from Wiktionary, Creative Commons Attribution/Share-Alike License.
- initialism electronics Asynchronous Transfer Mode Adaption Layer Type 2,
ATMAdaption Layer Type 2.
Sorry, no etymologies found.
In practice, however, most operators have deployed either time-division multiplexing (TDM) or asynchronous transfer mode (ATM) (AAL2) backhaul facilities to take advantage of their metro infrastructure and core technology.
AAL2: known as Variable Bit Rate (VBR), allows more variation in delay, which is tolerable for services such as digitized video and some digital voice