... E1, such as PDH, SDH, micro-wave, etc 4E1 to Ethernet Protocol ConverterE1-10/100Base-TX Protocol Converter is the equipment ... that extends Ethernet through telecom- line( E1 or network carrying E1, such as ... -wave, etc). It is also called Network Bridge. It changes Ethernet frame into E1 to transmit. And then it changes E1 ...