ATM networks accessed through LAN emulation are attached to VTAM® through an IBM® Open Systems Adapter (configured in SNA mode). They appear to VTAM as though they are Ethernet or Ethernet-type LANs or token-ring networks. ATM LAN emulation connections offer the benefits of fast data transfer, but they do not offer the full services of ATM networks, such as guaranteed bandwidth and Quality of Service.

ATM LAN emulation connections through an IBM Open Systems Adapter are defined to VTAM in the same way as LAN connections through an IBM 3172 Nways Interconnect Controller. To define ATM LAN emulation connections through the IBM Open Systems Adapter, apply the information about defining LAN connections through the IBM 3172 Nways Interconnect Controller, found in External communication adapter (XCA) connections and IBM 3172 Nways Interconnect Controller connections between APPN nodes.