UCLouvain, Belgium UCLouvain, Belgium UCLouvain, Belgium The RRG is working on the design of an alternate Internet Architecture in order solve issues of the current architecture related to scalability, mobility, multi-homing, and inter-domain routing. Among the various proposals, LISP (Locator/ID Separation Protocol) is one of the most advanced. The present draft describes the overall architecture of OpenLISP, an open source implementation of the LISP proposal. Further, the draft contains some general remarks concerning the design and the implementation of the LISP protocol.