3Com 3036, Руководство по настройке

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51
C
ONFIGURING
DCC
This chapter covers the following topics:
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DCC Overview
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Configuring DCC
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Displaying and Debugging DCC
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DCC Configuration Examples
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Troubleshooting DCC
DCC Overview
Dial Control Center (DCC) is the routing technique adopted when the routers
interconnect via a PSTN (Public Switched Telephone Network) or ISDN (Integrated
Services Digital Network). In DCC, the routers are interconnected through PSTN.
The connections are established through dialing when data transmissions are
required. A DCC dialing is required to set up a link for transmitting information.
When the link becomes idle, the link established by DCC will be automatically
disconnected.
Under certain circumstances, routers establish connections for communications to
satisfy specific requirements. Therefore, the data transmission are
time-independent, burst and in small size. DCC provides a flexible, economical,
and efficient solution for such applications. In practice, DCC guarantees the
priority of communications through designated backup lines. In the case that a
primary line for normal communications become unavailable for any reasons, DCC
uses the designated backup channels to carry out the communications to assure
the required services are timely completed.
Frame Relay network through a leased line. To reduce the cost, you can adopt
frame relay over ISDN to access the frame relay network through ISDN line.
Meanwhile, ISDN network can act as the backup of frame relay network.
Terms in DCC
Configuration
The following terms are commonly used in DCC configurations:
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Physical interface: The physical interface that actually exists, like the serial, BRI,
asynchronous, and AM interfaces.
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Dialer interface: Logical interface set for configuring DCC parameters. A
physical interface can inherit the DCC configuration after it is bound to the
dialer interface.
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Dial interface: A general term describing an interface for dialup connection. It
can be a dialer interface, a physical interface bound to the dialer interface, or a
physical interface directly configured with DCC parameters.