Hi Community,
We had encountered an issue regarding the SDCCH channel not being released
immediately after a "Radio Link Failure" is detected in osmo-bsc and an
equivalent error of "Sending Connection Failure: cause = 0x01" in osmo-bts-trx.
Error in osmo-bts-trx:
<0000> rsl.c:797 (bts=0,trx=0,ts=0,ss=0) Sending Connection Failure: cause =
0x01
Error in osmo-bsc:
<0003> abis_rsl.c:1372 (bts=0,trx=0,ts=0,ss=0) CONNECTION FAIL in state ACTIVE
CAUSE=0x01(Radio Link Failure)
With this issue, the SDCCH channel will then be exhausted and no other
subscriber can attach and do any services (call and SMS).
As per advised by Neels, we tried to used the neels/inter_bsc_ho branch for
osmo-bsc to test if this issue is fixed.
We are happy to inform the community that the SDCCH channel issue we had is not
experienced from the neels/inter_bsc_ho branch but a different bug was
experienced.
The bug we seen in this branch is that, even we have a 2 TRX configuration in
our setup, the osmo-bsc only uses the first TRX configuration. Kindly see logs
below for your reference.
OSMO-BSC:
# /usr/local/osmo-bsc/src/osmo-bsc/osmo-bsc -c /root/demo/osmo-bsc.cfg
logging level cc (everything|debug|info|notice|error|fatal)
logging level mgcp (everything|debug|info|notice|error|fatal)
<001f> osmo_ss7.c:1270 0: ASP Restart for server not implemented yet!
[0;m% Ignoring deprecated logging level everything
<0013> telnet_interface.c:104 telnet at 127.0.0.1 4242
[0;m<0015> input/ipaccess.c:846 enabling ipaccess BSC mode on 0.0.0.0 with OML
3002 and RSL 3003 TCP ports
[0;m<001a> control_if.c:887 CTRL at 127.0.0.1 4249
[0;m<0007> osmo_bsc_sigtran.c:466 Initializing SCCP connection to MSC msc-0
[0;m<0007> osmo_bsc_sigtran.c:476 CS7 Instance identifier, A-Interface: 0
[0;m<0020> sccp_user.c:397 msc-0: Using SS7 instance 0, pc:0.23.3
[0;m<0020> sccp_user.c:421 msc-0: Using AS instance MSC_Test
[0;m<0020> sccp_user.c:426 msc-0: Creating default route
[0;m<0020> sccp_user.c:481 msc-0: Using ASP instance Huawei_MSC_Test
[0;m<0020> sccp_user.c:484 msc-0: Creating SCCP instance
[0;m<0007> osmo_bsc_sigtran.c:519 (msc-0) A-interface: local (BSC) SCCP
address: RI=SSN_PC,PC=0.23.3,SSN=BSSAP
[0;m<0007> osmo_bsc_sigtran.c:521 (msc-0) A-interface: remote (MSC) SCCP
address: RI=SSN_PC,PC=0.23.1,SSN=BSSAP
[0;m<0007> a_reset.c:106 A-RESET(msc-0)[0xce7480]{DISC}: (re)sending BSSMAP
RESET message...
[0;m<0007> osmo_bsc_sigtran.c:92 Sending RESET to MSC:
RI=SSN_PC,PC=0.23.1,SSN=BSSAP
[0;m<001f> m3ua.c:507 XUA_AS(MSC_Test)[0xcdb9d0]{AS_DOWN}: Event
AS-TRANSFER.req not permitted
[0;m<0007> a_reset.c:106 A-RESET(msc-0)[0xce7480]{DISC}: (re)sending BSSMAP
RESET message...
[0;m<0007> osmo_bsc_sigtran.c:92 Sending RESET to MSC:
RI=SSN_PC,PC=0.23.1,SSN=BSSAP
[0;m<001f> m3ua.c:507 XUA_AS(MSC_Test)[0xcdb9d0]{AS_DOWN}: Event
AS-TRANSFER.req not permitted
[0;m<0007> a_reset.c:106 A-RESET(msc-0)[0xce7480]{DISC}: (re)sending BSSMAP
RESET message...
[0;m<0007> osmo_bsc_sigtran.c:92 Sending RESET to MSC:
RI=SSN_PC,PC=0.23.1,SSN=BSSAP
[0;m<001f> m3ua.c:507 XUA_AS(MSC_Test)[0xcdb9d0]{AS_INACTIVE}: Event
AS-TRANSFER.req not permitted
[0;m<0022> m3ua.c:634 asp-Huawei_MSC_Test: Received NOTIFY Type State
Change:AS Inactive ()
[0;m<001f> xua_default_lm_fsm.c:353
xua_default_lm(Huawei_MSC_Test)[0xce6de0]{ACTIVE}: Ignoring primitive
M-ASP_ACTIVE.confirm
[0;m<0022> m3ua.c:634 asp-Huawei_MSC_Test: Received NOTIFY Type State
Change:AS Active ()
[0;m<0007> a_reset.c:106 A-RESET(msc-0)[0xce7480]{DISC}: (re)sending BSSMAP
RESET message...
[0;m<0007> osmo_bsc_sigtran.c:92 Sending RESET to MSC:
RI=SSN_PC,PC=0.23.1,SSN=BSSAP
[0;m<0007> osmo_bsc_bssap.c:58 RESET ACK from MSC:
RI=SSN_PC,PC=0.23.1,SSN=BSSAP
[0;m<0007> a_reset.c:74 A-RESET(msc-0)[0xce7480]{DISC}: SIGTRAN connection
succeded.
[0;m<0015> input/ipa.c:265 accept()ed new link from 192.168.1.170 to port 3002
[0;m[1;36m<0004> abis_nm.c:499 BTS0 feature 'EGPRS' reported via OML does not
match statically set feature: 0 != 1. Please fix.
[0;m[1;36m<0004> abis_nm.c:499 BTS0 feature 'OML Alerts' reported via OML
does not match statically set feature: 1 != 0. Please fix.
[0;m[1;36m<0004> abis_nm.c:499 BTS0 feature 'Fullrate speech V1' reported via
OML does not match statically set feature: 1 != 0. Please fix.
[0;m[1;36m<0004> abis_nm.c:499 BTS0 feature 'Halfrate speech V1' reported via
OML does not match statically set feature: 1 != 0. Please fix.
[0;m[1;36m<0004> abis_nm.c:499 BTS0 feature 'Fullrate speech EFR' reported
via OML does not match statically set feature: 1 != 0. Please fix.
[0;m[1;36m<0004> abis_nm.c:499 BTS0 feature 'Fullrate speech AMR' reported
via OML does not match statically set feature: 1 != 0. Please fix.
[0;m[1;36m<0004> abis_nm.c:499 BTS0 feature 'Halfrate speech AMR' reported
via OML does not match statically set feature: 1 != 0. Please fix.
[0;m[1;36m<0004> abis_nm.c:566 OC=BTS(01) INST=(00,ff,ff): BTS0: ARI reported
sw[0/2]: osmobts is 0.8.1.35-6575f0
[0;m[1;36m<0004> abis_nm.c:438 BTS0 reported variant: omso-bts-trx
[0;m[1;36m<0004> abis_nm.c:460 BTS0 Attribute Manufacturer Dependent State is
unreported
[0;m[1;36m<0004> abis_nm.c:566 OC=BTS(01) INST=(00,ff,ff): BTS0: ARI reported
sw[0/1]: TRX_PHY_VERSION is Unknown
[0;m[1;36m<0004> abis_nm.c:460 BTS0 Attribute Manufacturer Dependent State is
unreported
[0;m[1;36m<0004> abis_nm.c:566 OC=BTS(01) INST=(00,ff,ff): BTS0: ARI reported
sw[0/1]: TRX_PHY_VERSION is Unknown
[0;m[1;36m<0004> abis_nm.c:2827 IPA RSL CONNECT IP=0.0.0.0 PORT=3003
STREAM=0x00
[0;m[1;36m<0004> abis_nm.c:2827 IPA RSL CONNECT IP=0.0.0.0 PORT=3003
STREAM=0x00
[0;m<0015> input/ipa.c:265 accept()ed new link from 192.168.1.170 to port 3003
[0;m[1;35m<0003> osmo_bsc_main.c:282 bootstrapping RSL for BTS/TRX (0/0) on
ARFCN 111 using MCC-MNC 101-01 LAC=20259 CID=6966 BSIC=63
[0;m<0015> input/ipa.c:265 accept()ed new link from 192.168.1.170 to port 3003
[0;m[1;35m<0003> osmo_bsc_main.c:282 bootstrapping RSL for BTS/TRX (0/1) on
ARFCN 13 using MCC-MNC 101-01 LAC=20259 CID=6966 BSIC=63
[0;m[1;31m<0011> bts_ipaccess_nanobts.c:314
timeslot(0-0-0-CCCH_SDCCH4)[0xce0220]{UNUSED}: Event TS_EV_OML_READY not
permitted
[0;m[1;31m<0011> bts_ipaccess_nanobts.c:314
timeslot(0-0-1-SDCCH8)[0xce0650]{UNUSED}: Event TS_EV_OML_READY not permitted
[0;m[1;31m<0011> bts_ipaccess_nanobts.c:314
timeslot(0-0-2-TCH_F)[0xce0c00]{UNUSED}: Event TS_EV_OML_READY not permitted
[0;m[1;31m<0011> bts_ipaccess_nanobts.c:314
timeslot(0-0-3-TCH_F)[0xce11b0]{UNUSED}: Event TS_EV_OML_READY not permitted
[0;m[1;31m<0011> bts_ipaccess_nanobts.c:314
timeslot(0-0-4-TCH_F)[0xce1760]{UNUSED}: Event TS_EV_OML_READY not permitted
[0;m[1;31m<0011> bts_ipaccess_nanobts.c:314
timeslot(0-0-5-TCH_F)[0xce1d10]{UNUSED}: Event TS_EV_OML_READY not permitted
[0;m[1;31m<0011> bts_ipaccess_nanobts.c:314
timeslot(0-0-6-TCH_F)[0xce22c0]{UNUSED}: Event TS_EV_OML_READY not permitted
[0;m[1;31m<0011> bts_ipaccess_nanobts.c:314
timeslot(0-0-7-TCH_F)[0xce2870]{UNUSED}: Event TS_EV_OML_READY not permitted
[0;m
[1;35m<0003> abis_rsl.c:1364 (bts=0) CHAN RQD: reason: other (ra=0xfe,
neci=0x00, chreq_reason=0x04)
[0;m[1;32m<0010> lchan_fsm.c:76
lchan(0-0-0-CCCH_SDCCH4-0)[0xce7f70]{WAIT_RLL_RTP_ESTABLISH}: (type=SDCCH)
lchan allocation failed in state WAIT_RLL_RTP_ESTABLISH: Timeout
[0;m[1;32m<0010> lchan_fsm.c:95
lchan(0-0-0-CCCH_SDCCH4-0)[0xce7f70]{WAIT_RLL_RTP_ESTABLISH}: (type=SDCCH) Tx
Immediate Assignment Reject (lchan allocation failed in state
WAIT_RLL_RTP_ESTABLISH: Timeout)
[0;m[1;35m<0003> abis_rsl.c:1364 (bts=0) CHAN RQD: reason: Location updating
(ra=0x09, neci=0x00, chreq_reason=0x03)
[0;m<0007> fsm.c:299 SUBSCR_CONN[0xce7910]{INIT}: Allocated
[0;m<000f> fsm.c:299 LCLS[0xce7a40]{NO_LCLS}: Allocated
[0;m<000f> fsm.c:329 LCLS[0xce7a40]{NO_LCLS}: is child of SUBSCR_CONN[0xce7910]
OSMO-BSC CLI:
OsmoBSC# show network
BSC is on MCC-MNC 101-01 and has 1 BTS
Encryption: A5/0
NECI (TCH/H): 0
Use TCH for Paging any: 0
Handover: Off
Current Channel Load:
CCCH+SDCCH4: 25% (1/4)
TCH/F: 0% (0/6)
SDCCH8: 0% (0/8)
Last RF Command:
Last RF Lock Command:
OsmoBSC# show run
Current configuration:
!
!
bts 0
type sysmobts
band GSM900
cell_identity 6966
location_area_code 20259
base_station_id_code 63
ms max power 15
cell reselection hysteresis 4
rxlev access min 0
radio-link-timeout 32
channel allocator ascending
rach tx integer 9
rach max transmission 7
channel-descrption attach 1
channel-descrption bs-pa-mfrms 5
channel-descrption bs-ag-blks-res 1
no access-control-class-ramping
access-control-class-ramping-step-interval dynamic
access-control-class-ramping-step-size 1
early-classmark-sending forbidden
early-classmark-sending-3g allowed
ip.access unit_id 1800 0
oml ip.access stream_id 255 line 0
neighbor-list mode manual-si5
neighbor-list add arfcn 100
neighbor-list add arfcn 200
si5 neighbor-list add arfcn 10
si5 neighbor-list add arfcn 20
codec-support fr hr efr amr
gprs mode none
no force-combined-si
trx 0
rf_locked 0
arfcn 111
nominal power 23
max_power_red 20
rsl e1 tei 0
timeslot 0
phys_chan_config CCCH+SDCCH4
hopping enabled 0
timeslot 1
phys_chan_config SDCCH8
hopping enabled 0
timeslot 2
phys_chan_config TCH/F
hopping enabled 0
timeslot 3
phys_chan_config TCH/F
hopping enabled 0
timeslot 4
phys_chan_config TCH/F
hopping enabled 0
timeslot 5
phys_chan_config TCH/F
hopping enabled 0
timeslot 6
phys_chan_config TCH/F
hopping enabled 0
timeslot 7
phys_chan_config SDCCH8+CBCH
hopping enabled 0
trx 1
rf_locked 0
arfcn 13
nominal power 23
max_power_red 20
rsl e1 tei 0
timeslot 0
phys_chan_config TCH/F
hopping enabled 0
timeslot 1
phys_chan_config TCH/F
hopping enabled 0
timeslot 2
phys_chan_config TCH/F
hopping enabled 0
timeslot 3
phys_chan_config TCH/F
hopping enabled 0
timeslot 4
phys_chan_config TCH/F
hopping enabled 0
timeslot 5
phys_chan_config TCH/F
hopping enabled 0
timeslot 6
phys_chan_config TCH/F
hopping enabled 0
timeslot 7
phys_chan_config TCH/F
hopping enabled 0
OSMO-BTS-TRX CLI:
OsmoBTS# show run
Current configuration:
!
!
line vty
no login
!
e1_input
e1_line 0 driver ipa
e1_line 0 port 0
no e1_line 0 keepalive
phy 0
osmotrx ip local 127.0.0.1
osmotrx ip remote 127.0.0.1
no osmotrx ms-power-loop
osmotrx timing-advance-loop
osmotrx base-port local 5800
osmotrx base-port remote 5700
osmotrx fn-advance 5
osmotrx rts-advance 5
instance 0
osmotrx rx-gain 0
osmotrx tx-attenuation 7
instance 1
osmotrx rx-gain 0
osmotrx tx-attenuation 7
bts 0
band GSM900
ipa unit-id 1800 0
oml remote-ip 5.40.0.1
rtp jitter-buffer 100
rtp port-range 16384 17407
paging queue-size 200
paging lifetime 0
uplink-power-target -75
gsmtap-sapi ccch
gsmtap-sapi pdtch
min-qual-rach 50
min-qual-norm -5
max-ber10k-rach 1707
trx 0
power-ramp max-initial 0 mdBm
power-ramp step-size 2000 mdB
power-ramp step-interval 1
ms-power-control dsp
phy 0 instance 0
trx 1
power-ramp max-initial 0 mdBm
power-ramp step-size 2000 mdB
power-ramp step-interval 1
ms-power-control dsp
phy 0 instance 1
end
OSMO-TRX CLI:
OsmoTRX# show run
Current configuration:
!
!
stats interval 5
!
line vty
no login
!
trx
bind-ip 127.0.0.1
remote-ip 127.0.0.1
multi-arfcn disable
swap-channels disable
egprs disable
chan 0
chan 1
end
Best Regard,
Ron Menez
[email protected]<mailto:[email protected]>
