NaturalAccess™ ISUP supports one or more applications with service access points (SAPs). One SAP is defined for each application that uses the ISUP service. An application binds to a particular service access point at initialization and specifies the service access point ID to which it wants to bind.
A switch type (CCITT, ANSI-88, or ANSI-92) is associated with each user service access point in the ISUP configuration file. The ISUP task associates the switch type with its configured network connections. Multiple service access points, and hence multiple applications, for a particular switch type can be defined for outgoing call requests.
Incoming messages that are associated with a previously issued outgoing request are always routed to the service access point that issued the original outgoing request. Incoming call requests, however, are always routed to the first service access point with a switch type that matches the switch type of the network connection over which the request was received.
Note: The ISUP configuration file specifies the number of service access points and the characteristics of each one. Refer to the Dialogic® NaturalAccess™ Signaling Software Configuration Manual for more information.