A 100G QSFP28 AOC is an integrated cable assembly with optical transceiver ends and fiber permanently connected together. Once this cabling approach has been selected, the next step is to specify a cable that fits the actual equipment and installation route.

A useful purchase request needs more than speed and length. Confirm the endpoints, connection type, physical route and maintenance requirements before placing an order.

How to Specify a 100G QSFP28 AOC Cable Before Ordering

Record the exact switch or network adapter model at each end, together with the port number, software or firmware version and intended Ethernet speed.

A QSFP28 port does not automatically guarantee compatibility with every 100G AOC cable. Check the equipment documentation and request compatibility confirmation for both endpoints.

For a mixed-brand connection, identify each device separately rather than requesting compatibility with only one manufacturer.

Confirm Straight-Through or Breakout Operation

A standard QSFP28-to-QSFP28 AOC provides a single connection between two compatible 100G ports.

A 100G-to-4×25G connection requires a purpose-built breakout AOC and compatible host ports configured for breakout operation.

Not every 100G QSFP28 port supports breakout mode. Confirm the required configuration before selecting the cable.

Do not assume that a standard 100G AOC can be converted into a breakout assembly by adding a passive fiber harness.

Choose the Correct 100G AOC Cable Length

Measure the actual installation route through vertical cable managers, overhead trays and rack entry points. Include the additional length required for installation and future maintenance.

For example, two racks separated by four meters may require a longer cable once the complete routing path is considered. This is a planning example, not a fixed length recommendation.

Specify the finished cable assembly length and confirm how the supplier measures it. Avoid excessive slack that could obstruct airflow or complicate cable management.

Check Cable Routing and Installation Requirements

Confirm the cable diameter, minimum bend radius and available routing space. The integrated transceiver ends must also pass through any openings along the installation route.

Check the cable jacket specification, operating temperature range and port power budget against the selected part number.

When reviewing power consumption, confirm whether the quoted value applies to one transceiver end or the complete AOC assembly.

Do not assume that installation limits or electrical specifications from another supplier apply to the selected cable.

Plan Compatibility Testing and Replacement

Where available, request validation using the intended equipment combination.

Acceptance criteria should include successful link establishment, sustained traffic transmission and acceptable error counters under the required configuration.

A replacement plan is also important. Because an AOC integrates the fiber and transceiver ends, damage to the cable or failure of either end normally requires replacing the complete assembly rather than an individual optical module.

Example: 100G AOC Purchase Specification

The following example illustrates the information that procurement and engineering teams can confirm before requesting a quotation.

The 5 m length is an example only. Actual specifications depend on the equipment and installation route.

Conclusion

A complete 100G AOC purchase request should identify both endpoints, connection type, routed cable length, compatibility requirements and installation constraints.

Confirming these details before ordering helps procurement and engineering teams select the same cable specification, reduce avoidable compatibility problems and prepare for installation and maintenance.