Recently, several biometric and tele-care based user authentication schemes have been proposed to enhance the safe and security of the systems. In 2013, the authors, namely Das et al. improved the authentication scheme of Chang et al. to overcome the severe security flaws, such as failed to protect man-in-the-middle attack, failed to provide the reliable authentication and flaws in client login-phase. Besides, the authors evaluated the authentication in the simulation tool of AVISPA. In the same year, the authors, namely Khurram et al. proposed an improved the authentication scheme of Youngwa An to eradicate the security flaws, like impersonation attack, mutual authentication and user anonymity. The authors, like Das et al. and Khurram et al. have had their own strategies to mitigate the security flaws, though they are still not able to evaluate their schemes in the real time medical information systems. Besides, both authors fail to prove the privacy preservation to the user systems. Thus, this paper proposes a dynamic-identity based multimedia server client authentication scheme to resolve the major security threats of Das et al. and Khurran et al. We prove that our proposed scheme is secure and efficient in comparison with the authentication schemes, namely Youngwa An, Khurram et al., Das et al. and Chang et al. We also depict that our proposed scheme can offer the features like privacy preservation and service scalability reliably for the user systems. Eventually, we design an develop a real time testbed of multimedia medical information system to cross-examine the authentication schemes. In the cross-examination, our authentication scheme shows the most achievable results for the metrics like call setup time, signal congestion and bandwidth consumption in relation to the other authentication schemes, such as Youngwa An, Khurram et al., Das et al. and Chang et al. © 2015, Springer Science+Business Media New York.