Synchronization errors on T2 Access

[Schpice]

Hello Everybody,

so, I have some synchronization errors and the local provider has already come 2 times and for him, everything seems ok. I would like to be sure that is a provider issue.
I lose synchronization nearly every minutes and I have a lot of AIS errors. In the ALU documentations, they say that AIS errors is clearly a problem with the provider. I checked and checked again all my settings of my T2 access to be sure I correctly set everything.
So, either I'm so stupid and I can't set a T2 access or there is an issue with the local provider.

Code: Select all

+------------------------------------------------------------------------------+
| T R U N K    S T A T E     -    PRA T Coupler               Crystal_nbr = 2  |
|                                 IN SERVICE                  Coupler Nbr = 6  |
+------------------------------------------------------------------------------+
| Access 0  Type : T2   access : ENABLED           level2 : ATT_CONNECT2       |
|                                                                              |
| Trunk Grp      963  963  963  963  963  963  963  963  963  963  963  963    |
| Channel          1    2    3    4    5    6    7    8    9   10   11   12    |
| State           hs   hs   hs   hs   hs   hs   hs   hs   hs   hs   hs   hs    |
|                                                                              |
| Trunk Grp      963  963  963  963  963  963  963  963  963  963  963  963    |
| Channel         13   14   15   17   18   19   20   21   22   23   24   25    |
| State           hs   hs   hs   hs   hs   hs   hs   hs   hs   hs   hs   hs    |
|                                                                              |
| Trunk Grp      963  963  963  963  963  963                                  |
| Channel         26   27   28   29   30   31                                  |
| State           hs   hs   hs   hs   hs   hs                                  |
+------------------------------------------------------------------------------+
|  F:  Free   |    B: Busy   |   Ct: busy Comp trunk   |  Cl: busy Comp link   |
|  WB: Busy Without B Channel|   Cr: busy Comp trunk for RLIO inter-ACT link   |
|  WBD: Data Transparency without chan.| WBM: Modem transparency without chan. |
|  D: Data Transparency      |   M: Modem transparency                         |
+------------------------------------------------------------------------------+
|                        ALARM                COUNTERS                         |
+------------------------------------------------------------------------------+
|       NOS      |      AIS      |      LOS      |     FEC/CEC  |      RAI     |
|      9         |     11362     |     0         |    0         |    0         |
|------------------------------------------------------------------------------|
| NOS   :   no signal               |  LOS     : loss of synchronization       |
| AIS   :   alarm indication signal |  FEC/CEC : Frame/Checksum error counter  |
| RAI   :   remote alarm indication |                                          |
+------------------------------------------------------------------------------+

Code: Select all

18/06/12 12:19:44 000063M|002/06/0/000|=4:2113=T2 lapD not established still trying
18/06/12 12:19:48 000063M|002/06/-/---|=4:3580=remove TEI: mod ISDN UNSUCCESSFULL_RETRANS_OF_SABME (0) realy:0 info:0
18/06/12 12:19:58 000063M|002/06/0/000|=4:2085=Access T2, board (2,6) : synchronization stopped
18/06/12 12:19:58 000063M|002/06/0/000|=4:2112=AIS alarm on T2 access
18/06/12 12:20:08 000063M|002/06/0/000|=2:2101=T2 access still in state of alarm
18/06/12 12:21:04 000063M|002/06/-/---|=4:2103=T2 access end of 75 time-out unusual
18/06/12 12:21:35 000063M|002/06/-/---|=4:2103=T2 access end of 75 time-out unusual
18/06/12 12:22:31 000063M|002/06/0/000|=4:2080=T2 access is synchronizing on Board (2,6)
18/06/12 12:22:31 000063M|002/06/0/000|=5:2102=T2 access back to normal
18/06/12 12:22:31 000063M|002/06/0/000|=4:2113=T2 lapD not established still trying
18/06/12 12:22:35 000063M|002/06/-/---|=4:3580=remove TEI: mod ISDN UNSUCCESSFULL_RETRANS_OF_SABME (0) realy:0 info:0
18/06/12 12:22:40 000063M|002/06/-/---|=4:3580=remove TEI: mod ISDN UNSUCCESSFULL_RETRANS_OF_SABME (0) realy:0 info:0
18/06/12 12:22:58 000063M|002/06/0/000|=4:2085=Access T2, board (2,6) : synchronization stopped
18/06/12 12:22:58 000063M|002/06/0/000|=4:2112=AIS alarm on T2 access
18/06/12 12:23:08 000063M|002/06/0/000|=2:2101=T2 access still in state of alarm
18/06/12 12:24:34 000063M|002/06/-/---|=4:2103=T2 access end of 75 time-out unusual
18/06/12 12:25:00 000063M|002/06/-/---|=4:3580=remove TEI: mod ISDN UNSUCCESSFULL_RETRANS_OF_SABME (0) realy:0 info:0
18/06/12 12:25:05 000063M|002/06/0/000|=4:2080=T2 access is synchronizing on Board (2,6)
18/06/12 12:25:05 000063M|002/06/0/000|=5:2102=T2 access back to normal
18/06/12 12:25:05 000063M|002/06/0/000|=4:2113=T2 lapD not established still trying
18/06/12 12:25:07 000063M|002/06/0/000|=4:2085=Access T2, board (2,6) : synchronization stopped
18/06/12 12:25:07 000063M|002/06/0/000|=4:2112=AIS alarm on T2 access
18/06/12 12:25:17 000063M|002/06/0/000|=2:2101=T2 access still in state of alarm
(63)vnai-cs-01>

Code: Select all

 +---------------------------------------------------------------------+
 | Synchronization on global domain                                    |
 +---------------------------------------------------------------------+
 +---------------------------------------------------------------------+
 | Synchronization on domain no   2                                    |
 +---------------------------------------------------------------------+
 | N_CR | N_CPL |   TYPE     |  N_ACCES | PRIO | SYNC_CLOCK  |  TG/LK  |
 +---------------------------------------------------------------------+
 |    2 |   6   |     PRA T2 |      0   | 201  |     SYNCHRO | TG:963  |
 +---------------------------------------------------------------------+

So could you tell me what do you think about ?

Thanks in advance

[enio.eltz]

Hi there

In my opinion, be sure you have a problem with the public provider. AIS is usually a logic problem, in other words, you have phisical synchronization between OXE and the provider equipment in your customer but there's no logical signal, something like public PBX goes down.
Now, you must prove that it is a provider problem.

Regards.

[oxeman4400]

maybe you have to change your synchronization on your PRI board.

[vad]

If you have AIS error - check equipment between your and provider PBX (xDSL modems, MUX or what you use).
PBX1-E1-modem1---------modem2-E1-PBX2. Usualy you have AIS error when you have problem between modem 1 and 2.

[Medbck]

Hi everybody,

I have exactly the same issue, and the local provider confirm after testing the T2 accesses that the issue is from PBX side.
the PBX version is J1.410.40c.

Please inform me if you did find the solution to this issue.

Thanks by advance,

Best Regards

[vad]

You have problem with syncronization - from the begining, after upgrade or...?
From my practice - the main problem for synchronization - equipment between PBX and PSTN. Like MUX, SDH, modems (copper or fiber optic).
You need to manage synchronization priority not only in PBX but in this equipment too.

[Medbck]

Hi,
Thanks for answering.
The installation was done last May. and issue appeared since October 15th. they weren't any upgrade between installation date and the issue date. Yesterday, i tried to upgrade the software release to j1.410.49a, but unfortunatly, the issue still there.
Regarding synchronisation on the equipement between PBX and PSTN,
The local provider is in charge for the configuration of the this equipment, and when the guy from the local provider came to test the access, he connected his tester (Argus 125) instead of the PBX (for 7 hours), he didn't receive any error. So, in my opinion, if the issue is from this equipment, we should receive errors even by using the tester.

Thanks to share with me any idea about that.

[haroun]

Check also modem1 modem 2 synchro ; i was a similar isuue under pcmr2 and only was solved when the carrier provider synchronise his mux wich was running without !

[Medbck]

Thanks for your suggestions
I opened an eSR, and the issue was because they were no electrical connection to the ground. Shelves had some static electricity which disturb the T2 Accesses.

Thanks again, hoping that it will help some others if they encounter this kind of issues.

Regards