The global telephone system is a complex transmission
network, the features of which are defined to a very high
level by ITU-T standards. It is therefore a prime candidate
at which to target the application of software product line
techniques, and feature modelling in particular, in order to
handle the inherent commonality of protocols and variability
in equipment functionality. This paper reports on an experimental
feature modelling notation and illustrates it with
application to the modelling of embedded software for the
core network elements. We look at three of the fundamental
challenges facing the adoption of feature modelling in
the field and explain how we have strived to address these
within our tools set
