22 Dec
2022
22 Dec
'22
3 p.m.
Dear Harald,
Sorry to spam the openbsc list with this, but if you (or someone) can
confirm if the Sgsn-emu part of Osmo-GGSN utilizing the kernel GTP
module or not, that would be lovely.
FYI, I was not able to pass more than 280Mbit and the sgsn-emu process
was maxing out a single core. Based on this I suspect that it does not
use the kernel GTP module. I have seen some commits that indicates
preparation work for this feature, but it is unclear at least to me,
if this was finished or not. In the Osmo-GGSN.cfg example config I can
see the config option for kernel GTP, but not in the sgsn-emu.cfg
example.
Regards,
Csaba
23 Dec
23 Dec
6:38 p.m.
Hi Csaba,
On 12/22/22 15:00, Sipos Csaba wrote:
Dear Harald,
Sorry to spam the openbsc list with this, but if you (or someone) can
confirm if the Sgsn-emu part of Osmo-GGSN utilizing the kernel GTP
module or not, that would be lovely.
sgsnemu is not using the kernel module, only osmo-ggsn has support for
it so far.
See osmo-ggsn.git/./sgsnemu/sgsnemu.c line 1905 calling:
"""
if (tun_new((struct tun_t **)&tun, options.tun_dev_name, false, -1, -1))
"""
See tun_new() function used by both osmo-ggsn and sgsnemu:
"""
int tun_new(struct tun_t **tun, const char *dev_name, bool use_kernel,
int fd0, int fd1u) {
"""
So sgsnemu is passing use_kernel=false, which makes the lib skip
gtp-kernel functions like gtp_kernel_create().
FYI, I was not able to pass more than 280Mbit and the sgsn-emu process
was maxing out a single core. Based on this I suspect that it does not
use the kernel GTP module. I have seen some commits that indicates
preparation work for this feature, but it is unclear at least to me,
if this was finished or not. In the Osmo-GGSN.cfg example config I can
see the config option for kernel GTP, but not in the sgsn-emu.cfg
example.
You could try passing use_kernel=true to tun_new(), and see how far you
can get. Patches welcome.
Regards,
Pau
--
- Pau Espin Pedrol <pespin(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
6:47 p.m.
Hi Csaba and Pau,
On Fri, Dec 23, 2022 at 06:38:55PM +0100, Pau Espin Pedrol wrote:
You could try passing use_kernel=true to tun_new(),
and see how far you can
get. Patches welcome.
The GTP kernel module needs to be told if it operates in SGSN or GGSN mode.
grep for GTP_ROLE_SGSN in libgtpnl. I don't know all of the related functions
off my head, but on the SGSN side you need to make sure to initialize the kernel
GTP with GTP_ROLE_SGSN instead of GTP_ROLE_GGSN.
--
- Harald Welte <laforge(a)gnumonks.org> https://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
25 Dec
25 Dec
10:53 p.m.
Hi Harald and Pau,
The GTP_ROLE_SGSN part is set in gtp_new(), for both the sgsn-emu.c
and the ggsn.c code. What I cant figure out is what to change in order
for that to be passed to the GTP kernel module... Spent some time
modifying the sgsnemu.c but the only thing I achieved was a
segmentation fault...
I am not even sure how can I distinguish which part is using the
kernel GTP headers and which part is using the internal GTP
implementation...
Modifying the tun_new() function to set the use_kernel parameter to
true is definitely not enough:
Line 1905 (sgsnemu.c):
if (tun_new((struct tun_t **)&tun, options.tun_dev_name, true, -1, -1)) {
Regards,
Csaba
510
days inactive
513
days old
3 comments
3 participants
participants (3)
-
Harald Welte -
Pau Espin Pedrol -
Sipos Csaba