Configuration of live migration for VoIP applications

The use of VoIP technologies is still growing: a SIP based client is nowadays integrated even in the Google´s smartphone operating system Android. Recent progress in virtualization technology allows the use of virtual machines for real-time applications like VoIP. A continuous live migration of a whole system without breaking down of existing TCP and TLS connections is improving the availability and the hardware fault tolerance. Furthermore, it´s transparent for clients without impact on the existing application. One of observed issues is the latency and the jitter added by buffering the network output between two virtual machine replication cycles. This problem can be disregarded for the signalling data, but it needs to be solved for the user data where the jitter must be compensated, otherwise it impairs the voice quality. In this article we present the impact of the live migration on the latency and jitter. We show that the utilisation of continuous live replication without network buffering improves the quality of user experience to the detriment of the data consistency. The impact of network buffering on network characteristics is also shown.