ISDN PRI interface provides leased line T1 or E1. The main tasks of PRI interface settings are:
Use the isdn switch-type command to specify the ISDN switch used by the provider that connects the PRI interface. As with BRI, this command can be entered in global configuration mode or interface configuration.
Router (config) # isdn switch-type primary-Net5
Configuring a T1 or E1 controller is done in four steps:
1. From the global configuration mode, specify the controller and the PRI port on the router.
Router (config) # controller [t1 | e1] [slot / port]
Router (config-controller) #
2. Set the frame type, line coding and synchronization, as indicated by the service provider. Framing command is used to select the frame type using the ISDN PRI service provider. For T1 lines, use the following command:
Router (config-controller) # framing [nd | esf]
For E1 lines, use the framing command with the following options:
Router (config-controller) # framing [crc4 | no-crc4] [place]
Use the command linecode to identify the signaling method of the physical layer in the digital terminal equipment provider.
Router (config-controller) # linecode [ami | B8ZS | HDB3]
In North America, providers of T1 connections using B8ZS signaling method. Lets take full advantage of the 64 Kbps for each channel ISDN. Commonly used in Europe HDB3 encoding.
3. Configure PRI interface to use and the number of fixed time intervals allocated in the digital terminal equipment provider.
Router (config-controller) # pri-group [timeslotsrange]
For T1, the range of time intervals used is 1-24. For E1 is 1-31.
4. Specify an interface for PRI D channel operation. The interface is a serial link connected to a T1/E1 line in the router:
Router (config) # interface serial [slot / port: | unit:] [23 | 15]
In the E1 or T1 lines, the channels start their numbering at 1. The numbering ranges from 1 to 31 for E1 and 1 to 24 for T1. The Cisco router serial interfaces begin their numbering at 0. Therefore, channel 16, the signaling channel in an E1 connection, the channel 15 of the interface. Channel 24, the T1 signaling channel becomes the channel 23 in the interface. Thus, the serial interface 0 / 0: 23 refers to the D channel T1 PRI interface.
ISDN PRI dial Profiles
Dial A profile is a separate logical configuration of a physical connection, so you can make or receive a call using any physical interface placed in a warehouse associated with a profile.
These profiles define a network, encapsulation, an access control list, the number of calls, etc. Using dialing profiles can be configured ISDN B channels with different subnet address and a particular encapsulation for each of them.
The following command lets you configure the dial interface or profile from the interface:
Router (config) # interface dialer [logical interface number]
Router (config-if) # dialer string [number to dial]
Router (config-if) # dialer pool-member [number 1-255]