Telecommunications Cheat Sheet 2026
The 30 highest-yield Telecommunications facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.
- What does an SLA (Service Level Agreement) typically specify for telecom services? → Guaranteed uptime, latency, jitter, and packet loss thresholds
- What is the function of a VoIP gateway? → Convert between VoIP and PSTN/analog signals
- What is Frame Relay primarily known as in telecom history? → A legacy packet-switched WAN technology using virtual circuits
- How many layers are in the OSI model? → 7
- What is the purpose of a jitter buffer in VoIP? → Store packets temporarily to reduce delivery variation
- What does PON stand for and where is it typically used? → Passive Optical Network; used in fiber-to-the-home (FTTH) deployments
- What is RF interference and how does it affect wireless networks? → It degrades signal quality and reduces throughput
- What does the First Responder Network Authority (FirstNet) provide? → A nationwide broadband network dedicated to public safety communications
- Which transmission medium offers the highest bandwidth for telecommunications? → Fiber optic cable
- Adjacent Satellite Interference (ASI) in the geostationary arc is caused by: → Signals from nearby satellites being captured along with the intended satellite's signal
- What is the purpose of a fiber optic attenuator? → Intentionally reduce optical signal power to prevent receiver saturation
- What US government agency regulates interstate and international telecommunications? → FCC
- What does the FCC's Part 68 regulation govern? → Connection of customer-provided terminal equipment to the public telephone network
- What does DNS resolve? → Domain names to IP addresses
- What protocol does IPsec use for key exchange? → IKE (Internet Key Exchange)
- What does SS7 stand for in telecom signaling? → Signaling System Number 7
- Which protocol operates at the Transport layer and provides reliable, connection-oriented delivery? → TCP
- What wireless security protocol replaced WEP due to its vulnerabilities? → WPA
- What is spectrum allocation in the context of US wireless policy? → The government assignment of radio frequency bands to different services and licensees
- The G/T ratio used to characterize satellite receiver performance stands for: → Gain-to-Noise Temperature ratio
- What does LTE stand for? → Long Term Evolution
- What is a tariff in telecommunications regulation? → A filed document specifying rates, terms, and conditions for telecom services
- What does the DSCP EF (Expedited Forwarding) designation ensure for voice traffic? → Low latency, low jitter, and low packet loss treatment
- What causes chromatic dispersion in fiber optic cables? → Different wavelengths traveling at slightly different speeds
- What type of fiber splice permanently joins two fibers with minimal loss? → Fusion splice
- What does MOS stand for in VoIP quality assessment? → Mean Opinion Score
- What is the function of PPP in WAN communications? → Provide a standard data link protocol for point-to-point serial connections
- What is the maximum theoretical speed of 802.11ac (Wi-Fi 5)? → 1.3 Gbps
- What does the Communications Act require regarding broadband in the US? → The FCC must promote broadband deployment to all Americans
- What connector type is most commonly used in enterprise fiber deployments in the US? → LC
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