22 Feb
2012
22 Feb
'12
8:15 p.m.
Hey Osmoworld,
Just a little intro before my rambling questions... I've been working on
connecting OpenBTS and osmo-bts/OpenBSC together, and everything works well
enough to at least send messages between the two (it's somewhat hackish but
it works for me so far). The phone sees the network and when I attempt to
connect, it is assigned a SDCCH and starts the typical location update
process. This makes me think the underlying issue is in my OpenBSC/network
setup.
Now for the problems: (probably best to check the console output below
first)
Even though the MS receives an ID request and returns an ID response, the
LU Request times out and returns cause=13 (default from config). I'm not
sure what happens after the ID response since it doesn't seem to have sent
anything else down to the MS.
I also don't know too much about the MS's job, but it seems to send 3 LU
requests every time (2 of which are unnecessary and rejected as
duplicates). I assume that's what the preceding ERROR IND messages are
referring to, but I don't know for certain.
My BTS BCCH has LAI=001/01/1, which is correctly set in both OpenBTS and
OpenBSC config files. The Location Updating Request contains
LAI=001/01/65534, which I think may be the main issue since LAC=65534 is
reserved (even looking in GSM-04.08, I couldn't find any details about
this; can you shed some light please?). The MS works with standard OpenBTS
by the way.
I've looked through the gsm_04_08 code and Wireshark capture, but no clues
stick out. I'm not too familiar with OpenBSC in general, so this could be
as simple as setting some kind of config parameter. I figured I'd ask on
here for help in case I'm just missing something basic.
Here is the console output (with debug and authorize-everyone flags on):
Wed Feb 22 13:06:24 2012 <0004> abis_rsl.c:1317 (bts=0,trx=0,ts=0,ss=0)
Activating ARFCN(51) SS(0) lctype SDCCH r=LOCATION_UPDATE ra=0x0e ta=0
Wed Feb 22 13:06:24 2012 <0004> abis_rsl.c:1064 (bts=0,trx=0,ts=0,ss=0)
CHANNEL ACTIVATE ACK
Wed Feb 22 13:06:25 2012 <0000> abis_rsl.c:1493 (bts=0,trx=0,ts=0,ss=0)
SAPI=0 ESTABLISH INDICATION
Wed Feb 22 13:06:25 2012 <0002> gsm_04_08.c:1023 LOCATION UPDATING REQUEST:
mi_type=0x01 MI(460020020292786) type=NORMAL
Wed Feb 22 13:06:25 2012 <0001> gsm_04_08.c:114 (bts 0 trx 0 ts 0 pd 05)
Sending 0x18 to MS.
Wed Feb 22 13:06:25 2012 <0000> abis_rsl.c:1493 (bts=0,trx=0,ts=0,ss=0)
SAPI=0 Wed Feb 22 13:06:25 2012 <0000> abis_rsl.c:1439
(bts=0,trx=0,ts=0,ss=0) ERROR INDICATION cause=unknown 0x0
Wed Feb 22 13:06:25 2012 <0000> abis_rsl.c:1493 (bts=0,trx=0,ts=0,ss=0)
SAPI=0 ESTABLISH INDICATION
Wed Feb 22 13:06:25 2012 <0002> gsm_04_08.c:1023 LOCATION UPDATING REQUEST:
mi_type=0x01 MI(460020020292786) type=NORMAL ignoring request due an
existing one: 0x20f1350.
Wed Feb 22 13:06:25 2012 <0002> gsm_04_08.c:383 Subscriber 460020020292786:
LOCATION UPDATING REJECT LAC=1 BTS=0
Wed Feb 22 13:06:25 2012 <0001> gsm_04_08.c:114 (bts 0 trx 0 ts 0 pd 05)
Sending 0x04 to MS.
Wed Feb 22 13:06:25 2012 <0000> abis_rsl.c:1493 (bts=0,trx=0,ts=0,ss=0)
SAPI=0 Wed Feb 22 13:06:25 2012 <0000> abis_rsl.c:1439
(bts=0,trx=0,ts=0,ss=0) ERROR INDICATION cause=unknown 0x0
Wed Feb 22 13:06:25 2012 <0000> abis_rsl.c:1493 (bts=0,trx=0,ts=0,ss=0)
SAPI=0 ESTABLISH INDICATION
Wed Feb 22 13:06:25 2012 <0002> gsm_04_08.c:1023 LOCATION UPDATING REQUEST:
mi_type=0x01 MI(460020020292786) type=NORMAL ignoring request due an
existing one: 0x20f1350.
Wed Feb 22 13:06:25 2012 <0002> gsm_04_08.c:383 Subscriber 460020020292786:
LOCATION UPDATING REJECT LAC=1 BTS=0
Wed Feb 22 13:06:25 2012 <0001> gsm_04_08.c:114 (bts 0 trx 0 ts 0 pd 05)
Sending 0x04 to MS.
Wed Feb 22 13:06:25 2012 <0000> abis_rsl.c:1493 (bts=0,trx=0,ts=0,ss=0)
SAPI=0 DATA INDICATION
Wed Feb 22 13:06:25 2012 <0003> bsc_api.c:430 CLASSMARK CHANGE CM2(len=3)
CM3(len=4)
Wed Feb 22 13:06:27 2012 <0000> abis_rsl.c:1493 (bts=0,trx=0,ts=0,ss=0)
SAPI=0 DATA INDICATION
Wed Feb 22 13:06:27 2012 <0002> gsm_04_08.c:446 IDENTITY RESPONSE:
mi_type=0x02 MI(357966009107140)
Wed Feb 22 13:06:30 2012 <0002> gsm_04_08.c:484 Location Updating Request
procedure timedout.
Wed Feb 22 13:06:30 2012 <0002> gsm_04_08.c:383 Subscriber 460020020292786:
LOCATION UPDATING REJECT LAC=1 BTS=0
Wed Feb 22 13:06:30 2012 <0001> gsm_04_08.c:114 (bts 0 trx 0 ts 0 pd 05)
Sending 0x04 to MS.
Wed Feb 22 13:06:30 2012 <0000> chan_alloc.c:429 (bts=0,trx=0,ts=0,ss=0)
starting release sequence
Wed Feb 22 13:06:30 2012 <0003> gsm_04_08_utils.c:231 Sending Channel
Release: Chan: Number: 0 Type: 1
Wed Feb 22 13:06:30 2012 <0004> abis_rsl.c:579 (bts=0,trx=0,ts=0,ss=0)
DEACTivate SACCH CMD
Wed Feb 22 13:06:31 2012 <0000> abis_rsl.c:1493 (bts=0,trx=0,ts=0,ss=0)
SAPI=0 RELEASE INDICATION
Wed Feb 22 13:06:31 2012 <0004> abis_rsl.c:621 (bts=0,trx=0,ts=0,ss=0) RF
Channel Release CMD due error 0
Wed Feb 22 13:06:31 2012 <0004> abis_rsl.c:658 (bts=0,trx=0,ts=0,ss=0) RF
CHANNEL RELEASE ACK
Thanks for any help,
Tom Cooper
--
Graduate Research Assistant
Wireless @ Virginia Tech
tacooper(a)vt.edu