Claims
- 1. A trunk transmission network comprising:
a plurality of nodes connected via physical transmission lines; a plurality of paths for transmitting information signals being set up on physical transmission lines between nodes; for an information signal which is to be transmitted from one of the plurality of nodes termed a source node to another of the plurality of nodes termed a destination node, each path connects the source node and the destination node either directly or via other nodes; said paths which are between source and destination node pairs being set up on the basis of pre-classification into higher service class paths in which any loss of information occurring in that path is made good, and lower service class paths which permit loss of information to occur in the path; and each node including means which, when that node is a source node, recognizes the service class of the information signal to be sent to the destination node and selects a path corresponding to that service class.
- 2. A trunk transmission network according to claim 1, wherein:
the higher service class is further divided into a highest class and a middle class; a highest class path employs complete diversity routing wherein a plurality of different routes are set up for that path; a middle class path can be re-routed around the location of a failure when a failure has occurred in a portion of the route traversed by the path; and a lowest service class path is not alternatively routed when a failure has occurred in the route traversed by the path.
- 3. A trunk transmission network according to claim 1, wherein each of at least some of the plurality of nodes has a distributed path setup means which sets up paths prior to transmission of an information signal by using a control channel to exchange control signals with other nodes.
- 4. A trunk transmission network according to claim 3, wherein the distributed path setup means selects a route, in accordance with the required service class, from among the plurality of routes which can connect the source and destination nodes, and then successively sets up a path along the selected route, starting from the source node.
- 5. A trunk transmission network according to claim 2, wherein:
the physical transmission lines are in the form of a plurality of ring networks connected together, each ring network comprising at least two nodes connected in a ring; each ring network is connected to another ring network by means of some of the network nodes acting as bridge nodes; and the distributed path setup means includes means which, for a highest class path, sets up two paths in mutually opposite directions around each ring network through which the highest class path passes; and which, for a middle class path and a lowest service class path, sets up a path in one direction around each ring network.
- 6. A trunk transmission network according to claim 5, wherein the means for path setup comprises:
means which, when the node is a source node, gets a token that is circulating around the ring network to which that node belongs, and then sends path setup request packets in two mutually opposite directions; means which, when the node is a bridge node, transfers the path setup request packet that has arrived in one direction to the next ring network in the same direction; and means which, when the node is a destination node and the packets received from the two directions request setup of a highest class path, sends back a response to these packets in two mutually opposite directions, and when the packets received from the two directions request setup of a middle class path or a lowest service class path, sends back a response to one of these packets in one direction only.
- 7. A trunk transmission network according to claim 5 or 6, wherein each node has means for hitlessly selecting the better quality route of the highest quality path comprising two routes for which that node is the destination node.
- 8. A trunk transmission network according to claim 5 or 6, wherein the path setup means includes means for automatically restoring a middle service class path by re-routing in the event of a failure.
- 9. A trunk transmission network according to claim 8, wherein the aforesaid restoration means includes means for looping back a token contained in the aforementioned control channel when a node has detected a failure in an adjacent link or node.
- 10. A trunk transmission network according to claim 5, wherein:
each ring network is connected to another ring network via at least two bridge nodes; at least one node of any of the ring networks comprises means for transmitting, in one direction around the ring network to which that node belongs, a node information collecting packet for collecting information relating to the network configuration of node deployment and operating state of the nodes in that ring network and in other of said ring networks; and means which terminates a node information collecting packet which has returned to that node which originally transmitted it, and which stores the information collected by that packet; each node of each ring network comprises means which writes its node ID and state in a received node information collecting packet and transfers the packet to the next node; and each node used as a bridge node comprises, in addition to this node information collecting packet writing and transfer means, means for temporarily storing a node information collecting packet received from one of two ring networks mutually connected by the bridge node in question; means which, when a right to transmit to another of the two ring networks has been received, transfers to said another ring network the node information collecting packet stored in the aforementioned temporary storage means; means which deletes the node information collecting packet stored in the temporary storage means if a node information collecting packet from another bridge node has been received but no transmitting right has been obtained; and means for terminating a node information collecting packet which has returned to the bridge node which originally transferred it, and for write inhibiting that packet and returning it to the original ring network.
- 11. A trunk transmission network according to claim 10, wherein each node of each ring network, including the bridge nodes, comprises means which, if it receives the same node information collecting packet within a predefined time, deletes this packet.
- 12. A node for transmitting information signals via paths set up in advance in physical transmission lines in a trunk transmission network, comprising:
means which, for the transmission of an information signal from that node as a source node, recognises whether the service class of that information signal is a higher service class for which any loss of information in the path has to be made good, or a lower service class which permits loss of information in the path, and selects a path corresponding to that service class.
- 13. A node according to claim 12, wherein the means for selecting a path includes means which further divides the higher service class into a highest class and a middle class; and which, for an information signal of the highest class, selects a path comprising a double route; and, for an information signal of the middle class, selects a path in one direction which can detour around the location of a failure when a failure has occurred in a portion of the route; and, for an information signal of the lowest service class, selects a path in one direction, which is not alternatively routed when a failure occurs in that route.
- 14. A node according to claim 12, which has a distributed path setup means which sets up paths prior to transmission of an information signal by using a control channel to exchange control signals with other nodes.
- 15. A node for transmitting information signals via a trunk transmission network in which a plurality of ring networks are connected together, said node comprising:
distributed path setup means which sets up paths between itself and a destination node, a path being the unit of information transfer, by using a control channel to exchange control signals with other nodes; wherein this distributed path setup means comprises:
means which gets a token which is circulating around the ring network to which the node belongs, and then sends path setup request packets in two mutually opposite directions; means which, for a high grade path for which reliability and quality are required, after its has received from the two directions response packets in reply to the path setup request packets, sets up two paths in mutually opposite directions in each ring network through which the high grade path will pass; and means which, for a low grade path for which less reliability and quality are required, after it has received from one direction a response packet in reply to a path setup request packet, sets up a path in one direction in each ring network.
- 16. A node according to claim 15, wherein the distributed path setup means includes means which further divides the lower grade path into two grades, and which, for a relatively higher grade path, automatically restores the path by re-routing when a failure has occurred.
- 17. A node for transmitting information signals via a trunk transmission network in which a plurality of ring networks are connected together, said node comprising:
distributed path setup means which uses a control channel to exchange control signals with other nodes in order to set up paths between a source node and a destination node, a path being the unit of information transfer between a source node and a destination node, said distributed path setup means including means which, when it receives a path setup request packet, decides whether or not the path can be transferred in that direction, adds to that packet information indicative of the result of this decision, and transfers the packet to the next node.
- 18. A node according to claim 17, wherein the distributed path setup means includes means for looping back a token contained in the aforesaid control channel when a failure has been detected in an adjacent link or node.
- 19. A node used as a bridge node for mutually connecting two ring networks for transmission of information signals, said node comprising:
distributed path setup means which uses a control channel to exchange control signals with other nodes in order to set up paths between a source node and a destination node, a path being the unit of information transfer between a source node and a destination node, said distributed path setup means including:
means which, for a path setup request packet which has arrived in one direction in one ring network, decides whether or not the path can be transferred in the same direction of another ring network, adds to that packet information indicative of the result of this decision, and transfers the packet in the same direction; and means which transmits to the aforesaid one ring network a response packet to which has been added information indicative of the result of the aforesaid decision.
- 20. A node for transmitting information signals via a trunk transmission network in which a plurality of ring networks are connected together, said node comprising:
distributed path setup means which uses a control channel to exchange control signals with other nodes in order to set up paths between a source node and itself, a path being the unit of information transfer; said distributed path setup means including:
means which, upon receipt from two directions path setup request packets that terminate at the node in question, and the path in question is a high grade path for which reliability and quality are required, sends a response packet to which has been added information indicative of whether or not those paths can actually be set up, said response packet being sent in each of the opposite directions to the aforesaid two directions; and which, when the path in question is a low grade path for which reliability and quality are not required to such an extent, sends a response packet in the opposite direction to one of the aforesaid two directions.
- 21. A node according to claim 20, including means for hitlessly selecting the better quality route from the high grade path that has been set up between a source node and itself.
- 22. A node for transmitting information signals via a trunk transmission network in which each of a plurality of ring networks is connected to another ring network via two or more bridge nodes, said node comprising:
means for transmitting in one direction around the ring network to which it belongs, a node information collecting packet for collecting information relating to the network configuration of node deployment and operating conditions of nodes in the ring network to which it belongs, and in the other ring networks; and means which terminates a node information collecting packet which has returned to the node in question, which originally sent it, and which stores the information which has been collected by this packet.
- 23. A node for transmitting information signals via a trunk transmission network in which each of a plurality of ring networks is connected to another ring network via two or more bridge nodes, said node comprising:
means which, when it receives a node information collecting packet, writes its own ID and node conditions in said packet, and means which transfers the packet to the next node.
- 24. A node used as a bridge node for mutually connecting two ring networks for transmission of information signals, said node comprising:
means which, when it receives a node information collecting packet, writes its own ID and node conditions in said packet and transfers the packet to the next node; means which temporarily stores a node information collecting packet which has been received from one of two ring networks which the node in question mutually connects; means which, when a transmitting right for the other of the two ring networks has been obtained, transfers the node information collecting packet stored in the temporary storage means to the other ring network; means for deleting the node information collecting packet stored in the temporary storage means when it has received a node information collecting packet from the other bridge node without obtaining a transmitting right; and means for terminating a node information collecting packet which has returned after being transferred by the node in question, write inhibiting this packet, and sending it back to the original network.
Priority Claims (3)
Number |
Date |
Country |
Kind |
8-225492 |
Aug 1996 |
JP |
|
8-326944 |
Dec 1996 |
JP |
|
8-232169 |
Sep 1996 |
JP |
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority from Japanese Application No. 8-225492 filed Aug. 27, 1996, No. 8-237169 filed Sep. 2, 1996, and No. 8-326944 filed Dec. 6, 1996, the contents of each of which is incorporated hereinto by reference.
Divisions (1)
|
Number |
Date |
Country |
Parent |
08918103 |
Aug 1997 |
US |
Child |
09738978 |
Dec 2000 |
US |