For an overview of Terminating Access Domain Selection (T-ADS) see Terminating Access Domain Selection (T-ADS).
T-ADS features implement the routing strategy for a terminating call. It provides support for route signaling towards PS and CS domains, in a sequential, parallel or exclusive manner.
Sequential routing attempts to route towards a single preferred domain, and "falls back" to the non-preferred domain upon receipt of certain responses.
Parallel routing routes towards the PS and CS domains simultaneously. It decides the "chosen" domain based on responses that it receives.
The conditions for routing to PS and CS are checked by the SCCTADSDataLookup feature.
|What it does
T-ADS Data Lookup gathers information from the received SIP signalling, and optionally queries the HSS, in order to determine available PS and CS routes that can be used to deliver the call to the served user.
It takes the T-ADS preferred routing decision from SCCTADSDataLookup, and uses it to attempt routing.
The T-ADS Parallel Routing feature parallel-forks the incoming message to both CS and PS legs, and forwards the response from the leg that successfully responds first
Retrieves the Correlation MSISDN (C-MSISDN) from the HSS by using the "Sh-Pull" operation
Retrieves the Mobile Station Roaming Number (MSRN) from the HLR by using MAP "Send Routing Information" operation
Retrieves the Temporary Local Directory Number (TLDN) from the HLR by using the MAP "Location Request" operation
determines the two-letter ISO Country Code for a subscriber’s location, based on their MSRN.
The following pages also have data relevant to T-ADS
Provides information about the custom headers and header parameters, that influence system behaviour.