Hasslinger 2nd part

➢ Overlays of various type are used to bridge heterogeneous interconnecting networks for comfortable end-to-end service delivery ➢ P2P networks establish overlays on user terminals offering global services without or at a minimum of own network infrastructure ➢ Overlays can provide new services or extend existing services or networks on top of & independent of underlying infrastructure ➢ Overlays introduce more overhead - Additional encapsulation and control data - Protocol functions may overlap on different layers - Awareness of and cooperation with lower layers required for popular P2P services to stay competitive, e.g. for shorter paths