ATM is widely used as a backbone technology in carrier networks and large enterprises， but never became popular as a local network (LAN) topology。 ATM is highly scalable and supports transmission speeds of 1。 5， 25， 100， 155， 622， 2488 and 9953 Mbps。 ATM is also running as slow as 9。 6 Kbps between ships at sea。 An ATM switch can be added into the middle of a switch fabric to enhance total capacity， and the new switch is automatically updated using ATM's PNNI routing protocol。
