| A | B |
|---|
| IPsec | Internet Protocol Security |
| IPv4 | Internet Protocol version 4 |
| IPv6 | Internet Protocol version 6 |
| ISDN | Integrated Services Digital Network |
| IS-IS | Intermediate System-Intermediate System |
| ISP | Internet Service Provider |
| IT | Information Technology |
| Kbps | Kilobits per second |
| L2F | Layer 2 Forwarding |
| L2TP | Layer 2 Tunneling Protocol |
| LACP | Link Aggregation Control Protocol |
| LAN | Local Area Network |
| LC | Logical Connector |
| LDAP | Lightweight Directory Access Protocol |
| LEC | Local Exchange Carrier |
| LED | Light Emitting Diode |
| LLC | Logical Link Control |
| MAC | Media Access Control/Medium Access Control |
| Mbps | Megabits per second |
| MBps | Megabytes per second |
