| Abbreviation | Definition |
|---|---|
| ESP | Enhanced System Protocol |
| ESPAN | Egress Switched Port ANalyzer |
| ESPAN | Enhanced Switched Port ANalyzer |
| ESPI | Enhanced Serial Peripheral Interface |
| ESS | Electronic Switching System |
| ESS | Extended Service Set |
| ESSN | Enterprise Servers Storage and Networking |
| EST | Expressed Sequence Tag |
| ESTI | European Telecommunications Standards Institute |
| ETA | Estimated Time Available |
| ETC | Existing Transmission Commit |
| ETCB | End To Cyber Bullying |
| ETL | Electrical Testing Laboratory |
| ETN | Enterprise Telecommunications Network |
| ETN | ETS Trancesphere Network |
| ETOS | Ethernet Transport Optical Switch |
| ETS | Enterprise Translation Server |
| ETTH | Ethernet To The Home |
| ETTX | Ethernet To The X (X = whatever) |
| EUI | External User Interface |