A badly designed business network rarely announces itself with an outright failure. It shows up as unexplained slowness, intermittent drops and diagnoses that take days. Here are the structural decisions, and the most frequent mistakes.
Cabling: the investment you do not redo
It is the least visible part and the most durable. Cabling laid today will serve ten to fifteen years, well beyond the active equipment it connects.
The classic mistakes: under-specifying the cable category to save on installation, neglecting to label the outlets, and planning too few points per office. Adding an outlet afterwards costs several times what it costs to lay it during the works.
Segmentation: the most profitable measure
Separating traffic into distinct logical networks is the action that brings the most gain for the least investment. In practice:
- the workstation network
- the server network
- the telephony network
- the video surveillance network, often a heavy consumer of bandwidth
- a guest network, strictly isolated from the rest
This separation limits how far an incident spreads, simplifies diagnosis and stops a camera from saturating the link accounting is using.
The most widespread mistake remains the flat network: everyone on the same segment, including visitors and connected devices.
Professional Wi-Fi is not a home router
Three fundamental differences. Density: several coordinated access points beat one powerful isolated unit. Roaming: a user must move between access points without dropping a call or a session. Separation: the guest network must be genuinely partitioned, not simply given a different password.
Another frequent mistake: placing access points according to what is convenient for the cabling rather than according to a coverage survey. Dead zones discovered afterwards are expensive to fix.
Useful redundancy
Duplicating everything makes no sense. Identify the single point whose failure stops the business. In most SMEs, that is the internet link or the core switch.
A second internet connection with a different operator, with automatic failover, costs moderately and covers the most likely scenario.
What almost always gets neglected
- Documentation. An up-to-date plan of outlets, equipment and configurations saves hours at diagnosis time.
- The UPS. A server brought down abruptly by a brief power cut can lose data.
- Monitoring. Knowing that a link is saturating before users complain changes the nature of the job.
- Configuration backups for network equipment, which take days to rebuild by hand.
Frequently asked questions
Do we need fibre inside the building?
Between buildings or over long distances, yes. To connect workstations on the same floor, copper of the right category remains simpler and cheaper.
How many Wi-Fi access points should we plan for?
That depends on the floor area, the partitions and user density, not on a general rule. A coverage survey avoids both under-equipping and unnecessary spending.
Can an existing network be upgraded in stages?
Yes, and it is often the right approach: start with segmentation and monitoring, which bring immediate gains, before considering replacing the cabling.
How we work
Systomap designs, deploys and maintains network infrastructure: cabling, switching, professional Wi-Fi, video surveillance and monitoring. See our services.
