CTA IP Networking & Telecommunications Protocols 2

Question 1

In telecommunications, what is a 'trunk' in the context of traditional telephony?

Accepted Answer

A high-capacity communication link that carries multiple voice circuits between switching centers or between a PBX and the PSTN

Answer

A telephone trunk aggregates multiple voice channels between switching points (e.g., central offices or PBX to CO), enabling efficient shared transport of many simultaneous calls.

Question 2

What is the significance of RFC 1918 address space in enterprise telecommunications?

Accepted Answer

It designates private IP address ranges (10.x.x.x, 172.16–31.x.x, 192.168.x.x) that are not routable on the public internet

Answer

RFC 1918 defines three private IP ranges that organizations use internally; these addresses must be NATed to a public IP when accessing the internet.

Question 3

What is the difference between UDP and TCP in the context of VoIP transport?

Accepted Answer

UDP is preferred for VoIP because it has lower overhead and no retransmission delays; TCP retransmits lost packets, which causes unacceptable voice delay

Answer

VoIP uses UDP via RTP because retransmitting late or lost packets would cause voice to sound worse than simply concealing a lost packet; TCP's retransmissions add unacceptable jitter.

Question 4

What does the term 'AS number' (ASN) refer to in internet routing?

Accepted Answer

A unique identifier assigned to an autonomous system for use in BGP routing between organizations

Answer

An ASN (Autonomous System Number) uniquely identifies a network or collection of networks under a single administrative domain that uses BGP to exchange routing information with other ASes.

Question 5

What is 'jitter' in VoIP networks and how does it affect call quality?

Accepted Answer

Variation in packet arrival times; high jitter causes choppy audio if the jitter buffer is insufficient

Answer

Jitter is the variability in inter-packet arrival times; when jitter exceeds the jitter buffer depth, packets arrive out of order or too late, resulting in choppy voice audio.

CTA - Certified Telecommunications Analyst Practice Test

CTA - Certified Telecommunications Analyst Practice Test

CTA IP Networking & Telecommunications Protocols 2