  We consider a lossy multicast network in which the reliability is provided by
means of Random Linear Network Coding. Our goal is to characterise the
performance of such network in terms of the probability that a source message
is delivered to all destination nodes. Previous studies considered coding over
large finite fields, small numbers of destination nodes or specific, often
impractical, channel conditions. In contrast, we focus on a general problem,
considering arbitrary field size and number of destination nodes, as well as a
realistic channel. We propose a lower bound on the probability of successful
delivery, which is more accurate than the approximation commonly used in the
literature. In addition, we present a novel performance analysis of the
systematic version of RLNC. The accuracy of the proposed performance framework
is verified via extensive Monte Carlo simulations, where the impact of the
network and code parameters are investigated. Specifically, we show that the
mean square error of the bound for a ten-user network can be as low as $9 \cdot
10^{-5}$ for non-systematic RLNC.
