Performance optimization of VoIP calls over wireless links using H.323 protocol

Intelligent mobile terminals (or users) of next generation wireless networks expected to initiate voice over IP (VoIP) call's using, session set-up protocols like H.323 or SIP (session initiation protocol). To guarantee the service quality of such applications, the call set-up protocol should be robust against network impairments, In this paper, we analyze the performance of the H.323 call se-up procedure over Wireless links using a simple calf model under two modes of operations, namely, Regular and Fast Connect. The proposed model assumes the presence, of a radio link protocol (RLP) and recommends that the VolP packets be transferred without any RLP retransmissions, while H.323 control packets tie transferred with RLP retransmissions. Our analytical models and detailed experiments show that the VoIP call set-up performance can undergo-significant degradation it RLP is hot used at all, even for moderately high frame error rates (FERs) in wireless links. On the other hand, a robust radio link layer; such as. RLP, can improve the call-set-up delay performance as compared to the existing wireless, voice call-set-up delay.