7893X · Question #101
Which statement is an example of "Top Down Troubleshooting" with an IP Phone that is not working?
The correct answer is D. Listen for a dial tone, and if not heard, then check for an indicator light where the telephone is. https://downloads.avaya.com/elmodocs2/ip_phones/r2_0/233507_2/lanad052.html
Question
Which statement is an example of "Top Down Troubleshooting" with an IP Phone that is not working?
Options
- ACheck the IP Phone configuration and confirm that the gateway IP address is present.
- BPing the telephone, and if successful, try to call it.
- CSwap out the telephone patch cord, and if the telephone boots up, call the telephone.
- DListen for a dial tone, and if not heard, then check for an indicator light where the telephone is
How the community answered
(42 responses)- A7% (3)
- B17% (7)
- C5% (2)
- D71% (30)
Explanation
https://downloads.avaya.com/elmodocs2/ip_phones/r2_0/233507_2/lanad052.html
Topics
Community Discussion
5
Njoroge O.Jun 26, 2026D is your answer. Top-down troubleshooting starts at the application layer and works toward the physical, so you begin at layer 7 by lifting the handset and listening for dial tone, then if that fails you step down toward layer 1 by checking the link indicator at the port, which matches exactly how that methodology flows on the 7893X.
Prof. SaraJun 28, 2026Solid flow, Njoroge, but one quick note: a dial tone lives at layer 1 to 2 territory since it is a physical signaling function from the PSTN, so if you are strictly anchoring your top-down start at layer 7, listening for dial tone is already a skip downward, not your true layer-7 entry point.
Prof. SaraJun 24, 2026Option B is the biggest trap here because pinging and then calling feels systematic and logical, but you are starting at Layer 3 (Network), not Layer 7 (Application), so that is actually Middle-Out at best, not Top Down. The textbook definition of Top Down means you start at the Application layer and work your way toward the Physical, which is exactly what D does: you first check for a dial tone (can the user make a call, i.e., does the application function?) and only then drop down to inspect a physical indicator light.
Bao N.Jun 26, 2026Been grinding this one and I keep landing on C, hear me out. Top Down in the OSI sense means you start at the physical layer and work your way up, so swapping the patch cord is exactly that, you rule out layer 1 first before you even bother looking at configs or call routing. If the phone boots after the cord swap, you just isolated the fault to a busted cable without ever touching software, which is clean and efficient troubleshooting. The other options either jump straight to layer 3 stuff like pinging or checking gateway config, which skips the foundation entirely, or they are too vague like listening for a dial tone that does not tell you where in the stack the problem actually lives.
Njoroge O.Jun 28, 2026Bao, you actually have it flipped, because top down in the OSI model means you start at layer 7 application and work toward layer 1, so D is correct since it has you checking call processing or registration first rather than going straight to the cable. What you described, ruling out the physical layer before anything else, is bottom up troubleshooting.