ETCP Core Network Architecture 1 — Questions and Answers
Question 1: In Ericsson's 5G core (5GC), what function handles session management for user data bearers?
- AMF
- SMF (Correct answer)
- UPF
- NRF
Correct answer: SMF
The SMF (Session Management Function) establishes, modifies, and releases PDU sessions and assigns IP addresses to UEs in the 5G core.
Question 2: Which 5G core network function is responsible for authenticating subscribers and managing mobility?
- PCF
- UDM
- AMF (Correct answer)
- AUSF
Correct answer: AMF
The AMF (Access and Mobility Management Function) handles UE registration, authentication coordination, and mobility management in the 5GC.
Question 3: In Ericsson's EPC (4G core), what does the PGW do?
- Manages mobility and authentication
- Acts as the gateway between the LTE core and external data networks (internet) (Correct answer)
- Provides radio resource management
- Routes voice calls in IMS
Correct answer: Acts as the gateway between the LTE core and external data networks (internet)
The PDN Gateway (PGW) serves as the anchor point between the EPC and external packet data networks, performing IP address allocation and policy enforcement.
Question 4: What is the role of the NRF (Network Repository Function) in Ericsson's 5G core?
- Routing SMS messages to subscribers
- Maintaining a registry of available NFs and enabling service discovery (Correct answer)
- Managing RAN handover procedures
- Storing subscriber policy profiles
Correct answer: Maintaining a registry of available NFs and enabling service discovery
The NRF acts as a service registry where 5GC network functions register their profiles and discover other NFs they need to communicate with.
Question 5: In Ericsson's IMS (IP Multimedia Subsystem), what is the function of the P-CSCF?
- Provides the first SIP contact point for UEs registering to IMS (Correct answer)
- Stores subscriber profiles and authentication data
- Translates between SIP and legacy PSTN protocols
- Manages media gateway resources
Correct answer: Provides the first SIP contact point for UEs registering to IMS
The P-CSCF (Proxy Call Session Control Function) is the entry point into the IMS for UEs, forwarding SIP messages to the serving CSCF.
Question 6: What interface connects the eNB (4G base station) to the EPC's MME in Ericsson LTE deployments?
- X2
- S1-MME (Correct answer)
- Uu
- S11
Correct answer: S1-MME
The S1-MME interface carries control plane signaling between the eNB and the MME for handover signaling, registration, and bearer setup.
ETCP Core Network Architecture 1
In Ericsson's 5G core (5GC), what function handles session management for user data bearers?