Quality of service (QoS) method compatible with automated teller machine (ATM) and based on internet protocol (IP) layer 2/layer 3 switching

The invention provides a quality of service (QoS) method compatible with an automated teller machine (ATM) system and based on internet protocol (IP) layer 2/layer 3 switching. A system for realizing the method consists of two parts, i.e., an ATM cell adapting unit and an IP layer 2/layer 3switching unit. The ATM cell adapting unit is responsible to adapt an ATM cell that is received from a certain link layer medium into an Ethernet frame according to an adapting rule specified by a IP layer 2/layr 3, send the Ethernet frame to the IP layer 2/layer 3 switching unit and reversely adapt the Ethernet frame that is received from the IP layer 2/layer 3 switching unit into the ATM cell; the IP layer 2/layer 3 switching unit is responsible to provide services, such as switching, flow controlling, priority scheduling and the like for the Ethernet frame sent by the switched ATM cell adapting unit. With the adoption of the two units, the effects of compatibility of an ATM system and continuousness of QoS service can be achieved. Compared with the prior art, the method disclosed by the invention has the beneficial effects that two sets of ATM and IP maintenance and management modules are not required to be maintained, the ATM only needs to have an addressing capability, and then a IP-based switching chip can provide a flow control capability, therefore the structure of a network system is simplified.