SIP Signaling and QoS for VoIP over IPv6 DVB-RCS Satellite Networks

With the rapid development of the Internet, new technologies and applications are emerging. One of the important applications is voice over IP. Satellites are playing an important role to provide VoIP services with their global coverage and on-board processing ability over IP networks. Satellite network environment, generally characterized by large delay and erroneous link, is considered to be unfriendly to VoIP. The performance of VoIP is adversely influenced by these characteristics. The performance metrics of VoIP are signaling, bandwidth, delay, jitter and packet loss. Signaling plays a key role in call establishment and rest of the parameters signifies the quality of service (QoS). In this paper, the performance related issues of SIP-based VoIP over current, IPv4, and next generation, IPv6 satellites is studied. A comparative analysis is performed for different voice codecs. The experimentation is carried out on the satellite network testbed at Centre for Communication Systems Research (CCSR), University of Surrey. The results show that delay, jitter and packet loss are quite comparable for both IPv4 and IPv6 over satellites. SIP signaling performs poorly in IPv6 as compared to IPv4. IPv6 can be adapted for VoIP over satellites, but with some modifications for SIP signaling.