Types of DSL
Asymmetric DSL (ADSL)
- Uses three FDM channels
- 4 KHz analog voice channel
- A simplex data channel for downstream traffic
- A slower full-duplex data channel for Upstream traffic
- Size of digital channels
- Depends on the distance (CPE-Office) (up to 18,000 ft)
- Most common (T1): 1.5 Mbps down; 384 Kbps up
Very high data rate DSL (VDSL)
- Designed for local loops of 4500 ft or less (1000 ft ideal)
- Also uses three FDM channels as in ADSL
- Size of digital channels (distance sensitive)
- Most common (1/4OC1): 12 Mbps down; 1.6 Mbps up