Verifying QSIG Trunks
To display information about the PRI interface controller, use the show controllers command,
as demonstrated in Example 4-21.
Example 4-21 show controllers Command
Chapter 4: Performing Call Signaling over Digital Voice Ports 239
Router#show controllers t1 0/1/0
T1 0/1/0 is up.
Applique type is Channelized T1
Cablelength is long gain36 0db
No alarms detected.
alarm-trigger is not set
Soaking time: 3, Clearance time: 10
AIS State:Clear LOS State:Clear LOF State:Clear
Version info Firmware: 20051006, FPGA: 20, spm_count = 0
Framing is ESF, Line Code is B8ZS, Clock Source is Line.
CRC Threshold is 320. Reported from firmware is 320.
Data in current interval (601 seconds elapsed):
2 Line Code Violations, 3 Path Code Violations
601 Slip Secs, 0 Fr Loss Secs, 2 Line Err Secs, 1 Degraded Mins
601 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Use the show isdn status command, as illustrated in Example 4-22, to verify the ISDN
Layer 1 is ACTIVE and the Layer 2 state is MULTIPLE_FRAME_ESTABLISHED. If
these conditions are satisfied, any problem you encounter with the QSIG trunk is probably
not with ISDN Layer 1 or Layer 2, and troubleshooting should focus on ISDN Layer
3 using the debug isdn q931 command. If a TEI_UNASSIGNED or AWAITING_
ESTABLISHMENT state is reported, verify the configuration. For a back-to-back configuration,
such as in a connection between a voice gateway and a PBX, one of the sides
must be set to emulate the network.
Example 4-22 show isdn status Command
Router#show isdn status
Global ISDN Switchtype = primary-qsig
ISDN Serial0/1/1:23 interface
dsl 0, interface ISDN Switchtype = primary-qsig
**** Slave side configuration ****
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)
continues
Example 4-22 show isdn status Command (continued)
240 Authorized Self-Study Guide: Cisco Voice over IP (CVOICE)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x00000000
Number of L2 Discards = 0, L2 Session ID = 0
Total Allocated ISDN CCBs = 0
Note Remember, if network emulation is not correctly set, Layer 2 will not come up.
There are a few commands you can use to debug a QSIG trunk.