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Hi all,
I am having problems with few cells where number of unsuccessful RRC establishments is unusally high ( counter: pmTotNoRrcConnectReq, vendor: Ericsson ), but at the same time I don’t have any unsuccessful CS or PS RRC establishments ( counters pmTotNoRrcConnectReqCs and pmTotNoRrcConnectReqPs are both zero ). I haven’t found any other counters to determine which kind of traffic could be having problems during RRC establishment, so if you could help me determine what is causing this fails?
BR,
LLmehi llme,
pmTotNoRrcConnectReq shows the number of RRC requests, not the failures !!
Of course pmTotNoRrcConnectReq is very high, it represents all the RRC requests in your cell.The failures are shown by the difference between pmTotNoRrcConnectReq and pmTotNoRrcConnectReqSuccess
You can also find all the subcauses of failures below :
rrc denied adm
rrc fail after adm
utran rejection
loadsharing requestregards
Hi pix, thank you for your answer!
Yes, you are right, difference between pmTotNoRrcConnectReq and pmTotNoRrcConnectReqSuccess
is high, not the counter pmTotNoRrcConnectReq alone.I have checked counter pmNoFailedAfterAdm and realise that it’s value is almost the same as difference between pmTotNoRrcConnectReq and pmTotNoRrcConnectReqSuccess on that problematic day.
What are the most common reasons for failed RRCs and RABs after admission?
hi llme,
Thanks a lot for sharing your issue here, it’s very interesting.
Failure after Adm are a pain in the a$$…. Did it increase suddenly, or was it always high ?
Possible causes :
1/ TN issue (Iub)
2/ RNC issue (sw issue)
3/ Core network issueTry doing a Iub lock + cold restart of the RBS.
Also, please show the values for one day, so I can have a better understanding.
pmxh cell=… afteradm|pmTotNoRrcConnectReq -m 4 -a
If the RBS Restart did not work, then GPEH traces are the next step.
So let me recap:
1/ sudden increase ?
2/ share pmx results
3/ do a iub lock + rbs cold restartRegards
pixHi pix,
unfortunately, Iub lock and restart did not help.
The increase was sudden, it started 10 days ago, and jumped from 90 to 400 a day.
Here are the stats:
Start Time: 2013-11-07 08:15:00 End Time: 2013-11-08 08:00:00
Object
UtranCell=3G2120B
pmNoFailedAfterAdm 227
pmTotNoRrcConnectReq 57021
pmTotNoRrcConnectReqCs 6420
pmTotNoRrcConnectReqCsSucc 6412
pmTotNoRrcConnectReqPs 12147
pmTotNoRrcConnectReqPsSucc 12138
pmTotNoRrcConnectReqSms 9166
pmTotNoRrcConnectReqSubTr 2255
pmTotNoRrcConnectReqSuccess 56803Regards,
LLhi,
In your output, I can’t see the counter related to the failures. Maybe i’m wrong with the name. “aftAdm” perhaps ?
It contains the string “RRC” 🙂Could you do it again with the counters, including the one i’m talking about ?
Also include all counters related to:
RrcDenied
LoadSharing
RrcLc
IratThanks,
Cheers
pixThat’s the problem, I’m not sure what counters are you talking about exactl:)
I am calcualting failed RRCs as:
pmTotNoRrcConnectReq-pmTotNoRrcConnectReqSuccessFailed CS RRCs as:
pmTotNoRrcConnectReqCs-pmTotNoRrcConnectReqCsSuccand failed PS RRCs as:
pmTotNoRrcConnectReqPs-pmTotNoRrcConnectReqPsSuccSo, for example, newest stats are:
Start Time: 2013-11-22 05:30:00 End Time: 2013-11-22 09:15:00
pmTotNoRrcConnectReq 7310
pmTotNoRrcConnectReqSuccess 6356
pmTotNoRrcConnectReqCs 770
pmTotNoRrcConnectReqCsSucc 769
pmTotNoRrcConnectReqPs 706
pmTotNoRrcConnectReqPsSucc 704which means there are:
7310-6356=954 failed RRCs,
770-769=1 failed CS RRC,
706-704=2 failed PS RRCs.Other stats you’ve asked for:
Object
pmNoLoadSharingRrcConn 0
pmNoLoadSharingRrcConnCs 0
pmNoLoadSharingRrcConnPs 0
pmTotalTimeRejRrcConnRrcLc 0
pmNoRejRrcConnRrcLc 0
pmNoReqDeniedAdm 0
pmNoRlDeniedAdm 0
pmNoRrcCsReqDeniedAdm 0
pmNoRrcPsReqDeniedAdm 0
pmNoRrcReqDeniedAdm 0
pmNoRrcReqDeniedAdmDlChnlCode 0
pmNoRrcReqDeniedAdmDlHw 0
pmNoRrcReqDeniedAdmDlPwr 0
pmNoRrcReqDeniedAdmUlHw 0
pmTotNoRrcConnectAttIratCellResel 1262
pmTotNoRrcConnectSuccessIratCellResel 1049BR,
LLhi lily,
Ok great 🙂 Let me go back to work on monday and i’ll give you the names of the counters that are used to classify “failure after adm”.
Because there are only 900 fails, which are all happening on RRC “signalling” (not CS, not PS), I strnogly expect a real radio issue. Signalling usually occurs at cell border, where radio conditions are the worst.
Please ensure you didn’t change any neighbours parameter, utranrelation parameters or that a neighbour is not down.On monday, we will perform some kpi collection. the best would be to perform some traces (gpeh), but anyway, i’ll do my best with counters.
regards
Thanks pix!
In the meantime, another cell is also having similar problems. But, it’s degradation started on the day we have increased number of HsPdschCodes to 15. Is there any corelation between this and the number of unsuccessful RRCs for signalling?
llme,
no, it’s not related.
In your shoes, i would just do a gpeh trace, extract a failure after adm, and see the cause 🙂 That takes one hour and then you’re done !
In your previous pmx extract, it’s a pity you didn’t put the number of fail after adm. In a previous post though, you stated it is equal to the number of rrc failures.
And i told you the main causes for fail after adm : it is a RNC or transport network or Core Network issue.
Have you chercked your RNC load ? Maybe the RNC is in overload ?GPEH would tell you all that. If you have no decoder for gpeh trace, i can help (but take a very small trace : 30mn in one worst site + CM export).
Cheers
RNC is over-dimensioned, it shouldn’t be the problem.
I’ve done a gpeh trace, but I don’t know how to analyze it, what to search for? Ive never used it before. Regarding adimssion, I have only found this event: INTERNAL_ADMISSION_CONTROL_RESPONSE.
llme,
you can share it somewhere (file share)
and give me the link there : pix_erlang@yahoo.com
you must also share your CM export from the oss (common explorer ; click on the RNC where you did th trace ; right click ; export NE ; Radio Only, Compressed Mode)
You give me the gpeh files + this CM, and i can analyse them, i’ve got a tool.
Regards
pixHi,
Fow which system you guys are facing this Problem, Pix Please share the Outcome of this study..Thanks,Suzi
hi,
it’s on ercisson system.
any input from your side?
we had some issues exchanging the gpeh files, and now the files are good but i have not ime to look at them…
cheers
pixHi pix what could be the cause of utran rejection.upon reading thr docs about it,it seems to be a little bit broad.and what can be done to reduce this?thanks
