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TBF Drop due to N3105?

  • This topic has 3 replies, 1 voice, and was last updated 13 years ago by noob.
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  • #66162

    I have the following problem:
    High TBF DL drop (recently UL too) on a site.
    The reason is due to N3105 (NPO stats) and according to Gb measurements “active” cards with terminated MSISDNs are causing the problem (the number of drops are equal to the number of attempts from those IMSIs to make routing update and get rejected from the HLR with “GPRS servise not allowed”). Test with inactive card led to no results (i clearly see that tbf is formed and released but in any of the tested conditions (baterry removal, restarts, waiting for n3169 to expire) no drop were observed).
    Please share your opinions if thats is possible and what can be done to over come this problem.
    Thanks in advance.


    hi noob,

    could you please explain this part:
    “Gb measurements “active” cards with terminated MSISDNs are causing the problem”

    N3105 means that the MS does not ack/nack the DL RLC BLOCKS. I don’t see why this would be linked to GMM message content. Maybe the rejection from the HLR provokes a TBF immediate release in the MS : the GPRS service being “not allowed”, it wouldn’t surprise me if the MS stopped the TBF immediately, without informing the MFS.

    Why does the HLR says “GPRS service not allowed” ? Isn’t it the actual problem, right there ?



    Hi Noob,

    We have the same problem here, BSS B10 but on all BSCc

    We opened a ticket with TAC when we activated SIM prepaid where most of these SIM do not have access to GPRS, high UL TBF failures suddendly raised.

    Still no answers but according to NPO support, counters are not properly reported in NPO.

    We noticed ous customers are not impacted with this, it is just counters.

    Last week, we reset a BSC and UL_DL TBF failures raised down of 10 per cent, this is the magic of ALU !

    hope that help, keep us updated on your findings.



    ty both. i will try to update if possible (cant reply for unknown reason)

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