As a function of the combination of source/destination nodes, different LCR routes can be selected without rendering a special LCOS assignment necessary. This source/destination controlled seizure of LCR routes is achieved through modification of the LCR class marks (LCR-LCOS's from LCOVS or LCOSD - i.e. service-independent) upon entry in the path selection) with the AMO KNLCR.

As every connection is specified by a combination of source node and destination node, an expansion or reduction of individual LCOS's can be administrated for a node number pair (SNNO / DNNO). These changes in the authorization transmitted are taken into account during the test of the access rights in AMO LDAT, in order to seize a trunk group. Thus, the option of using or blocking an LCR route can be enabled both for single and multiple nodes of a network. (e.g.: to prevent or selectively enable central office breakouts.)