# Plan values

The following table lists the valid calling, called, and redirecting number plan values for ACU_ALERT_IN, ACU_CONN_IN, ACU_CONN_RQ, and ACU_SETUP_REPORT_IN messages.

These values are defined in isdnval.h.

Plan | Description
--- | ---
N_PLAN_UNKNOWN (Default for all variants except VN6) | Unknown.
N_PLAN_ISDN (Default for VN6 and AusTel variants) | ISDN/telephony numbering plan (CCITT E.164/E.163).
N_PLAN_TELEPHONE | Telephony - not in CEPT.
N_PLAN_DATA | Data numbering plan (CCITT x.121).
N_PLAN_TELEX | Telex numbering plan (CCITT f.69).
N_PLAN_NATIONAL | National standard numbering plan.
N_PLAN_PRIVATE | Private numbering plan.