5 Jun
2014
5 Jun
'14
11:52 a.m.
So it is the communication between osmoSGSN and sim-bss (Attach procedure).
The problem comes in attach accept/complete. OsmoSGSN sends message attach
accept with currenr TLLI = 0x78000001 and with new allocated P-TMSI =
0x475b916b. Sim-bss answeres with message attach complete with new tlli
made/generated im osmoSGSN from new P-TMSI...and as I said and as 3GPP
24.008 spec. says new TLLI = new allocated P-TMSI = 0x475b916b. And there
comes the problem that it is not LOCAL TLLI. So the point of the problem is
that new P-TMSI/TLLI is not generated correctly and could be said osmoSGSN
rejects what it generated and that is the problem. If it helps, I connects
osmo-SGSN_vty output.
Regards Michal
2014-05-28 14:38 GMT+02:00 Michal Grznár <mihal.grznar(a)gmail.com>om>:
Hi, it wasn´t handly written diffs but here I send
diff made by using git
diff. And the problem you can see in packets with number 27-40 (especially
see in number 30 you see there the old tlli and newly generated P-TMSI in
message attach accept and in number 31 there is new TLLI which is the same
as generated P-TMSI in previous message) and that is the problem I needed
to solve, that the new TLLI was not LOCAL.
regards Michal
2014-05-23 13:16 GMT+02:00 Holger Hans Peter Freyther <holger(a)freyther.de>
:
On Fri, May 23, 2014 at 11:44:40AM +0200, Michal Grznár wrote:
Hi,
And the problem was as I said in Imsi attach
procedure new TLLI == new
allocated P-tmsi, and there was a problem that the function
gprs_tmsi2tlli()
function there was not called and so I had to
mask the upper bits in
function where the p-tmsi is allocated, there is also a pcap trace where
you can see it.
Could you please elaborate of what/were (e.g. packet numbers) we
can see "it" and what it should be instead? And please use "git
diff"
or preferable "git commit" and git format-patch. The "diff" you
include
is hand-written and sadly not usable because of this.
And as written by Harald before. The place you patch is not correct.
The method you patch should generate a unique P-TMSI. It might should
mask some of the higher bits. But you need to look at the callers of
this function if the tlli is not updated.
e.g. in src/gprs/gprs_gmm.c you will see something like this:
ctx->p_tmsi = sgsn_alloc_ptmsi();
#endif
/* Even if there is no P-TMSI allocated, the MS will switch from
* foreign TLLI to local TLLI */
ctx->tlli_new = gprs_tmsi2tlli(ctx->p_tmsi, TLLI_LOCAL);
/* Inform LLC layer about new TLLI but keep old active */
gprs_llgmm_assign(ctx->llme, ctx->tlli, ctx->tlli_new,
GPRS_ALGO_GEA0, NULL);
So this call to gprs_tmsi2tlli will make sure that 0xc0000000 will
be set. In fact I see two calls to sgsn_alloc_ptmsi and both of them
do the above and assign the new tlli to the context. So please could
you try to explain what you are trying to solve?
holger