RCDD (RCDD): Case Studies and Concepts 4 — Questions and Answers
Question 1: A school district is deploying IP security cameras throughout 15 buildings on a campus. The cameras require PoE and 4K video streaming. What cabling category does the RCDD recommend as the minimum for reliable performance?
- CAT 5e
- CAT 6
- CAT 6A (Correct answer)
- CAT 7
Correct answer: CAT 6A
CAT 6A supports 10GBASE-T and full 4-pair PoE (IEEE 802.3bt) power delivery without significant heat buildup, making it the recommended minimum for high-bandwidth PoE cameras.
Question 2: The RCDD is performing a post-installation test of newly installed CAT 6A cabling. One link fails the alien crosstalk (ANEXT) test. What is the most likely cause?
- Improper termination causing pair untwist beyond 13 mm
- Cables bundled tightly together without maintaining separation (Correct answer)
- Use of non-matched plugs and jacks from different manufacturers
- Exceeding the maximum 90 m horizontal cable length
Correct answer: Cables bundled tightly together without maintaining separation
Tight bundling of CAT 6A cables significantly increases alien crosstalk (ANEXT/AFEXT) by allowing coupling between adjacent cable pairs.
Question 3: An RCDD is designing a wireless LAN system and must place access points to achieve -67 dBm signal coverage. The facility has concrete walls with 15 dB attenuation. The AP transmits at 20 dBm with a 3 dBi antenna. How many AP placements are needed across a 50,000 sq ft floor?
- Determine by calculating maximum radius from signal budget before coverage overlap (Correct answer)
- Divide floor area by 2,500 sq ft per AP as a fixed standard
- Place APs at 30 m intervals regardless of wall attenuation
- Install one AP per 10 users based on client density only
Correct answer: Determine by calculating maximum radius from signal budget before coverage overlap
Proper AP placement requires a link budget calculation (Tx power + antenna gain − wall losses ≥ target RSSI) to determine maximum usable radius, then plan overlapping cells.
Question 4: During a design review for a new corporate campus, the RCDD identifies that the proposed main cross-connect (MC) is located in a space that floods during heavy rain events. What is the most appropriate corrective action?
- Install a raised floor to protect equipment from water damage
- Relocate the MC to a space that meets ANSI/TIA-569-D environmental requirements (Correct answer)
- Add a sump pump and waterproof the existing space
- Move the MC to the rooftop to avoid flooding entirely
Correct answer: Relocate the MC to a space that meets ANSI/TIA-569-D environmental requirements
ANSI/TIA-569-D requires that telecommunications rooms be located away from areas prone to flooding; the correct action is to relocate the MC.
Question 5: A case study involves a retail chain deploying a converged network for POS systems, inventory scanners, and VoIP phones across 50 stores. Which network architecture concept should the RCDD apply to prioritize POS and VoIP traffic?
- VLAN segmentation with QoS policies applied at the distribution layer (Correct answer)
- Separate physical cable runs for each application type
- Using CAT 7 cabling to inherently prioritize traffic
- Implementing fiber only between distribution and access switches
Correct answer: VLAN segmentation with QoS policies applied at the distribution layer
VLAN segmentation with QoS (Quality of Service) policies allows the network to prioritize latency-sensitive POS and VoIP traffic over a shared physical infrastructure.
Question 6: The RCDD is reviewing a 40-story office tower design. Which document should define the telecommunications room locations on each floor, the backbone pathways, and the equipment room location for inclusion in the construction documents?
- Network topology diagram
- Telecommunications infrastructure design drawing set (Correct answer)
- Equipment vendor cut sheets
- Cable management schedules
Correct answer: Telecommunications infrastructure design drawing set
The telecommunications infrastructure design drawing set (floor plans, riser diagrams, pathway details) is the formal deliverable that communicates all TR, ER, and backbone information to the construction team.
Question 7: An RCDD is asked to evaluate a proposal to use wireless technology instead of structured cabling for a temporary modular office building used for 18 months. What is the RCDD's most appropriate recommendation?
- Wireless is always inferior; install full CAT 6A horizontal cabling regardless of occupancy duration
- A hybrid approach with minimal structured cabling for critical systems and wireless for general use is appropriate for temporary occupancy (Correct answer)
- Install fiber only since it can be reused at a permanent location
- Defer entirely to the network engineer as this is outside the RCDD scope
Correct answer: A hybrid approach with minimal structured cabling for critical systems and wireless for general use is appropriate for temporary occupancy
For temporary structures with short occupancy, a hybrid approach balances cost and functionality while ensuring critical systems (fire alarm, access control) have dedicated cabling.
RCDD (RCDD): Case Studies and Concepts 4
A school district is deploying IP security cameras throughout 15 buildings on a campus.
The cameras require PoE and 4K video streaming.
What cabling category does the RCDD recommend as the minimum for reliable performance?