Keep Legacy Optical Links Legible During a Network Refresh

A network refresh often leaves several generations operating at once. The useful catalog question is not whether every older product should disappear. It is whether the record still states clearly what that exact product connects, which protocol it supports and what lifecycle information the manufacturer publishes.

The MFA1A00-C015, C020 and C050 variants are a straightforward example. Their length-specific records describe 100GbE QSFP28 active optical assemblies. Their integrated engines distinguish them from detachable optics connected by passive fiber. A general MFA1A00 family introduction also discusses EDR, but the exact -C ordering and release rows are the correct basis for the Ethernet claim. Preserving the suffix prevents a broad family statement from turning into an unsupported protocol promise.

Lifecycle is a separate dimension. The inspected current release lists those three variants as EOL [HVM]. It also marks the MFS1S50-H010V splitter EOL [HVM], while historical releases record earlier phases. A clear product page can retain the valid identity and technical role while displaying that lifecycle context. Neither an EOL label nor an old GA entry proves the condition, availability or test result of any particular unit.

This matters when preparing a replacement plan. A 100G replacement must match the endpoint’s electrical lane arrangement as well as its total bandwidth. The HDR splitter’s two-lane 50G-PAM4 branches are different from four-lane 25G-NRZ QSFP28 links. A new cable with a familiar rate label can therefore be the wrong choice even when its form appears similar.

Treat the refresh as a documented transition: record the existing exact OPN, the active port mode, the route length and the replacement’s validated endpoint pairing. Keep a separate acceptance record for the supplied units. Historical LinkX deployments provide useful context for why cabling discipline matters, but they do not establish that these exact OPNs were used in a named installation. The goal is a maintainable, technically honest migration record rather than a blanket claim that older means unsuitable or newer means interchangeable.

Scope: Original engineering article based on manufacturer manuals; no fabricated deployment result or owned-customer success claim.

Public references

• MFA1A00-xxxx 100Gb/s QSFP28 MMF Active Optical Cable Product Specifications | MFA1A00-xxxx 100Gb/s QSFP28 MMF Active Optical Cable Product Specifications
• Ordering Information | MFA1A00-xxxx 100Gb/s QSFP28 MMF Active Optical Cable Product Specifications
• Validated and Supported Cables and Switches | ConnectX-7 Firmware RN
• ConnectX-6 Dx Firmware RN v22.43.4100 LTS: Validated and Supported Cables and Switches
• MFS1S50-H0xxV 200Gb/s QSFP56 to 2x100Gb/s QSFP56 Low Latency MMF AOC Product Specifications | MFS1S50-H0xxV 200Gb/s QSFP56 to 2x100Gb/s QSFP56 Low Latency MMF AOC Product Specifications