Who makes OSFP/QSFP cages for AI data centers

A pluggable transceiver needs somewhere to plug in. The cage is the sheet-metal housing soldered or pressed onto the board that receives the module, holds it mechanically, provides the electrical connector, and — increasingly the hard part — conducts heat out of the module and shields the port electromagnetically. It is sold with the connector and often with an integrated heat sink as one assembly. The thermal job is what has changed. Higher-rate optical modules dissipate more power in the same faceplate opening, and a switch front panel packs those openings as tightly as the mechanics allow, so the cage has become part of the cooling design rather than just a socket. Ganged cages that share airflow and riding heat sinks that press onto the module top are both responses to that. AI fabrics drive the volume directly, since port count per switch has risen alongside lane rates, and every port carries a cage whether the module in it is optical or copper. What to look for is the form factor generation a supplier is shipping and whether it supplies the connector and thermal parts as one assembly, because switch vendors increasingly buy it that way. The suppliers are the large interconnect houses that also appear on board- level connectors in the parent part — the same manufacturing base serves both.