Influence of Jitter on Reliable Multicast Data Transmission Rate in Terms of CDN Networks

This paper devotes to evaluation of performance bottlenecks and algorithm deficiencies in the area of contemporary reliable multicast networking. Hereby, the impact of packet delay jitter on the end-to-end performance of multicast IP data transport is investigated. A series of tests with two most significant open-source implementations of reliable multicast is performed and analyzed. These are: UDP-based File Transfer Protocol (UFTP) and NACK-oriented Reliable multicast (NORM). Tests were targeted to simulate scenario of content distribution in WAN – sized Content Delivery Networks (CDN). Then, results were grouped and averaged, by round trip time and packet losses. This enabled us to see jitter influence independently on round trip time(RTT) and packet loss rates. Revealed jitter influence for different network conditions. Confirmed, that appearance of even small jitter causes significant data rate reduction.

Storing Data in the Trial of Complex Technical Products

The article considers the ways of organization of databases for the storage of the results obtained during testing. A new variant of the organization of the data to ensure the ability to write to the database different sets of parameters in the form of chronological series. The required set of parameters depends on the modification of the tested technical installation.