How should I initiate a call involving Access to Operator Services/Operator Express?
To request the feature, “Access to Operator Services,” users must send an appropriately coded Network-Specific Facilities (NSF) Information Element in a SETUP message. Complete information about coding the NSF is found in AT&T Technical Reference TR 41459, Part III, Section 3.6.5.19. TR 41459 also provides more detail about Access to Operator Services in Part III, Section 3.15.12. In summary, the NSF should be coded with 2 appearances of octet 4. The first serves to request the feature of “Access to Operator Services,” and the second indicates the service used for access to the AT&T Network (i.e., MEGACOM®, Software Defined Network (SDN), or Long Distance Service (LDS)).
