command: Home(config-if)#dialer-group 1 In the command, group-number specifies the number of the dialer group to which the interface belongs. The group number can be an integer from 1 to 10. This number must match the dialer-list group-number. Each interface can have only one dialer group. However, the same dialer list can be assigned to multiple interfaces with the dialer-group command. The correct dialing information for the remote DDR interface needs to be specified. This is done using the dialer map command. The dialer map command maps the remote protocol address to a telephone number. This command is necessary to dial multiple sites. Router(config-if)#dialer map protocol next-hop-address [name hostname] [speed 56 | 64] [broadcast] dial-string If dialing only one site, use an unconditional dialer string command that always dials the one phone number regardless of the traffic destination. This step is unique to legacy DDR. Although the information is always required, the steps to configure destination information are different when using dialer profiles instead of legacy DDR. The dialer idle-timeout seconds command may be used to specify the number of idle seconds before a call is disconnected. The seconds represent the number of seconds until a call is disconnected after the last interesting packet is sent. The default is 120. Web Links Configuration Examples http://www.cisco.com/en/US/tech/tk801/ tk133/tech_configuration_ examples_list.html
Content 4.3 DDR Configuration 4.3.6 Dialer profiles Legacy DDR is limited because the configuration is applied directly to a physical interface. Since the IP address is applied directly to the interface, then only DDR interfaces configured in that specific subnet can establish a DDR connection with that interface. This means that there is a one-to-one correspondence between the two DDR interfaces at each end of the link. Dialer profiles remove the configuration from the interface receiving or making calls and only bind the configuration to the interface on a per-call basis. Dialer profiles allow physical interfaces to dynamically take on different characteristics based on incoming or outgoing call requirements. Dialer profiles can do all of the following: Dialer profiles aid in the design and deployment of more complex and scalable circuit-switched internetworks by implementing a more scalable DDR model in Cisco 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. Using dialer profiles, the following tasks may be performed: A dialer profile consists of the following elements: Like legacy DDR, dialer profiles activate when interesting traffic is queued to be sent out a DDR interface. First, an interesting packet is routed to a remote DDR IP address. The router then checks the configured dialer interfaces for one that shares the same subnet as the remote DDR IP address. If one exists, the router looks for an unused physical DDR interface in the dialer pool. The configuration from the dialer profile is then applied to the interface and the router attempts to create the DDR connection. When the connection is terminated, the interface is returned to the dialer pool for the next call. Web Links Dialer Profiles http://www.cisco.com/en/US/tech/ tk801/tk133/tk159/ tech_protocol_home.html
Content 4.3 DDR Configuration 4.3.7 Configuring dialer profiles 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. To configure the dialer interface, perform the following tasks:
  1. Configure one or more dialer interfaces with all the basic DDR commands:
  2. Configure a dialer string and dialer remote-name to specify the remote router name and phone number to dial it. The dialer pool associates this logical interface with a pool of physical interfaces.
  3. Configure the physical interfaces and assign them to a dialer pool using the dialer pool-member command.
An interface can be assigned to multiple dialer pools by using multiple dialer pool-member commands. If more than one physical interface exists in the pool, use the priority option of the dialer pool-member command to set the priority of the interface within a dialer pool. 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. A combination of any of these interfaces may be used with dialer pools: Lab Activity Lab Exercise: Configuring Dialer Profiles In this lab, the student will configure ISDN Dialer Profiles on the routers. Web Links Dialer Profiles http://www.cisco.com/en/US/tech/ tk801/tk133/tk159/ tech_protocol_home.html
Content 4.3 DDR Configuration 4.3.8 Verifying DDR configuration The show dialer interface [BRI] command displays information in the same format as the legacy DDR statistics on incoming and outgoing calls. The message “Dialer state is data link layer up” suggests that the dialer came up properly and interface BRI 0/0:1 is bound to the profile dialer1. The show isdn active command displays information about the current active ISDN calls. In this output, the ISDN call is outgoing to a remote router named Seattle. The show isdn status command displays information about the three layers of the BRI interface. In this output, ISDN Layer 1 is active, ISDN Layer 2 is established with SPID1 and SPID2 validated, and there is one active connection on Layer 3. Web Links Configuration Examples http://www.cisco.com/en/US/tech/
tk801/tk133/tech_configuration_
examples_list.html
Content 4.3 DDR Configuration 4.3.9 Troubleshooting the DDR configuration There are two major types of DDR problems. Either a router is not dialing when it should, or it is constantly dialing when it should not. Several debug commands can be used to help troubleshoot problems with a DDR configuration.The debug isdn q921 command is useful for viewing Layer 2 ISDN call setup exchanges. The “i =” field in the Q.921 payload field is the hexadecimal value of a Q.931 message. In the following lines, the seventh and eighth most significant hexadecimal numbers in the “i =” field indicate the type of Q.931 message: