In this paper, the authors analyze a discrete-time priority queue with a session-based arrival process. They consider an infinitely large user population, where each user can start and end sessions. Sessions belong to one of two classes and generate a variable number of fixed-length packets which arrive to the queue at the rate of one packet per slot. The lengths of the sessions are generally distributed. Packets of the first class have transmission priority over packets of the other class. The model is motivated by E-commerce web servers and web servers handling delay-sensitive and delay-insensitive content.