HP MSR2000/3000/4000 Router Series Layer 2 - WAN Configuration Guide

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For example, on an ISDN BRI interface, all the B channels inherit its configuration in the C-DDR approach.
The static binding between call destination address settings and physical interface configurations will
restrict the use of C-DDR, because dialer routes are becoming increasingly complicated as a result of
network growth and support for increasing protocols.
Figure 34 Associations between physical interfaces and dialer interfaces in C-DDR
As shown in Figure 34, a physical interface can be assigned to only one dialer interface, but each dialer
interface can contain multiple physical interfaces and be mapped to multiple destination addresses. In
addition, a physical interface can be directly mapped to one or more destination addresses without
being assigned to any dialer interface.
In the figure, physical interfaces Serial 2/1, BRI 1/1, and Serial 2/2 belong to Dialer 2, where mappings
between dial strings and destination addresses are configured. Physical interface Async 5/0 is directly
mapped to multiple destinations.
B-DDR
B-DDR separates logical configuration from physical configuration, so it is simpler and more flexible than
C-DDR. B-DDR delivers the following features:
• Physical interface configuration and logical configuration for calls are separate. They are
associated dynamically for processing calls. This allows a physical interface to provide services for
different dial applications.
• Associations between dialer interfaces and call destination addresses are one-to-one. You can
configure them with the dialer number command.
• Each dialer interface can contain multiple physical interfaces, and each physical interface can be
assigned to multiple dialer interfaces.
• Dial attributes, such as dialer interface, dialer bundle, and physical interface, are described by a
B-DDR set. All the calls destined to the same network use the same B-DDR set.
• B-DDR parameters cannot be directly configured on physical interfaces. A physical interface can
participate in B-DDR only after it is assigned to a dialer interface.