Cisco QSFP-40G-SR4 uses four 10G lanes over parallel multimode fiber via MPO-12 connector for 40GbE connectivity up to 150m on OM4 fiber in data center top-of-rack and end-of-row switching.
| Pin | Name | Function | Type |
|---|---|---|---|
| TX | TX Array | 40G optical transmit 4 lanes MPO | BUS |
| RX | RX Array | 40G optical receive 4 lanes MPO | BUS |