CTE System Architecture & Design 4

Question 1

In a telecom network using MPLS, what is the role of the Label Edge Router (LER)?

Accepted Answer

To assign and remove MPLS labels at the ingress and egress of the MPLS domain

Answer

The LER (also called PE router) imposes MPLS labels on incoming packets and removes them when packets exit the MPLS network, enabling label-switched forwarding.

Question 2

What is the key architectural difference between TDM (Time Division Multiplexing) and packet-switched networks for voice transport?

Accepted Answer

TDM allocates fixed time slots guaranteeing bandwidth while packet networks share capacity dynamically

Answer

TDM reserves a dedicated time slot per call guaranteeing constant bandwidth, while packet networks share capacity dynamically, requiring QoS mechanisms to protect voice.

Question 3

A CTE candidate is asked about 'loose coupling' in telecom service design. Which example best demonstrates this principle?

Accepted Answer

Services that communicate via published APIs with well-defined contracts, minimizing dependencies

Answer

Loose coupling means services interact through stable published interfaces, allowing each service to evolve independently without breaking its consumers.

Question 4

In telecom capacity planning, what does Erlang B formula specifically calculate?

Accepted Answer

The probability of call blocking given traffic intensity and number of circuits

Answer

Erlang B calculates the probability that a new call will be blocked (finding all circuits busy) for a given offered traffic load and circuit count, assuming blocked calls are lost.

Question 5

Which 5G network function is responsible for storing subscriber data and providing it to other network functions upon request?

Accepted Answer

UDM (Unified Data Management)

Answer

UDM stores subscriber profiles, authentication credentials, and subscription data, serving as the central repository in the 5G core network service-based architecture.

(CTE) Certified Telecommunications Executive Practice Test

(CTE) Certified Telecommunications Executive Practice Test

CTE System Architecture & Design 4