Content










5.1



Legacy DDR
 



 


5.1.1



Legacy DDR with a single
destination
 







Legacy DDR is powerful and comprehensive.
It supports Frame Relay, the International Organization for
Standardization Connectionless Network Service (ISO CLNS), the Link
Access Procedure Balanced (LAPB) protocol, snapshot routing, and all
routed protocols that are supported on Cisco routers.
However, the limitations of legacy DDR
can inhibit scalability. For instance, legacy DDR is based on static
binding of a physical interface to one per-destination call
specification.

The problem with legacy DDR is that
legacy DDR statically binds a physical interface into only one
configuration. For example, DDR BRI0 can have only one Internet
Protocol (IP) address, one encapsulation type, and one set of dialer
timers. Consider the configuration in Figure
.

Legacy DDR configuration uses dialer
map statements. Dialer map statements are convenient when one physical
interface is responsible for calling one destination. As configured,
the Basic Rate Interface (BRI) in Figure
can only
dial a host named RTB, and can only use Point-to-Point Protocol (PPP)
with a dialer idle-timeout of 30 seconds when connected.

















 



Web Links

ISDN Glossary

http://www.cisco.com/en/US/tech/tk801/ tk379/technologies_tech_
note09186a0080094423.shtml