NCS 30022252510 NCSP 2G 3G PaCo OaM 2 2 Practice
Exam
Question 1. Which core network element is primarily responsible for managing
mobility and session management for a 2G/3G subscriber?
A) GGSN
B) SGSN
C) HLR
D) AuC
Answer: B
Explanation: The Serving GPRS Support Node (SGSN) handles mobility
management, session management, and logical link management for mobile
subscribers.
Question 2. The GGSN's main function is to:
A) Authenticate the subscriber on the radio interface
B) Allocate IP addresses and route traffic to external packet data networks
C) Store subscriber profiles and subscription data
D) Manage radio resource allocation
Answer: B
Explanation: The Gateway GPRS Support Node (GGSN) acts as the gateway
between the mobile packet core and external IP networks, providing IP address
allocation and routing.
Question 3. In the PaCo architecture, which interface connects the SGSN to the
GGSN within the same PLMN?
, NCS 30022252510 NCSP 2G 3G PaCo OaM 2 2 Practice
Exam
A) Gi
B) Gn
C) Gp
D) Gr
Answer: B
Explanation: The Gn interface is used for control and user plane signaling between
the SGSN and GGSN in the same public land mobile network.
Question 4. The Gr interface is used for communication between which two
entities?
A) SGSN and GGSN
B) SGSN and HLR
C) GGSN and external PDN
D) SGSN and MSC
Answer: B
Explanation: The Gr interface carries MAP messages between the SGSN and the
Home Location Register (HLR) for subscriber data retrieval.
Question 5. Which protocol is used on the Gn/Gp interfaces for tunnel
management?
A) SIP
B) GTP-C (Control) and GTP-U (User)
, NCS 30022252510 NCSP 2G 3G PaCo OaM 2 2 Practice
Exam
C) PPP
D) DHCP
Answer: B
Explanation: GPRS Tunneling Protocol (GTP) consists of GTP-C for control plane
signaling and GTP-U for user plane data over Gn/Gp interfaces.
Question 6. The Gi interface connects the GGSN to:
A) The radio access network
B) The Home Location Register
C) External IP networks such as the Internet
D) The MME in LTE
Answer: C
Explanation: Gi is the interface between the GGSN and external packet data
networks (PDNs) like the Internet.
Question 7. A Primary PDP Context differs from a Secondary PDP Context in that:
A) It can only be activated after a Secondary context is active
B) It defines the main IP address and QoS for the subscriber session
C) It is used only for SMS services
D) It does not require authentication
Answer: B
, NCS 30022252510 NCSP 2G 3G PaCo OaM 2 2 Practice
Exam
Explanation: The Primary PDP Context establishes the main IP address and QoS
parameters; secondary contexts are additional sessions that share the primary's IP
address.
Question 8. Which of the following is NOT a typical function of the HLR in a
GPRS/UMTS network?
A) Storing subscriber’s APN subscriptions
B) Performing ciphering of user data
C) Providing subscriber authentication vectors to the AuC
D) Managing location updates for mobile devices
Answer: B
Explanation: Ciphering of user data is performed by the SGSN and the radio
interface, not by the HLR.
Question 9. The GTP version used in 2G/3G packet core is:
A) GTPv0
B) GTPv1 (Control and User)
C) GTPv2-C only
D) GTPv3
Answer: B
Explanation: GTP version 1 (GTPv1) is used for both control (GTP-C) and user plane
(GTP-U) signaling in 2G/3G packet core networks.
Exam
Question 1. Which core network element is primarily responsible for managing
mobility and session management for a 2G/3G subscriber?
A) GGSN
B) SGSN
C) HLR
D) AuC
Answer: B
Explanation: The Serving GPRS Support Node (SGSN) handles mobility
management, session management, and logical link management for mobile
subscribers.
Question 2. The GGSN's main function is to:
A) Authenticate the subscriber on the radio interface
B) Allocate IP addresses and route traffic to external packet data networks
C) Store subscriber profiles and subscription data
D) Manage radio resource allocation
Answer: B
Explanation: The Gateway GPRS Support Node (GGSN) acts as the gateway
between the mobile packet core and external IP networks, providing IP address
allocation and routing.
Question 3. In the PaCo architecture, which interface connects the SGSN to the
GGSN within the same PLMN?
, NCS 30022252510 NCSP 2G 3G PaCo OaM 2 2 Practice
Exam
A) Gi
B) Gn
C) Gp
D) Gr
Answer: B
Explanation: The Gn interface is used for control and user plane signaling between
the SGSN and GGSN in the same public land mobile network.
Question 4. The Gr interface is used for communication between which two
entities?
A) SGSN and GGSN
B) SGSN and HLR
C) GGSN and external PDN
D) SGSN and MSC
Answer: B
Explanation: The Gr interface carries MAP messages between the SGSN and the
Home Location Register (HLR) for subscriber data retrieval.
Question 5. Which protocol is used on the Gn/Gp interfaces for tunnel
management?
A) SIP
B) GTP-C (Control) and GTP-U (User)
, NCS 30022252510 NCSP 2G 3G PaCo OaM 2 2 Practice
Exam
C) PPP
D) DHCP
Answer: B
Explanation: GPRS Tunneling Protocol (GTP) consists of GTP-C for control plane
signaling and GTP-U for user plane data over Gn/Gp interfaces.
Question 6. The Gi interface connects the GGSN to:
A) The radio access network
B) The Home Location Register
C) External IP networks such as the Internet
D) The MME in LTE
Answer: C
Explanation: Gi is the interface between the GGSN and external packet data
networks (PDNs) like the Internet.
Question 7. A Primary PDP Context differs from a Secondary PDP Context in that:
A) It can only be activated after a Secondary context is active
B) It defines the main IP address and QoS for the subscriber session
C) It is used only for SMS services
D) It does not require authentication
Answer: B
, NCS 30022252510 NCSP 2G 3G PaCo OaM 2 2 Practice
Exam
Explanation: The Primary PDP Context establishes the main IP address and QoS
parameters; secondary contexts are additional sessions that share the primary's IP
address.
Question 8. Which of the following is NOT a typical function of the HLR in a
GPRS/UMTS network?
A) Storing subscriber’s APN subscriptions
B) Performing ciphering of user data
C) Providing subscriber authentication vectors to the AuC
D) Managing location updates for mobile devices
Answer: B
Explanation: Ciphering of user data is performed by the SGSN and the radio
interface, not by the HLR.
Question 9. The GTP version used in 2G/3G packet core is:
A) GTPv0
B) GTPv1 (Control and User)
C) GTPv2-C only
D) GTPv3
Answer: B
Explanation: GTP version 1 (GTPv1) is used for both control (GTP-C) and user plane
(GTP-U) signaling in 2G/3G packet core networks.
