In this paper, we develop a mathematical model of a load control mechanism for SIP server signaling networks based on a hysteretic technique. We investigate loss-based overload control, as proposed in recent IETF documents. The queuing model takes into account three types of system state - normal load, overload, and discard. The hysteretic control is made possible by introducing two thresholds, L and H, in the buffer of total size R. We denote the mathematical model using the modified Kendall notation as an queue with hysteretic load control and bursty input flow. Algorithms for computation the key performance parameters of the system were obtained. A numerical example illustrating the control mechanism that minimizes the return time from overloading states satisfying the throttling and mean control cycle time constraints is also presented. © 2013 Springer-Verlag.