Surveillance
CCTV network design — PoE budgets that survive commissioning
Almost every surveillance project that goes wrong goes wrong for one of two reasons, and neither of them is bandwidth. Either the PoE budget was counted per port instead of per switch, or a camera ended up further from the switch than copper will carry.
Both are arithmetic problems. They are cheap to solve on a drawing and expensive to solve on a ladder, which is why this page leads with the numbers rather than the feature list.
- 370 W
- PoE budget on the 24-port managed switch
- 120
- Cameras at 200 W class on one LS2-24GT4SFP-P
- 5 km
- Wireless span instead of a fibre trench
- +75 °C
- Rating on the industrial cabinet switch
What goes wrong
The failure modes this design exists to prevent
Not a list of pain points — the specific ways this kind of deployment gets found out, usually after handover.
A 24-port PoE switch does not power 24 large cameras
Port count and power budget are different numbers, and datasheets rarely put them side by side. A 370 W budget across 24 PoE+ ports averages 15 W per port. Fine for a fixed dome; not fine for a PTZ with a heater running through a Delhi winter or a Chennai monsoon. Add IR illuminators at night, when every camera draws its maximum simultaneously, and a switch that tested clean in the afternoon starts dropping ports at 7pm.
The far camera is past 100 metres
Ethernet stops at 100 m. Gate cameras, perimeter poles, warehouse ends and the second block across the compound are all routinely further, and the honest answer has usually been a trench, a fibre pair and a media converter at each end — quoted at more than the cameras.
A hung camera means a truck roll
IP cameras lock up. On an unmanaged switch the fix is someone physically unplugging and replugging a cable, which on a remote site is a half-day and a bill your customer did not expect.
Nobody notices the recording stopped
A camera that drops off at 2am and comes back at 6am leaves a gap nobody sees until footage is needed — which is exactly when its absence matters most.
The design
How we build it
In build order, with the models that carry each part and why they were chosen.
Size the switch on published camera capacity, not port count
Every Lysora switch publishes how many cameras it carries at 200 W class and at 400 W class. The LS2-24GT4SFP-P is rated for 120 and 60 respectively across its 370 W budget; the 48-port LS2-48GT4SFP-P for 200 and 100. Those figures go into the quote, so the budget is checked before the purchase order rather than during handover.
Replace the trench with a 5 GHz span
A Base5i base station with a 15 dBi antenna covers a 120-degree sector out to 5 km, and pairs with CPE5 units at 16 dBi. TDMA scheduling keeps throughput predictable as CPEs are added, so a second and third block do not degrade the first. Where the far end is a single camera rather than a building, the CPE3-P has a 15.4 W PoE output and powers it directly.
Put PoE watchdog on every camera port
The switch pings each powered device and cycles the port when it stops answering. A locked-up camera recovers by itself in under a minute instead of generating a site visit. On cloud-managed models the same behaviour is configurable from the mobile app.
Segment cameras away from everything else
Cameras belong on their own VLAN with DHCP snooping and IP-MAC-port binding, so a compromised camera cannot reach the office network and a misconfigured DHCP server cannot hand addresses to the estate. The managed line carries all 4094 VLANs rather than the 16 that smart switches cap at.
Aggregate on fibre and watch it from the cloud
Uplink each edge switch on SFP into a Layer 3 aggregation switch so recording traffic never crosses the access layer twice. Lysora Cloud reports port and device state across sites, so a camera that goes quiet raises an alert rather than a gap in the archive.
Reference bill of materials
What typically goes in the quote
A starting point, not a fixed kit. Quantities and models move with the site — that is what the design conversation is for.
| Role | Model | Why this one |
|---|---|---|
| Camera access, main block | LS2-24GT4SFP-P | 24× PoE+, 370 W, rated for 120 cameras at 200 W class, 4× SFP uplinks |
| Camera access, large block | LS2-48GT4SFP-P | 48× PoE+, 104 Gbps switching, 16 K MAC table for a dense camera estate |
| Small cluster or gate house | LCS-4GS-P | 4× PoE+, 54 W, fanless and silent, PoE watchdog and camera detection |
| Link to a remote block | Base5i + CPE5 | 5 GHz, 15/16 dBi, up to 5 km, TDMA scheduled, IP55 |
| Single remote camera | CPE3-P | 3 km link with 15.4 W PoE output — powers the camera at the far end |
| Core aggregation | LS3-24SFP/8GT4XS | 24× SFP with OSPF routing and 4× 10GE SFP+ for the NVR |
| Outdoor cabinet | LCST-8GT2SFP-HP | DIN-rail, IP40, −40 to +75 °C, 300 W PoE with a PoE++ port |
Field notes
What catches people out on Indian sites
The things a datasheet will not tell you and a survey usually misses, gathered from deployments rather than from a brochure.
- Count the night draw, not the day draw. IR illuminators bring every camera to maximum power at the same moment, and that is the number the budget has to clear.
- Leave 20 percent headroom on the PoE budget. Cameras get added; nobody has ever specified a surveillance system that shrank.
- Outdoor cabinets in Indian summers routinely pass 60 °C internally. A commercial switch derates and then fails there — the DIN-rail LS2T and LCST models are rated to +65 °C and +75 °C.
- On a wireless span, check line of sight against tree growth over five years, not against the site as it looks today.
- Ask for the switch to be delivered pre-configured with the camera VLAN and watchdog set. It costs us nothing and saves a commissioning day.
FAQ
CCTV and surveillance — common questions
How many cameras can a 24-port PoE switch actually run?
It depends on the power budget, not the port count. The LS2-24GT4SFP-P has 370 W across 24 PoE+ ports and the manufacturer rates it for 120 cameras at 200 W class or 60 at 400 W class. A fixed dome drawing 8 W behaves very differently from a PTZ with a heater drawing 30 W, so we size the budget against the actual camera model in your BOQ rather than a port count.
Can I run a camera further than 100 metres without fibre?
Beyond 100 m you need either fibre or a wireless span. For a remote block a Base5i base station and CPE5 pair covers up to 5 km over 5 GHz with TDMA scheduling. For a single distant camera the CPE3-P covers 3 km and has a 15.4 W PoE output, so it powers the camera at the far end and no separate supply is needed there.
What happens when a camera freezes?
The switch's PoE watchdog pings each powered device and power-cycles the port when it stops responding, so the camera reboots by itself in under a minute. Without it, a frozen camera needs someone on site to unplug the cable — which on a remote installation is a half-day visit for a thirty-second fix.
Other deployment patterns
Send the site. Get the design and the BOQ.
A floor plan, a camera count or an existing BOQ is enough to start — and the coverage heatmap comes back with it, free.