7.9.3.4. XAPX - Managing classes of service 
ADD- COSSU:NEWCOS=24,AVCE=TA&PUPHON&TNOTCR&CDRATN&CDRINT&CDRS&CDRC;
- PUPHON ... Public telephone
Different clock intervals can be sent for each station type according
to the assigned class of service. If a station does not have a special
class of service, it is treated as a "normal station".