To provide seamless mobility to the wireless user, a continuous connection to the Internet is required while moving from one administration domain to another. To enable continuous connectivity, one prerequisite is the incorporation of seamless handover. The make-before-break approach facilitates seamless handover by means of executing an authentication to a new domain simultaneously while maintaining connection to current domain. The connection is only terminated after the handover to the new domain is successfully completed. However, the duration of the authentication is critical for the handover process because if the mobile nodes move very fast the remaining amount of time of connection to the current domain can become very limited. Therefore, it is a vital issue for seamless mobility to study the authentication performance of a pre-authentication framework. In this paper we model an authentication infrastructure and consider a scenario in which a high number of nodes handover to a new administration domain. The simulation of the authentication process shows the relation between authentication performance and traffic intensity. Furthermore we identify some critical points and potential bottlenecks of this pre-authentication approach