Carrying Wireless Traffic over IP Using Realtime Transport Protocol Multiplexing

The RTP/UDP/IP protocol suite is in the process of being standardized for multiplexing realtime flows. It aims at reducing header overhead, therefore, it is apt for transporting compressed voice in access links or in the core of mobile communication networks. To provide realtime quality of service, networks require traffic parameters which can be met using a spacer. In this paper, an exact analysis for the RTP/UDP/IP multiplexing scheme including spacing is derived. Influences on the performance of the system are investigated and an optimum value for the multiplexing timer is found. A numerical comparison to the data tunneling method is also presented. Additionally, a leaky bucket description of the multiplexed IP packet output stream is given as an alternative to spacing. The affinity to AAL-2 multiplexing in ATM is pointed out and the fundamental differences with respect to performance are explained.