Losing ACKs due TLLI changes?

Vladimir Rolbin vrolbin at gmail.com
Tue Oct 29 10:35:19 UTC 2013


Hi,

            Let me participate in the discussion to improve my
understanding.
            If I see well the new TLLI (after changing by Attach Accept for
example)  may be obtained from the first RLC data block belonging to the UL
TBF allocated for Attach Complete transfer (in the case of resource request
on RACH) or from still existing DL TBF context   (in the case the channel
request is included in PACCH downlink packet ack/nack) where it has to be
updated on P-TMSI change. For paging group choosing in the later stage
(after attaching procedure) it's enough that IMSI is known in SGSN and
 delivered to pcu with the downlink packets.

Regards,
Vladimir.



On Mon, Oct 28, 2013 at 5:23 PM, Holger Hans Peter Freyther <
hfreyther at sysmocom.de> wrote:

> On Mon, Oct 28, 2013 at 06:17:50PM +0400, Ivan Kluchnikov wrote:
> > Hi Holger,
>
> Hi,
>
> >
> > Can you send full pcu tbf debug log for this attach procedure?
> > I want to understand, in which place of TBF MS starts use new TLLI.
> > What do you mean by "no content resolution on the UL"?
>
> s/content resolution/contention resolution/. Sorry.
>
> I don't have a log file but with the routing area update, the
> SGSN may assign a new P-TMSI and if a new P-TMSI was assigned
> with the "Accept" message, a "Complete" message needs to be
> generated by the MS. This message can/should already contain
> the new TLLI (which is derived from the P-TMSI).
>
>
>
> > Also I can't understand why we should use IMSI in pcu?
> > Why it is not enough to use TLLI?
>
> The TLLI is either random (I have not seen this), foreign
> or local. In the last two cases it is derived from the P-TMSI.
> The P-TMSI can change (e.g. at routing area update).
>
> --
> - Holger Freyther <hfreyther at sysmocom.de>       http://www.sysmocom.de/
> =======================================================================
> * sysmocom - systems for mobile communications GmbH
> * Schivelbeiner Str. 5
> * 10439 Berlin, Germany
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>
>
>
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