If the LAPD is not alive, the reason could be one of the following:
1.
Note:
2.
Step 3: Are ISDN calls connecting successfully?
If the router has an LAPD connection to the switch, then when an outgoing call is made from
the router, it will send call setup messages to the switch. If the switch believes that the packet
is valid and there are channels available in the ISDN network, it will forward it on to the
router at the far end of the link. The receiving router will then either accept or reject the
call, depending on the contents of the packet.
If the receiving router accepts the call setup request, the ISDN call will come open, and the
routers will endeavour to exchange data packets. If the call does not come open, then there
will obviously be no exchange of data. In order to determine whether calls are coming open,
use the command:
which will output a record of the last few ISDN calls, successful or otherwise, as shown in
the following figure.
Call Name
-----------------------------------------------------------------------------
tdc
chs
ajpwlg
ajpwlg
abb
ajpwlg
ajpwlg
ajpwlg
gc
ppta
to_boe
pfricc
-----------------------------------------------------------------------------
No ISDN logging port defined.
5
The TEI mode has been set incorrectly.
On a Basic Rate interface, the TEI mode ought to be automatic, so that the router does
not mandate a TEI value to the switch, but will automatically accept whatever value is
assigned by the switch. The TEI mode of the BRI interface is shown in the first line of
output from the show lapd command. If the value shown in the TEI Mode column is
automatic, then the interface has been set properly. If the value is shown as non-automatic,
then the interface has not been set up properly. Use the command:
set lapd=n mode=automatic
It may be necessary to set this in the router's config script, and reboot the router.
There is a problem in the ISDN network.
If the router is sending valid LAPD packets, and the switch is not responding correctly, then
LAPD will stay in the DEAD state. Contact your ISDN network provider and report a
network fault.
show isdn log
Start Time
12-Dec-1997 11:18:51
12-Dec-1997 11:19:03
12-Dec-1997 11:19:36
12-Dec-1997 11:23:12
12-Dec-1997 11:23:33
12-Dec-1997 11:24:05
12-Dec-1997 11:24:25
12-Dec-1997 11:24:27
12-Dec-1997 11:25:14
12-Dec-1997 11:25:38
12-Dec-1997 11:26:13
12-Dec-1997 11:26:38
Duration Dir Number
CLEARED OUT 035439003
CLEARED OUT 073333333
0:01:01 OUT 044940190
0:01:01 OUT 044940190
0:00:49 OUT 093560114
CLEARED OUT
0:01:02 OUT 044940190
CLEARED OUT 044940190
CLEARED OUT 3776569
CLEARED OUT 043842672
CLEARED OUT 00441256376991
CLEARED OUT 3432977
Cause
U16,-
N1,-
U16,-
U16,-
U16,-
-
U16,-
N21,-
N27,-
N17,-
N18,-
N17,-
Imprimir página