Benz Collision: a network core in a closet

Benz Collision is an auto body shop in Redwood City that needed real Wi-Fi across four spaces that behave nothing alike: a front office, an upstairs office, a metal-heavy shop floor, and a rear exterior work area. The strongest decision on the job came from the walkaround, not the catalog: an upstairs utility closet could become the network core, because the existing camera cabling already ran through it.

The problem

Coverage gaps across rooms with completely different RF behavior: drywall offices, an open shop floor full of steel and vehicles that absorb 5 GHz, and an outdoor work area with no wired drop nearby. One flat, aging setup could not serve all four, and the shop could not stop working while it got fixed. This was not a blank-slate install. It was a redesign around live internet, live cameras, and cable paths that were only partially documented.

What was already there

• Comcast Business internet terminating on coax in the main office, into a Comcast gateway feeding the office.
• Two Verkada cameras home-run back to the main-office Lite 8, their cables passing through an upstairs utility closet on the way.
• A UniFi Lite 8 PoE switch in the main office.
• A long cable run from the front office all the way to the rear of the shop, feeding an exterior UniFi USW-Flex switch that powers a Verkada beacon.
• Partially understood cable paths: some runs documented, some traced by hand during the survey.

Constraints

• An operating business, no real downtime. Repairs could not stall for a network cutover; the work had to be staged around shop hours.
• Reuse over rewiring. Pulling new cable through a working body shop is expensive and disruptive, so existing runs had to be reused wherever it was safe to.
• Camera connectivity is non-negotiable. The Verkada cameras had to survive the change, during and after.
• ~$1,500 hardware ceiling.

Architecture decisions

• The upstairs closet becomes the network core. Two of the existing camera cables pass straight through an upstairs utility closet. That made the closet the natural home for the core, a UniFi Dream Machine SE: central to the building, out of the work areas, and already holding the cabling I needed. Reading that off the site survey is what turned a coverage job into a clean redesign.
• Reuse the two camera cables instead of pulling new WAN and LAN runs. Both cables get cut and terminated in the closet. Each split yields an office-side end and a camera-side end, and all four ends get a job:
  • Office-side end 1 becomes the WAN feed, carrying internet from the Comcast gateway in the main office up to the UDM-SE.
  • Office-side end 2 becomes the LAN return, carrying the network back down from the UDM-SE to the main-office switch.
  • Both camera-side ends plug into the UDM-SE PoE ports, keeping the two Verkada cameras online, now powered and switched by the core.
  The result is a full uplink plus two live camera drops with zero new cable pulled through the building.
• The downstairs Lite 8 becomes a LAN edge switch for the main office, fed by the LAN return, so the existing office drops keep working without change.
• Keep the rear subsystem, shorten its dependency. The existing long run to the back of the shop already feeds an exterior USW-Flex that powers the Verkada beacon. That stays as-is, but the run gets re-homed to terminate at the closet core instead of the front office: a shorter, cleaner uplink that no longer leans on the office switch. A new U7 Outdoor AP goes about six feet below the beacon on the same USW-Flex, giving the rear yard real coverage off a wired backhaul.
• Wired APs placed for line of sight, not mesh. The main office gets a wall-mounted AP, since the UDM-SE upstairs does not throw useful signal down into the office. The upstairs office gets an AP fed directly from the closet, and the shop floor is covered by wired APs positioned for line of sight across the metal. Mesh is designed in only as a fallback for the hardest corner, never as the primary link: in a steel shop, mesh is a coverage patch, not a plan.

Tradeoffs

• Cutting live camera cables is the risky move, so it gets planned the hardest: label both ends before cutting, terminate and test each camera drop before moving on, and stage the work so the cameras are down for minutes, not the day.
• Reusing camera runs for WAN and LAN saves a full day of cable pulling and keeps the build under the hardware ceiling, at the cost of a more careful termination plan. For an operating shop, less disruption is worth more than a textbook home-run.
• Wired APs over a mesh-first design cost a little more cabling effort now and buy reliability that survives a floor full of moving steel and vehicles.

Status and deliverables

Site survey, constraint analysis, topology design, hardware selection, and the install plan are complete. Phase 1 deployment is scheduled for 2026.

• A labeled network diagram and the cable-termination map: which end lands where in the closet, and why.
• The AP placement plan, with the wired-versus-mesh reasoning written down.
• A short runbook so the shop, or the next technician, can maintain it without calling me.

The point of this one is not "I installed UniFi gear." It is infrastructure reasoning under real constraints: read the site, respect what is already working, reuse what you can, protect what cannot go down, and leave behind something documented enough to outlast you. An undocumented network is a permanent dependency on whoever built it, and permanent dependencies are bad engineering and worse business.