| 摘要 |
PURPOSE: An ISDN call control signal processing protocol using a virtual task ID is provided to carry out synchronization between an upper layer and a lower layer using virtual task ID at a hierarchical protocol structure. CONSTITUTION: A setup request signal is transferred from a call process layer to a call control signal process layer(S301). A call process layer receiving the setup request signal generates virtual task ID for a corresponding call using a manner of assigning the predetermined amount of memory, and stores information comprising a call channel, a call reference value, a timer, and a state(S302). The setup request signal is sent from a call control process layer to a data link layer(S303). At a switchboard of the other party, a data link layer receives a call process signal via a physical layer and transfers a received signal to a call control signal process layer, which sends the call process signal with virtual ID information to a call process layer(S304). A data link layer receives ring signal information from a telephone of the other party and sends a received signal to a call control signal process layer(S308), which sends the ring signal information with virtual task ID information to a call process layer(S309). When a call is connected(S316), a data link layer receives a connection signal and sends a received signal to a call control signal process layer(S311,S312), which sends a setup confirm signal with the virtual task ID information to a call process layer(S313,S314,S315).
|
