 The "core router" was a dedicated minicomputer called an IMP Interface Message Processor.Link speeds increased steadily, requiring progressively more powerful routers until the mid-1990s, when the typical core link speed reached 155 Mbit/s.At that time, several breakthroughs in fiber optic telecommunications (notably DWDM and EDFA) technologies combined to lower bandwidth costs that in turn drove a sudden dramatic increase in core link speeds