Automatic Repeat reQuest (ARQ) protocols are used to control transmission errors in data communications. They are used at Data Link Control (DLC) sublayer of Data Link Layer (DLL) of OSI (Open Systems Interconnection) network model to achieve flow and error control and provide smooth and reliable transmission between network nodes. ARQ protocols use acknowledgments and timeouts to satisfy reliable data transmission over noisy channels. Types of ARQ protocols include Stop-and-wait ARQ, Go-Back-N ARQ, and Selective Repeat ARQ. This paper presents a new mathematical model to analyze performance of Go-Back-N ARQ protocol over noisy channels. Many performance measures of Go-Back-N ARQ protocols are discussed. The analysis uses Stochastic Process and a two-dimensional Markov Chain to present the proposed model. We study the distributions of system occupancy and waiting time when implementing Go-Back-N ARQ protocol in data transmission. Results include: Probability Generating Functions (PGF) of system occupancy and waiting time. Moreover, mean values of previous system parameters are derived. ARQ protocols are essential for peer-to-peer protocols that provide reliable data transmission. The obtained results can be adopted and implemented in simulations of similar communication systems or approximating relevant systems.