Question: For a UE capable of E-UTRAN, what input can be used by the SGSN to select between SGW/PGW and GGSN during PDP Context activation, in addition to network local policy?
Option 1: Only the UE's subscription restrictions for voice services
Option 2: The UE capability (as indicated in the MS Network Capability) and configuration about roaming agreements for E-UTRAN with the HPLMN of the UE
Option 3: The type of APN requested by the UE and the SGSN's current load
Option 4: The UE capability, subscription restriction to use NR as secondary RAT, roaming agreement configurations for E-UTRAN with the HPLMN, and UE Usage Type (if DCNs are deployed)
Explanation: This option is correct because, at PDP Context activation, the SGSN can use a combination of inputs for selecting GGSN/PGW or SGW/PGW. These include the UE's capabilities, subscription restrictions related to using New Radio (NR) as a secondary RAT, E-UTRAN roaming agreements with the UE's Home Public Land Mobile Network (HPLMN), and the UE Usage Type if Dual Connectivity Networks (DCNs) are deployed, allowing for a nuanced selection process.