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GCE A/L General Information Technology study materials
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Hotel Wi-Fi Under Evening Load

GCE A/L General Information Technology · Put your knowledge to work in context.

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Hotel Wi-Fi Under Evening Load

A three-storey hotel has 24 rooms and up to 60 guests. A 100 Mbps fibre connection enters the lobby. One consumer Wi-Fi router serves the whole building, with two cheap repeaters on the upper floors. The same flat network also carries the front-desk booking terminal, a network printer, and an IP camera recorder. Walls are concrete and the repeater signal is weak in rooms at the back. In the evening, guests report that video calls freeze and pages load slowly; the front-desk terminal becomes sluggish between 7 and 8 p.m. while an online backup runs. A guest in room 12 can see the printer in the list of available devices. The owner wants to add 20 more rooms next year and asks whether a second fibre line is needed.

1. Diagnose the likely causes of the evening slowdown. Distinguish wireless problems, internet capacity, and local network contention, and use the numbers given.

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Several bottlenecks overlap; a single cause is unlikely.

  • Wireless: 60 guests with phones and laptops can mean 120–180 devices. A consumer router often supports only a few dozen clients comfortably and has one or two radios. Two repeaters share airtime with the router, and each hop roughly halves throughput. Concrete walls increase retries, so a weak client occupies the channel for longer. This alone can make video calls freeze.
  • Internet: the 100 Mbps fibre is shared. A 2–4 Mbps video call times 20 simultaneous calls is 40–80 Mbps before streaming, updates and the backup. The uplink can be saturated at peak.
  • Local contention: the backup between 7 and 8 p.m. runs over the same flat network and likely the same uplink. Without quality-of-service, it competes with the booking terminal. The flat network also lets the guest see the printer, which confirms there is no separation.
  • Measurement: check WAN utilisation, Wi-Fi channel utilisation, client counts per radio, and ping latency during the backup. Do not buy a second line until these distinguish the causes.

2. Propose a segmented network design for the hotel. Include VLANs, DHCP scope sizes, and where access points should connect.

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Use a wired distribution and separate logical networks.

  • VLANs: VLAN 10 guest, VLAN 20 staff/booking, VLAN 30 CCTV, VLAN 99 management. Put the booking terminal and printer on VLAN 20; CCTV on VLAN 30 with no internet access; access points and switch on VLAN 99.
  • DHCP: guest 192.168.10.0/24 gives 254 usable addresses, enough for about 180 devices now; plan a /23 if the 20 new rooms will push beyond 200 guest devices. Staff /25 or /24; CCTV static addresses or a small pool. Lease guest addresses for 4 hours; reserve addresses for the printer, recorder and access points.
  • Access points: install wired PoE access points on each floor, connected by Cat6 to a PoE switch; do a site survey and expect two per floor if concrete walls are bad. Disable the repeaters. Use 5 GHz where possible and a 2.4 GHz channel plan of 1, 6 and 11.
  • Guest control: separate SSID with captive portal, client isolation and a per-device rate limit (for example 5 Mbps). Firewall rules must block guest-to-LAN and guest-to-CCTV traffic. Put the nightly backup on a scheduled off-peak window and apply QoS to booking traffic.

3. The owner proposes buying a second 100 Mbps line instead of fixing the LAN. Evaluate this proposal and state what you would do first.

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A second line is not the first fix. The symptoms show a weak wireless design, a flat network and an unmanaged backup competing with the front desk. Another 100 Mbps line would not repair retries caused by concrete walls, a client limit on the router, or a backup saturating the existing link.

First: measure the WAN link for a week. If it is below about 70–80% at peak after QoS, segmentation and moving the backup to 2–5 a.m., a second line is unnecessary. Install wired access points and separate the networks. Only if the WAN is consistently saturated should the owner add a second line, and then with a router or firewall that can load-balance and apply policy routing. Keep the booking traffic on a preferred path and do not put the CCTV on the internet-facing link. Compare the cost of the line with the cost of the LAN fixes before deciding.