Analysis of the secure RTP protocol on voice over wireless networks using extended MedQoS

ABSTRACT

This paper presents an empirical investigation of the impact of Secure RTP (SRTP) on VoIP calls over wireless networks: 802.11 and Bluetooth. For the purpose of evaluating this impact we developed an analysis tool based on E-Model and security aspects of SRTP which attempts to determine the balance of quality of service versus security.

The results demonstrate that the impact of SRTP to VoIP should not be disregarded. MOS scores of secure calls computed from E-Model pointed out an undesirable level of quality of service on single calls using wireless channels. This quality degradation also leads to the reduction of channel capacity to offer simultaneous calls. The developed analysis tool indicated three important factors to this degradation: time to encrypt, time to authenticate and time to form a cryptographic context for each SRTP packet sent and received.

REFERENCES

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INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS

Keywords:
QoS, SRTP, VoIP, authentication, encryption, quality of service, voice over IP, wireless security