27 Nov
2016
27 Nov
'16
9:01 a.m.
Good Evening,
With the recent commits for the OM2000 protocol, I figured it was time
to dust off the RBS2308 and see what would happen. I am using the latest
version of DAHDI, with a TE122P T1 card. All osmocom software was pulled
yesterday and installed successfully on a machine running Debian Stable.
When OpenBSC starts, all appears normal with regards to bringing the BTS
up until the timeslots for the first TRX are being configured. When the
timeslots are configured, a protocol error is given for each. If I
change trx0/ts0 from the default of CCCH+SDCCH4 to CCCH, that timeslot
is successfully brought up, and the BTS transmits. Other configurations
(TCH/F, TCH/F, PDCH, SDCCH8, TCH/F_TCH/H_PDCH) on timeslots 1-7 give the
same protocol error.
I have attached my openbsc.cfg, the output from the OpenBSC console, a
pcap of the failed startup, and my DAHDI configuration. If they do not
come through the list server, they are also available at:
http://cleb.org/RBS/
Thanks,
Caleb
29 Nov
29 Nov
8:43 p.m.
Hello Caleb,
On 11/27/16 9:01 AM, Caleb Pal wrote:
Good Evening,
With the recent commits for the OM2000 protocol, I figured it was time
to dust off the RBS2308 and see what would happen. I am using the latest
version of DAHDI, with a TE122P T1 card. All osmocom software was pulled
yesterday and installed successfully on a machine running Debian Stable.
Maybe you
want to try to switch you DAHDI config from T1 to E1 first
since you use the BSC config with E1.
T1 uses 24 channels and E1 uses 32 channels.
Second thing is that from what I saw on the wiki and on the Harald's
blog posts the Ericsson RBS units never worked fully and there is still
work to be done. Would be helpful if you have some traces on Abis from a
real Ericsson BSC to see what is going on there.
Regards,
R.
1 Dec
1 Dec
11:07 p.m.
Hello again,
I will reply to my own email because I did a mistake. Sorry for any
inconvenience. I mismatched the DAHDI conf with another one that had E1
config inside.
DAHDI config is fine for T1 link but OpenBSC is still is not clear if
timeslot allocation is OK or maybe someone with more experience can
share why they are allocated like that.
I checked the default config in osmocom-nitb and also the one attached
by Caled and it is not clear for me why we have the following
arrangement compared to the E/// documentation for BSS:
I would re-write Caleb's config as it is the below one for an
Unconcentrated LAPD:
oml e1 line 0 timeslot 1 sub-slot 0 -->> CF is only found in timeslot 1
trx 0
rf_locked 0
arfcn 512
nominal power 24
max_power_red 12
rsl e1 line 0 timeslot 1 sub-slot 1 -->> TRXC is multiplexed only for
first TRX. The other RSL/TRXC links for other TRXes use the full timeslot.
rsl e1 tei 0
timeslot 0
phys_chan_config BCCH+CCCH --> air timeslot 0 runs BCCH and CCCH
hopping enabled 0
e1 line 0 timeslot 1 sub-slot 2
timeslot 1 -->> air timeslot 1 runs a SDCCH8
phys_chan_config SDCCH8
hopping enabled 0
e1 line 0 timeslot 2 sub-slot 3
timeslot 2 -->> subrate 0+1 are spare for 1st TRX in LAPD
Unconcentrated mode. At least the E/// docs show the following:
PCM TS2(spare/spare/TCH0/TCH1)
PCM TS3(TCH2 /TCH3 /TCH4/TCH5)
so I interpreted that subrate 0+1 are the spare ones.
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 3 sub-slot 2
timeslot 3
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 3 sub-slot 3
timeslot 4
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 4 sub-slot 0
timeslot 5
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 4 sub-slot 1
timeslot 6
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 4 sub-slot 2
timeslot 7
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 4 sub-slot 3
Regards,
Razvan
On 11/29/16 8:43 PM, Labs wrote:
Hello Caleb,
On 11/27/16 9:01 AM, Caleb Pal wrote:
Good Evening,
With the recent commits for the OM2000 protocol, I figured it was time
to dust off the RBS2308 and see what would happen. I am using the latest
version of DAHDI, with a TE122P T1 card. All osmocom software was pulled
yesterday and installed successfully on a machine running Debian Stable.
Maybe you
want to try to switch you DAHDI config from T1 to E1 first
since you use the BSC config with E1.
T1 uses 24 channels and E1 uses 32 channels.
Second thing is that from what I saw on the wiki and on the Harald's
blog posts the Ericsson RBS units never worked fully and there is still
work to be done. Would be helpful if you have some traces on Abis from a
real Ericsson BSC to see what is going on there.
Regards,
R.
11:25 p.m.
Hi,
Maybe its not completely related, but my experience with Nokia Site is to use full E1
timeslots (64kbit) for RSL and OML signalling, otherwise it is not working, and this is
not a Nokia limitation.
Just try using:
rsl e1 line 0 timeslot 1 sub-slot full
and for the rest:
timeslot 0
phys_chan_config CCCH+SDCCH4
hopping enabled 0
e1 line 0 timeslot 2 sub-slot 0
timeslot 1
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 2 sub-slot 1
timeslot 2
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 2 sub-slot 2
timeslot 3
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 2 sub-slot 3
timeslot 4
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 3 sub-slot 0
timeslot 5
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 3 sub-slot 1
timeslot 6
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 3 sub-slot 2
timeslot 7
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 3 sub-slot 3
And don't forget to configure the BTS Abis allocation accordingly!
Also for DAHDI, you will need to use the correct config with CCS signalling. This is an
example for the system.conf for an E1 based BTS:
span=1,0,0,ccs,hdb3,crc4
bchan=1-31
Regards,
Csaba
----- Eredeti üzenet -----
Feladó: "Labs" <rp.labs(a)gmx.ch>
Címzett: "Caleb Pal" <cleb(a)defcon-3.net>et>, openbsc(a)lists.osmocom.org
Elküldött üzenetek: Csütörtök, 2016. December 1. 23:07:11
Tárgy: Re: RBS 2308 Protocol Error
Hello again,
I will reply to my own email because I did a mistake. Sorry for any
inconvenience. I mismatched the DAHDI conf with another one that had E1
config inside.
DAHDI config is fine for T1 link but OpenBSC is still is not clear if
timeslot allocation is OK or maybe someone with more experience can
share why they are allocated like that.
I checked the default config in osmocom-nitb and also the one attached
by Caled and it is not clear for me why we have the following
arrangement compared to the E/// documentation for BSS:
I would re-write Caleb's config as it is the below one for an
Unconcentrated LAPD:
oml e1 line 0 timeslot 1 sub-slot 0 -->> CF is only found in timeslot 1
trx 0
rf_locked 0
arfcn 512
nominal power 24
max_power_red 12
rsl e1 line 0 timeslot 1 sub-slot 1 -->> TRXC is multiplexed only for
first TRX. The other RSL/TRXC links for other TRXes use the full timeslot.
rsl e1 tei 0
timeslot 0
phys_chan_config BCCH+CCCH --> air timeslot 0 runs BCCH and CCCH
hopping enabled 0
e1 line 0 timeslot 1 sub-slot 2
timeslot 1 -->> air timeslot 1 runs a SDCCH8
phys_chan_config SDCCH8
hopping enabled 0
e1 line 0 timeslot 2 sub-slot 3
timeslot 2 -->> subrate 0+1 are spare for 1st TRX in LAPD
Unconcentrated mode. At least the E/// docs show the following:
PCM TS2(spare/spare/TCH0/TCH1)
PCM TS3(TCH2 /TCH3 /TCH4/TCH5)
so I interpreted that subrate 0+1 are the spare ones.
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 3 sub-slot 2
timeslot 3
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 3 sub-slot 3
timeslot 4
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 4 sub-slot 0
timeslot 5
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 4 sub-slot 1
timeslot 6
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 4 sub-slot 2
timeslot 7
phys_chan_config TCH/F
hopping enabled 0
e1 line 0 timeslot 4 sub-slot 3
Regards,
Razvan
On 11/29/16 8:43 PM, Labs wrote:
Hello Caleb,
On 11/27/16 9:01 AM, Caleb Pal wrote:
Good Evening,
With the recent commits for the OM2000 protocol, I figured it was time
to dust off the RBS2308 and see what would happen. I am using the latest
version of DAHDI, with a TE122P T1 card. All osmocom software was pulled
yesterday and installed successfully on a machine running Debian Stable.
Maybe you
want to try to switch you DAHDI config from T1 to E1 first
since you use the BSC config with E1.
T1 uses 24 channels and E1 uses 32 channels.
Second thing is that from what I saw on the wiki and on the Harald's
blog posts the Ericsson RBS units never worked fully and there is still
work to be done. Would be helpful if you have some traces on Abis from a
real Ericsson BSC to see what is going on there.
Regards,
R.
2 Dec
2 Dec
12:41 a.m.
Hello Csaba,
On 12/1/16 11:25 PM, Sipos Csaba wrote:
Hi,
Maybe its not completely related, but my experience with Nokia Site is to use full E1
timeslots (64kbit) for RSL and OML signalling, otherwise it is not working, and this is
not a Nokia limitation.
Nokia did a different implementation on Abis. I'm hoping to get a Nokia
soon and play with it.
Just try using:
I can't try it because I don't have a PCM based Ericsson but an IP based
one and I really don't know how to make the openbsc.cfg for that one
since I couldn't find anything in the wiki for it. I was trying to help
Caleb and also understand the OM2000. I worked previously on RAN part
with E/// and we integrated this RBSes with real BSCes and according to
my notes E/// is not using full PCM timeslots (64kbit) exactly. They
have 3 types of LDAP configurations for their Abis to RBS.
- Unconcentrated LAPD
For E1 they leave the full timeslot 0 free for synchronization and
utilize timeslots 1-31. In this mode they use a full timeslot for
signaling to TRU (TRXC) and 2 other full timeslots submultiplexed each
in 4x 16kbit for voice and data. OML(CF) is not mentioned specifically
but it says "TRXC-0 and CF goes together on the same timeslot". The E///
naming TRH (Transceiver Handler) says that is handling all LAPD
signaling, signaling BTS to MS and O&M (CF). For T1 lines there is not
synchronization timeslot used and sync is done from the overall T1 line
so T1 config should start with "timeslot 0".
- Concentrated LAPD
Recommended for 3 or more TRUs. Here TS0 64kbit is for synchronization
in E1 links, TS1 is used as 4x16kbit signaling for the first 4 TRXes,
TS2-9 submultiplexed each in 4x16kbit for traffic, TS10 again 4x
signaling,etc. For T1 the same but no TS0 so config starts with TS0 for
4x signaling links for the first 4 TRXes. Since in this mode you need
also configuration for CON the CF(OML) is added by CON to the same
timeslot as the first 4x TRXes that means TS1.
- Multiplexed LAPD
This is used for small cells and here I made the mistake in my previous
mail saying is "Unconcentrated". This type of config multiplexes TRX
signaling + CF(OML) + BCCH/CCCH + SDCCH8 in one full 64kbit timeslot and
on the second timeslot keeps 2x 16kbit subrates spare.
So in the end I am still not sure how the config should look like to
have a PCM based RBS working with OpenBSC.
And don't forget to configure the BTS Abis
allocation accordingly!
Also for DAHDI, you will need to use the correct config with CCS signalling. This is an
example for the system.conf for an E1 based BTS:
span=1,0,0,ccs,hdb3,crc4
bchan=1-31
Thanks for config.
Regards,
Csaba
Regards,
Razvan
3124
days inactive
3128
days old
4 comments
3 participants
participants (3)
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Caleb Pal -
Labs -
Sipos Csaba