Optical Converter or SFP Uplink? Extending a Network Past 100 m

When a camera sits further than 100 m from its cabinet, there are two engineering answers: keep the copper switch and put a media converter in front of it, or buy a switch that has an SFP cage and skip the converter entirely. Both work. They differ in cost, in what you can see when something breaks, and in how many boxes sit in the cabinet.

1. The two topologies

2. Where a converter is the right answer

• One existing non-fibre switch and one long run to extend — the cheapest fix.
• A legacy cabinet that must not be touched during production hours.
• A single remote camera or a small cluster behind an existing copper switch.
• A location where only a single 1G link is needed, now and for the foreseeable future.

3. Where an SFP uplink is the right answer

As soon as there are two or more fibre links in the same cabinet, converters stop making sense: you need one converter, one PSU and one patch lead per link, and none of them appear in any monitoring. A switch with SFP cages gives you the same connectivity with port diagnostics — receive power, temperature, link state — which is what turns a "site is down" call into a specific answer.

• Two or more fibre uplinks in one cabinet: switch with cages.
• Any uplink that must be redundant: pairs of cages, not pairs of converters.
• 10G aggregation to a head end: cages, since 10G converters are costly and rarely managed.
• Any site where someone will be paged at night: diagnostics pay for themselves once.

4. The details that cause the actual failures

• Wavelength pairing: 1310/1310 pairs with 1310/1310. A BiDi pair uses two different wavelengths and must be bought as a set.
• Speed matching: a 100M converter will not link to a 1G SFP cage unless the port is configured to match.
• Reach class: SR optics over multimode, LR over singlemode; a mismatch gives you no link or a link that drops in heat.
• Dirty ferrules: a single dirty connector can cost 10 dB — clean before you conclude the module is dead.
• Converter PSUs: cheap units fail in heat, and a failed PSU looks exactly like a failed fibre link.

Both options exist in our catalogue: the optical converter range for one-off extensions on existing copper switching, and the switches with SFP cages where the uplink belongs inside the switch. Module choice itself is covered in SFP module selection.

5. A rule that saves argument

Tell us the distance, the fibre type already in the ground and how many links share the cabinet, and we will confirm converter or cage. Ask for a quote.

FAQ

Les spécifications techniques détaillées sont fournies en anglais.