High-speed modular connectors are cage-and-module systems where the cage is soldered to the PCB and the transceiver module plugs in — letting you swap the optical or copper interface without touching the board. SFP, SFP+, SFP28, QSFP28, QSFP-DD, and OSFP are the dominant form factors in networking equipment, telecom line cards, and data centre switches. The cage is the PCB-mounted component TRX sources; the transceiver module is a separate item.

Form factors break down by data rate. SFP handles 1G, SFP+ runs 10G, SFP28 targets 25G. SFP, SFP+, and SFP28 cages are mechanically identical — only the electrical spec and module differ, so an SFP28 cage accepts SFP+ modules at a reduced data rate. QSFP28 hits 100G using four lanes at 25G each. QSFP-DD pushes 400G across eight lanes at 50G, and OSFP covers 400G to 800G. QSFP28 and QSFP-DD cages are not interchangeable — different module depths.

Applications include data centre switching, telecom line cards, 5G fronthaul and backhaul, fibre channel storage networks, industrial ethernet switches, and test and measurement equipment.

Cage selection depends on data rate, link medium — single-mode optical, multimode optical, or Direct Attach Copper (DAC cables use SFP+/QSFP connectors with copper, no optical components, lower cost for short reaches) — cage configuration (single, ganged, stacked), available PCB real estate, airflow direction, heat sink clearance, and whether an EMI gasket system is needed for regulatory compliance.

TRX sources SFP and QSFP cage assemblies from Amphenol, Molex, TE Connectivity, and Foxconn Interconnect through authorised distribution. No minimum order. In-stock lines ship to Johannesburg, Cape Town, Durban, and Pretoria. For sourced parts, we'll give you an actual lead time.

Send us your part number or describe the application — we'll come back with availability and pricing.