High Quality Content by WIKIPEDIA articles! ATM25 is an ATM (Asynchronous Transfer Mode) version wherein data is transferred at 25.6 Mbit/s over Category 3 cable. ATM25 has no particular distinctions from other ATM versions. However, ATM25 chipsets are inexpensive in comparison to faster ATM chipsets, having the result of making ATM technology available for small office/home office environments. However, these networks no longer have much potential for expansion, as Ethernet has become the first choice in this domain.