When would you need this: When you are using ISDN links between more than two nodes.

Special Requirements: The router should have ISDN interface(s).

If you are implementing ISDN between two nodes only, you probably do not need to use this procedure, please refer to the BRI ISDN configuration procedure.

What the dialer profiles do is that it maps a dial string along with username to a certain destination. This way, the router knows what number to dial for different ISDN destinations using the same link. The main problem that you may face without the use of dialer profiles is that the configuration is applied directly to the physical interface. This would cause that different logical links will need to use the same IP address and other configuration settings. The dialer profile applies the settings to the interface on on-call basis.

Multiple dialer interfaces may be configured on a router. Each dialer interface is the complete configuration for a destination. The ‘interface dialer’ command creates a dialer interface and enters interface configuration mode.

I will assume that you already set the switch-type and SPIDs, and start the configuration as the following:

1. Create a dialer-interface that contains the configuration of the interface to be used with a certain destination.

Router(config)#interface dialer X

where X is the dialer interface number that you may choose.

2. Configure the dialer interface as if you are configuring the regular DDR (refer to this procedure for more information). This configuration can be, IP address, encapsulation and authentication types, idle-timer, and dialer-group for interesting traffic. You can configure the encapsulation and authentication types on the physical interface later, if all of your connections use the same encapsulation and authentication types.

3. Configure a dialer-string to this interface, along with a ‘dialer remote-name’,

Router(config-if)#dialer string XXXXX

Router(config-if)#dialer remote-name YYYYY

where XXXXX is the dial string for the destination and YYYYY is the name of the destination. Usually you are supplied with two dial strings for each ISDN end. Just repeat the ‘dial string’ command once for each dial string.

4. Associate the dialer interface to a dialer pool. This pool will be associated to one or a group of physical interfaces such that the physical interfaces use these dialer settings on on-call basis.

Router(config-if)#dialer pool N

where N is the dialer pool number.

Now, repeat steps 1 to 4 for as many destinations as you have that can be contacted by this router (using the ISDN network). For the destinations you want to use the same physical interface, give the same dialer pool number (N).

5. After you finish setting the dialer interfaces, one step is left; associating the physical interfaces to the dialer pool. This is done using the following command:

Router(config-if)#dialer pool-member N

where N is the dialer pool number that you want this physical interface to be associated with.

Please note that this command must be issued on the physical interface NOT the dialer interface. And you can make the same physical interface a member of more than one dialer pool.

As an optional parameter, you can set priority of the physical interface in the dialer pool if the pool contains more than one physical member. An example is the following,

Router(config-if)#dialer pool-member 1 priority 100

where 100 is the priority you chose for this physical interface.

If multiple calls need to be placed and only one interface is available, then the dialer pool with the highest priority is the one that dials out.

In general, the dialer pool can be used with any combination of synchronous, asynchronous, BRI, and PRI interfaces.

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