Specifications

DC-2
Cisco IOS Dial Technologies Configuration Guide
Overview of Dial Interfaces, Controllers, and
Lines
This chapter describes the different types of software constructs, interfaces, controllers, channels, and
lines that are used for dial-up remote access. It includes the following main sections:
• Cisco IOS Dial Components
• Logical Constructs
• Logical Interfaces
• Circuit-Switched Digital Calls
• T1 and E1 Controllers
• Non-ISDN Channelized T1 and Channelized E1 Lines
• ISDN Service
• Line Types
• Encapsulation Types
For a complete description of the commands in this chapter, refer to the Cisco IOS Dial Technologies
Command Reference. To locate documentation of other commands that appear in this chapter, use the
command reference master index or search online.
Cisco IOS Dial Components
Different components inside Cisco IOS software work together to enable remote clients to dial in and
send packets. Figure 2 shows one Cisco AS5300 access server that is receiving calls from a remote
office, branch office (ROBO); small office, home office (SOHO); and modem client.
Depending on your network scenario, you may encounter all of the components in Figure 2. For
example, you might decide to create a virtual IP subnet by using a loopback interface. This step saves
address space. Virtual subnets can exist inside devices that you advertise to your backbone. In turn, IP
packets get relayed to remote PCs, which route back to the central site.