L
- L2TP (Layer 2 Tunneling Protocol)
- LAN (Local Area Network)
- Latency (Latenza)
- Latency Optimization
- Least Cost Routing (LCR)
- Licensing
- Lightweight Directory Access Protocol (LDAP)
- Line Appearance
- Line Card
- Line Hunting
- Line of Sight (LOS)
- Line Supervision
- Link Aggregation
- LNP (Local Number Portability)
- Load Balancing
- Load Shedding
- Local Exchange Carrier (LEC)
- Local Loop
- Location-Based Services (LBS)
- Log File
- Log Management
- Logical Channel
- Login Banner
- Loop Start
- Loopback Test
- Loud Ringing Unit
