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4278 discussions

core/conv: SCH decoding problem
by Vadim Yanitskiy 02 May '17

02 May '17

Hi Tomas, I again have a question related to your SSE accelerated Viterbi decoder, and I hope it's the last issue, which prevents us from finishing this work. In short, SSE based implementation provides one-byte different decoding result for SCH transcoding test. So, the whole GSM 05.03 coding test fails. I have done some debugging, and would like to share some results. Have a look at the tests/coding/test_sch(), which first encodes a L3 packet into ubits and sbits, then some bits are getting destroyed, then the gsm0503_sch_decode() is being called to get decoded bytes back, and finally decoded bytes are being compared with original bytes. As long as encoder implementation is not covered by SSE code, it works as before. But SSE accelerated decoder outputs one-byte different result in case of SCH: int gsm0503_sch_decode(uint8_t *sb_info, sbit_t *burst) { ubit_t conv[35]; int rv; osmo_conv_decode(&gsm0503_sch, burst, conv); rv = osmo_crc16gen_check_bits(&gsm0503_sch_crc10, conv, 25, conv + 25); if (rv) return -1; // ... } // Original implementation ubit_t conv[35] = { 0x01 0x01 0x00 0x01 0x00 0x00 0x00 0x00 0x01 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x01 0x00 0x00 0x01 0x01 0x01 0x00 0x01 0x00 }; // Accelerated implementation ubit_t conv[35] = { 0x01 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x01 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x01 0x00 0x00 0x01 0x01 0x01 0x00 0x01 0x00 }; As you can see, the conv[3] isn't the same in both cases. So, at the next step the osmo_crc16gen_check_bits() returns -1. Latest version of this change: https://gerrit.osmocom.org/#/c/2454/ Do you have any ideas? Despite SCH decoding isn't required on BTS side, the problem may be more global, than the test shows. With best regards, Vadim Yanitskiy.

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Accelerate3g5 femto-cell configuration
by Nikolya 01 May '17

01 May '17

Hello It may not be an appropriate mail-list to ask questions about OsmoBTS inside femto-cell of Accelerate3g5 "promo", but i need some directions. I undestand that i need to build OpenBSC (OpenNITM), so that femto-cell start "working" . But i can't find any documentation regarding how to configure OsmoBTS inside femto-cell . I knew root account password for the cell, but didn't find passwords resting in [root@ip302ff:~#]cat /var/www/.htpasswd nano-admin:SO0umwXJnpBjo femto-admin:gRWqmPZknka4g developer:.QIQ0JPRQ3PKA [root@ip302ff:~#] so i just move this file aside and access http://cell-ip:8089/ cgi-bin/connection_config.cgi . It giving this HTML <pre> $ curl http://cell-ip:8089/cgi-bin/connection_config.cgi <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> <title>ip.access 3G AP Web-if</title> <link href="/styles.css" rel="stylesheet" type="text/css"> </head> <NOSCRIPT> <meta http-equiv=REFRESH content=0;URL="/no_javascript.html"> </NOSCRIPT> <body onLoad="myOnLoad()"> <div id="header"> <img src="/top_banner.png" usemap="#logomap" border="0" align="middle" vspace="0"> <MAP name="logomap" border="0"> <AREA href="http://www.ipaccess.com" shape="rect" coords="0,0,160,65"/> </MAP> </div> <div id="container"> <div id="title"><h2>3G AP</h2></div> <div id="leftcol"> <ul id="nav" class="nav">  </ul> </div> <div id="content"> <b>Serial Number: </b></p> <b>Sorry - couldn't find '/cgi-bin/connection_config.cgi' page here.</b><br> Server name: ip302ff<br>PathTranslated: <br>PathInfo: <br> </div> <div id="footer"> <p/> <hr/> <h3>Copyright © 2010 <a href="http://www.ipaccess.com">ip.access ltd</a></h3> </div> </div> </body> </html> $ </pre> one of the URLs that work is http://cell-ip:8089/cgi-bin/swversion.cgi , which giving <pre> Serial Number: Firmware Version Information Flash Contents Kernel Bank 1: xc-220.3.0 Kernel Bank 2: xc-225.2.0 Filesystem Bank 1: EMPTY Filesystem Bank 2: 579.26.7 Default Filesystem: ## Error: "rootdev" not defined sh: 5: unknown operand sh: 6: unknown operand Default OS: ## Error: "kernel_flash_addr" not defined sh: 0x20080000: unknown operand sh: 0x20280000: unknown operand Booted version: Bootloader version: OS version: xc-225.2.0 #1 PREEMPT Thu Jul 11 17:54:07 BST 2013 Filesystem version: 579.26.7 Detailed List: etc </pre> There are open TCP ports on femto-cell ip 22,8089,8090,10002 . One of them 8090, when telnet to it, it providing some "vty" <pre> dmi> help SYNTAX : help [cmd]|[attribute_id_list] where cmd is one of quit q call wait get set action alarm getobj restore regatt deregatt regact deregact dmidata endscript exitscript history buildco print help dmi> </pre> But it doesn't look like VTY that documented in http://ftp.osmocom.org/docs/latest/osmobts-usermanual.pdf I may need to build linux for femto-cell by myself, but need some help of how to build and write builded image to femto-cell --- WBR Nikolay

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osmo-stp / nightly builds
by Neels Hofmeyr 27 Apr '17

27 Apr '17

Just asked holger: the osmo-stp build from cellmgr in the nightly debian packages can be switched off. Since you've been fixing debian these days, could you do that one as well? Hopefully we will have no more failures then. (...except on the new ubuntu 17.04 of course, no idea what's up with that. Not sure who added it and who will resolve those, or whether that's already done?) Thanks! ~N

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ip.access nano3G Help
by Junaid Saeed Uppal 27 Apr '17

27 Apr '17

Hi, I am trying to setup the 3G Project and have bought a used nano3G BTS (S8 - Model 237A) . The problem i am facing is that the telnet port is not open. I have tried to reset the device using the pin-hole reset button as per documentation but it still doesn't open up the ports and still tries to lookup operator's NTP and tries to establish a IPSEC tunnel. Any pointers on how i can reset this so that I can get it to work with the project? Thanks,

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nano3G S8 Help
by Junaid Saeed Uppal 27 Apr '17

27 Apr '17

##Resending again as the previous message didn't make it to the list. Hi, I am trying to setup the 3G Project and have bought a used nano3G BTS (S8 - Model 237A) . The problem i am facing is that the telnet port is not open. I have tried to reset the device using the pin-hole reset button as per documentation but it still doesn't reset or open up the ports and still tries to lookup operator's NTP and tries to establish a IPSEC tunnel. Any pointers on how i can reset this so that I can get it to work with the project? Thanks,

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Thoughts on a next generation MIB/VTY replacement
by Harald Welte 26 Apr '17

26 Apr '17

Hi All, Using zebra/quagga VTY code was a great idea back then and has served us nicely in all those years. I like the general style of the command-line based interface with its various nodes, the strict syntax checking, the tab completion and the interactive context-sensivive help. However, it feels a bit 20ieth-century-ish to have to manually write code to parse and to save the respective values. This is not a productive way to spend our development resources, and it is error prone. The "save" can be forgotten, resulting in non-saveable config parameters. The save can store values that the "parse" function will not be able to read again, etc. Furthermore, the VTY is inherently a human user interface, not intended for programmatic consumption. For programmatic access, we have developed the control interface. In reality though, only 1% of the parameters available in the VTY are exported via the control interface. And rather than adding all the missing bits and pieces with hand-crafted code to the control interface, we should have a generic way to define a new configuration value, and that value should then be automatically parse- and storable via VTY as well as a programmatic interface. The next "problem' is that the current telnet connections live within the process of the application. This means that a user can effectively "stall" the main application by performing I/O intensive operation on the VTY, or even on as many VTY/telnet sessions as he wants. There shouldn't be any need for this, at least not for something as mundane as performing configuration changes. Of course the VTY has different use cases such as runtime introspection of system state as well as logging. But still. Yet another concern is "VTY and telnet port proliferation". Particularly with the conversion from NITB to BSC+MSC+HLR, we are yet again getting more network elements with their own telnet ports. Remembering the port numbers is clumsy. It would be more convenient if a single command line interface could provide access to the configuration and the state of multiple different processes / network elements. Last, but not least, the current implementation is fixed to telnet, without any form of authentication, and without a path to migrate e.g. to something like SSL or SSH. I don't think it is a major concern (you can always SSH to the system and then telnet locally). So what I had in mind for quite some time (actually since netconf 1.2 about one year ago), is to have some kind of an external "VTY/MIB daemon" (or even separate daemons for each) which maintains a hierarchical database of configuration values. The MIB deamon simply offers an API (via client library) to GET or SET the individual values, or to NOTIFY an application about a changed value. This API is both used by the actual Osmocom programs to obtain their configuration (and obtain updates to it during runtime), as well as by the "VTY daemon" providing interactive shell access to it. Finally, other external applications could use the same interface/client library to do the same. A proxy to SNMP or REST interfaces can be imagined, for even more interfacing with the outside world. What I don't like about many existing MIBs I've used (as a sysadmin/user, not a developer) is their simple type system. You can often specify any random value to such a MIB, even one that is completely useless. A simple INT or STRING type is not sufficient, we really want the ability to have ENUM types, to have integers with ranges, etc. - just like we have in the VTY. Also, the MIBs I've used typically are nothing more than a hierarchical key-value store. They do not contain the information required for interactive, context-sensitive help needed for the "VTY" feel :( This is btw also the problem I have with OpenWRT's uci: It just has keys and values, with no way to constrain those values to something that's reasonable to the given program/context that is being configured, and there's no help or other information associated with those keys and values. So what I would like to see in this context, is some way to have a machine-parseable description of a "MIB/config item", together with syntax, ranges, enum values, help texts, etc (ideally in the C source code, possibly in comments?) which is used by some kind of MIB compiler to build up the hierarchical structure of the MIB and all of its keys as well as their permitted values and syntax reference. This information is then available to the VTY/telnet connections, irrespective of whether a given application [using those values] is running at all. Once an application starts, it can query for the configuration values it is interested in and populate its internal data structures from it. Ideally, one would even be able to generate a 'struct' from the MIB compiler, so that there is no need to explicitly call a "get" function on each single configuration value, but one simply gets a C-language 'struct' with all the values filled in by the client library. As stated above, there should be some way how he MIB can notify applications about changes to certain nodes in the MIB tree, so the application[s] can react to that. I don't have a clear picture yet how transaction logic (like changing multiple values and then committing them at once) would work, or whether applications should even be able to reject/revert a modification? In either case, I just wanted to share my thoughts on this. I know it sounds rather complex, but I think the investment in some kind of unified configuration database system would save us of a lot of boilerplate code and subtle bugs and inconsistencies. I've created https://osmocom.org/issues/1975 with above text to keep track of it, but I think at this point it's more of a mailing list discussion rather than something we can put into an issue. I guess the progress would rather be * first discuss it here and/or at OsmoDevCon * create something like a specification in the wiki * then follow-up with actual tickets on the work items All of this is brainstorming and vaporware, but I can't help to think of better ways of doing this. If somebody has experience with any existing systems and wants to share if and how they might fit, or what other ideas are useful to borrow: Please share! Regards, Harald -- - 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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openbsc 3G supoort with octasic phy
by Snehasish Kar 26 Apr '17

26 Apr '17

Hi I just wanted to know has anyone tried to use openbsc 3G with octasic 3G phy. BR Snehasish

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gerrit trouble "Change is New"
by Harald Welte 25 Apr '17

25 Apr '17

I want to merge the patchset from my libosmo-sccp sigtran branch to master, but gerrit doesn't allow me to. I've re-pushed the patch set already multiple times, the last time also doing a minor cosmetic change to the commit log message of the first patch in the series (https://gerrit.osmocom.org/#/c/2191/). gerrit refuses to merge even that very first patch in the series with "change is new". What should I do to get this merged? -- - 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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osmocom-bb moved to gerrit
by Neels Hofmeyr 24 Apr '17

24 Apr '17

The osmocom-bb git repository has now moved to gerrit. For patch submission to osmocom-bb, see https://osmocom.org/projects/cellular-infrastructure/wiki/Gerrit ~N

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FSM for lchan release handling -- release indication after SACCH deactivation timeout
by Holger Freyther 24 Apr '17

24 Apr '17

Good Evening, this is a bit of speculation but Keith showed me a trace with some network delay that makes a case for using FSM for the lchan itself. It seems the following can happen: * LU REJECT * Start Channel Release ** Send RR Release to the MS ** Deactivate SACCH ** Start Timer ... network transmission issues... at least 5s * SACCH deactivate timeout ** Start error release procedure.. ... * LATE RELEASE INDICATION arrives triggering other release procedure? So with a proper FSM we would have transitioned into the error path and would just ignore the RELEASE INDICATION. The question is if someone has budget to do a FSM transition here? I will try to build a simulated testcase for that. The other part that seems to happen (and I don't understand yet): * Allocating a lchan before it is fully freed?! * The BTS sending us RF Channel Releasse ACK twice cheers holger

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