Specifications
Overview of Modem Interfaces
Logical Constructs in Modem Configurations
DC-58
Cisco IOS Dial Technologies Configuration Guide
Modem Calls
Modem calls travel through traditional telephone and ISDN lines. Regardless of the media used, these
calls are initiated by a modem and terminate on another modem at the remote end.
Figure 17 shows a remote laptop using a V.90 internal modem to dial in to a Cisco AS5300 access server,
which is loaded with 96 internal V.90 MICA technologies modems.
Figure 17 Remote Node Dialing In to a Cisco AS5300 Access Server
Asynchronous Line Configuration
Asynchronous line configuration commands configure ports for the following options:
• Physical layer options such as modem configuration
• Security for login in EXEC mode
• AppleTalk Remote Access (ARA) protocol configuration (PPP is configured in interface
configuration mode)
• Autoselect to detect incoming protocols (ARA and PPP)
To enter line configuration mode, first connect to the console port of the access server and enter
privileged EXEC mode. Then enter global configuration mode and finally enter line configuration mode
for the asynchronous lines that you want to configure. The following example shows how you enter line
configuration mode for lines 1 through 16:
Router> enable
Router# configure terminal
Router(config)# line 1 16
Router(config-line)#
Absolute Versus Relative Line Numbers
When you enter line configuration mode, you can specify an absolute line number or a relative line
number. For example, absolute line number 20 is vty 2 (line 18 is vty 0). Referring to lines in a relative
format is often easier than attempting to recall the absolute number of a line on a large system. Internally,
the router uses absolute line numbers.
On all routers except the Cisco AS5350, AS5400, AS5800, AS5850 access servers, you can view all of
the absolute and relative line numbers using the show users all EXEC command.
PSTN/ISDNPOTS
Async PRI Fast
Ethernet
Cisco AS5300
equipped with
96 V.90 MICA
modems
PC laptop with
internal V.90 modem
dialing in to large
business LAN
14052
PPP