Abstract Queueing networks are of interest for analyzing congestion and delay in communication networks and complex manufacturing systems.
Heavy traffic is a very common phenomenon in the queueing networks.
In general, the exact analysis of such system is quite difficult to obtain, both theoretically and computationally. One way to cope with these difficulties is to develop methods of the diffusion approximations. Usually, before establishing the diffusion approximations, we need to obtain the fluid approximation. This motivates us to study the relationship between fluid approximations and diffusion approximations for multiclass queueing networks. In particular, we focus on priority multiclass queueing networks.