Voice over IP (VoIP) that involves the delivery of voice, data to the end user. The performance metrics of VoIP are signaling, bandwidth, delay, jitter and packet loss. Voice and data convergence is happening not just in terrestrial communication links, but also in satellite links. In satellite networks, VoIP performance is affected by mainly three factors long delay, limited bandwidth and channel error. Both call setup time and Quality of Service (QoS) for voice calls are affected. The VoIP uses signaling protocol like Session Initiation Protocol (SIP) and H.323 and transport protocol like Real Time Protocol (RTP).