Hi,
I have finally an idea on how to go from varpoware "oh I need to merge that" to
actually merging stuff and started to work on that.
The one goal I have is to create a BSC/MSC split inside our codebase and to
make MSC functionality only communicate via a given BSC API. This move will
allow to do some things transparently to the MSC code, it includes automatic
RLL establishes for SAPI, very early/early assignment will become transparent
and in the future I can roll out my "subscriber task" scheduler to do stuff
like SMS submit during a voice call...
Here is my plan on how to get there...
1.) Create a new structure for the MS Connection. This would happen on a GSM
0808 Complete Layer3 Information message (e.g. CM Service Request, Paging
Response). The name I picked is total rubish but can easily changed later.
I have embedded this connection into the struct gsm_lchan and moved all MSC
attributes into this new structure. So right now we have a 1:1 mapping between
a GSM LCHAN and the Subscriber Connection.
2.) Moved transaction code to work on this new structure instead of the lchan,
I verified MT-SMS, MO-SMS, MT-Call, MO-Call. So the plan is to remove the
occurence of GSM LCHAN from the MSC code paths, this will also mean to remove
direct calls to RSL, RLL, paging.c.
3.) I picked gsm_04_11.c as the first file from the MSC (actually SMSC) code to
go without the lchan. I have removed the direct call to RSL and placed it
behind a new GSM0808 DTAP API. This would be the place where we figure out the
real LCHAN..
This is all working and I can build on top of that until I reach the goal at
which point I can forward port some of my code from the On Waves branch and
instead of playing MSC myself, put it into SCCP...
<- now comes the stuff that I want to complete by the end of next month ->
4.) Currently when compiling you see a "BROKEN" warning, this is more that it
is broken conceptually as the code handles paging and RLL establishment by
itself. So the idea will be to move my "bssap.c" code to master and handle the
RLL establishment and paging inside the new BSC API. This would involve
queuing of messages...
5.) Remove the callback for SMS from abis_rsl.c and create a bsc_api_init with
callbacks for various things (mostly Create Connection, Clear Request, Data).
At this point the gsm_04_11.c will be free of BSC code.
6.) Move it to gsm_04_08. This will involve adding new commands (resembling
the GSM 08.08) message names, sharing some callbacks between SAPI=0 and SAPI=3
and having a dispatch. E.g. later we should have a handler for new connection
which would run authentication and then dispatch the handling of the
connection to a task, on task completion close the channel or give it to the
next task. After this we should magically be able to switch between very
early/early assignment in the BSC code and the MSC will not recognize this,
also TCH/H handling with be mostly transparent.
7.) Remove the 1:1 mapping of of GSM LChan to the new struct. Actually the new
struct should include two lchan's (in case of handover or assignment), I will
have to figure out on how to marry the handover code with that...
8.) I could rebuild my bsc_msc_ip.c on top of the new BSC API and all I need
to do is to handle MSC. We could also create a msc_bsc_ip.c which takes these
SCCP messages and sticks it into the MSC code of ours and we have a MSC.
as usual... any help is more than welcome.
z.
Hi!
I don't exactly remember in which context I was last communicating with
whom of you about the question whether or not the BA of a cell should
include its own BCCH frequency or not.
I think from commercial networks we could see both behaviors, and it was
thus unclear what we should do for OpenBSC.
I've now found a reference for this in the GMS specs: GSM 3.22 Chapter
4.8:
> NOTE: The PLMN operator cannot expect the ME to store the BCCH or
> CPBCCH carrier frequency of the serving cell in the SIM unless the
> BA(BCCH) includes the BCCH or CPBCCH carrier frequency on which it is
> broadcast.
So now we know at least the difference when it comes to those two
options.
Regards,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Hello Harald,
On Sun, 28 Mar 2010 13:16:36 +0800, "Harald Welte" <laforge(a)gnumonks.org> wrote:
>
> as far as I know, it has to change on every retransmission. Dieter is
> probably the person who knows all RACH aspects in detail, maybe he can
> comment on this.
According to the specification the random value has to change on every
transmission:
a random reference which is drawn randomly from a uniform probability
distribution for every new transmission.
In the TSM30 firmware this is done by having a table with random values
and an index into the table which is initialised to a random value when
the Immediate Assignment Procedure is started and incremented with every
random number taken for a retransmission. The table has 32 values because
the random reference is not larger than 5 bits.
Best regards,
Dieter
--
Dieter Spaar, Germany spaar(a)mirider.augusta.de
Hi Andreas,
some comments regarding your issues.txt:
> must random value in chan_request change on every resend or only on
> every RR establishment? (currently it changes on every RR
> establishment only.)
as far as I know, it has to change on every retransmission. Dieter is
probably the person who knows all RACH aspects in detail, maybe he can
comment on this.
> must be expanded: struct osmocom_ms:
no problem here, expand it how you see fit. I just generally prefer
caller-allocated structures to callee-allocated ones, and I'd like to
use static allocation whenever possible. So if there's only one 'struct
rrlayer' per ms, then we should simply include 'struct rrlayer' as
sub-structure of 'struct osmocom_ms', rather than having two structures
and pointers between them.
> OpenBSC: if tx-msg fails during process, the msg must be freed to
> avoid memory leak.
I don't understand, can you please explain this further?
> random acces via RSL?
I think we simply add some new / non-standard primitives, as it does not
have any notion of RACH bursts.
It might also be possible to encode it as UNIT DATA REQUEST for channel
(chan_nr) RACH (CCCH uplink), but then we still cannot specify details
like at which frame number, etc. From what I can see, your
RSL_MT_RAND_ACC_REQ approach looks fine to me. As a minor improvement
we could call it RSLms_MT_RAND_ACC_REQ to indicate that it is our custom
RSLms message and nothing specified in the original RSLms spec.
Cheers,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Hi!
One of the bigger missing parts in libosmocore is the debug support that
we have in OpenBSC, including support for multiple debug categories,
log levels, log targets, filters, context, etc.
I'm currently half-way through splitting/generalizing the core code from
the OpenBSC specific bits (like IMSI context/filter). It's coming along
quite nicely - actually less of a problem than I originally thought.
The purpose of this is (as usual) to enable OsmocomBB to use the same
codebase as OpenBSC for logging/debugging.
So this mail is simply a heads-up that some changes will be visible in
this area, once again requiring you to update + build libosmocore and
OpenBSC after the changes have been committed.
The good news, at least it should fail gracefully now, as the OpenBSC
autotools magic is now requesting a certain libosmocore version during
./configure.
Cheers,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
Hi,
i have a problem with bs11_config. When i start it, i get this:
---------------------------------------------------------
# ./bs11_config -p /dev/ttyS0 /path/to/BTSBMC76.SWI
bs11_config (C) 2009 by Harald Welte and Dieter Spaar
This is FREE SOFTWARE with ABSOLUTELY NO WARRANTY
Invalid length in hdr: 0
Speicherzugriffsfehler
---------------------------------------------------------
Thanks
Marcus
--
Marcus Specht
open|MVNO
c/o Cyber-Dynamix Gesellschaft für Systemintegration GmbH
Heiner-Stuhlfauth-Str. 28
90480 Nürnberg
Tel.: 0911 / 1809105
Fax.: 0911 / 1809109
Geschäftsführer: Heiko Thierbach, Gerhard Feder
Sitz der Gesellschaft ist Nürnberg
Amtsgericht Nürnberg, HRB 16704
Ust-Id.-Nr. DE204640808
------------------------------------------------------------------------------
Diese Nachricht ist eine nicht öffentliche Mitteilung.
Sollten Sie diese Nachricht versehentlich erhalten haben
und nicht der gewünschte Empfänger sein,
so bitten wir Sie, diese Nachricht zu löschen, keine
Kopien anzufertigen und nicht weiterzuleiten. Bitte
informieren Sie uns per eMail über den Zustellungsfehler
und entschuldigen Sie die Unannehmlichkeit.
Bitte beachten Sie: Unabhängig vom Inhalt stellt diese
Nachricht keinerlei vertragliche Verpflichtung,
Zusicherung, Bestellung, Angebot oder ähnliches dar,
solange keine schriftliche Bestätigung von uns vorliegt.
On Saturday 06 March 2010 00:58:50 Harald Welte wrote:
>
> I think OpenBSC has been quite useful and stable for quite some time, it
> would be great to make something like an 1.0 release at some point soon.
> Maybe zecke and myself can do this in the next couple of weeks.
Shall we pick 1.0.0 for both OpenBSC and libosmocore?
Hi,
I have downloaded and compiled both libosmocore and OpenBSC. However, when
I try to execute an OpenBSC program (for example ipaccess-find) I see the
following error
~/openbsc/openbsc/src# ./ipaccess-find eth0
./ipaccess-find: error while loading shared libraries: libosmocore.so.0:
cannot open shared object file: No such file or directory
could you help me. Thanks.
Ahmet
On Saturday 06 March 2010 00:58:50 Harald Welte wrote:
>
> I think OpenBSC has been quite useful and stable for quite some time, it
> would be great to make something like an 1.0 release at some point soon.
> Maybe zecke and myself can do this in the next couple of weeks.
Shall we pick 1.0.0 for both OpenBSC and libosmocore?
Hi All
Just to clarify this (since we've had another question on the ML)
On Wed, Mar 03, 2010 at 10:15:44AM +0100, Holger Freyther wrote:
> You are using the latest version of libosmocore but not the one of OpenBSC.
You always need to use latest OpenBSC with latest libosmocore. We really
cannot afford to spend more time in supporting any kind of forward/backward
compatibility on a commit level.
However, what we should do, is to make official releases of both the library
and the OpenBSC program. OpenBSC will then require a particular version of
libosmocore, and the configure script will notice if it is not available.
I think OpenBSC has been quite useful and stable for quite some time, it would
be great to make something like an 1.0 release at some point soon. Maybe
zecke and myself can do this in the next couple of weeks.
> libosmocore is a rather new library and we move stuff from OpenBSC into this
> library, which means if you have a new version of libosmocore and a bit older
> one of OpenBSC your compiler will see stuff twice.
This will probably still be the case for the weeks to come, while even more
stuff (e.g. 04.08 call control IE parsing / generation) moves into libosmocore.
So please, always do a full cycle of
* "git pull" on libosmocore
* "git pull" on openbsc
* "./configure && make install" on libosmocore
* "./configure && make" on openbsc
This way you'll get a consistent build.
Thanks for your understanding,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
