We're still having massive stability problems with osmo-bts-trx on the osmo-gsm-tester.
I have run a tcpdump on the ntp port for the past days, and nothing is doing
ntp besides the actual ntp service.
Today I started ntp while an osmo-bts-trx run was active and what do you know,
the osmo-bts-trx process exits immediately. I think this is bad, osmo-bts-trx
shouldn't use wall clock time for precise timing needs.
Besides that, I have no idea what could cause the clock skews, except maybe
that the CPU or the USB are not fast enough?? I'm wondering, is there still
such a thing as a separate linux realtime kernel?
We will soon take to productive use another main unit which will be a cleanly
installed OS. If we see the same problems on that system and can't find a
software fix, we may need to reconsider the tester for osmo-bts-trx...
~N
Hi,
I’ve been looking into getting ussd working with an external application. I
found a branch from last year (fairwaves/sup-ussd) that looks like it has
implemented most of ussd sessions and possibly communicates with an
external application. Does anyone know if it was finished or what still
needs to be done?
I also found a python script called ussd_example.py which looks like it is
supposed to act as a gateway and receive used connections from openbsc. Is
this correct and did it work or am I misunderstanding its purpose?
Thanks!
- Rowan Phipps
I'd like to share a VTY config error analysis that has a tricky solution:
I started osmo-bsc -c osmo-bsc.cfg with, according to
openbsc/doc/examples/osmo-bsc:
net
[...]
bts 0
[...]
periodic location update 30
trx 0
[...]
and get this error:
There is no such command.
Error occurred during reading below line:
trx 0
what? 'net / bts / trx' is no command??
Solution: I'm on the vlr_3G branch (incorporating 2G via A-interface) and on
this branch, I've actually moved the 'periodic location update N' command a
level up, from net / bts / periodic to net / periodic (background: assuming
that OsmoMSC does not have individual BTS info, we moved some settings up to
network level; whether this makes sense for osmo-bsc is a different question,
it's just what happens to be on the vlr_3G branch now).
So there is no net / bts / periodic command.
Why do I get an error for net / bts / trx instead?
two reasons:
1. 'trx 0' was the line following the 'periodic' command,
2. since 'periodic' exists one level above, the vty code goes to the parent
node automatically.
About 2: we tend to indent our VTY config files, but in fact the indentation
has no effect whatsoever, it is just eye candy (very useful eye candy).
The code in question: If a command does not exist, try 'vty_go_parent()' and
see if the command exists there. That's what allows us to omit 'exit' in our
config files to go to the parent node explicitly:
libosmocore/src/vty/command.c:
int config_from_file(struct vty *vty, FILE * fp)
{
int ret;
vector vline;
while (fgets(vty->buf, VTY_BUFSIZ, fp)) {
vline = cmd_make_strvec(vty->buf);
/* In case of comment line */
if (vline == NULL)
continue;
/* Execute configuration command : this is strict match */
ret = cmd_execute_command_strict(vline, vty, NULL);
/* Try again with setting node to CONFIG_NODE */
while (ret != CMD_SUCCESS && ret != CMD_WARNING
&& ret != CMD_ERR_NOTHING_TODO
&& is_config_child(vty)) {
HERE -----> vty_go_parent(vty);
ret = cmd_execute_command_strict(vline, vty, NULL);
}
cmd_free_strvec(vline);
if (ret != CMD_SUCCESS && ret != CMD_WARNING
&& ret != CMD_ERR_NOTHING_TODO)
return ret;
}
return CMD_SUCCESS;
}
In this case the 'periodic...' command does in fact now exist one level above,
so the vty_go_parent() is successful and running that command works. But, the
vty config parsing then sits above on the 'network' level, is no longer in 'bts
0' and hence refuses to accept the following bts-level command, in this case
'trx 0'. Confusing!
So it's not a bug, it's a feature. But it's a feature we might see quite often
if we move the 'periodic' command up to network level and users attempt to use
their old config files.
Same goes for the 'timezone' command, BTW, so we might want to rename commands,
or re-consider moving commands one level up in the first place. Maybe we should
leave backward compat catchers in place that print a warning.
~N
--
- Neels Hofmeyr <nhofmeyr(a)sysmocom.de> http://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt-Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschäftsführer / Managing Directors: Harald Welte
Hi!
We have some builds that happen inside a docker, and some that happen natively
on the (Debian 8) build slave. Can somebody involved with this illustrate
why that is the case, and what's the rationale here?
Just looking at the setup, I'm unable to figure out whether there's any
particular reason for this, or whether it's simply "we started without and
then did some builds in docker but nobody migrated the other builds over"
>From my point of view, I would have assumed that building in different containers
would make sense to e.g. build on different distributions / versions, or
building against older libosmo* vs. building against libosmo* from nightly
package feeds vs. re-building all dependencies from master.
But it appears that only a single container is built, and that container is
used for some jobs (like osmo-msc-gerrit) but not for other jobs.
If I missed some wiki page or mailing list posts with related information,
a pointer would be helpful. Thanks in advance.
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)
I would have welcomed more patience in merging https://gerrit.osmocom.org/3685,
"Use value string check from osmo-ci" in libosmocore.
(the commit log of which fails to indicate removal of the script, btw)
Moving to the new repositories, I have enough loose ends flapping in the wind,
and dropping the script from libosmocore has added yet another distraction,
while not being necessary to start using the one from osmo-ci.
Max clearly posted "N. B: this should be merged last, after all the repos
converted to check script from osmo-ci." -- which is not the case for the new
repositores split from openbsc.git.
In osmo-msc I have >50 patches waiting to be merged. The timing could hardly
have been worse, luckily only a few gerrit builds are affected. Will try to
sort out merging of the patches without needing a rebase and >50 rebuilds.
Thanks for you attention :)
~N
Hi.
I'd like to propose to switch from local (unmaintained?) copy of git-version-gen
script and use it directly from upstream gnulib package. It's available pretty-much
everywhere (including ancient Debian which we support for nightly). It's also
available in meta-oe: https://layers.openembedded.org/layerindex/recipe/47365/
It doesn't feel right to use copy-pasted code when we could offload the maintenance
work to packaging/dependency tools.
What do you think? Please contribute to https://osmocom.org/issues/2467 which I've
created to track this RFC.
--
Max Suraev <msuraev(a)sysmocom.de> http://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt-Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschaeftsfuehrer / Managing Director: Harald Welte
Dear Osmocom community,
from August 26th 06:54 UTC through August 31st 06:22 UTC our Osmocom.org
redmine could not send any e-mails. This was due to a configuration
file syntax error introduced by me, my apologies.
If you rely on redmine e-mail notifications to the issues you have
subscribed to, please double-check as related notifications during that
interval were unfortunately lost.
Best regards,
Harald
p.s.: The reason for the config change was to enable e-mail
notifications from jenkins.osmocom.org (which it now has, if you want to
configure e.g. post-build notification actions).
--
- 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 All!
I'm wondering if there are any users of the Osmocom cellular stack in Pakistan
around. If so, please kindly follow-up by private mail, as there might be
some projects in which your help would be appreciated. Thanks in advance.
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)
Dear all,
I've started to implement some test cases that validate the accuracy of
OsmoBTS and OsmoBSC SYSTEM INFORMATION generation.
Those test cases are written in TTCN-3, which is a special programming
language specifically designed for testing and validation of protocol
stacks. For those present at OsmoDevCon, I've briefly presented about
it there.
In terms of general core infrastructure, I've written:
* Definition of GSM RR and some other commonly used GSM types using the
TTCN-3 type description language and the TITAN RAW (binary) encoder/decoder.
The beauty of this is that one can simply describe the message
structure without having to generate any code for encoding/decoding
the message. See
http://git.osmocom.org/osmo-ttcn3-hacks/tree/library/GSM_Types.ttcn
and
http://git.osmocom.org/osmo-ttcn3-hacks/tree/library/GSM_SystemInformation.…
* A GSMTAP Test Port, whcih is basically how a TTCN-3 testcase/testsuite
interacts with a given IUT (implementation under test). It is
implemented as dual-faced port on top of the TITAN IPL4asp (ip layer 4)
port and implements GSMTAP header encoding/decoding from/to TTCN-3
structured data types:
http://git.osmocom.org/osmo-ttcn3-hacks/tree/library/GSMTAP_PortType.ttcn
which uses
http://git.osmocom.org/osmo-ttcn3-hacks/tree/library/GSMTAP_Types.ttcn
describing the GSMTAP header format.
* Helper functions to emulate interactive use of the VTY based on the
existing TITAN TELNETasp Test Port:
http://git.osmocom.org/osmo-ttcn3-hacks/tree/library/Osmocom_VTY_Functions.…
* L1CTL type definition (again using auto-generated encoder/decoders!)
http://git.osmocom.org/osmo-ttcn3-hacks/tree/library/L1CTL_Types.ttcn
as well as an L1CTL Test Port at
http://git.osmocom.org/osmo-ttcn3-hacks/tree/library/L1CTL_PortType.ttcn
Using the above one can easily interface from TTCN3 with L1CTL of
virtphy in order to e.g. sync to a BTS on a given ARFCN and establish
a dedicated radio channel. Here is where the beautoy of the TTCN3
type language, templates and matching can be seen. It's very easy to
perform something like "does this IMMEDIATE ASSIGNMENT match the RA +
FN of the RACH request that I sent?
Based on all of the above, there's two test suites:
== Test Suites
1) SYSTEM INFORMATION contents and scheduling validation
I've written some SI validation code which can be found at
http://git.osmocom.org/osmo-ttcn3-hacks/tree/sysinfo
SI scheduling is quite complex, particularly when you have many of the
2ter/2bis/2quater/13/2n/... enabled. At some point actually you will
overflow what's possible to comply with the rules in a BCCH Norm. and
you have to go to a BCCH Extd. (OsmoBTS doesn't implement the latter
yet, btw).
See e.g. function f_validate_si_scheduling() for validation of scheduling
constraints:
http://git.osmocom.org/osmo-ttcn3-hacks/tree/sysinfo/Test.ttcn#n229
Later in the file you can find test cases TC_cellid() and below for the
individual test cases that validate that individual VTY configured
values such as BSIC, CellId, LAC, ... are actually broadcast in the SI
message. IT will update its internal matching template and then perform
a sequence of VTY commands to e.g. change the LAC followed by verifying
that the LAC of the decoded SI has actually changed.
The above tools have helped to discover (and fix) the following bugs:
* http://osmocom.org/issues/2368
* http://osmocom.org/issues/2367
* http://osmocom.org/issues/2365 (very critical, I believe)
and also the not-yet-fixed but low-importance
* http://osmocom.org/issues/2364
2) LAPDm testing
I've written some (early) LAPDm testing code at
http://git.osmocom.org/osmo-ttcn3-hacks/tree/lapdm
The idea here is to test for valid and invalid transactions on the Um
interface and see how OsmoBTS and the libosmcore lapdm code perform.
With very few lines, this has already uncovered the following issues:
* http://osmocom.org/issues/2370
* http://osmocom.org/issues/2380
Unfortunately my progress was severely affected over the weekend as I
spent about one working day wrapping my head around something that
turned out to be a bug in the Eclipse TITAN RAW coder, see
https://www.eclipse.org/forums/index.php/t/1087557/ - fortuantely the
Titan team has provided both a work-around and a fix today, which I
count as excellent service.
If you're curious about TTCN-3, I strongly recommend
http://www.ttcn-3.org/files/TTCN3_P.pdf as an introductory slide deck.
== Outlook
I want to add more test cases to the sysinfo and lapdm test suites and
get hands-on experience with the Junit XML output plugin. At that
point, a Debian 9 build slave of our jenkins should be able to
automatically build + run the latest test cases from
osmo-ttcn3-hacks.git and present the individual test case results inside
jenkins.
I also want to add test suites for validation of:
* proper generation + scheduling of of PAGING REQUEST in the BTS,
considering paging groups particularly in the context of different
BS_AG_BLKS_RES values
* CBCH validation
* proper generation of CCCH load indications by the BTS, i.e. generate a
certian load e.g. on uplink RACH and check the reports
* TA loop verification (add timing information to GSMTAP and then
dynamically change timing from MS side to see that BTS is compensating
as expected
* power control loop verification: GSMTAP already has a field for
transmitting RSSI in dBm. We can adjust this from the MS side to
validate the BTS will adjus the instructed transmit power level of the
virtual MS accordingly
* actually exhaust all channels of a multi-TRX virtual BTS in different
channel combinations, verify we can establish all existing logical
channels in each configuration
* combine the last topic with configurations that have dynamic PDCH/TCH
channels to verify we properly switch forward and backward
* various link failure conditions, i.e. does the BTS close the logical
channel in the expected timing after uplink loss?
Despite my current excitement about all of this, I'm not sure how much
time I will be able to spend on this, given that the sysmocom customer
priority is typically not the development of automatic test suites. But
I'll try my best.
If anyone wants to join: TITAN is just one "apt-get install eclipse-titan"
away!
== What's not good to test with TTCN-3 / TITAN:
While the existing infrastructure I've built is very suitable to test
low-level protocol topics, I think it's not particularly
useful/applicable in other areas:
* SI REST OCTETS and GPRS RLC/MAC, as they're defined in CSN.1 and TITAN
has no CSN.1 encoder/decoder. For easy mathing/generation of those
messages, we'd have to find something like an external
CSN.1-to-ASN.1-BER or CSN.1-to-XML converter which we could use. I'd
be happy to consider paying a reasonable amount for a proprietary
product, just as long as we are sure that it will provde the kind of
productivity that's useful here.
* full end-to-end tests with actual mobile phones, RF and BTSs in the
picture. We already have osmo-gsm-tester for this, and Titan with its
powerful type language, templates and matching capabilities doesn't
provide all that much benefit here over other languages/approaches
* higher-layer protocol testing. We do have OsmocomBB as a L2 + L3
MS-side implementation, and I don't think it makes sense to replicate
this. Even while the message encoding/decoding is super easy with
TITAN, we still have all the related state machines. So I'd rather
extend OsmocomBB where needed for automatic test cases than reinvent
the wheel here.
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)