Specifications

2-23
Cisco AS5x00 Case Study for Basic IP Modem Services
11/24/1999
Section 2 Commissioning the Cisco AS5300 Hardware
Configuring the Serial Interfaces
!
interface Serial3:23
isdn incoming-voice modem
!
Different versions of Cisco IOS enables different default commands. Release 12.0(5)T enables the
commands in Table 2-8.
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.
5300-NAS#show isdn status
Global ISDN Switchtype = primary-5ess
ISDN Serial0:23 interface
dsl 0, interface ISDN Switchtype = primary-5ess
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
. . .
Snip

Verify that PRI is working between the remote switch and the Cisco AS5300. After you enter the
debug isdn q921
command, you should see a SAPI message transmitted and received every
10 seconds. A SAPI message indicates that Layer 2 is functioning properly, and there are no
apparent cable problems.
5300-NAS#debug isdn q921
ISDN Q921 packets debugging is on
5300-NAS#
Sep 23 04:19:07.887: ISDN Se0:23: TX -> RRp sapi = 0 tei = 0 nr = 23
Sep 23 04:19:07.891: ISDN Se0:23: RX <- RRf sapi = 0 tei = 0 nr = 23
5300-NAS#undebug isdn q921
ISDN Q921 packets debugging is off
Table 2-8 Release 12.0(5)T Default Commands
Command Purpose
no ip directed-broadcast
Enhances security by preventing broadcasts to this subnet
from unauthorized sources.
isdn switch-type primary-5ess
The ISDN global switch type value is propagated to the
serial-interface level. This happens during initial
configuration or a reload.
Per interface switch-types are first introduced in Release
11.3AA.
no cdp enable
Turns off the cisco discovery protocol (cdp). Otherwise,
the protocol attempts to be negotiated on the PPP links.