Simulation a modified Erlang system with priority customers

We consider a modified Erlang loss system with two-class priority customers. Class-1 customers are lost if meet all servers busy but may terminate class-2 customers, while class-2 customers may stay in infinite capacity queue. We show the stability condition of this system and conduct discrete event simulation to verify this condition. We conduct simulation for both exponential and Pareto service time distributions. Results include sample mean of queue sizes in cases, when the stability condition is satisfied or not, and completely confirm this condition.