Method and Apparatus of ATM(Asynchronous Transfer Mode) Firewall Switch having distributed CAC(Call Admission Control) and Parallel Cell Screen Structure

摘要

PURPOSE: An ATM firewall switch device with a call admission control structure and a parallel cell screen structure and a method therefor are provided to minimize the deterioration of an ATM switch and delay of a cell processing time when adopting a virtual connection or packet level security policy. CONSTITUTION: A signal cell filter(200) extracts a signal cell from cells introduced into a screened input unit(102). A management cell filter(201) extracts a management cell from cells which have passed the signal cell filter(200). A parallel cell screen unit(202) reduces a cell processing time delay according to a screen policy application. A header converter(205) adds switch information to a user cell which has passed the parallel cell screen unit(202), and outputs it to a cell switching unit(104). A VP(Virtual Path)/VC(Virtual Connection) table(206) stores allocated VPI(Virtual Path Indicator)/VCI(Virtual Connection Indicator) information and policy information on a virtual line. A security policy cash(207) is referred to determine a security policy. A cell duplicator(203) duplicates introduced user cell as many as the user cell filters(204) and transfers it to a cell filter(204). The user cell filter(204) filters only the cells allocated to itself by referring a VPI(Virtual Path Indicator).