  We propose a notion of convergence-sensitive bisimulation that is built just
over the notions of (internal) reduction and of (static) context. In the
framework of timed CCS, we characterise this notion of `contextual'
bisimulation via the usual labelled transition system. We also remark that it
provides a suitable semantic framework for a fully abstract embedding of
untimed processes into timed ones. Finally, we show that the notion can be
refined to include sensitivity to divergence.
