Minimum cost routing based on relative costs of node resources

A communications network comprising:

• a plurality of network nodes interconnected by a plurality of incoming communication links and a plurality of outgoing communication links,
• each of said network nodes comprising:
• a first module, having a plurality of input ports and a plurality of output ports, for handling a group of channels between said input ports and said output ports as a routing unit;
• a second module, having an input port and an output port, for handling a channel between the input port and the output port as said routing unit;
• a module state database for storing module cost data of said first and second modules and module cost data of other network nodes;
• a link state database for storing link cost of each of said incoming links and each of said outgoing links,
• a switching system for determining a route of minimum cost by using said module state database and said link state database and establishing, according to the determined route, a connection between one of the incoming communication links and one of the input ports of said first and second modules and establishing a connection between one of the output ports of said first and second modules and one of said outgoing communication links;
• and
• terminating circuitry for transmitting a message to neighboring network nodes for communicating the contents of said module state database and receiving a message from said neighboring network nodes for updating said module state database according to the received message.

A centralized network management system comprising:

• a plurality of network nodes interconnected by communication links;
• a management center connected to said network nodes via control channels,
• each of said network nodes comprising:
• a first module, having a plurality of input ports and a plurality of output ports, for handling a group of channels between said input ports and said output ports as a routing unit;
• a second module, having an input port and an output port, for handling a channel between the input port and the output port as said routing unit;
• and
• a switching fabric having a plurality of incoming interfaces for interfacing incoming links and a plurality of outgoing interfaces for interfacing outgoing links;
• and
• said management center comprising:
• a module state database;
• a link state database for storing link cost of each of said incoming links and each of said outgoing links;
• and
• a path controller for storing module cost data of said first and second modules of each of said network nodes into said module state database and determining a route of minimum cost by using said module state database and said link state database and controlling said switching fabric to establish a connection between one of the incoming interfaces and one of the input ports of said first and second modules and establish a connection between one of the output ports of said first and second modules and one of said outgoing interfaces.

A routing method comprising the steps of:

• a) providing, in each of a plurality of network nodes interconnected by communication links, a first module having a plurality of input ports and a plurality of output ports, the first module handling a group of channels between said input ports and said output ports as a routing unit;
• b) providing, in each of a plurality of network nodes, a second module having an input port and an output port, the second module handling a channel between the input port and the output port as said routing unit;
• c) storing module cost data of said first and second modules of said plurality of network nodes in a module state database;
• d) storing link cost of said communication links in a link state database;
• and
• e) determining a route of minimum cost by using said module state database and said link state database.