Hello guys,

I found an interesting issue. After I place a call to a number which is not existent in HLR DB I am not able to make a call to an existing one anymore.  Seems the timeslot is not released properly. If I am doing a BSC config adjustment like channel allocator mode assignment to descending (assuming it was ascending before) I am able to make a call again (until i call a wrong number and the lchan gets stucked).

The error looks like: <000f> lchan_select.c:454 lchan(0-0-1-TCH_F-0)[0x55babd2a89c0]{UNUSED}: (type=TCH_F) Selected <0011> assignment_fsm.c:709 assignment(msc0-conn79_subscr-IMSI- xxxxxxxxxxxxxxxx-TMSI-0x63d29a26_0-0-1-TCH_F- 0)[0x55babd2a69a0]{WAIT_LCHAN_ACTIVE}: (bts=0,trx=0,ts=1,ss=0) Starting Assignment: chan_mode=SPEECH_V1, chan_type=FR, aoip=yes MSC- rtp=127.0.0.1:4382 (osmux=no) <000f> lchan_fsm.c:838 lchan(0-0-1-TCH_F- 0)[0x55babd2a89c0]{WAIT_TS_READY}: (type=TCH_F) Activation requested: ACTIVATE_FOR_ASSIGNMENT rtp=yes MGW-ci=new type=TCH_F tch- mode=SPEECH_V1 encr-alg=A5/0 ck=none <000f> lchan_fsm.c:1027 lchan(0-0-1-TCH_F- 0)[0x55babd2a89c0]{WAIT_ACTIV_ACK}: (type=TCH_F) Rx Activ ACK SPEECH_V1 <000f> lchan_rtp_fsm.c:369 lchan(0-0-1-TCH_F- 0)[0x55babd2a89c0]{WAIT_RLL_RTP_ESTABLISH}: (type=TCH_F) lchan-rtp failure in state WAIT_IPACC_CRCX_ACK: Received NACK on IPACC CRCX <000f> lchan_fsm.c:1147 lchan(0-0-1-TCH_F- 0)[0x55babd2a89c0]{WAIT_RLL_RTP_ESTABLISH}: (type=TCH_F) lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH: Failed to setup RTP stream: LCHAN_EV_RTP_ERROR in state WAIT_RLL_RTP_ESTABLISH <000f> lchan_fsm.c:160 lchan(0-0-1-TCH_F- 0)[0x55babd2a89c0]{WAIT_RLL_RTP_ESTABLISH}: (type=TCH_F) Signalling Assignment FSM of error (lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH: Failed to setup RTP stream: LCHAN_EV_RTP_ERROR in state WAIT_RLL_RTP_ESTABLISH) <0011> assignment_fsm.c:1043 assignment(msc0-conn79_subscr-IMSI- xxxxxxxxxxxxxxxx-TMSI-0x63d29a26_0-0-1-TCH_F- 0)[0x55babd2a69a0]{WAIT_RR_ASS_COMPLETE}: (bts=0,trx=0,ts=1,ss=0) Assignment failed in state WAIT_RR_ASS_COMPLETE, cause RADIO INTERFACE MESSAGE FAILURE: Failed to activate lchan (bts=0,trx=0,ts=1,ss=0) <0007> osmo_bsc_sigtran.c:624 (msc=0) Tx MSC: BSSMAP: ASSIGNMENT FAIL

Im using an ipaccess nanoBTS (fw version 168d502_v206b17d0) as hardware and latest versions of Osmocom packages (BSC, MSC, HLR, MGW and STP) with minimal changes of example configuration (from /etc/osmocom).

Do you have any idea if could be an issue related to nanoBTS firmware?

Regards, Cristian