VPI and VCI assignment system in ATM system

A channel assignment system in combination with a network having a plurality of nodes and a plurality of terminals, each of the nodes including a conversion unit which generates fixed-length cells, including channel identification and data, from data sent from one of the terminals, and a node management unit which manages a corresponding node, said channel assignment system comprising:

• management means for assigning virtual channels to calls and managing information concerning virtual channels currently assigned to the calls and idle virtual channels;
• assignment requesting means, provided in each of the nodes and connected to said management means, for requesting said management means to assign an idle virtual channel to a call received from one terminal of the plurality of terminals;
• channel identification set means for setting channel identification of the cells based on the idle virtual channel;
• and
• assignment cancelling means, provided in each of the nodes and connected to said management means, for requesting said management means to set said virtual channel assigned to said call in an idle state in response to an end of a communication related to said call.