Specifications

Configuring and Managing Integrated Modems
Managing Modems
DC-79
Cisco IOS Dial Technologies Configuration Guide
Note When Multilink PPP (MLP) is configured on a dialer interface, the dialer configuration has a default
value of 2 minutes for dialer idle timeout. For leased-line connections, set the dialer idle timeout to
infinity by adding dialer idle-timeout 0 to the configuration.
Verifying the Analog Leased-Line Configuration
The following information is important for verifying or troubleshooting your configuration. The show
modem log command displays the progress of leased-line connections. Here is an example log for a
leased-line answerer. Note the “LL Answering” state and “LL Answer” in the “Direction” field of the
connection report:
00:44:03.884 DTR set high
00:44:02.888 Modem enabled
00:43:57.732 Modem disabled
00:43:52.476 Modem State:LL Answering
00:43:52.476 CSM:event-MODEM_STARTING_CONNECT New
State-CSM_CONNECT_INITIATED_STATE
00:43:51.112 Modem State:Waiting for Carrier
00:43:43.308 Modem State:Connected
00:43:42.304 Connection:TX/RX Speed = 33600/33600,
Modulation = V34
Direction = LL Answer, Protocol = MNP, Compression =
V42bis
00:43:42.304 CSM:event-MODEM_CONNECTED New
State-CONNECTED_STATE
00:43:42.300 RS232:noCTS* DSR* DCD* noRI noRxBREAK
TxBREAK*
00:43:41.892 PPP mode active
00:43:41.892 Modem enabled
00:43:39.888 PPP escape maps set:TX map=00000000 RX
map=FFFFFFFF
00:43:39.724 PPP escape maps set:TX map=00000000 RX
map=000A0000
00:43:34.444 RS232:CTS* DSR DCD noRI noRxBREAK TxBREAK
00:43:11.716 Modem Analog Report:TX = -20, RX = -34,
Signal to noise = 61
Cisco 2600 and 3600 Series Analog Modem Leased-Line Support Examples
In the following examples, one Cisco 3620 router and one Cisco 3640 router are connected back-to-back
using leased lines. The Cisco 3620 router has the originating configuration, and the Cisco 3640 router
has the answering configuration.
In the dialer interface configuration, the dialer idle-timeout 0 command is added to set the dialer idle
timeout to be infinity. Otherwise the leased line will go down and up every 2 minutes because the default
dialer interface idle timeout is 2 minutes.
Note Except for passwords and logins, the Cisco IOS command-line interface (CLI) is case-insensitive.
For this document, an uppercase “L” has been used in the command examples to avoid confusion with
the numeral “1”.
Leased-Line Originating Configuration
version 12.1
service timestamps debug uptime
service timestamps log uptime
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