QSFP28 Cages & Connectors

QSFP28 Cage and Host Connector Selection

QSFP28 cages and host connectors provide the mechanical and electrical interface between a QSFP28 module and the host board. The cage guides and retains the module and can contribute to EMI shielding at the front panel. The host connector provides the electrical interface between the module and the PCB.

QSFP28 is commonly used in 100G networking equipment. When selecting the cage and connector, consider the intended module, port layout, host channel, module power and available cooling. Check the individual product page and drawing for the selected part's construction and specifications.

Choose a QSFP28 Cage by Port Configuration

Start with the number of ports required on the front panel. Then review the PCB mounting pattern, connector arrangement, heat sink clearance and airflow for the complete assembly.

• 1x1 QSFP28 cage: A single module position for one host port. Confirm whether the host connector and heat sink are included with the selected part.
• 1x2 and 1x3 QSFP28 cages: Multiple module positions arranged side by side in one row. Compare the PCB footprint, front-panel opening and cooling space between ports.
• 1x4 QSFP28 cage: Four ports in one horizontal row for multi-port host designs. Check the connector locations, mounting features, lightpipes and thermal envelope.
• 1x6 QSFP28 cage: Six ports in one horizontal row. Review the front-panel width, PCB mounting pattern and airflow under the intended module power and operating conditions.

Use the port configuration categories above to browse available QSFP28 products. Product features and included components vary by part number.

What to Check Before Selecting a QSFP28 Cage

• Product type: Confirm whether the listing is a cage only, a separate host connector, or a cage-and-connector assembly.
• Port configuration: Match the number of ports and their arrangement to the PCB and front-panel design.
• PCB mounting: Check the mounting method, finished plated-through-hole requirements and board thickness specified for the selected part.
• Host connector and channel: Verify the connector rating, PCB land pattern and high-speed channel requirements for the intended module and host.
• EMI interface: Compare the spring fingers, gasket or other shielding features with the front-panel opening and grounding design.
• Heat sink and airflow: Check the installed height, module contact, airflow direction and available clearance under the intended operating conditions.
• Lightpipe alignment: Where lightpipes are included or required, compare their positions with the PCB LEDs and front-panel openings.
• Operating conditions: Confirm the operating temperature and other environmental limits in the specific product documentation.

QSFP28 Cage, Host Connector and 100G Channel

In a QSFP28 host port, the cage and connector perform different functions. The metal cage provides mechanical guidance and a shielding interface, while the host connector carries the electrical signals between the module and the PCB.

A typical 100G QSFP28 host interface uses four high-speed electrical lanes. Connector ratings may be expressed per lane or per channel; check the manufacturer's definition for the exact part. The complete channel must also meet the requirements of the module, PCB and host system.

A cage's appearance or a connector's advertised maximum data rate does not by itself establish acceptable insertion loss, crosstalk or system performance. Review the applicable connector data and qualify the complete design.

QSFP28 Heat Sink and EMI Selection

QSFP28 cage configurations may be supplied with a heat sink, designed for a compatible heat sink, or offered without one. Check the exact part number and drawing before selecting thermal hardware.

For the intended module and enclosure, review module power, airflow direction, inlet temperature, installed height and clearance above the assembly. The required cooling depends on the complete system; a taller heat sink does not guarantee adequate cooling in every airflow arrangement.

For EMI control, compare the cage's shielding features with the panel opening, grounding contacts and assembly tolerances. Verify the installed system against the applicable EMC requirements.

For additional thermal design considerations, see QSFP28 riding heat sinks and vented cages .

QSFP28 Cage Cross-Reference and Replacement

For an existing PCB or enclosure, compare the complete original manufacturer part number and drawing with the proposed candidate. Review the PCB mounting holes, rear grounding features, connector position, front-panel interface, heat sink envelope and lightpipe alignment.

Parts in the same manufacturer series can differ by suffix. Confirm those differences before preparing a sample or approving a replacement. A shared port count or similar appearance does not establish a drop-in substitute.

See the SFP+ and QSFP28 cage cross-reference for examples of part-number and drawing-based comparisons. Replacement candidates should be qualified for the intended application before production use.

Frequently Asked Questions

What is the difference between a QSFP28 cage and a host connector?

The cage is the mechanical housing that guides and retains the module and can contribute to EMI shielding. The host connector provides the electrical interface between the module and the PCB. Depending on the product, they may be separate parts or supplied as an assembly.

What is the difference between a 1x1 and a 1x4 QSFP28 cage?

A 1x1 cage provides one module position. A 1x4 cage provides four positions in a single row. Compare the PCB footprint, front-panel space, connector locations and cooling requirements when choosing between them.

Does every QSFP28 cage include a heat sink?

No. Some products are supplied with a heat sink, while others require a separately selected compatible heat sink or have no heat sink. Check the individual part number and product drawing.

Can a QSFP+ cage or connector be used for a QSFP28 design?

Similar mechanical features do not establish support for a QSFP28 data rate or thermal requirement. Review the exact cage and connector specifications, module interface, PCB channel and host requirements before selecting and qualifying the assembly.

Does a press-fit QSFP28 cage require an SMT host connector?

Some designs use a press-fit metal cage with a separate surface-mount host connector. Other product constructions are available. Check the mounting method and included components for the exact cage and connector selected.

Can one QSFP28 cage replace another with the same port count?

Not automatically. Compare the PCB hole pattern, rear grounding features, connector location, EMI interface, heat sink dimensions and lightpipe arrangement. Qualify the candidate in the intended system before approving it for production.

What information should I provide for a QSFP28 cage inquiry?

Provide the port configuration, product type, mounting method, module power and any heat sink, EMI or lightpipe requirements. For an existing design, include the original manufacturer's full part number, drawing revision, PCB thickness and available front-panel and thermal clearance.

Request QSFP28 Cage and Connector Support

Need help selecting a QSFP28 cage or reviewing a replacement candidate? Send your port layout, module type, PCB and enclosure requirements, together with any available drawings, to the LINK-PP team.

Contact LINK-PP for QSFP28 Cage Selection