Specifications

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Cisco AS5x00 Case Study for Basic IP Modem Services
11/24/1999
Section 3 Commissioning the Cisco AS5800 Hardware
Configuring the Serial Interfaces
Task 4. Configuring the Serial Interfaces
Configure the serial D channels to route incoming voice calls from the PSTN to the integrated modems.
The behavior of the B channels is controlled by the D channels’ configuration instructions.
The D channel is the signaling channel.
Table 3-8 describes the relationship between T1 controllers and serial interfaces.

After timeslots are assigned by the
pri-group
command, D-channel serial interfaces are
automatically created in the configuration file (for example S1/0/0:0:23, S1/0/0:1:23, and so on).

Individual B-channel serial interfaces are created as rotary members (dialers) of their signaling
D-channels (for example S1/0/0:0:0 through S1/0/0:0:22). The D-channel interface functions like
a dialer for all the 23 B-channels using the controller.
An ISDN switch type defined on the global level is automatically propagated to the serial D-channel
interface level. However, a switch type defined on the serial-interface level overrides a switch type
defined on the global level. Per interface switch types are first introduced in Release 11.3AA.
Step 1
Apply the
isdn incoming-voice modem
command to each D-channel serial interface. In this example,
one interface is configured.
!
interface Serial1/0/0:4:23
isdn incoming-voice modem
!
Step 2
Verify that ISDN is functioning properly, and the serial channels are up:

Check the ISDN status. Confirm that Layer 1 reports ACTIVE, and the display field
MULTIPLE_FRAME_ESTABLISHED appears at Layer 2. For PRI lines, the terminal endpoint
identifier (TEI) is always 0. The Layer 3 status reports no active calls.
5800-NAS#show isdn status
Global ISDN Switchtype = primary-ni
ISDN Serial1/0/0:4:23 interface
dsl 0, interface ISDN Switchtype = primary-ni
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 0, Ces = 1, SAPI = 0, State = MULTIPLE_FRAME_ESTABLISHED
Layer 3 Status:
0 Active Layer 3 Call(s)
Activated dsl 0 CCBs = 0
The Free Channel Mask: 0x807FFFFF
Total Allocated ISDN CCBs = 0
Table 3-8 Controller-to-Channel Relationships
T1 Controllers D Channels B Channels
Controller T1 1/0/0:0 Interface Serial 1/0/0:0:23 S1/0/0:0:0 through S1/0/0:0:22
Controller T1 1/0/0:1 Interface Serial 1/0/0:1:23 S1/0/0:1:0 through S1/0/0:1:22
Controller T1 1/0/0:2 Interface Serial 1/0/0:2:23 S1/0/0:2:0 through S1/0/0:2:22
Controller T1 1/0/0:3 Interface Serial 1/0/0:3:23 S1/0/0:3:0 through S1/0/0:3:22
Controller T1 1/0/0:4 Interface Serial 1/0/0:4:23 S1/0/0:4:0 through S1/0/0:4:22
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