WAN protocols HDLC PPP Frame Really NAT PAT

WANs are most often charge-for-service networks, providing the means for users to access resources across a wide geographic area. Some services are considered Layer 2 connections between your remote locations, typically provided by a telephone company (telco) over its WAN switches. Some of these technologies include a serial point-to-point (leased line) connection and Frame Relay connections.

Other connections leverage the Internet infrastructure, a Layer 3 alternative, to interconnect the remote locations of an organization. To provide security across the public Internet, you can implement a virtual private network (VPN) solution.

This section introduces the components of a VPN solution for WAN connectivity, explains how to configure a PPP connection, and describes Frame Relay operation, configuration, and troubleshooting.

In this section we would cover following CCNA objectives

• Describe the uses of VPNs for site-to-site and remote-user access
• Connect to a service provider over a network and describe the operation and configuration of PPP
• Connect to a service provider over a network and describe the operation and the basic configuration of Frame Relay
• Identify an approach for troubleshooting common Frame Relay problems and offer solutions