This simple step resolves many issues with sfp optical transceivers in access switches and core routers. Test with a known-good module or patch cable. Hello, from your output I can't see which type of QSFP you have installed, your QFX discovers. @LapointeMichel that known EX2300. An optical transceiver, also known as an optical module, is a device that converts electrical signals into optical signals for transmission over fiber-optic cables. When issues like signal loss, slow speeds, or intermittent connectivity arise, systematic troubleshooting is key.