Communication network having multi-conjunction architecture

• US 4,887,259 A
• Filed: 09/07/1988
• Issued: 12/12/1989
• Est. Priority Date: 09/08/1987
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Morita, Tetsuya
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/241,414
• Time in Patent Office: 461 Days
• Field of Search: 370/58, 370/60, 370/94, 340/825.5
• US Class Current: 370/401
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04Q 3/0016 Arrangements providing connection between exchanges

Abstract

A communication network structure including a plurality of communication networks, and a plurality of router hosts for coupling the communication networks. The router hosts which are directly connected to an arbitrary communication network store as a whole the host numbers of all of the terminal hosts which are directly connected to certain ones of the communication networks. The certain communication networks are indirectly coupled to the arbitrary communication network through the router hosts. The router hosts which are directly connected to the arbitrary communication network do not store the host number of a terminal host which is directly connected to the arbitrary communication network.

Claims

1. A communication network structure comprising:

a plurality of communication networks, each of said communication networks having a multi-conjunction architecture and including a plurality of node apparatuses, a plurality of first transmission paths for coupling the node apparatuses, and a plurality of terminal hosts connected to at least an arbitrary one of the node apparatuses, a maximum propagation delay time of the first transmission path being less than a predetermined value;

one or a plurality of router hosts connected to each of said communication networks; and

a second transmission path for coupling two said communication networks through a pair of said router hosts respectively located on ends of said second transmission path, a maximum propagation delay time of said second transmission path being greater than or equal to said predetermined value,

said router host having first means for multiplexing signals to and separating signals from said second transmission path, second means coupled to said first means for storing identification information including host numbers of at least the terminal hosts which are directly connected to a said communication network which is coupled to said router host through a said second transmission path, third means coupled to said first and second means for controlling operations of said router host, input and output channels connected to one of the node apparatuses of a said communication network and to said third means, and input and output ports connected to said third means and said second transmission path,

said third means detecting a first receiving input channel which receives a first sending signal first out of unused light channels connected to said one of the node apparatuses of a said communication network and closing an output channel having a channel number corresponding to that of the first receiving input channel and all of the unused input channels except the first receiving input channel when the first receiving input channel is detected to immediately output an active signal to the output channel having the channel number corresponding to that of the first receiving input channel,

said third means collating a destination host number included in the first sending signal and the host numbers stored in said second means and outputting a temporary first returning signal to the output channel having the channel number corresponding to that of the first receiving input channel when the destination host number exists in the host numbers stored in said second means, so as to fix a temporary path between a source host which originates the first sending signal and said router host;

said third means outputting to a control output port of the output ports a caller information including a port designation information and the first sending signal when the destination host number exists in the host numbers stored in said second means, said port designation information being an identification information of a port of said first means corresponding to the first receiving input channel,

said third means detecting a receipt of a connection completion information including the port designation information and a first returning signal at a control input port of the input ports and connecting the designated output port to the output channel having the channel number corresponding to that of the first receiving input channel so as to output the first returning signal from the output channel having the channel number corresponding to that of the first receiving input channel and connecting the first receiving input channel to one of the output ports corresponding to the first receiving input channel when the destination host number exists in the host numbers stored in said second means,

said third means opening the closed channel other than the designated channels after the first receiving input channel and the output channel having the channel number corresponding to that of the first receiving input channel are connected to the corresponding input and output ports,

said third means supervising a channel with a fixed path and releasing the channel as an unused channel when a signal received at the channel continues a predetermined state for a communication end detection time constant.

2. A communication network structure as claimed in claim 1 in which said third means supervises a receipt of the caller information at the control input port and when the receipt of the caller information is detected said third means extracting the port designation information from the caller information, disconnecting the input and output channels other than those corresponding to the designated port, and connecting the control input port to the output channel corresponding to the designated port, said third means connecting the designated input and output ports of said second transmission path to the output and input channels corresponding to the designated input and output ports, outputting the connection completion information from the control output port, and opening the channels other than the closed channels corresponding to the designated port when the first returning signal is detected at the input channel corresponding to the designated output channel after a network time constant elapses from a time when the first sending signal is outputted.

3. A communication network structure as claimed in claim 1 in which a said terminal host which is connected to a said communication network to which an arbitrary one of said router hosts is directly connected requests registration of a terminal registration information with respect to a predetermined one of said router host which is coupled to said arbitrary router host through a said second transmission path, said third means of said arbitrary router host outputting the active signal to the control port and transmitting the terminal registration information from the control port to said predetermined router host when the first sending signal includes the terminal registration information intended for said arbitrary router host and outputting a terminal registration completion information to a control output channel of the output channels when the terminal registration completion information is received from said predetermined router host to thereby register the terminal registration information in said predetermined router host, said terminal registration information including a host number of said terminal host making the request.

4. A communication network structure as claimed in claim 3 in which said third means of said predetermined router host stores the host number included in said terminal registration information in said second means thereof when a receipt of the first sending signal including said terminal registration information is detected and transmitting the terminal registration completion information to the control output port thereof.

5. A communication network structure as claimed in claim 3 in which said third means of said predetermined router host makes an inquiry to all of said router hosts directly connected to a said communication network to which said predetermined router host is directly connected on whether or not the host number of said terminal host making the request is already registered in one of said router hosts when a receipt of the first sending signal including said terminal registration information is detected, and if the host number included in said terminal registration information is already registered in one of said router hosts said predetermined router host storing the host number in said second means of said predetermined router host and transmitting the terminal registration completion information to the control output port thereof.

6. A communication network structure as claimed in claim 1 in which a said terminal host which is connected to a said communication network to which an arbitrary one of said router hosts is directly connected requests erasure of a terminal registration information with respect to a predetermined one of said router host which is coupled to said arbitrary router host through a said second transmission path, said third means of said arbitrary router host outputting the active signal to the control port and transmitting a terminal erase information from the control port to said predetermined router host when the first sending signal includes the terminal erase information intended for said arbitrary router host and outputting a terminal erase completion information to a control output of the output channels when the terminal erase completion information is received from said predetermined router host to thereby erase the terminal registration information in said predetermined router host, said terminal erase information including a host number of said terminal host making the request.

7. A communication network structure as claimed in claim 6 in which said third means of said predetermined router host erases the host number included in said terminal erase information from the host numbers stored in said second means thereof when a receipt of the first sending signal including said terminal erase information is detected and transmitting the terminal erase completion information to the control output port thereof.

8. A communication network structure as claimed in claim 6 in which said third means of said predetermined router host makes an inquiry to all of said router hosts directly connected to a said communication network to which said predetermined router host is directly connected on whether or not the host number of said terminal host making the request is registered in one of said router hosts when a receipt of the first sending signal including said terminal erase information is detected, and if the host number included in said terminal erase information is registered in one of said router hosts said predetermined router host erasing the host number from the host numbers stored in said second means of said predetermined router host and transmitting the terminal erase information to all of said router hosts directly connected to said communication network to which said predetermined router host is directly connected.

9. A communication network structure as claimed in claim 1 in which said communication networks are coupled in a form of an open loop, and said second means of said router host stores the host numbers of all of the terminal hosts which are indirectly coupled to said router host through the second transmission path and another router host excluding the host number of the terminal host which is directly connected to the communication network to which said router host is directly connected.

10. A communication network structure as claimed in claim 1 in which said communication networks are coupled in a form of an open loop, and the host numbers of all of the terminal hosts which are indirectly coupled to the communication network are stored without overlap by said second means of all of the router hosts directly connected to said communication network.

11. A communication network structure as claimed in claim 1 in which said communication networks are coupled in a form of a closed loop, and the host numbers of all of the terminal hosts which are indirectly coupled to the communication network are stored without overlap by said second means of all of the router hosts directly connected to said communication network.

12. A communication network structure as claimed in claim 2 in which said network time constant is a time in which a receipt of a first returning signal from a destination terminal host is guaranteed and is set to a sum of two times a propagation delay time of a maximum tolerable network length and a time it takes for the destination terminal host to start sending the first returning signal.

13. A communication network architecture comprising:

a plurality of communication networks, each of said communication networks having a multi-conjunction architecture and including a plurality of node apparatuses, a plurality of first transmission paths for coupling the node apparatuses, and a plurality of terminal hosts connected to at least an arbitrary one of the node apparatuses, a maximum propagation delay time of the first transmission path being less than a predetermined value;

one or a plurality of router hosts connected to each of said communication networks; and

a second transmission path for coupling two said communication networks through a pair of said router hosts respectively located on ends of said second transmission path, a maximum propagation delay time of said second transmission path being greater than or equal to said predetermined value,

said router host having first means for multiplexing signals to and separating signals from said second transmission path, second means coupled to said first means for storing identification information including host numbers of at least the terminal hosts which are directly connected to a said communication network which is coupled to said router host through a said second transmission path, third means coupled to said first and second means for controlling operations of said router host, input and output channels connected to one of the node apparatuses of a said communication network and to said third means, and input and output ports connected to said third means and said second transmission path,

a said router host forming a temporary link between a source terminal host which originates a first sending signal including a destination host number as the identification information when the destination host number is included in the host numbers stored in said second means, the formation of the temporary link being repeated until the first sending signal reaches the destination host.

14. A communication network architecture as claimed in claim 13 in which said second means of said router host stores the host numbers of all of the terminal hosts which are indirectly coupled to said router host through the second transmission path and another router host excluding the host number of the terminal host which is directly connected to the communication network to which said router host is directly connected.

15. A communication network architecture as claimed in claim 13 in which the host numbers of all of the terminal hosts which are indirectly coupled to a said communication network are stored without overlap by said second means of all of the router hosts directly connected to said communication network.

16. A router host for coupling first and second communication networks through a first transmission path and another router host having an identical construction, each of said first and second communication networks having a multi-conjunction architecture and including a plurality of node apparatuses, a plurality of second transmission paths for coupling the node apparatuses, and a plurality of terminal hosts connected to at least an arbitrary one of the node apparatuses, a maximum propagation delay time of the second transmission path being less than a predetermined value, a maximum propagation delay time of said first transmission path being greater than or equal to said predetermined value, said router host comprising:

first means for multiplexing signals to and separating signals from said first transmission path;

second means coupled to said first means for storing identification information including host numbers of at least the terminal hosts which are directly connected to said first communication network which is coupled to said router host through said first transmission path and said other router host;

third means coupled to said first and second means for controlling operations of said router host;

input and output channels connected to one of the node apparatuses of said second communication network and to said third means; and

input and output ports connected to said third means and said first transmission path,

said router host forming a temporary link between a source terminal host which is directly connected to said second communication network and originates a first sending signal including a destination host number as the identification information when the destination host number is included in the host numbers stored in said second means.