Engineering blog
The numbers behind a link that works.
Twelve engineering notes on PoE budget, PoF reach, split ratio and optical margin — each note ends at the product family, model datasheet and a quotation you can check.
- Notes
- 12
- Topics
- 7
- Tools
- 2
- Updated
- 2026
4 guides
PoE engineering
Distance, power classes, switch sizing, surge.
PoE Distance Limit: How Far Can PoE Really Run?
The 100 m PoE limit is a standard, not a suggestion. Here is what counts inside the channel, why Cat5e/Cat6/Cat6a do not extend it, and the three ways to reach 200–500 m.
PoE Surge Protection: Why Copper Outdoor Runs Fail
A copper Ethernet run to a pole is a lightning path. Learn where surges enter, what a Type 2 SPD does, and how fibre and PoF change the protection plan.
PoE Standards: 802.3af vs at vs bt in Plain Numbers
A practical table of PoE classes, source and device power, cable requirements and the 100 m limit, with the arithmetic that keeps a switch budget honest.
How to Choose a PoE Switch: Ports, Budget, Uplink
A six-step method to size a PoE switch from the device list: port count, power budget, uplink, management, form factor and environment.
2 guides
Power over Fiber
PoF vs PoE, hybrid cable, 12 W limits.
Power over Fiber vs PoE: Which Power Path Fits?
PoF and PoE are not competitors; they solve different last-metre problems. Compare reach, power, cable, standards and failure modes before choosing.
Hybrid Cable vs Fiber Cable: What Changes on Site
A hybrid cable adds a copper pair to a fibre drop. Learn where that helps, where it does not, and how to specify length, bend radius and protection.
3 guides
PON & ODN
GPON/EPON/XGS-PON, link budgets, OLT/ONU compatibility.
GPON vs EPON vs XGS-PON: Which PON Generation Fits?
Compare GPON, EPON, XG-PON and XGS-PON by line rate, split ratio, reach, ONU cost and coexistence. A selection table for FTTH, campus and CCTV.
OLT and ONU Compatibility: Six Checks Before You Mix Vendors
PON mode, optical class, connector polish, management protocol, VLAN profile and firmware: the six checks that prevent a mixed-vendor PON from failing at commissioning.
When Is a 4-Port OLT Enough?
Four PON ports can serve 128–256 ONUs at 1:32/1:64, which is enough for a hotel, a clinic, a campus building or a small ISP. Here is how to size it.
2 guides
Optical budget
Split ratios, loss, measurement.
Fiber Optic Splitter Ratios: 1:2 to 1:64 in dB
Insertion loss, uniformity and return loss for PLC splitters, and how to choose a ratio from the PON optical budget instead of the subscriber count.
Optical Link Budget: The Calculation Behind a Working PON
A step-by-step PON link budget with transmit power, splitter loss, fibre loss, connectors, splices and ageing margin — plus a worked 20 km example.
1 guides
Procurement
HS codes and import documents.
Next step
Have a design that does not add up?
Send the split ratio, the span and the connector count. We will check the budget and show where the margin goes.
No obligation. The plan states its assumptions so your engineer can check it.