Telecommunications Voice over IP (VoIP) 2

Question 1

What is a PBX in the context of business telephony?

Accepted Answer

Private Branch Exchange

Answer

A PBX (Private Branch Exchange) is a private telephone network used within an organization to manage internal and external calls.

Question 2

What is E.164 number formatting used for?

Accepted Answer

Standardizing international telephone numbers

Answer

E.164 is the ITU-T standard that defines the format for international telephone numbers (e.g., +1-800-555-0100).

Question 3

Which transport protocol does SIP most commonly use?

Accepted Answer

UDP or TCP

Answer

SIP can use UDP for low-overhead signaling or TCP for reliable delivery, with the choice depending on deployment needs.

Question 4

What does PSTN stand for?

Accepted Answer

Public Switched Telephone Network

Answer

PSTN (Public Switched Telephone Network) is the worldwide circuit-switched telephone network, also known as POTS.

Question 5

What is G.729 commonly used for in VoIP?

Accepted Answer

Low-bandwidth compressed voice at 8 kbps

Answer

G.729 compresses voice to 8 kbps using CS-ACELP, making it ideal for bandwidth-constrained VoIP deployments.

Telecommunications Practice Test