10.1.10. A-Law/µ-Law Conversion in AP Shelf 
It is possible to connect telephones in AP shelves that work with
companding algorithms different to the host system (e.g. host system
in Germany (A-law), access point in the USA (µ-law)).
For a detailed description, refer to Section
2.15, “A-Law/µ-Law Conversion in AP Shelf”.