Switches, VLANs, PoE, Network Topology & Device Management

Est. 55 minCompetency: Choose switches, segment with VLANs, and use PoE correctly.

Learning objectives

Choose an appropriate switch for AV.
Segment AV traffic with VLANs.
Apply PoE correctly to powered devices.
Describe a star topology and managed switch basics.

Vocabulary

Managed switch: A switch you can configure: VLANs, QoS, IGMP, port settings.
VLAN: A virtual LAN separating traffic at the switch into broadcast domains.
PoE: Power over Ethernet — DC power on the data cable to a PoE device.
Star topology: Devices each home-run to a central switch.
Trunk: A link carrying multiple VLANs between switches.

Lesson content

The switch is the AV network's heart. A managed switch gives you VLANs, QoS, IGMP snooping, and per-port control — all needed for reliable AV-over-IP.

Switch choice

Use managed switches for AV; unmanaged switches cannot do VLANs, QoS, or IGMP.
Match port speed to need (1 Gb for control and Dante, 10/25/40/100 Gb for high-count uncompressed video where used).
Plan PoE budget: each PoE port draws watts; the switch's total PoE budget must cover all ports in use.

VLAN segmentation

1Put AV control on its own VLAN, separate from corporate data.
2Put AV-over-IP video on a dedicated VLAN when possible.
3Put Dante on its own VLAN (or a well-isolated one) with IGMP snooping.
4Route between VLANs only where necessary; keep AV off the open corporate network.

PoE

PoE delivers power on the data cable; classes define wattage.
Check each device's PoE class and budget the switch accordingly.
Some devices (touchpanels, small endpoints) are PoE; others (amps, displays) are not.

Field caution — PoE budget

A switch may have 24 PoE ports but only enough budget for 16 at full power. Count the watts before the install, or devices will randomly fail to power up.

Topology and management

Use a star topology: every device home-runs to the switch.
Avoid daisy-chaining AV devices unless the design specifically calls for it.
Manage the switch: set its management IP, disable unused ports, save the config.

Worked example

A meeting suite switch: 24-port managed, PoE+ on ports 1–16 for touchpanels and endpoints, uplink to core on port 24. VLAN 100 control, VLAN 200 Dante, VLAN 300 AV-over-IP video. PoE budget checked to cover all 16 PoE devices.

Implementation checklist

✓Managed switch chosen with needed features.
✓VLANs separate control, Dante, and AV-over-IP.
✓PoE budget covers all powered ports.
✓Star topology; management IP set; unused ports disabled.

Downloadable study guide

study-guide.txtcopy-paste ready

01. Managed switches for AV (VLANs, QoS, IGMP, per-port).
02. Segment control / Dante / video onto separate VLANs.
03. PoE budget must cover all powered ports by class.
04. Star topology; home-run each device to the switch.