This document outlines the issues facing nomadic communications in an IP-based environment. While cellular systems epitomise current concepts of mobility, there is an industry need to support similar functions in non-cellular environments as well. Unfortunately, solutions defined to-date by the cellular industry tend to be closely tied to the technology employed over the radio link (e.g. GSM, cdma2000, UMTS, EDGE). To facilitate discussion, this document begins with a high-level description of functional entities comprising an Open IP Network Infrastructure. It then defines an abstract model of the access link used to connect a mobile host to the network. Using these entities and model, we then go on to discuss the issues facing nomadic computing that could be usefully addressed by an IETF working group like CRAPS.