The final test

E1 A colleague asks in what order the messages of a PDU session establishment go. Which document answers that?

• TS 23.502, the procedures and flows
• TS 23.503, policy control and charging
• TS 23.501, the one this course is about

E2 Somebody draws the core as a graph of labelled links and calls it the alternative architecture. What is the correction?

• It is a view of the same network, because control plane functions shall only use service-based interfaces
• It is the older 4G drawing
• It is a second architecture an operator may choose instead

E3 Three names appear in a trace: Namf, N11 and N4. What kind of thing is each?

• All three are service-based interfaces
• All three are point-to-point links
• A producer's interface, a label for service calls between two functions, and a genuine link

E4 A phone in a pocket has not sent anything for ten minutes. Which pair of states describes it, and who knows where it is?

• RM-DEREGISTERED and CM-IDLE; nobody knows where it is
• RM-REGISTERED and CM-IDLE; the AMF knows it to the accuracy of a tracking area list
• RM-REGISTERED and CM-CONNECTED; the radio network knows the cell

E5 One device holds two sessions to two data networks, each with several flows. What decides how a single packet is treated?

• The session it belongs to
• The QFI it is marked with
• The device's subscription alone

E6 A network runs four slices and one device is served by three of them. What is shared and what is not?

• Everything is shared; the slice is only a billing label
• The AMF is common to all three, and each PDU session belongs to exactly one slice
• Each slice has its own AMF, and a session may span two slices

E7 An SMF instance is added to a running network. What has to happen before another function can call it?

• Nothing; the other functions scan for it
• It informs the NRF of the services it supports, or an authorised entity does so for it
• The operator reconfigures every consumer by hand

E8 A subscriber roams abroad and one session breaks out locally while another goes home. Who decided that?

• The home operator, through subscription data per data network name and per slice
• The visited operator's radio network
• The device, per session

E9 Which stage of a 3GPP specification is TS 23.501?

• Stage 2, how the system is put together
• Stage 3, what goes on the wire
• Stage 1, what the system must do

E10 A device moves to a new tracking area and the network has to know where it is. Which function's job is that?

• The SMF
• The AMF
• The UPF

E11 What does the name "Nsmf" stand for?

• The link between the SMF and the UPF
• The service-based interface the SMF offers to others
• The protocol the SMF speaks to the radio network

E12 A phone is registered but has nothing to send. Which pair of states is it in?

• RM-REGISTERED and CM-CONNECTED
• RM-REGISTERED and CM-IDLE
• RM-DEREGISTERED and CM-IDLE

E13 What is the finest thing a 5G network can give a separate quality treatment to?

• A PDU session
• A QoS Flow
• A single packet

E14 What is an S-NSSAI made of?

• A data network name and a session type
• A slice/service type, and optionally a slice differentiator
• A country code and a network code

E15 In home-routed roaming, where does the traffic leave the mobile network?

• In the home network
• Wherever the device asks
• In the visited network