Question 630
An engineer observes: An installation map labels AOC and DAC assemblies interchangeably and technicians order the wrong reach for distant racks. Which underlying mechanism is most relevant?
Explanation
Correct Answer
This case illustrates that Active optical and direct-attach copper cables differ in reach, power and handling requirements. An engineer should Inventory actual cable media, supported distance, vendor compatibility and bend requirements by link and independently verify that Each installed cable part number matches the approved link budget and passes physical and electrical checks.
Incorrect Answers
This option serves the scenario “A 400G fabric port uses a short passive copper cable beyond its approved reach and link quality is unstable”. The operational evidence follows from the mechanism that Passive copper, active copper and optical transceivers have distinct reach and signal-integrity envelopes. The present scenario is distinguished by “Active optical and direct-attach copper cables differ in reach, power and handling requirements”.
This alternative addresses the separate case “An engineer installs an optic that matches the physical cage but uses a wavelength incompatible with the remote transceiver”. The operational evidence follows from the mechanism that Matching connector geometry does not imply optical signaling compatibility between transceiver endpoints. The deciding requirement here is “Active optical and direct-attach copper cables differ in reach, power and handling requirements”.
The option would apply to “A fabric upgrade uses 400G-to-4x100G breakout cable but leaves the switch port configured as one unsplit interface”. The controlling explanation is that Breakout cabling and switch logical port allocation must agree for every lane and endpoint. This question instead requires “Active optical and direct-attach copper cables differ in reach, power and handling requirements”.