Alcatel-Lucent Bell Labs Alcatel-Lucent Bell Labs The goal of Application-Layer Traffic Optimization (ALTO) is to bridge the gap between network and applications by provisioning network related information. This allows applications to make informed decisions, for example when selecting a target host from a set of candidates. Therefore an ALTO server provides network and cost maps to its clients. This draft discusses options on how to provide incremental updates for these maps, with the goal of reducing the amount of data needed for transmitting the maps and shortly evaluates the two most promising options.