Cisco Aironet 2802i

Cisco · ceiling access point, Wi-Fi 5 Wave 2 · AIR-AP2802I

what it is

A ceiling-mount access point operating in the 802.11ac Wave 2 standard, in a 4×4:3 configuration. Polycarbonate enclosure, a square plate 220 × 220 mm, 55 mm thick, weighing 1.6 kg. The letter i in the designation means internal antennas — built into the enclosure and non-detachable.

The connections are on the narrow edge of the enclosure, not visible after mounting: two gigabit ports, a console port, a USB port, a mode button and a security cable slot. Power only over the cable, PoE+ standard. This model has no DC power jack, unlike the larger 3800 and 4800 models of the same family.

Power draw reaches 20 W, and 23 W with the USB port enabled. When planning the power budget on the switch, the second number counts, not the first.

The 2.4 GHz radio is flexible. Radio slot 0 can operate on 2.4 GHz, on 5 GHz or only listen; slot 1 is fixed 5 GHz. The controller shows three radio slots, but there are two transmitting radios — the third is the spectrum analysis chip. The device can also act as the network controller itself (Mobility Express).

Watch the designation. The second-to-last part (-E-, -B-, -K-, -Z-) is the regulatory domain, i.e. the country, not the hardware version. For Poland the correct one is -E. The domain determines which channels the device sees at all — two units of the same model in different domains have different channel plans and their radio results are not directly comparable.

what we read from it

Almost everything this access point exposes concerns the air, not the cable.

• Channel utilization separately for 2.4 and 5 GHz, broken down into transmit and receive. The breakdown matters here: congestion from own traffic and congestion from someone else's look the same in total, but require completely different actions.
• Noise floor in each band — the number that reveals interference that is not a Wi-Fi network.
• Operating channel and transmit power in each band — and whether they are set automatically. Without the latter it is unknown whether a channel change is a decision of the system or someone's hand.
• Number of radio neighbors seen in each band — a measure of how dense the surroundings are.
• Radar events and DFS switches on 5 GHz. An access point that leaves its channel once a day because of radar looks to users like a momentary network outage.
• Coverage, interference, load and noise assessment issued by the controller itself — four separate "within norm / out of norm" verdicts, plus a count of clients with insufficient coverage. This is the system's opinion of installation quality, not a raw reading.
• Uptime of the tunnel to the controller — separate from the uptime of the device itself.
• State of the link to the switch: port number, negotiated speed, duplex, link-down counter, frame errors and CRC errors, spanning tree changes and a link quality assessment.
• Power drawn over the cable — seen from the switch side.

port layout

The visible face has no ports at all — after ceiling mounting you see a smooth square plate with a single status indicator. The LED is not in the center: it sits roughly at half the width, but lower than half the height, measured from the edge with the connections.

All connections are on the narrow edge, in order from the left: mode button, console port, USB port, two gigabit ports adjacent to each other and the security cable slot at the right end.

The two gigabit ports can be bonded into a single link with up to 2 Gb/s of throughput. The vendor does not publish a straight-on view of this edge, so the height of the ports is not known.

what to watch out for

• The 2.4 GHz radio is configured with a different command family. The controller calls the flexible radio 802.11-abgn; 802.11b commands respond that there is no such radio. The channel change command first asks for confirmation, and only then rejects the whole thing.
• The flexible radio in the automatic role ignores manual settings. The message "XOR radio is not manual role." goes to the output stream, not as an error — the command "succeeds" and nothing changes. The role must first be set to manual.
• Changing the access point's operating mode reboots it.
• CRC error counters for its own port are known only to the access point's console. The controller does not show them.
• The access point's console paginates long output differently than usual — with "(Enter:next line Space:next page Q:quit R:show the rest)", not "--More--".

what we cannot read

• Temperature — the device does not expose it.
• Client lists with names — aggregate statistics are visible, not a list of people.
• CPU and memory utilization — this data appears only on an access point acting as the controller.

full parameter list

A full parameter list for this model is not here yet — the ones described above are those we have read and verified. A missing list does not mean the device exposes nothing more.