  We study the version age of information in a multi-hop multi-cast
cache-enabled network, where updates at the source are marked with incrementing
version numbers, and the inter-update times on the links are not necessarily
exponentially distributed. We focus on the set of non-arithmetic distributions,
which includes continuous probability distributions as a subset, with finite
first and second moments for inter-update times. We first characterize the
instantaneous version age of information at each node for an arbitrary network.
We then explicate the recursive equations for instantaneous version age of
information in multi-hop networks and employ semi-martingale representation of
renewal processes to derive closed form expressions for the expected version
age of information at an end user. We show that the expected age in a multi-hop
network exhibits an additive structure. Further, we show that the expected age
at each user is proportional to the variance of inter-update times at all links
between a user and the source. Thus, end user nodes should request packet
updates at constant intervals.
