Conventional network management protocols are insufficient especially in dealing with frequent security attacks. Our research has developed a Mobile Agent Security framework for Autonomic network Management (MASAM) which intends to address the above limitations. In this paper, we aim to evaluate the performance of the MASAM framework when dealing with security attack event management. The evaluation focuses on the traffic cost comparison between the new framework and SNMPv3. Event management traffic models are proposed and utilised to facilitate this evaluation. In order to validate the derived formulas, a corresponding set of simulation experiments have been conducted and the results are analysed. Positive evaluation results have been obtained from three focus points: the entire network, the manager and the managed device. We conclude that the MASAM framework reduces the amount of management traffic generated to respond to security attacks and also scales better than SNMP as a function of network size.