METHOD FOR PROCESSING TRAFFIC IN AN ATM SWITCHING SYSTEM, ESPECIALLY CONCERNED WITH INCLUDING ASSOCIATED PHYSICAL LINK IDENTIFICATION INFORMATION IN A CELL HEADER, IN THE CASE OF TRANSMITTING ATM CELL TRAFFIC TO A SUBSCRIBER BOARD HAVING CAPACITY SMALLER THAN THAT OF A SWITCH, AND EXECUTING ATM CELL DISTRIBUTION TO EACH PHYSICAL LINK BY USING IT

摘要

PURPOSE: A method for processing traffic in an ATM(Asynchronous Transfer Mode) switching system is provided to obtain physical link identification information for ATM cell distribution through a masking process for the physical link identification field only of an ATM cell header, without the necessity of executing VPI(Virtual Path Identifier)/VCI(Virtual Channel Identifier) lookup procedures, by including associated physical link identification information in a cell header in the case of transmitting ATM cell traffic to a subscriber board having a plurality of physical links, of which the capacity is smaller than a switch. CONSTITUTION: In case that ATM cells are received to an STM-4 physical link(S51), an internal processor of an STM-4 subscriber board reassembles related ATM cells to configure an IP packet(S52). The internal processor confirms whether the configured IP packet is an IP forwarding packet or a GTP-U packet(S53). If it is an IP forwarding packet, the internal processor extracts a destination IP address from the IP forwarding packet(S54-1). If it is a GTP-U packet, the internal processor extracts a TEID address from the GTP-U packet(S54-2). Then, the internal processor searches a VPI/VCI lookup table for obtaining VPI/VCI information and the physical link identification information of the other side's subscriber board by using the extracted destination IP address or TEID address as a lookup key(S55). The internal processor configures an ATM cell header by using the obtained VPI/VCI information and physical link identification information(S56), forms an ATM cell containing the ATM cell header, and transmits it to an associated STM-1 subscriber board through a switch(S57).