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Bug #1795

closed

osmo-bts-trx: fails to assign second lchan on TCH/H TS

Added by neels over 5 years ago. Updated almost 5 years ago.

Status:
Closed
Priority:
High
Assignee:
Category:
-
Target version:
Start date:
08/09/2016
Due date:
% Done:

100%

Spec Reference:
http://www.qtc.jp/3GPP/Specs/GSM_GERAN/0502-8b0.pdf

Description

With osmo-bts-trx and a TS configuration featuring TCH/H timeslots,
a call between two phones on the same TRX BTS does never succeed to
use the second lchan of a TCH/H timeslot.

(I do have general unreliability of osmo-trx in my setup but this error
appears consistently)

  • First available TCH/H is ts=5, lchan=0 [0]
  • Second available TCH/H is ts=5, lchan=1 [1]
    But this apparently times out and then [2]
  • Third available TCH/H on ts=6, lchan=0 is actually used
[0]
20160809212237806 DRLL <0000> chan_alloc.c:342 (bts=0,trx=0,ts=5,pchan=TCH/H) Allocating lchan=0 as TCH_H
20160809212237806 DRSL <0004> abis_rsl.c:1705 (bts=0,trx=0,ts=5,ss=0) Activating ARFCN(868) SS(0) lctype TCH_H r=CALL ra=0x40 ta=1
20160809212237806 DRSL <0004> abis_rsl.c:539 (bts=0,trx=0,ts=5,pchan=TCH/H) Tx RSL Channel Activate with act_type=INITIAL
20160809212237806 DRSL <0004> abis_rsl.c:1105 (bts=0,trx=0,ts=5,ss=0) state NONE -> ACTIVATION REQUESTED
20160809212237806 DRSL <0004> abis_rsl.c:1434 (bts=0,trx=0,ts=5,ss=0) CHANNEL ACTIVATE ACK
20160809212237806 DRSL <0004> abis_rsl.c:1105 (bts=0,trx=0,ts=5,ss=0) state ACTIVATION REQUESTED -> ACTIVE
20160809212238175 DRLL <0000> abis_rsl.c:1893 (bts=0,trx=0,ts=5,ss=0) SAPI=0 ESTABLISH INDICATION
20160809212238175 DRLL <0000> gsm_04_08.c:3667 Dispatching 04.08 message, pdisc=5
20160809212238175 DMM <0002> gsm_04_08.c:987 <- CM SERVICE REQUEST serv_type=0x01 MI(TMSI)=2191222410
20160809212238183 DMM <0002> gsm_04_08_utils.c:681 -> CM SERVICE ACK
20160809212238500 DRLL <0000> abis_rsl.c:1893 (bts=0,trx=0,ts=5,ss=0) SAPI=0 DATA INDICATION
20160809212239700 DRLL <0000> abis_rsl.c:1893 (bts=0,trx=0,ts=5,ss=0) SAPI=0 DATA INDICATION
20160809212239700 DRR <0003> bsc_api.c:647 BSC: Passing unknown 04.08 RR message type 0x60 to MSC
20160809212239700 DRLL <0000> gsm_04_08.c:3667 Dispatching 04.08 message, pdisc=6
20160809212239700 DRR <0003> gsm_04_08.c:1281 MSC: Unimplemented GSM 04.08 RR msg type 0x60
20160809212239972 DRLL <0000> abis_rsl.c:1893 (bts=0,trx=0,ts=5,ss=0) SAPI=0 DATA INDICATION
20160809212240213 DRLL <0000> abis_rsl.c:1893 (bts=0,trx=0,ts=5,ss=0) SAPI=0 DATA INDICATION
20160809212240213 DRLL <0000> gsm_04_08.c:3667 Dispatching 04.08 message, pdisc=3
20160809212240214 DMSC <000a> bsc_api.c:402 Sending ChanModify for speech: SPEECH_V1 on channel TCH_H
20160809212240215 DMM <0002> gsm_subscriber.c:176 Subscriber 901990000000038 not paged yet.
20160809212240938 DRLL <0000> abis_rsl.c:1893 (bts=0,trx=0,ts=5,ss=0) SAPI=0 DATA INDICATION
20160809212240938 DRSL <0004> abis_rsl.c:2110 (bts=0,trx=0,ts=5,ss=0) IPAC_BIND speech_mode=0x13 RTP_PAYLOAD=96
20160809212240938 DRSL <0004> abis_rsl.c:1453 (bts=0,trx=0,ts=5,ss=0) CHANNEL MODE MODIFY ACK
20160809212240977 DRSL <0004> abis_rsl.c:2290 (bts=0,trx=0,ts=5,ss=0) IPAC_CRCX_ACK LOCAL_IP=127.0.0.1 LOCAL_PORT=23536 CON_ID=0 
[1]
20160809212241451 DRLL <0000> chan_alloc.c:342 (bts=0,trx=0,ts=5,pchan=TCH/H) Allocating lchan=1 as TCH_H
20160809212241451 DRSL <0004> abis_rsl.c:1705 (bts=0,trx=0,ts=5,ss=1) Activating ARFCN(868) SS(1) lctype TCH_H r=PAGING ra=0x27 ta=2
20160809212241451 DRSL <0004> abis_rsl.c:539 (bts=0,trx=0,ts=5,pchan=TCH/H) Tx RSL Channel Activate with act_type=INITIAL
20160809212241451 DRSL <0004> abis_rsl.c:1105 (bts=0,trx=0,ts=5,ss=1) state NONE -> ACTIVATION REQUESTED
20160809212241451 DRSL <0004> abis_rsl.c:1434 (bts=0,trx=0,ts=5,ss=1) CHANNEL ACTIVATE ACK
20160809212241451 DRSL <0004> abis_rsl.c:1105 (bts=0,trx=0,ts=5,ss=1) state ACTIVATION REQUESTED -> ACTIVE
[2]
20160809212243806 DRLL <0000> chan_alloc.c:342 (bts=0,trx=0,ts=6,pchan=TCH/H) Allocating lchan=0 as TCH_H
20160809212243806 DRSL <0004> abis_rsl.c:1705 (bts=0,trx=0,ts=6,ss=0) Activating ARFCN(868) SS(0) lctype TCH_H r=PAGING ra=0x27 ta=2
20160809212243806 DRSL <0004> abis_rsl.c:539 (bts=0,trx=0,ts=6,pchan=TCH/H) Tx RSL Channel Activate with act_type=INITIAL
20160809212243806 DRSL <0004> abis_rsl.c:1105 (bts=0,trx=0,ts=6,ss=0) state NONE -> ACTIVATION REQUESTED
20160809212243806 DRSL <0004> abis_rsl.c:1434 (bts=0,trx=0,ts=6,ss=0) CHANNEL ACTIVATE ACK
20160809212243806 DRSL <0004> abis_rsl.c:1105 (bts=0,trx=0,ts=6,ss=0) state ACTIVATION REQUESTED -> ACTIVE

So it seems TRX is not capable of using two lchans on one TCH/H timeslot.


Files

osmo-bts.cfg osmo-bts.cfg 717 Bytes OsmoBTS configuration fixeria, 03/21/2017 03:54 PM
openbsc.cfg openbsc.cfg 3.41 KB OpenBSC configuration fixeria, 03/21/2017 03:54 PM
bad_tch_calypso.pcap.gz bad_tch_calypso.pcap.gz 3.55 KB A-bis communication of CalypsoBTS based network fixeria, 03/21/2017 04:54 PM
bad_tch_umtrx.pcap.gz bad_tch_umtrx.pcap.gz 24.2 KB A-bis communication of OsmoTRX based network fixeria, 03/21/2017 04:54 PM
bad_tch_ms_side.pcap.gz bad_tch_ms_side.pcap.gz 11.2 KB MS side Um communication fixeria, 03/21/2017 05:26 PM

Related issues

Related to OsmoPCU - Bug #1524: PACCH on the wrong timeslotFeedbackroh02/22/2016

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