| 摘要 |
PURPOSE: A method for switching an AAL using an AAL2 is provided to use the set ATM virtual channel band width for an AAL2 connection. CONSTITUTION: An input FIFO stores inputted ATM cells(301). An AAL2 receiving task reads a cell from the input FIFO and processes a cell header if an ATM to be processed exists(303). The AAL2 receiving task reads a VCI value and searches a VCI value of a VCI-CID look-up table(307). The AAL2 receiving task reads and processes an AAL2 STF value. In the case of being overlapped, the AAL2 STF value is processed by using a CID split and CID part located in a processing table by virtual channels. In the case that an AAL2-PH is overlapped, an AAL2 CPS-PH is primarily completed by finding the corresponding temporary buffer. In the case that an AAL2-CPS payload is overlapped, the corresponding CID is searched and attached on the corresponding VC buffer. The AAL2 CPS-PH is processed. A transmitting VCI-CID value being mapped to the received VCI-CID is calculated. The CPS-PH is completed using the transmitted VCI-CID value. It is periodically checked whether a timer value is expired by a global timer with respect to a VC buffer. A transmitting of a cell is prepared in the case that a time is expired or the VC buffer becomes full by checking the status of a build-up of a VC buffer whenever one CPS-PK is appended. If a cell to be transmitted is prepared, the STF and the ATM header are completed. The completed ATM cells are stored in an output buffer for a transmission.
|
