Configuring a PRI Block Example
In this example, you accept been asked to configure a PRI affiliation to the PSTN according
to the afterward arrangement requirements. Figure 4-19 presents the cartography acclimated in this
example.
Figure 4-19 ISDN PRI Agreement Cartography Example
The requirements are as follows:
■ The ISDN about-face is amid in Munich, Germany. According to the ISDN Switch
Type BRI Parameters table, you charge to configure the isdn switch-type as
primary-net5.
■ The DSP clocking will be synchronized with the WIC in aperture 0.
■ The band coding for the E1 ambassador will be linecoding ami. (This is not apparent in
Example 4-9 because this is the absence configuration.)
■ The framing needs to be authentic for the E1 controller. In this case, crc4 framing will
be used. (This is not apparent in Archetype 4-9 because this is the absence configuration.)
■ The alarm antecedent will be set to the PSTN. (This is the absence setting, so it is additionally not
shown in the configuration.)
■ The analytic articulation ports charge to be created. This is done with the pri-group timeslots
1-31 command, which defines all 30 B channels as analytic articulation ports. (Again, this is
the absence configuration.)
■ A variable-length calculation plan needs to be configured. Although the users accept a
four-digit extension, the switchboard is accessible via a “0” extension. You therefore
configure overlap-receiving.
■ To ascertain admission calls as voice-only, you configure isdn incoming-voice voice.
This will accelerate admission calls to the DSP resources.
Perform these accomplish to body the PRI block to the PSTN:
Step 1. Configure the ISDN about-face blazon according to the country’s ISDN
implementation.
Step 2. Configure DSP clocking so it is synchronized with the PSTN clock.
Step 3. Configure the E1 band code. Refer to the bounded account provider for the correct
setting.
224 Authorized Self-Study Guide: Cisco Articulation over IP (CVOICE)
V
Router2
ISDN PRI
30 B Channels
+
1 D Channel
Munich
PSTN
Step 4. Configure the E1 anatomy format. Refer to the bounded account provider for the correct
setting.
Step 5. Configure the alarm antecedent to ascertain which ancillary will accommodate clocking.
Step 6. Configure a analytic articulation anchorage to ascertain which channels will be acclimated for voice.
Step 7. Configure ISDN overlap-receiving for countries with variable-length numbering
plans.
Step 8. Configure admission ISDN calls as voice. The calls will be anon anesthetized to
the DSPs.
Step 9. Reset the interface if necessary, depending on the configuration.
Example 4-9 illustrates the completed configuration.
PRI Trunk
Chapter 4: Performing Call Signaling over Digital Articulation Ports 225
Router2(config)#network-clock-participate wic 0
Router2(config)#isdn switch-type primary-net5
Router2(config)#controller e1 0/0/0
Router2(config-controller)#pri-group timeslots 1-31
Router2(config)#interface Serial0/0/0:15
Router2(config-if)#isdn switch-type primary-net5 Router(config-if)# isdn overlapreceiving
Router2(config-if)#isdn incoming-voice voice