Release due to Utran Generated Reason and Radio Connection with UE lost

[shahinsha]

Hello Experts,


Recently in our network there has been change in the GGSN from one vendor to another vendor.
From the day of this changes Radio Connection with UE lost and Release due to Utran generated reasons has been increased in SGSN due to which PDP context fails.

Can any one tell when this events are pegged in SGSN and what are the necessary steps that can be done to reduce this ...

[hengbong]

Hello,

These are pure radio reasons. They got nothing to do with the GGSN.

[giegala]

maybe not -

for example E/// GSN allows HSDPA rabs to do HO to GSM, while HW GSN does not. You have to look at the network element that was changed - if sgsn, then it is sgsn fault.

[hengbong]

Giegala,

I agree with u that SGSN can make a difference but that is not the case here.
GGSN has nothing to do with RABs and as I understand it is the one changed.

[yafawi79]

I think its better to collect traces in the Iups interface for more investigation

[byron]

Hi Shahinsha,

This is a radio environment problem. If you have an increase with the PDP context failure, then you have to investigate what type of RAB is failing. You can gather this from stats in both real time, if you have protocol analyzer or by Moshell commands such as shown below.

pmxh -s 20110922.0000 -e 20110929.2200 IubDataStreams pmCapAllocIubHsLimitingRatioSpi03
pmx . aal2 -m 1 -a
pmx utrancell=xxxxx pmfailafteradm -m .25 -a

Has the increase in the PDP context failures been globally or is it restricted to a particular cell or cluster? If so, revise your your parameters such as sf4admUl etc. Have your team conduct a drive test to collect more data and you can also do a GPEH trace while this is being done.

Regards,
Byron

[byron]

Also verify that the LACs are correctly configured in the SGSN and ensure that they have not been erased.

[topoffenders]

Radio Connection with UE lost
could be because of messsage syncronization failure, or missing message,
for exampleL
if there is active set update request, but NW never received active set update complete, the call will be released.
GPEH will better serve you on the investigation.