The visual shows such a setup. The end users are located on LANs behind the ATM routers. The diagram illustrates an important point when considering ATM protocols and their interactions in existing networks. From ATM’s viewpoint, “end-to-end” is actually “router-to-router.” From TCP’s standpoint, “end-to-end” is “computer-to-computer.”
Caution must be exercised when reading ATM standards: AAL is often referred to as an end-to-end protocol. As the visual shows, this is not the true end of the communications session. The AAL stops at the routers, while the higher layers pass all the way to the end computers.