ATM connection band control method and control system

An asynchronous transfer mode (ATM) connection band control system in an ATM network may include a memory to store band acquiring data associated with one or more preferential switched virtual connections (SVCs) having high preference in the ATM network. The band acquiring data may include band data for preliminarily acquiring a band for the one or more preferential SVCs. The ATM connection band control system may also include a control portion to perform connection admission control such that a band for one of the preferential SVCs with band acquiring data in the memory is guaranteed regardless of whether a connection for the one of the preferential SVCs is established, and the band for the one of the preferential SVCs is available to a non-preferential SVC when the connection for the one of the preferential SVCs is not established.