Note: This Working Group is jointly chartered by the Routing Area. The Routing Area Director: Joel Halpern (jhalpern@newbridge.com) Motivation The Internetworking Over NBMA Working Group was formed to combine the work of two previous working groups, IP Over ATM (ipatm) and Routing Over Large Clouds (rolc), because these two groups were often working very closely together on similar, if not identical, problems and solutions. The group will be evolutionary, not revolutionary; it will continue the work in the previous groups on the NBMA Next Hop Resolution Protocol (NHRP), IPv4 over ATM, and IPv6 over ATM. Description This WG will focus on the issues involved in internetworking network layer protocols over NBMA (non-broadcast multiple access) subnetwork technologies, such as ATM, Frame Relay, SMDS, and X.25 private and public networks. The group will endeavor to make all its solutions applicable to the entire range of network layer protocols and NBMA subnetworks. We recognize, however, that there will be cases where specific optimizations to IPv4, IPv6, and particular subnetwork technologies will result in better service to the user. The group will focus on protocols for encapsulation, multicasting, addressing, address resolution and neighbor discovery, interactions with and optimization of internetworking-layer routing protocols when run over NBMA subnetworks, and protocol-specific network management support, as appropriate. The working group will submit these protocols for standardization. The working group may also produce experimental and informational documents, including "Best Current Practices" guidelines, as required. For ATM, the WG will continue the ipatm WG's transition from the LIS model described in RFC 1577 to the generalized NHRP model developed by the rolc WG, including a transition plan for existing networks. The working group will coordinate its activities with the following other working groups: 1) Integrated Services over Specific Lower Layers (issll), for coordinating Quality of Service (QoS) issues and the implementation of IP integrated services capabilities (RSVP, the service models, etc.) over NBMA networks. 2) IP Next Generation (ipng), for IPv6 over ATM coordination. The working group will also coordinate its work with other relevant standards bodies (e.g., ATM Forum, Frame Relay Forum, ANSI T1S1, ITU-T) and make recommendations to these organizations regarding the requirements for IP internetworking where the current published subnetwork standards, practices, or functionality do not meet the needs of internetworking. The working group will not develop subnetwork layer standards.