A Mass Appraisal Company Syncs Isolated County Networks in Both Directions With Files.com Agents

A US mass appraisal company runs countywide reappraisals for county assessors, on mass appraisal software its own people designed and programmed. And it goes a step further than most software vendors: it also runs day-to-day IT services for dozens of county assessor offices. The servers in those counties, the networks they sit on, and the data moving between them are the company's responsibility.

That data never stops moving. Mass appraisal runs on evidence: property photos, deeds, plats, and surveys, plus the appraisal database itself, entered on the county side and the company side at the same time. A field appraiser photographs a property, and staff at a regional office need that photo in front of them when they work the same parcel. The appraisal application has to show current imagery on either side, and the company's operating requirement is that a file entered at one site reaches the other within 5 to 15 minutes.

One more fact shaped everything that follows: each county network is deliberately its own contained network, separate from the company and from every other county. The company's entire service model puts time-critical files between networks that must never be joined.

Files.com gave the company a repeatable way to replace its per-county FTP infrastructure: Agents inside the county and regional networks connect outbound over HTTPS and synchronize appraisal files in both directions without bridging those networks or asking a county to open anything inbound.

A Server per County That Did Not Scale

For 15 years, those files moved over FTP servers inside each county network, with GoodSync handling appraisal data transfer and remote-management tools carrying files when a job called for it. The remote tools had file-size limits that appraisal data regularly exceeded, and every county meant one more FTP server to build and maintain. The company wanted one repeatable pattern in their place: outbound connections only, nothing new to ask a county firewall for, and the same install in every county.

The cost of a stalled file landed on people. Support staff and field appraisers depend on file movement to do their jobs at all. When a file stalls, an appraiser sits waiting on data instead of working parcels. And the stakes peak during the Board of Equalization cycle, when counties pull parcels for taxpayer appeals and must have current photos attached. Stale imagery is a failure in front of the taxpayer.

Isolation Was the Point

The obvious fixes were off the table, because the isolation was deliberate. When two servers share a network, a PowerShell script and XCOPY move files just fine, and the company uses exactly that internally. But its clients are not on the company's network, for good reason: each county is its own contained, secure network, and bridging them would undo that model. County firewall rules restrict which ports can be opened. The sync had to run in both directions, because data entry happens on both sides simultaneously. And any replacement had to roll out county by county across dozens of live production environments, without interrupting an operation that had run for 15 years.

So the fix had a specification before it had a name. It had to mirror folders across two isolated networks, in both directions, within minutes. It had to pass county firewalls without asking for new ports or protocols. And it had to be a repeatable per-county install, not a bespoke build for every client. The company selected Files.com to be that transfer layer.

One Files.com Agent Inside Each County Network, Outbound on Port 443

Files.com became the connective layer between networks that stay exactly as isolated as they were. The company installed one Files.com Agent inside each converted county network, paired with an Agent at its regional office. Each Agent makes only an outbound HTTPS connection to Files.com, so counties do not have to expose an inbound port.

Between each pair of Agents, Files.com runs bi-directional directory syncs on short intervals. A set of named folders on each local server, holding photos, deeds, plats, and surveys, is mirrored to its counterpart, so a file entered on either side appears on the other. Files.com carries the traffic as pass-through transit; the data keeps living on the servers inside each network.

The rollout was staged on purpose. The company tested the pattern on a handful of counties first, then expanded, creating the bulk of its sync jobs within about two months. The rollout continues county by county. Dozens of Agents now run in production across the deployment, carrying hundreds of sync jobs.

Files in Minutes, Outbound Only

The company is replacing its per-county FTP servers, and the workarounds built up around them, with one repeatable per-county pattern.

• A file dropped into a folder at one site appears at the counterpart site within minutes, well inside the 5-to-15-minute requirement. Appraisers work from current data instead of waiting on it.
• Each converted county's FTP server comes out, and GoodSync and the remote-tool file transfers go with it, with no new firewall rule asked of the county.
• Parcel imagery stays current through the Board of Equalization cycle, so when a county pulls a parcel for a taxpayer appeal, the current photos are attached.
• Bringing another county onto the pattern is an Agent install and a set of sync jobs, not another FTP server to build and maintain.

For the people doing the work, nothing changed, which was the point.

A Mechanics Swap Under a 15-Year Operation

The company describes the project as a mechanics swap. The operation is the same one it has run for 15 years, and the people in it work the way they always have. What changed is what carries the files.

Networks that are isolated on purpose never needed to be bridged to stay in sync. They needed a Files.com Agent inside each one.