| 摘要 |
PURPOSE:To attain the ISDN D-channel packet data communication by using a packet data terminal equipment accommodated in a private branch exchange. CONSTITUTION:A B-channel signal in an ISDN TRK 2 is connected to an exchange switch 3 as a 64kbps data. A D-channel signal is distributed in a transmission line according to a value of an SAPI in a D-channel signal layer 2 address field in the ISDN TRK 2. In the case of SAPI=0, the signal is given to a basic interface trunk CPU in the ISDN TRK 2 as call control procedure information. In the case of SAPI=16, the data speed is converted from 16kbps into 64kbps in the ISDN TRK 2 as packet communication information and the resulting data is connected to the exchange switch 3. The signal is decoded into the D-channel signal with 16kbps at a data adaptor via the exchange switch 3 and sent to a packet data terminal equipment 5. |
