Cisco 2501 - Router - EN, User Manual

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4-20 Router Installation and Configuration Guide
Configuring ISDN
Step 6 If you are using an ISDN switch type (such as Basic NI1 or DMS-100) that
requires a service profile identifier (SPID), enter the SPID and optional local
directory number (LDN). The SPID and LDN are assigned by the ISDN service
provider.
The SPID is a number that identifies the service to which you have subscribed.
A SPID is not required for AT&T 5ESS service configured for a point-to-point
connection.
The LDN is an optional seven-digit phone number for the channel.
Router (config-if)# isdn spid1 SPID_no [LDN]
Router (config-if)# isdn spid2 SPID_no [LDN]
Step 7 Configure the router for PPP encapsulation and CHAP authentication:
Router (config-if)# encapsulation ppp
Router (config-if)# ppp authentication chap
Step 8 Enter the load-threshold or ppp multilink command to set up a second
B channel.
For bandwidth on demand, enter the load-threshold command to set the ISDN
load threshold. The load threshold determines the percentage of network load at
which the second ISDN B channel is activated. The value ranges from 1 to 255
(100 percent). In the following example, the value of 128 means that when the
first B channel reaches 50 percent of its bandwidth capacity (128 equals
50 percent of 255), the second B channel will activate to assist with the
bandwidth load:
Router (config-if)# dialer load-threshold 128
Alternatively, you can use Multilink PPP to activate a second ISDN line. For
Multilink PPP to work, the router must be running Cisco IOS Release 11.0(3) or
a later release, and both the current router and target router must support
Multilink PPP:
Router (config-if)# ppp multilink