Linux over the past few years has gained in popularity as the OS fit for embedded networking equipment. Its reliability, low cost and undisputed networking capabilities made it one of the most popular choices for the networking market. This paper demystifies for the first time the performance of embedded Linux ATM on the MPC8260 communications processor and derivative CPUs. UTOPIA and serial ATM performance is extensively evaluated, including IP routing/forwarding between LAN and WAN interfaces and the consideration of IP packet filtering overhead. This work is important for the implementation of integrated broadband access devices and multi-service access platforms, including DSL applications and inverse multiplexing over multiple TDM access interfaces. The presented analysis is an important independent measurement-based evaluation since only a few publicly available papers investigate the performance issues of ATM networking devices and since the evaluations made available to the public by system vendors are biased by obvious business interests.