FIFO channel languages of Communicating Finite State Machines are useful for protocol verification The reachability set is the set of all reachable states and it's the purpose of reachability analysis. Computing this set is not reasonable especially if it's infinite. Context free grammars are defined for languages for FIFO channel systems. A grammar 'like' context free is defined for each CFSM. Each rule is of the form X \to u^{-1}Yv, where u^{-1}Yv stands for the residual of the language (L(Y)v) with regard to u. Context-free grammar properties are used to make transformations for calculating the channel languages which are fix-point of a system of equations. In this paper we use some acceleration techniques to calculate the channel languages and we show how we can use theoretical framework to verify some protocol properties such as reachability and deadlock problems.