Bandwidth: ATM uses fixed-length cells to transmit information. The cells consist of 48 bytes of payload and 5 bytes of header. An Ethernet has a bandwidth limit of 10 megabits per second (Mbps) for classic Ethernet, 100Mbps for Fast Ethernet, and 1000Mbps for Gigabit Ethernet. Ethernet has more bandwidth to the network technology but ethernet has some distance limitations. Ethernet is great for LAN but for WAN, ATM is efficient.
Scalability: ATM uses both WAN and LAN, which makes it a perfect fit for both larger/smaller geographical areas. Ethernet is mainly based on LAN. LAN can span over a limited range.
Interoperability: Gigabit Ethernet is a technology that has a speed of 1000Mbps although it has a higher data transfer speed the concept of LAN in Ethernet is the same and it has some downside. LAN can interoperate with ATM technology using an ATM LANE, ATM LANE is a protocol that allows existing networked applications to run over an ATM. LANE gives a pathway for ATM hardware/network to communicate with Ethernet.
Quality of Service: ATM has the best service to this date, ATM is the best network system to transfer most of the data types in comparison to Ethernet.