QSFP to CX4 are allowed on each line card ports

QSFP+ to CX4 Active Optical cables feature a QSFP+ Zinc Die Cast SFF-8436 connector on one end, and an External CX4 SFF-8470 with a pull latch connector on the other end. This cable is built using Optical Fiber for Active ports. Applications include DDR InfiniBand, Fibre Channel, and Serial Attached SCSI. Applications include DDR InfiniBand, Fibre Channel, and 10G Ethernet.  We offer standard lengths of 5 to 50 meters.SFPDA is similar in concept QSFP to CX4 but provides a bit more flexibility. Normally, you may have a switch or NIC that is designed to be able to support the addition of SFP based optics modules for a 10GbE fiber connection. Direct Attach allows for passive Twin-Axial (2 pair copper) cables to be plugged directly into the SFP+ cage (in place of an optical module) to carry the serial signal from the MAC directly over the cable to another SFP+ form factor enabled NIC or switch.