US Patent 7599391 Media and speed independent interface

A rate adaptation layer (RAL) module for converting from a first interface operating at a first rate to a second interface operating at a second rate comprises first and second input/output (I/O) modules that communicate with the first and second interfaces, respectively. A repeater module receives symbols from the first I/O module, and transmits the symbols n times to the second I/O module, where n is determined by the first and second rates. A pull-down module receives symbols from the second I/O module and selectively extracts symbols to be communicated to the first I/O module.