• Chapter 1: Describing Network Requirements
• Chapter 2: Topologies for Teleworker Connectivity
• Chapter 3: Using Cable to Connect to a Central Site
• Chapter 4: Using DSL to Connect to a Central Site
• Chapter 5: Configuring DSL Access with PPPoE
• Chapter 6: Configuring DSL Access with PPPoA
• Chapter 7: DSL Connection Troubleshooting
• Chapter 8: The MPLS Conceptual Model
• Chapter 9: MPLS Architecture
• Chapter 10: Configuring Frame Mode MPLS
• Chapter 11: MPLS VPN Technologies
• Chapter 12: IPsec Overview
• Chapter 13: Site-to-Site VPN Operations
• Chapter 14: GRE Tunneling over IPsec
• Chapter 15: IPsec High Availability Options
• Chapter 16: Configuring Cisco Easy VPN
• Chapter 18: Cisco Device Hardening
• Chapter 19: Securing Administrative Access
• Chapter 20: Using AAA to Scale Access Control
• Chapter 21: Cisco IOS Threat Defense Features
• Chapter 22: Implementing Cisco IOS Firewalls
• Chapter 23: Implementing Cisco IDS and IPS

Chapter 7: DSL Connection Troubleshooting

Physical Layer

Layer 1 has two sublayers: the transmission convergence (TC) and physical medium dependent (PMD) layers.

Framing is the process of ordering bits for transmission.

Line coding is the process of transmitting bits.

RJ-11/RJ-14 pinout:

1. (empty)
2. Black (Tip)
3. Red (Ring)
4. Green (Tip)
5. Yellow (Ring)
6. (empty)

Supported DSL Operating Modes

• auto - Automatic negotiation
• ansi-dmt - ANSI T1.413
• itu-dmt - G.992.1
• splitterless - G.992.2 or G.Lite

Carrierless Amplitude Phase (CAP) cannot be autonegotiated.

ATM Debugging

• debug atm events - Displays the allocated VPI/VCI pair
• debug atm packet - Displays VPI/VCI and packet type (MUX vs SNAP)

An ATM ping can be performed to test the ATM circuit:

Router# ping atm interface atm0/0 8 35 seg-loopback

PPP Operation

PPP phases:

1. Link Control phase
2. Authentication phase (optional)
3. Network Control phase

Monitoring:

• debug ppp negotiation
• debug ppp authentication