Commnication software supprorts communication protocol,which enables data and information exchanges between communication entities. Communication software handles tasks such as connection establishment, concurrency, event detection, synchronization, and so on. Application framework (called framework) was designed as semi-complete application that can be developed for building application , which makes use of a set of abstact classes and its interclass collaborations. Objective of this paper is using famework to develop communication software. Framework used is provided by ACE toolkit, an object oriented toolkit that provides framework dedicated for building communication software. Four of them (ACE Reactor, ACE Poactor, ACE Acceptor-Connector and ACE Task) are used in the case studies. The use of this framework is represented in the requirement specification, static structure design, sequential diagram design, and implementation (coding and testing). Framework of ACE has been used for developing communication software which is called SMS on LAN Application. Development of this application showed that the framework provided by ACE toolkit can be used for communication software development and handles task in that software. The SMS On LAN was defined, design, and implemented using microsoft visual C++tm version 6.0 Keywords: Framework, Communication Sofware, ACE Toolkit, SMS On LAN