| ICD | ICMP | IEEE | IEEE 802.1 | IEEE 802.3 | IEEE 802.5 | IGMP | IGP | ILMI | in-band management |
| insured burst | interarea routing | interface processor | Internet | internet | Internet protocol | internetwork | internetworking | intra-area routing | Inverse ARP |
| IP | IP address | IPCP | IP multicast | IPX | IPXCP | IPXWAN | ISDN | ISL routing | isochronous transmission |
| ITU-T |