| Abbreviation | Definition |
|---|---|
| ISDN | Integrated Services Digital Network |
| ISDP | IntelliLight Shared Dual Path |
| ISH | Intermediate System Hello |
| ISHO | Inter System Handover |
| ISI | Ibm Smartcard Identification |
| ISIN | Istituto sistemi informativi e networking |
| ISIS | Intermediate System to Intermediate System |
| IS-IS | Intermediate System to Intermediate System |
| ISL | Inter Switch Link |
| ISN | Information Services And Networking |
| ISN | Intelligent Sensor Network |
| ISNP | Insurance Self Networking Platform |
| ISPAN | Ingress Switched Port ANalyzer |
| ISR | Integrated Services Router (Cisco) |
| ISR | Integrated Switch Router |
| ISS | Initial Send Sequence |
| ISS | Internet Server Supplement |
| ISSA | Interoperable Signed Sender Address |
| ISSM | Integrated Safeguards and Security Management |
| ISSO | Information Systems Security Officer |