If you’re specifying optics for a new switch, router, or data centre fabric, the alphabet soup of SFP, SFP+, QSFP28 and QSFP-DD can be confusing. This guide breaks down what each transceiver type actually does, where it fits in an Australian network, and how to choose between them.
What is an SFP?
SFP stands for Small Form-factor Pluggable. It’s a hot-swappable transceiver that typically runs at 1 Gigabit per second and slots into a dedicated cage on a switch, router, or media converter. SFPs are still common on access switches, out-of-band management ports, and legacy WAN links.
What is an SFP+?
SFP+ is the 10 Gigabit evolution of the SFP form factor. It’s the same physical size, but supports 10GbE, making it the default choice for server uplinks, top-of-rack switching, and SAN connectivity in most Australian enterprise and data centre environments today.
What is QSFP28?
QSFP28 (Quad Small Form-factor Pluggable, 28 Gbps per lane) supports 100 Gigabit Ethernet by combining four 25G lanes. It’s widely used in leaf-spine data centre fabrics and core aggregation layers where high port density and throughput matter.
What is QSFP-DD?
QSFP-DD (Quad Small Form-factor Pluggable Double Density) adds a second row of electrical contacts to the QSFP form factor, enabling 400 Gigabit Ethernet (and higher) over eight lanes. It’s the current standard for hyperscale data centres, AI/ML clusters, and high-capacity backbone links. See our dedicated guide to 400G and 800G optics for AI workloads for planning larger GPU cluster fabrics.
How to choose between them
Match the transceiver to your switch port type first. Then consider distance (SR for short reach multimode, LR/ER/ZR for longer single-mode links), and whether you need DWDM coloured optics to run multiple wavelengths over one fibre pair. For most Australian SMB and enterprise networks, SFP+ remains the workhorse for 10G links, while QSFP28 and QSFP-DD are reserved for data centre cores and interconnect. Also confirm you’re using the right connector for the module, as outlined in our fibre connector guide.
Vendor compatibility
All four form factors are governed by Multi-Source Agreements (MSAs), meaning third-party, vendor-compatible modules from suppliers like Tikka Consulting can be used in Cisco, Arista, Juniper, Brocade, and Dell equipment, typically at 20-50% lower cost than OEM-branded optics, without sacrificing monitoring or diagnostics support.
Need help specifying the right optics for your network refresh or data centre build? Tikka Consulting supplies MSA-compliant SFP, SFP+, QSFP28, and QSFP-DD transceivers across Australia, backed by local support. Contact us to discuss your requirements. See our full range of optical transceivers and SFPs, or explore our guides on DWDM SFP selection guide, our SFP vendor compatibility guide, and our fibre connector guide.
