Question: What is a prerequisite for Cost Control with correlation to charging information from a GGSN/P-GW using CAMEL Services in a GPRS network?
Option 1: Unique Charging Id provided by GGSN (Gn/Gp) or S-GW (S4), with S5/S8 interface using GTP for S4.
Option 2: Subscription data received over Gr interface without MSISDN references.
Option 3: CAMEL Phase 4 implementation on the mobile network.
Option 4: PDP context establishment without charging information.
Explanation: For effective cost control that correlates with charging information from a GGSN/P-GW, a unique identifier is crucial. The Charging Id must be uniquely provided for each PDP context by the GGSN (in Gn/Gp scenarios) or S-GW (specifically in S4 scenarios). Moreover, for the S4 scenario to maintain this uniqueness, the S5/S8 interface must utilize GTP, ensuring seamless and correlated charging management across network elements. This setup is essential for accurate cost control and billing processes in a GPRS network utilizing CAMEL Services.