300-110 Exam Dumps - Designing Cisco Wireless Networks (300-110 WLSD) v1.2

In outdoor wireless deployments, foliage — particularly dense trees — represents the most significant and variable RF obstruction that engineers must account for during site survey and design. Trees are problematic for multiple compounding reasons: the high water content of living tissue causes signal absorption consistent with the principle that water is an effective absorber of 2.4 GHz and 5 GHz RF energy; the irregular branching structure causes multi-path scattering; and foliage density changes seasonally, meaning signal propagation characteristics measured during winter may differ substantially from summer readings when leaves are fully developed. A fully leafed deciduous tree can attenuate a 5 GHz signal by 6–15 dB depending on density and depth. Wind (Option A) causes only momentary mechanical movement of foliage and is not an obstruction itself. Rain (Option B) causes some absorption at higher frequencies but its effect at 2.4 GHz and 5 GHz in typical conditions is marginal compared to foliage. Poles (Option D) are thin structures with minimal RF impact. Outdoor surveys for university campuses must specifically account for tree locations, canopy density, and seasonal variation. Reference: WLSD Study Guide — Outdoor Wireless Design, Environmental RF Attenuation Factors, Outdoor Site Survey Considerations.

VoWLAN handoff quality is fundamentally determined by the AP placement strategy relative to the direction of user movement. When a user is in motion carrying an active voice call, the roaming event must occur before signal quality degrades below the minimum acceptable VoWLAN threshold (typically -67 dBm for voice, with a minimum SNR of 25 dB). This requires the user to encounter increasing signal strength from a neighboring AP before the current AP ' s signal drops below the threshold. The optimal AP placement follows the principle of overlapping coverage along the predicted path of travel — APs must be positioned so that as a user moves, they progressively enter the coverage zone of the next AP while still within adequate range of the current one. Floor plan B represents the correct design where APs are positioned along the travel path with sufficient cell overlap (typically 15-20%) to ensure seamless 802.11r fast BSS transitions. Incorrect floor plans place APs perpendicular to travel direction, at path endpoints only, or with insufficient overlap zones — all of which create roaming dead zones where the handoff occurs too late, causing voice call disruption. Reference: WLSD Study Guide — VoWLAN AP Placement, Roaming Design for Moving Users, Cell Overlap and Fast Transition Planning.

When configuring high availability on a Cisco access point, the AP can be configured with a maximum of three controllers: a primary controller, a secondary controller, and a tertiary controller. This three-tier hierarchy defines the failover order — the AP first attempts to join its primary controller, then the secondary if the primary is unavailable, and finally the tertiary if both the primary and secondary are unreachable. After exhausting all three configured options, the AP enters a discovery process to find any available controller. This three-controller configuration (primary, secondary, tertiary) allows network engineers to implement N+1 redundancy where critical APs can be directed to specific backup controllers in a deliberate sequence. Limiting the configuration to only 2 controllers (as stated in Option B which would be incorrect) would reduce redundancy options for environments with geographically distributed controllers requiring specific failover paths. Reference: WLSD Study Guide — AP High Availability Configuration, Primary/Secondary/Tertiary Controller Assignment, AP Failover Design.

A pre-site survey questionnaire is used to gather information before the physical survey begins, helping to define design requirements. The two most important information points it should contain are the access point density required and the applications that will run over the wireless network. Access point density (Option C) must be understood early because it depends on the number and types of users in each area, directly influencing the survey approach and AP placement strategy. Applications (Option E) are critical because they define the QoS requirements — a company developing code may run video conferencing, large file transfers, and real-time collaboration tools, each with distinct bandwidth and latency requirements that shape the RF design criteria. The total number of existing APs (Option A) and the current controller model (Option D) are inventory questions, not design requirement inputs. Client device types (Option B) are important but are a subset of the application question — applications drive the specific device capability requirements. Reference: WLSD Study Guide — Pre-Site Survey Requirements Gathering, Customer Questionnaire, Design Requirements Definition.