Hi, First, we are tying to connect our BTS directly to OsmoBSC. I'm trying to use configuration for Siemens Bs11, but I have problems with channels configuration in DAHDI. Do you have any advice for dahdi configuration?
Regards, Alina În mie., 29 mai 2024 la 09:09, Mychaela Falconia <[email protected]> a scris: > Hi Dan, > > > Yes, you are right, this is the motivation. I used to work with this > kind of > > equipment and I would like to see it working again. > > Yay, nice to hear! > > > Since we have here at the university Mobile Communications courses, > > I am also interested in the didactic aspect of this project. > > Which university is it? And approximately where in the world (which > geopolitical region) is this equipment located? > > > It seems that we have the same motivation, so indeed we can be friends > > and work on this nice project! > > Yes indeed. :-) Let me start with the documentation I was able to find > for Siemens' version of GSM network infrastructure: > > https://www.freecalypso.org/pub/GSM/Siemens/70183086-Siemens-D900-D1800.pdf > > Are you familiar with this document? Does it look like your hardware > is the same as what it describes, or something different? > > Are you able to identify the interfaces between components? You > already wrote this bit earlier about Abis: > > > Now the Abis interface is up and the BTS/BSC configuration is ok [...] > > What about A and Asub interfaces? Are you able to identify them? How > many E1 circuits are coming out of the TRAU toward the MSC: just one > or more? Are you able to identity the timeslot on the A interface on > which the BSC is trying to talk BSSAP to the MSC? And what about Asub, > the interface between the BSC and the TRAU - do you see just one E1 > there, or more than one? (Note for others following this thread on > the ML: the interface which Siemens called Asub is the same as Nokia's > Ater. The other diff in terminology is that Nokia used the term TRAU > to mean each individual speech/data channel, whereas for Siemens the > whole rack is called TRAU; Nokia called the latter TCSM.) > > Are you able to connect to the management interface of your BSC and > fully examine/modify its configuration? Do you see any config settings > related to the TRAU? Of particular interest to me, is there a setting > to enable or disable TFO? > > Toward your goal of bringing this equipment to life, using Osmocom to > fill in those network elements (MSC and above) where you don't have > corresponding legacy equipment, you will need to start by identifying > exactly where and how the MTP2/MTP3/SCCP/BSSAP interface is coming out > of your BSC. Then it will be a task to either extend OsmoMSC with its > underlying libraries to speak SCCP over MTP2/MTP3 directly, or find > some converter to SCCP over {SCTP,TCP}/M3UA which Osmocom currently > speaks. > > This signaling layer (BSSAP over lower layers) will need to be tackled > first. In the initial implementation, simply ignore all voice user > plane issues: calls won't work initially of course, but you need to > reach the point of an MS successfully finding the network and registering > (location update) before you can even begin playing with calls - hence > my recommendation is to ignore the voice user plane initially and > focus on BSSAP signaling. > > M~ >
