If a system is connected to different masters (of the same level) the quality of this system should be taken into consideration when allocating priorities. This can mean that higher priority is assigned for the exchange (system/carrier) with the most frequent or most important (data) traffic. Several masters may not always be synchronous or pseudosynchronous in relation to one another. There is, for instance, no error message reporting via the trunk that the local exchange switched to hold over mode. Up to now there is no carrier-wide network management. The effects in the private network only show as bit slips. It is helpful to mark the existing and possible plesiochronous interfaces in the network synchronization plan as such. This procedure helps quick and precise error diagnostics if bit slip frequently occurs on these lines. In important networks or network elements these problems can only be solved using an SASE.

( --> Clock generator selection)