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wireshark, viewing Abis communication
by Eric Cathelinaud 27 Jul '09

27 Jul '09

Hi, I am trying to deal with wireshark to understand what happening in each function in the code. It says that the file seems to be corrupted: "The capture files appears to be damaged or corrupted. (libpcap: LAPD file has a 15-byte packet, too small to have even a LAPD pseudo-header)" Is it a problem? I still can read the Abis communication. I saw that some rsl packets are malformed. Is it coming from a missing implementation in the code that need to be fixed? Thanks Eric

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AW: HAR2009 TODO list
by Andreas.Eversberg 26 Jul '09

26 Jul '09

>On Thu, Jul 23, 2009 at 12:26:14AM +0200, Harald Welte wrote: >> Hi again, >> >> I'm currently in the train, so forgive me posting the initial TODO list >> to the mailing list rather than the wiki. > >this is now at http://bs11-abis.gnumonks.org/trac/wiki/HAR2009 Check out Eventphone. They run DECT network. Why not linking to their network? I am not at HAR, but I can help setting it up. An extra E1 card is required to link to Eventphone's machine... http://www.eventphone.de/guru/?language=de

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Looking for 32.768MHz OCXO for BS-11 calibration
by Harald Welte 24 Jul '09

24 Jul '09

Hi! So for everyone who has problems with BS-11 clock accuracy, what would be the theoretical straight-forward way to solve the problem, is to replace the 32.768MHz crystal oscillator on the E1 card with a OCXO of the same frequency. So what we're looking for is an OCXO with +/- 0.05ppm or higher stability for 3.3V power supply. Unfortunately I was not able to find one at that frequency, even digikey doesn't have one. If anyone can find a source for a OCXO in the abovementioned parameter range (and small quantities), I think quite a number of people would be interested in buying one and connecting it to their E1 boards. Any help is much appreciated. Thanks! -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)

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Some changes to the gsm_transaction data model
by Harald Welte 23 Jul '09

23 Jul '09

Hi! For finishing proper SMS support, I need supoprt for transactions. Similar to Call Control, SMS can also have a number of different transactions active of any time. Before my changes, the transactions were tied to call control, which is obviously not good if that code is to be reused from SMS. Also, the transaction was linked to the gsm_network as well as the gsm_lchan. I think both are somehow wrong. Why are they not a property of the network? Because a transaction always belongs to a 'MM entity' (gsm spec language), or a gsm_subscriber in openbsc terminology. That subscriber then is part of a gsm_network. And why are they not part of a gsm_lchan? Because a transaction can be initiated on one lchan and then move to another lchan, e.g. in case a SMS is sent just before a call is made, where we start on an SDCCH and might continue on a SACCH. I will keep the lchan pointer in the meaning of 'current lchan through which we transmit messages to the remote MM entity'. Tying the transaction to the subscriber neatly addresses both of those issues. Regards, -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)

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new to OpenBSC
by raza shah 23 Jul '09

23 Jul '09

Hi everyone, I am new to OpenBSC and I think the best way to contribute to it is to get to know the source code first. I would appreciate any help regarding how to begin understanding the source code. And what are the main features of the code? What is the best approach to start learning OpenBSC. And is there any good material on OpenBSC.? Thanks. _________________________________________________________________ Share your memories online with anyone you want. http://www.microsoft.com/middleeast/windows/windowslive/products/photos-sha…

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Re: GSM license approval for HAR2009
by Dieter Spaar 23 Jul '09

23 Jul '09

Hello Harald, On Wed, 22 Jul 2009 23:49:00 +0200, "Harald Welte" <laforge(a)gnumonks.org> wrote: > > Even with two BTS at two TRX (exercising all our four ARFCN), the total call > capacity is not more than 13 simultanesous MS-to-MS calls (since each call > requires two timeslots). Yes we could do half-rate, but we have no software > support for that so far. You have the adjacent channels 121 to 124 for GSM 900 ? As far as I am aware, adjacent channels will disturb each other. From what I know, real networks usually have one free guard channel in between. So at least the configuration of using adjacent channels should be checked in advance (but you don't know how well different phones behave). Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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AW: mISDNdebugtool status
by Andreas.Eversberg 23 Jul '09

23 Jul '09

> can you comment on the status of mISDNdebugtool? As it seems, Eric is having > some problems using it. Also, in current mISDNuser.git (socket branch), > it doesn't compile since mISDNdebugtool.h is missing. hi, sorry for the late answer. i don't exactly know what this was for. i think it was used to debug the driver itself. to actually log frames from isdn interface and write a pcap file you need misdn_log. for logging first card use "misdn_log" or "misdn_log -c0". for writing pcap file use "misdn_log -c0 -w <file>" this connects to given isdn interface and shows transmitted data also. it must be started AFTER the application or it will set the mode to TE-mode. so first run bsc_hack, then start misdn_log. andreas

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Re: GSM license approval for HAR2009
by Dieter Spaar 22 Jul '09

22 Jul '09

Hello Stefan, On Wed, 22 Jul 2009 19:36:16 +0200, "Stefan Schmidt" <stefan(a)datenfreihafen.org> wrote: > > Hmm, if we would calculate with 200 cards we would have ~80 USD costs for them. > Maybe not the baddest thing. Let's wait to what conclusion we come here before > going ahead. A technical solution that let the user handle the registration on > it's own is still my favorit. Sadly we can't estimate how many subscribers we > will get. :) I don't know if you get a better price if you buy such a large amount of the SIM cards, but I would ask. One advantage of handing out SIM cards: You can play with authentication and encryption if you want to. The A3/A8 algorithm in the SIM cards seems to be different from COMP128-V1 (at least with the SIM I tested) so you cannot retrieve Ki. However you could run the authentication in advance and record a few challenge-reponse pairs and use them later. And if you take one Euro as deposit for the SIM, you might get them back or don't care if not. Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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Re: GSM license approval for HAR2009
by Dieter Spaar 22 Jul '09

22 Jul '09

Hello Stefan, On Wed, 22 Jul 2009 18:32:28 +0200, "Stefan Schmidt" <stefan(a)datenfreihafen.org> wrote: > > Hmm, another idea pops up into my mind right now. Any chance we can get a big > bunch of pre paid SIMs without money on the account? If we would get some 100s > of them we could prepare them in advance and just hand out to the people. Kai Muenz mentioned it on the list already, there are GSM SIMs available at http://www.dealextreme.com/details.dx/sku.16159. 10 pieces cost $US 3.94 including shipping. If you don't mind about a Chinese SIM Toolkit Menu which you can't read and also don't mind to remove a little bit of glue from some of the SIMs, they are fine for this purpose. Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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Re: Spectrum analysis shows strange carrier
by Dieter Spaar 21 Jul '09

21 Jul '09

Hello Philipp, On Mon, 20 Jul 2009 20:19:16 CEST, "Dieter Spaar" <spaar(a)mirider.augusta.de> wrote: > > Not sure what you are measuring on peak one and two, but channel 123 > should be 959.6 MHz, this is most certainly the third peak. There might > be small signals (e.g. from the oscillator of the BS-11) on other > frequencies, but they should be much smaller than the main signal. In the meantime I did check with my spectrum analyzer. There is indeed a signal coming from the BS-11, even if nothing else is connected to the BS-11 (no serial connection, no E1). The signal starts to be emitted after the firmware download is complete. I could measure the signal at 942.4 MHz, the level is about -42 dBm (cable connection from the spectrum analyzer to TRX0, low-quality cable). The signal strength does not depend on the power amplifier setting, I wonder where it comes from (some internal oscillator working at that frequency ?). The signal is not very strong, so it should not cause major trouble (besides disturbing a weak signal which might be there from an "official" source if you are close to the BS-11). Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

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