Editing Asynchronous Transfer Mode (section)

===Service types===
ATM supports different types of services via AALs. Standardized AALs include AAL1, AAL2, and AAL5, and the rarely used<ref>{{Cite web|title=A Brief Overview of ATM: Protocol Layers, LAN Emulation, and Traffic Management|url=https://www.cse.wustl.edu/~jain/papers/ftp/atm_tut/index.html|access-date=2021-07-21|website=www.cse.wustl.edu}}</ref> AAL3 and AAL4. AAL1 is used for constant bit rate (CBR) services and circuit emulation. Synchronization is also maintained at AAL1. AAL2 through AAL4 are used for [[variable bitrate]] (VBR) services, and AAL5 for data. Which AAL is in use for a given cell is not encoded in the cell. Instead, it is negotiated by or configured at the endpoints on a per-virtual-connection basis.

Following the initial design of ATM, networks have become much faster. A 1500 byte (12000-bit) full-size [[Ethernet frame]] takes only 1.2&nbsp;μs to transmit on a {{nowrap|10 Gbit/s}} network, reducing the motivation for small cells to reduce jitter due to contention. The increased link speeds by themselves do not eliminate jitter due to queuing.

ATM provides a useful ability to carry multiple logical circuits on a single physical or virtual medium, although other techniques exist, such as [[Point-to-Point Protocol#Multiclass PPP|Multi-link PPP]], Ethernet [[VLAN]]s, [[VxLAN]], [[MPLS]], and multi-protocol support over [[SONET]].