| Dialer profiles
separate the logical configuration from the interface that receives
or makes calls. Profiles can define encapsulation, access control
lists (ACLs), and minimum or maximum calls, and turn features on or off.
With dialer profiles, the logical and physical
configurations are dynamically bound to each other on a per-call
basis, allowing physical interfaces to dynamically take on
different characteristics based on incoming or outgoing calls, as
shown in Figure .
Dialer profiles help users design and deploy
complex and scalable circuit-switched internetworks by implementing
a new DDR model in both routers and access servers. Dialer profiles
separate the logical portion of DDR-such as the network layer,
encapsulation, and dialer parameters-from the physical interface
that places or receives calls, as shown in Figure .
Dialer profiles address several dialup issues:
- One configured interface
per ISDN interface -- Before
dialer profiles, all ISDN B channels inherited the physical
interface configuration.
- Dialer map complexity --
Before
dialer profiles, one dialer map was required per dialer per
protocol, making multiprotocol configurations very complex.
- Limited dial backup -- When
a BRI or PRI is
used to back up an interface, all the B channels are down and
the whole interface is idle. In addition, the one-to-one
relationship between interfaces and backup interfaces does not
scale well to a packet-switching environment, in which many
virtual circuits might need to be backed up individually and
floating static routes are not desirable.
Dialer profiles let you create different configurations for B channels on an ISDN PRI or BRI interface. Using dialer profiles, you can do the following:
- You can configure
B channels of an
ISDN interface with different IP subnets or (Internetwork Packet
Exchange (IPX) networks.
- You can use different encapsulations
of B channels of an ISDN interface. However, only PPP and High-Level Data Link Control (HDLC)
encapsulation are currently supported.
- You can set different DDR parameters
for B channels of an ISDN interface.
- You can eliminate the waste of ISDN
B channels by letting ISDN BRI interfaces belong to multiple
dialer pools.
The main difference between a rotary
group and a dialer profile is that a physical interface
participates in only one rotary group. With a dialer profile, a
physical interface can belong to many different pools.
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