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Technical Glossary
USB Connectors
USB cables have two classes of connectors. The Type A connectors are used to connect the cable from a
USB device to a Type A port on a computer or hub. The Type B connectors are used to attach the USB cable
from a USB host to a USB device or hub. There are full-sized, mini, and micro variants of both type A and B
connectors.
USB 3.0 introduces changes to the connectors. USB 3.0 and USB 2.0 Type A connectors are the same shape
and size and are compatible with each other. However, the USB 3.0 Type B connector will not fit in a USB 2.0
Type B port, though a USB 2.0 Type B connector will fit into a USB 3.0 Type B port.
Duplex LC Crossover
When a crossover fiber-optic cable is called for, the cable has the transmit signal on one end connected to
the receive signal at the other end.
Type A USB 3.0 and 2.0 Port
Type B USB 2.0 Port
Type B USB 3.0 and 2.0 Port
Type A USB 2.0
Connector
Type A USB 3.0
Connector
Type B USB 3.0
Connector
Type B USB 2.0
Connector
RX
TX
