1K0-002 · Question #201
Defective Local Loop may introduce what two problems? (Pick two of the following options.)
The correct answer is A. Cyclic Redundancy Errors E. Intermittent codec network connections. See the full explanation below for the reasoning.
Question
Defective Local Loop may introduce what two problems? (Pick two of the following options.)
Options
- ACyclic Redundancy Errors
- BNetwork Channel Clocking Delay
- COver-voltage to codec power supply
- DOver-voltage to the codec camera
- EIntermittent codec network connections
How the community answered
(21 responses)- A81% (17)
- B10% (2)
- C5% (1)
- D5% (1)
Community Discussion
9
Ola B.Jun 21, 2026A and E are your answers here. A defective local loop introduces physical layer problems that corrupt data in transit, which shows up as Cyclic Redundancy Errors (A), and the unstable or degraded line causes the codec to drop and reconnect repeatedly, giving you those intermittent network connections (E). Spin up a basic loopback test in your lab and deliberately introduce some line impairment, you will see both symptoms show up fast.
Carlos M.Jun 21, 2026Solid breakdown, just worth adding that on DSL specifically the retrain cycles from that unstable loop can also spike your error seconds counters on the DSLAM side, which gives you a second place to confirm the fault before you even roll a truck.
Luis F.Jun 8, 2026Yeah A and E are right, bad local loop causes signal errors and drops connection constantly.
Dervla O.Jun 26, 2026The local loop is your physical copper path, and when it degrades you are looking at signal integrity failures, not power supply issues, so you can cross off anything involving voltage to hardware components. Do you understand why a flaky physical medium would produce both data errors and connection drops rather than, say, a steady but slow connection?
Ola B.Jun 29, 2026Spot on, though I'd add that a marginally degraded loop can actually show up first as a steady slow connection before the SNR margin erodes enough to cause drops, so testing at different times of day tells you more than a single sync rate snapshot.
Renata L.Jun 26, 2026A defective local loop is going to hit you in two ways: signal integrity degrades, which means the physical layer starts throwing CRC errors (A), and that same degraded copper or fiber path causes the endpoint to drop and re-register intermittently (E). The CRC side is straightforward, bad loop means bit errors, and your codec or T1/E1 framer will log those immediately. The intermittent connection piece is what kills calls in production, you will see the endpoint cycling through registration states in your SIP proxy logs even though the device itself is fine. The over-voltage options are distractors, a local loop fault is a transmission medium problem, not a power delivery problem, so C and D make no sense here.
Dervla O.Jun 29, 2026Solid breakdown, though worth flagging that on older copper plants you can actually get a secondary effect where the degraded loop introduces enough impedance mismatch to cause echo and jitter that look like codec issues before the CRC errors even become obvious, so the sequencing of symptoms matters when you are triaging.
Carlos M.Jun 26, 2026A and E, no real debate here. A defective local loop degrades the physical signal, which is exactly what produces Cyclic Redundancy Errors since the receiving end keeps detecting corrupted frames, and that same flaky physical path causes the codec to drop and re-establish its network connection repeatedly, giving you the intermittent behavior in E. I know B sounds tempting if you're thinking a bad loop could mess with clocking, but clocking delay is a separate timing issue, not a direct symptom of a defective loop itself. C and D are just noise, over-voltage to a power supply or camera is an electrical fault scenario, not something a defective local loop introduces.
Dervla O.Jun 29, 2026Carlos has the core logic right, but worth flagging that the codec dropping its network connection in E is often the visible symptom of the CRC storm in A, meaning they're less two separate answers and more one cascading failure chain, which matters if the exam stem asks you to identify the root cause versus the downstream effect.