Dcc Features Available With V 2.41 - 3Com 3C13636 Configuration Manual

3Com Router 3000 Ethernet Family
Configuration Guide
As shown in Figure 1-2, a physical interface can belong to multiple dialer bundles and
serves for them, but each dialer interface can only associate with one destination
address. Only one dialer bundle can be used by each dialer interface, and each dialer
bundle contains multiple physical interfaces with different priorities.
In the above figure, Dialer2 uses Dialer bundle2, and physical interfaces Bri0/0/0,
Bri1/0/0 and Bri2/0/0 are members of Dialer bundle2. These physical interfaces have
different priorities. Suppose that Bri0/0/0 in Dialer bundle2 is assigned with the priority
100, Bri1/0/0 with 50, and Bri2/0/0 with 75. Since the priority of Bri0/0/0 is higher than
that of Bri1/0/0 and Bri2/0/0, Bri0/0/0 will be selected first when Dialer2 selects a
physical interface from Dialer bundle2.

1.1.3 DCC Features Available with V 2.41

I. Basic DCC features
V 2.41 provides users with flexible and practical dial interface solution, featuring:
Support various dial interfaces, such as synchronous/asynchronous serial
interface, AUX port, ISDN BRI or PRI interface, and AM interface. The user can
flexibly combine them, depending on the actual networking and network topology.
Support the link layer protocols, such as PPP and Frame Relay, on dial interfaces
(physical or dialer interfaces).
Support the network layer protocols, such as IP, IPX on dial interfaces.
Support dynamic routing protocols, such as RIP and OSPF, on dial interfaces.
Provide flexible dial interface standby modes.
Provide administer modem devices with the command in user-interface view.
II. Implementing callback through DCC
In callback, the "called party" originates a return call to the "calling party". In which, the
calling party is the client, and the called party is the server. The callback client
originates a call first, and the callback server determines whether to originate a return
call. If a callback is needed, the server will immediately disconnect and originate a
return call.
DCC callback can:
Enhance security: When placing a return call, the server will dial the calling
number configured at the local end. Hence, the insecurity resulted from the
distribution of user name and password can be avoided.
Change the charge bearer. This is useful for saving cost in the case that the call
rates in two directions are different.
Consolidate the call charge bills, which will facilitate the settlement.
At present, V 2.41 system provides the PPP callback and ISDN caller identification
callback features. The PPP callback conforms to RFC1570 system and supports that
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Chapter 1 DCC Configuration