The standard clock generator suffices for clock supply of a small private network in an analog environment. The default clock generator is sufficiently precise even for the clock requirements of cordless DECT. If better clock quality is required for the network, a networking clock generator must be installed in the master system. It already has the Stratum 3 clock quality, i.e. the quality of a USA CO, and the frequency stability and hold over function of an ITU local exchange, but not the same free-run accuracy. If free-run accuracy is important for the network or if independence from Telecom/the carriers is desired, an SASE must be installed in the master system and, in larger networks, also on the first level in front of the OpenScape 4000 clock generators. This provides clock quality of a local exchange or means Stratum 2 level.

As PDH networks are hardly ever used anymore and even SDH networks are slowly being replaced by MPLS networks and thus by VoIP technology, the demand for networking clock generators in OpenScape 4000 systems is decreasing. Clock distribution has been shifted to the transmission network in SDH networks. Responding to these changes is simply done in OpenScape 4000 by using the external clock box less and the frontref more. It is easy to connect to each T4 output with the special cables for the cPCI or IPDA shelves. From the clock perspective, this means there is no longer an OpenScape 4000 master system in the network.61.6 SDH, Cordless - CMI (DECT) and ATM