04-06-2009 06:29 AM - edited 03-15-2019 05:19 PM
We have a PRI being brought in on a 2851 router running 12-4-15-T5 code. It is configured as an h323 gateway. The controller shows up clean and the serial interface shows layer 2 going up and down. When I do a "sh isdn status" it shows it in TEI_ASSIGNED and after a few seconds goes to AWAITING_ESTABLISHMENT and after a little while it goes to MULTIPLE_FRAME_ESTABLISHED. After being in that state for a few seconds it fails back to TEI_ASSIGNED and goes through the same process again. I have included a debug isdn q921 in the attachment.
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04-06-2009 09:00 AM
If nothing has changed in the configuration from when it was working and you have replaced all of the hardware on your side, it has got to be a provider issue. That would have been the most likely issue to begin with, but considering the troubleshooting steps you have taken, it is the only possibility left.
04-06-2009 06:42 AM
Can you post a sh run and a sh isdn status ?
04-06-2009 07:01 AM
sh run is as follows:
boot-start-marker
boot-end-marker
!
card type t1 0 0
logging buffered 1000000
no logging rate-limit
no logging console
!
no aaa new-model
clock timezone CST6 -6
clock summer-time CDT6 recurring
network-clock-participate wic 0
network-clock-select 1 T1 0/0/0
dot11 syslog
!
isdn switch-type primary-4ess
!
voice-card 0
dspfarm
dsp services dspfarm
!
!
!
voice service voip
allow-connections h323 to h323
allow-connections h323 to sip
allow-connections sip to h323
allow-connections sip to sip
redirect ip2ip
h323
h450 h450-2 timeout T1 750
sip
no call service stop
!
!
voice class codec 1
codec preference 1 g729r8
codec preference 2 g711ulaw
!
!
!
voice class h323 1
h225 timeout tcp establish 2
!
application
global
service alternate DEFAULT
!
controller T1 0/0/0
framing esf
linecode b8zs
pri-group timeslots 1-24
!
voice-port 0/0/0:23
!
!
interface Serial0/0/0:23
no ip address
encapsulation hdlc
isdn switch-type primary-4ess
isdn protocol-emulate network
isdn incoming-voice voice
no cdp enable
!
04-06-2009 07:05 AM
show isdn status changes every few seconds. It bounces back and forth between the following three statuses:
gwshellrock#sh isdn status
Global ISDN Switchtype = primary-4ess
ISDN Serial0/0/0:23 interface
dsl 0, interface ISDN Switchtype = primary-4ess
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 0, Ces = 1, SAPI = 0, State = TEI_ASSIGNED
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x807FFFFF
Number of L2 Discards = 4, L2 Session ID = 232
Total Allocated ISDN CCBs = 0
gwshellrock#sh isdn status
Global ISDN Switchtype = primary-4ess
ISDN Serial0/0/0:23 interface
dsl 0, interface ISDN Switchtype = primary-4ess
Layer 1 Status:
ACTIVE
Layer 2 Status:
TEI = 0, Ces = 1, SAPI = 0, State = AWAITING_ESTABLISHMENT
Layer 3 Status:
0 Active Layer 3 Call(s)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x807FFFFF
Number of L2 Discards = 4, L2 Session ID = 232
Total Allocated ISDN CCBs = 0
gwshellrock#sh isdn status
Global ISDN Switchtype = primary-4ess
ISDN Serial0/0/0:23 interface
dsl 0, interface ISDN Switchtype = primary-4ess
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)
Active dsl 0 CCBs = 0
The Free Channel Mask: 0x807FFFFF
Number of L2 Discards = 4, L2 Session ID = 233
Total Allocated ISDN CCBs = 0
gwshellrock#
04-06-2009 07:12 AM
hi,
Why do you have "isdn protocol emalate network on your s0/0/0:23"
If your circuit is connected to the PSTN, then the PSTN is most times the network side while your end is the user side. YOu may want to remove this and hten test again
04-06-2009 07:16 AM
The telco requested we change the router to the network side to see if we could bring it up that way and they changed their side to user. We have since changed the router back to user and the telco has changed their side back to network as the change did not help at all. The debugs and sh isdn status are from after we changed our side back to user. The show run was just a little old. Sorry for the mixup.
Thanks,
Bud
04-06-2009 07:24 AM
Hi,
Have you tried a different encapsulation on the serial interface..eg encapsulation point-to-point (not sure of the exact command)
04-06-2009 07:47 AM
I tried "encapsulation ppp" on the serial interface and i continuted to get the same exact issues in teh q921 debug and the sh isdn status. The pri had been working for several months and it was always encapsulation hdlc while it was working.
04-06-2009 07:49 AM
Ok,
If it has always ben working then it could be a hadrware problem. If you have a spare t1 card, you may want to change the card and try again...
04-06-2009 08:11 AM
We swapped out the card already and still saw the exact same issue. We even swapped out the router for a replacement and that didn't help either. We've replaced about everything we can at this point.
04-06-2009 08:03 AM
I tried "encapsulation ppp" on the serial interface and i continuted to get the same exact issues in teh q921 debug and the sh isdn status. The pri had been working for several months and it was always encapsulation hdlc while it was working.
04-06-2009 09:00 AM
If nothing has changed in the configuration from when it was working and you have replaced all of the hardware on your side, it has got to be a provider issue. That would have been the most likely issue to begin with, but considering the troubleshooting steps you have taken, it is the only possibility left.
04-06-2009 09:03 AM
That was kind of my guess. Unfortunately convincing the Telco that this is the case is the hard part.
04-06-2009 10:49 AM
Hello,
I am guessing that when you call telco to have the PRI tested, they tell you that they test clean to the CSU with no errors. And that may be correct, but that is only testing Layer 1 connectivity. Your issue is at Layer 2, when you open the ticket with telco, advise them that the problem is in the switch itself, and not on the physical layer. In looking at the debug, when layer 2 is down, the router is sending frames to telco, but it doesnt appear the the switch is sending them back.
Hope that helped, if so please rate.
04-07-2009 01:17 AM
A guess, But I noitce you have not set the clock source line commend on the Controller for the link?
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