Creating a network app application transport network data link write programs that: physical run on (different)end systems communicate over network e.g.,web server software communicates with browser software application no need to write software for transport network data link pplication network-core devices physical transport network network-core devices do data link physical not run user applications applications on end systems allows for rapid app development, propagation Application Layer 2-5Application Layer 2-5 Creating a network app write programs that:  run on (different) end systems  communicate over network  e.g., web server software communicates with browser software no need to write software for network-core devices  network-core devices do not run user applications  applications on end systems allows for rapid app development, propagation application transport network data link physical application transport network data link physical application transport network data link physical