein said packet exchangers relay received packets to output routes connected thereto on the basis of the route information contained in said received packets,

• a control method comprising the steps of:
• generating a broadcast packet for finding a route to a destination terminal by inserting broadcast data in a transmitted packet, when a sending terminal detects a failure in one of the trunk circuits;
• sending out said broadcast packet from said sending terminal to a packet exchanger connected directly to said sending terminal;
• when any of said packet exchangers receives said broadcast packet, operating each of said packet exchangers to resend copies of said broadcast packet to all possible output routes by adding a pair of route identifiers, each pair representing a receiving route and a output route pertinent to the resnding packet exchanger, in the route information field of the resent copies of the broadcast packet;
• when the destination terminal receives a broadcast packet which contains the address of said destination terminal, operating said destination terminal to generate a responding packet which includes route information corresponding to the route information in the received packet and returning said responding packet to said sending terminal;
• and
• when said sending terminal receives said responding packet, storing said route information included in said responding packet, to use said stored route information in thereafter sending further packets from said sending terminal to said destination terminal.

A control system for reconfiguration of a network comprising a plurality of TDMs, each comprising a memory to store connection relationships between subscriber circuits connected to said TDMs and trunk circuits connecting said TDMs to each other, one of said TDMs being connected to a network controller which stores first parameters characteristic of said trunk circuits and second parameters characteristic of said subscriber circuits,

• said network controller comprising:
• means for detecting a failure in one or more of said trunk circuits;
• means for calculating evaluation indexes responsive to said first parameters, said second parameters and physical status information responsive to the trunk circuit(s) in which said failure has occurred;
• means for determining network reconfiguration data to be supplied to each of the TDMs on the basis of said evaluation indexes;
• and means for distributing frames including said network reconfiguration data from said network controller to each of the TDMs so that each of the TDMs changes the connecting relationships stored in its memory according to the distributed reconfiguration data.

In a packet exchange system which comprises a plurality of packet exchangers and packet terminals connected thereby by trunk lines, wherein, when a sending terminal sends a packet to be transmitted to a destination terminal via one or more packet exchanger(s), the sending terminal inserts route information in the packet to be transmitted, and said packet exchanger sends said packet to said destination terminal responsive to said route information,

• a network control system comprising:
• means for generating a broadcast packet by inserting broadcasting data in a transmitted packet when said sending terminal detects a failure in a trunk circuit connecting said packet exchangers;
• means for transmitting said broadcast packet to a packet exchanger connected directly to said sending terminal;
• means for operating each packet exchanger to insert a pair of route identifiers, identifying the receiving route and the sending route pertinent to that packet exchanger as a part of the route information inserted in said broadcast packet, and to transmit said broadcast packet over all routes connected thereto except the route by which the broadcast packet was received;
• means for operating said destination terminal to store the route information contained in the broadcast packet when received in a memory of said destination terminal, and to generate a responding packet including said route information and returning said responding packet to said sending terminal;
• and
• means in the sending terminal for storing said route information comprised by said responding packet and for using said route information thereafter.