Specifications

Overview of Dial Interfaces, Controllers, and Lines
Encapsulation Types
DC-17
Cisco IOS Dial Technologies Configuration Guide
Encapsulation Types
Synchronous serial interfaces default to High-Level Data Link Control (HDLC) encapsulation, and
asynchronous serial interfaces default to SLIP encapsulation. Cisco IOS software provides a long list of
encapsulation methods that can be set on the interface to change the default encapsulation method. See
the Cisco IOS Interface Command Reference for a complete list and description of these encapsulation
methods.
The following list summarizes the encapsulation commands available for serial interfaces used in dial
configurations:
• encapsulation frame-relay—Frame Relay
• encapsulation hdlc—HDLC protocol
• encapsulation lapb—X.25 LAPB DTE operation
• encapsulation ppp—PPP
• encapsulation slip—SLIP
To use SLIP or PPP encapsulation, the router or access server must be configured with an IP routing
protocol or with the ip host-routing command.