Transparent resource discovery for mobile computers

As mobile computers move from one place to another, their “physical” points of attachment to the network change from time to time. Host movement causes service disruption. The Mobile-IP protocol attempts to solve this problem by hiding the effect of change in network service access points from the transport and higher layers. Thus, Mobile-IP ensures that a mobile host remains “virtually” connected to its home regardless of its current point of attachment. This allows existing applications to operate over mobile nodes without any modifications. While away from home, mobile hosts continue to access services from servers located at the home network. Applications running on mobile hosts therefore experience increased latency as accesses to home resources (such as name servers, file servers, etc.) are routed over multiple links and routers. To alleviate this problem, new mechanisms are required that enable mobile hosts to discover and access needed resources on the foreign network. In this paper, we outline alternative approaches for providing such mechanisms and discuss their relative merits and limitations