220-1101 Question 157
Single answerDSLA technician is installing internet service for a small office that is switching from cable to DSL. The customer wants to keep using their analog desk phones on the same wall jacks they have today. After the DSL modem is connected, the internet works, but users report static and dropped connections when phone calls are made. Which of the following is the BEST action for the technician to take?
- A
Install DSL microfilters on the analog phone lines
- B
Replace the DSL modem with a cable modem
- C
Change the wireless router to use the 5 GHz band
- D
Terminate the phone cabling into a patch panel instead of wall jacks
Show answer and explanation
Correct answer: A
Explanation
DSL commonly operates over existing copper telephone lines while allowing traditional analog voice service on the same circuit. Best practice is to install DSL filters (also called microfilters) on analog devices such as telephones, fax machines, and answering machines, while leaving the DSL modem connection unfiltered. Without proper filtering, users may experience line noise on voice calls and instability in the DSL connection, especially when a phone goes off-hook. This aligns with standard telecom installation guidance and the practical A+ Core 1 expectation that candidates understand how DSL shares the local loop with POTS service.
- A. Correct.
Correct. DSL and analog voice service can share the same copper telephone line, but the voice devices must be filtered so they do not interfere with the higher-frequency DSL signal. Installing DSL microfilters on the analog phones is the standard fix when users hear static or the DSL connection drops during calls.
- B. Incorrect.
Incorrect. A cable modem uses a different service type and provider infrastructure than DSL. Replacing the modem would not address interference between analog voice devices and a DSL signal on the telephone line.
- C. Incorrect.
Incorrect. The issue occurs when phone calls are made on the shared telephone line, which points to a DSL/voice line-filtering problem, not a Wi-Fi frequency issue. Changing to 5 GHz might affect wireless performance, but it would not resolve static on analog phones or DSL drops caused by unfiltered lines.
- D. Incorrect.
Incorrect. Using a patch panel may improve cable organization in some environments, but it does not separate voice and DSL frequencies on the line. The symptom specifically indicates that analog phone devices need proper DSL filtering.