The following are the names of the proposed tables, their attributes and the suggested types. There is also a new treatment table to handle recorded announcements. The comments show what the fields are about and their type.
Foreign Keys are shown as “references” comments.
TABLE: FACILITIES  //represents things like lines or trunks that can be connected to //during a call  PORTID integer  address  integer //unique
TABLE: LINES  //represents lines connecting subscribers  //to the switch including their directory number  PORTID integer references portid in facilities  AREACODE  integer  OFFICECODE  integer  STATIONCODE integer  CHANNEL integer //always 0 (lines only have one channel)  STATE  string //”busy” or “idle”  LCA string //e.g. “Ottawa1”, “Ottawa2”, “Orleans3”   
TABLE: TRUNKS  //trunks that connect to other (foreign) switches  PORTID integer references portid in faclities  FOREIGN_SWITCH string //name of other switch
TABLE: SERVICES  SCODE string //e.g. “CFD”, “CFB”, “3WC”  SERVICE string //e.g. “Call Forward”, “Call Waiting”, …
TABLE: SERVICE_SUBSCRIBERS //matches lines to the services they use  LINEID integer references portid in lines, or facilities  SERVICECODE  string references scode in services
TABLE: CALL_FORWARD_NUMBERS  //Describes where to forward calls for subscribers with  //The call forward service  PORTID integer //id of subscriber line references portid in lines, (or facilities)  AREACODE  integer //area of number to forward call to  OFFICECODE  integer //office of number to forward call to  STATIONCODE integer //station of number to forward call to
TABLE: TREATMENTS  //Desribes announcement devices that can be connected to for providing announcements like “Sorry the number you have called is not in service”. A call can be connected to a treatment device instead of a line or trunk.
TCODE string //e.g. “BSY”, “NVS”, “INV”  PORTID integer references portid in facilities  CHANNEL integer //0..23 just like at T1 trunk  TREATMENT_NAME…