Routing system in data communication with frame relay procedure control

DETAILED DESCRIPTION What is claimed is: 1.
A routing system for use in each station of first through N-th exchange stations of a data communication network in selecting an alternative route from a plurality of transit trunks connecting said each station to others of said exchange stations to send a call with no interruption through said alternative route, where N represents an integer which is equal at least to two, said routing system including a trunk control section comprising: trunk terminator groups physically terminating said transit trunks to receive incoming signals and to send outgoing signals through said transit trunks; a switch for switching said incoming signals into switch output signals and transmitted signals into said outgoing signals; selecting means for conveying said switch output signals as conveyed signals and switch input signals as said transmitted signals and for selecting said alternative route; frame relay communication control means for processing said conveyed signals into processed signals and controlled signals into said switch input signals in accordance with frame relay protocols; frame relay procedure processing means for processing said processed signals into frame relay output signals and frame relay input signals into said controlled signals and for finding a fault sent through said transit trunks to locate a faulty trunk transmitting said fault, to produce a fault indication signal indicative of said faulty trunk during presence of said fault, to make said frame relay output signals carry said fault indication signal, to control said switch, and to make said selecting means select said alternative route in place of said faulty trunk during presence of said fault; monitor and control means connected to said frame relay procedure processing means, said monitor and control means for executing layer 1 and layer 2 protocols on said faulty trunk for restoration of said fault while said switch is controlled; and input-output means for processing said frame relay output signals into reception data signals and transmission data signals into said frame relay input signals