VDV Cheat Sheet 2026

The 30 highest-yield VDV facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Why is it important to avoid ground loops in telecommunications bonding systems? → Ground loops can induce noise and interference into telecommunications circuits
2. Which 802.11 amendment introduced the 6 GHz band for Wi-Fi use? → 802.11ax
3. When installing a video distribution system in a building, where should the head-end equipment typically be located? → In a central location to minimize cable runs
4. In a VoIP system, what is the recommended maximum one-way latency for acceptable voice quality? → 150 ms
5. During coaxial cable testing, a return loss of 20 dB is measured. What does this indicate? → Acceptable impedance matching with minimal reflections
6. Which TIA standard governs the design and layout of telecommunications rooms (TR) and equipment rooms (ER)? → TIA-569-D
7. In a structured cabling design, what is the maximum recommended horizontal cable run length including the patch cords? → 90 meters for the permanent link, with total channel up to 100 meters
8. What is the maximum data rate of 802.11ac (Wi-Fi 5) in the 80 MHz channel configuration? → 433 Mbps
9. Which wavelength window is most commonly used for single-mode fiber transmission in long-haul telecom? → 1550 nm
10. What is the MOST effective way for new VDV professionals to build competency in their field? → Combining formal education, mentored practice, and ongoing professional development
11. What does an 'APC' fiber connector end-face polish provide compared to a 'UPC' polish? → Higher return loss due to its angled 8-degree end-face
12. How does the VDV body of knowledge relate to daily professional practice? → It provides the foundational framework that guides decision-making and standard practices
13. According to TIA-568 standards, what is the maximum channel insertion loss allowed for OM3 multimode fiber at 850 nm for a 100 m horizontal link? → 2.4 dB
14. What does an optical power meter reading of -35 dBm on a single-mode fiber link (expected: -20 dBm) most likely indicate? → Excessive loss due to a dirty connector, bend, or break in the fiber
15. What does 'bend radius' refer to in fiber optic installations? → The minimum curve radius a fiber can be bent without excessive signal loss
16. What is the correct term for the point in a structured cabling system where outside plant cabling transitions to inside plant cabling? → Entrance Facility (EF)
17. Which parameter measures the difference in propagation delay between the fastest and slowest pairs in a Cat 6 cable? → Delay Skew
18. What does it mean when a cable tester reports an 'open' fault 23 meters from the near end? → A conductor has a break or disconnection at approximately 23 meters
19. What is the primary function of a splice enclosure in a fiber optic outside plant (OSP) installation? → To protect and organize fiber fusion or mechanical splices from environmental damage
20. What does the term 'Tier 1' testing mean in the context of fiber optic certification per TIA-526-14-B? → Insertion loss testing using a light source and power meter
21. What is the role of LLDP-MED in a VoIP deployment? → Allow IP phones to discover VLAN and QoS configuration from the switch
22. When testing installed fiber with an OTDR, a 'ghost' reflection appears beyond the far end of the fiber. What is the most likely cause? → A high-reflectance event re-reflecting back past the launch end
23. How does the VDV body of knowledge relate to daily professional practice? → It provides the foundational framework that guides decision-making and standard practices
24. What step should follow a successful fix? → Re-test and document
25. Which cable category is the minimum required to support 10GBASE-T Ethernet up to 55 meters? → Cat6
26. What does QoS DSCP marking AF41 indicate for VoIP traffic? → Assured Forwarding class 4, drop probability 1 — high priority multimedia
27. Which wiring standard requires that the green pair be placed on pins 1 and 2 of an 8P8C outlet? → T568A
28. What is the maximum allowable pair untwist at a termination point per TIA-568 for Cat6 cable? → 13 mm (0.5 inch)
29. Which cable type is most appropriate for running a balanced audio signal over 100 feet to minimize noise pickup? → Shielded twisted pair (STP) with XLR connectors
30. In Voice Data Video Technician Certified, what is the PRIMARY purpose of conducting regular safety drills and exercises? → To ensure personnel can respond effectively in emergencies