Mixed Deck — All CTA Topics Flashcards

What is XG-PON (10G-PON), standardized as ITU-T G.987?

Answer: A passive optical network standard providing 10 Gbps downstream and 2.5 Gbps upstream

XG-PON (10-Gigabit-capable PON), defined in ITU-T G.987, delivers 10 Gbps downstream and 2.5 Gbps upstream over the same passive fiber infrastructure used by GPON.

What phenomenon in fiber optic transmission causes different wavelengths of light to travel at slightly different speeds, limiting bandwidth over distance?

Answer: Chromatic dispersion

Chromatic dispersion occurs because different wavelengths travel at different speeds in glass, causing pulse spreading that limits high-speed transmission over long distances.

What is a 'softphone' in a unified communications environment?

Answer: A software application on a PC, smartphone, or tablet that emulates a full-featured telephone, using VoIP to make and receive calls through the network

Softphones replace physical desk phones with software clients, enabling employees to take and make calls from any device with internet access—a key enabler of remote and hybrid work.

In telecommunications, what is 'dark fiber' and why might an enterprise choose to lease it?

Answer: Installed fiber optic cable that carries no active signal, leased to customers who provide their own optical equipment for full control over capacity and protocols

Dark fiber gives enterprises or carriers raw fiber they can light with their own DWDM or Ethernet equipment, offering unlimited bandwidth scalability and protocol flexibility.

In enterprise telecom procurement, what is the difference between an ILEC and a CLEC?

Answer: ILEC (Incumbent Local Exchange Carrier) is the legacy monopoly local phone company; CLEC (Competitive Local Exchange Carrier) is a competitor that entered after deregulation under the Telecom Act of 1996

ILECs like AT&T and Verizon are the original Bell System successors; CLECs like Windstream or Cbeyond entered the market after the 1996 Telecom Act opened local markets to competition.

What is the primary purpose of BGP (Border Gateway Protocol) in telecommunications networks?

Answer: To exchange routing information between autonomous systems (ASes) on the internet

BGP is the exterior gateway protocol that enables different autonomous systems (ISPs, enterprises) to exchange reachability information and route traffic across the internet.

What is Broadband over Power Line (BPL) technology?

Answer: A technology that delivers broadband internet access over existing electrical power distribution lines

BPL (Broadband over Power Line) uses existing electrical power distribution infrastructure to carry broadband data signals, allowing internet access delivery over the same lines that carry electricity to homes and businesses.

Which technology is used for high-speed internet over phone lines?

Answer: DSL

DSL (Digital Subscriber Line) is a technology used to provide high-speed internet access over conventional telephone lines. It utilizes the unused frequencies on standard copper telephone wires to transmit data without interfering with voice calls. DSL offers a dedicated connection, providing faster speeds than traditional dial-up internet.

Which generation of mobile technology first introduced packet-switched data services alongside circuit-switched voice in the US?

Answer: 2G (GPRS/EDGE)

2G networks introduced GPRS and EDGE, enabling packet-switched data while still supporting circuit-switched voice calls.

In a Passive Optical Network (PON), what device splits the optical signal from the central office to multiple subscriber premises?

Answer: Optical splitter

A passive optical splitter divides the downstream optical signal from the OLT to multiple ONTs at subscriber locations without requiring electrical power.

Which software detects and removes malicious software?

Answer: Antivirus software

Antivirus software is specifically designed to detect, prevent, and remove malicious software, commonly known as malware, from computer systems. It scans files and programs for known threats and suspicious behavior, protecting users from viruses, worms, Trojans, and other harmful code.

In DWDM (Dense Wavelength Division Multiplexing), what is the standard channel spacing defined by the ITU-T grid?

Answer: 100 GHz (approximately 0.8 nm)

The ITU-T G.694.1 standard defines DWDM channel spacing at 100 GHz (or 50 GHz for denser grids), allowing many wavelengths to be transmitted simultaneously on one fiber.

Which cellular network element manages radio resources and controls base stations in a 4G LTE network?

Answer: eNodeB (eNB)

In LTE, the eNodeB (evolved Node B) manages radio resource allocation and connects directly to the core network, unlike older architectures with separate controllers.

Which multiplexing technique separates upstream and downstream signals on an HFC cable network?

Answer: Frequency Division Multiplexing (FDM)

HFC networks use Frequency Division Multiplexing to assign separate frequency bands for upstream (5–42 MHz) and downstream (54–1000+ MHz) transmissions.

In a GPON network, what is the maximum logical split ratio supported by the standard?

Answer: 1:128

The GPON standard (ITU-T G.984) supports a maximum logical split ratio of 1:128, meaning one OLT port can serve up to 128 ONUs, though typical deployments use 1:32 or 1:64 for bandwidth management.

What is 'Direct Inward Dialing' (DID) and why is it useful for enterprise phone systems?

Answer: A carrier service providing a block of telephone numbers that route calls directly to individual enterprise extensions without going through a receptionist or main number

DID numbers allow external callers to dial directly to an employee's extension using a unique PSTN number, while the enterprise shares a smaller pool of actual PSTN trunk lines.

What does OFDMA stand for and what is its key advantage in 5G NR?

Answer: Orthogonal Frequency Division Multiple Access; it allows multiple users to share subcarriers simultaneously

OFDMA divides the available spectrum into subcarriers that can be assigned to different users simultaneously, improving efficiency in dense networks.

What is G.fast technology as defined by ITU-T G.9700/G.9701?

Answer: A DSL technology using up to 212 MHz bandwidth over very short copper loops for speeds up to 1 Gbps

G.fast is an ITU-T standard (G.9700/G.9701) that uses frequencies up to 212 MHz over copper loops shorter than 250 meters, achieving downstream speeds up to 1 Gbps in FTTC/FTTdp deployments.

What device connects different networks together?

Answer: Router

A router is a networking device that forwards data packets between computer networks. It connects different networks, such as a local area network (LAN) to the internet (WAN), by determining the best path for data to travel. Routers use IP addresses to direct traffic, ensuring data reaches its intended destination across various interconnected networks.

In a call center, what is the difference between 'inbound' and 'outbound' telephony operations?

Answer: Inbound operations receive calls from customers (support, inquiries); outbound operations initiate calls to customers or prospects (sales, collections, surveys)

Inbound contact centers are reactive (customers call in for help), while outbound contact centers are proactive (agents initiate calls for sales or follow-up), each requiring different technology (ACD vs. predictive dialer) and staffing models.