Harald Welte laforge at
Wed Jul 17 23:28:22 UTC 2019

Hi Romeu,

On Wed, Jul 17, 2019 at 06:17:31PM -0300, Romeu Medeiros wrote:
> I some situations, when the MME lost connection with the OSMO-MSC and
> return this connection if I try send a MT-CSFB the OSMO-MSC is crashing.

that obviously shouldn't happen.

> I get this error in the log:
> <0006> sgs_iface.c:470 XXXXXXXXXX state == 1  conf_by_radio_contact_ind == 1
> <0011> sgs_iface.c:251 (sub
> IMSI-724210000000003:MSISDN-5544912340003:TMSI-0x8E44F269) Tx
> PAGING-REQUEST suitable MME found, but no SGS connection present!
> <0005> sgs_iface.c:480
> SGs-UE(imsi:724210000000003)[0x563949b08fc0]{SGs-ASSOCIATED}: Will not Page
> (no MME)
> <0005> paging.c:101 Paging:
> IMSI-724210000000003:MSISDN-5544912340003:TMSI-0x8E44F269 for MNCC:
> establish call: Starting paging failed (rc=-22)
> <0001> gsm_04_08_cc.c:1922 trans(CC
> IMSI-724210000000003:MSISDN-5544912340003:TMSI-0x8E44F269 callref-0x1396
> tid-255) Failed to allocate paging token.
> Segmentation fault (core dumped)

Thanks. I created a bug at

> I'll try why this happened, but I'm not getting used to it in the OSMO
> source code. Can you tell me (if you have time) how identify where this
> crash is occouring?

It's the same as any other C program:
* compile with "-g"
* run it in gdb
* provoke the setfault
* take a "backtrace full" after the crash

It would be great if you could amend the bugtracker with that information,
but I would guess the information you provided is already sufficient for Philipp,
the implementor of the SGs support in OsmoMSC.

- Harald Welte <laforge at> 
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)

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