Endpoint types

Control
EP0 always exists, and it is the Control Endpoint
It is bidirectional, with a request/response protocol
Bulk
Data channels without timing constraints
They are a one-way data stream
Usually, you run them in pairs (input and output)
Interrupt
Input channel, much alike an interrupt event channel
Actually, it's always the host who polls the device
Isochronous
Sustained data flow, with guaranteed bandwidth
Typically used to deliver audio or video streams


For all types, transmission is packet- and frame-oriented
The receiver is aware of the size of each frame
A packet can span multiple frames (e.g.: more than 64 bytes).