5.16.8.2. Service Information 
IMPORTANT:
All area codes (tie line access code) of a network
must be unique and may not be station numbers.
- Open numbering and LCR are used to realize ISDN (E.164) and PNP (E.189) or EPNP numbering plans.
- The subscriber numbers of a network need not necessarily be unique
in this context.
Figure 31. Call Setup Procedure via LCR
