- Enterasys Security Router User's Guide

Implementing Dial Services
XSR User’s Guide 10-5
to support point-to-point or point-to-multi-point connections and can be non-spoofed for
backup purposes. Refer to “Dialer Interface Spoofing” on page 10-18 for more information.
• Dialer map class defines all line characteristics of calls to the destination including the interval
to wait for a dial signal. It is specified with the
map class dialer command.
• IP address identifies the local side of the connection. It is configured with the
ip address
command.
• Dialer strings are phone numbers used to reach a destination. They are set with the
dialer
string
command.
• Dialer pool is a virtual group of physical interfaces used to reach a destination. Interfaces in a
dialer pool are weighted by priority. It is configured with the
dialer pool command.
Dialer Interface
A dialer interface, which is a group of settings used by the XSR to connect to a remote network,
can include multiple dial strings. Each dial string, in turn, can be associated with its own map
class which defines all the characteristics for any call to the specified dial string. Refer to dialer
profiles of interface dialer 0 which are illustrated in Figure 10-5 on page 10-9 and Figure 10-6 on
page 10-10.
Dialer Strings
Setting dialer strings is straightforward but their configuration is very flexible. You can specify
multiple dialer strings for the same dialer interface and each dialer string can be associated with a
different dialer map class.
Dialer Pool
Each dialer interface uses one group of physical interfaces called a dialer pool. The physical
interfaces in a dialer pool are called into use based on a priority value for selection by the XSR.
Again, Serial interfaces can belong to multiple dialer pools, allowing a small number of resources
to service a large number of users. The disadvantage of this method is that all resources may be in
use when a user tries to access them.
Addressing Dialer Resources
There are two ways of setting up addressing on dialer resources, as follows.
• Applying a Subnet to the Dialer Cloud —Each site linked to the dialer cloud receives a unique
node address on a shared subnet for use on its dialer interface. This method is similar to
numbering a LAN or multipoint WAN and simplifies the addressing scheme and creating
static routes.
• Using Unnumbered Interfaces —Similar to using unnumbered addressing on leased line point-
to-point interfaces, the address of another interface on the XSR is borrowed for use on the
dialer interface. Unnumbered addressing takes advantage of the fact that there are only two
devices on the point-to-point link.
The routing table points to an interface (the dialer interface) and a next-hop address. When
building static routes for unnumbered interfaces the XSR must be configured with the interface
that finds the next-hop out.