RBS 2308 Protocol Error

[Sipos Csaba]

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 at gmx.ch>
Címzett: "Caleb Pal" <cleb at defcon-3.net>, openbsc at 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.
>