OsmoNITB LCR » History » Revision 12
Revision 11 (jolly, 02/19/2016 10:47 PM) → Revision 12/23 (Anonymous, 02/19/2016 10:47 PM)
== Howto OpenBSC with Asterisk and LCR == This is a short walk-through to setup OpenBSC and LCR with Asterisk. In the end we'll have a working setup to route calls from our BTS to the PTSN via VoIP. === Prerequisites === * OpenBSC equipment (BTS, E1 Card) * We're using a Siemens BS11 microBTS and a Cologne Chips E1 PCI card * The latest snapshot from the !LibOmsocore repository * git clone git://git.osmocom.org/libosmocore.git * The latest snapshot from the OpenBSC repository * git clone git://bs11-abis.gnumonks.org/openbsc.git * LCR from git repository * git-clone git://git.misdn.org/lcr.git/ git://git.misdn.org/git/lcr.git/ * A working kernel for your linux system * Support for your E1 card * mISDN's l1loop module (mISDN_l1loop.ko) * mISDN's DSP module (mISDN_dsp.ko) * You can obtain a working package for Debian at https://brezn.muc.ccc.de/~codec/openbsc/ * Supports cards from Cologne Chips and Junghanns * libgsm + header files (libgsm / libgsm-dev on Debian) * A working Asterisk setup * Original howto from https://brezn.muc.ccc.de/~codec/openbsc/howto.txt Alternatively you can download a snapshot of the source codes, which have been tested: http://www.linux-call-router.de/download/ (go to the latest lcr-* subdirectory) === Installation === First of all we assume the following: * Layout of your working directory: * libosmocore/ - checkout from !LibOmsocore rep * openbsc/ - checkout from OpenBSC repo * lcr/ - checkout from LCR repo * Installation directories: * /opt/openbsc for OpenBSC * /opt/lcr for LCR We need to compile and install !LibOsmocore and OpenBSC first: {{{ $ cd libosmocore/ $ autoreconf -i $ ./configure $ make $ sudo make install $ cd ../openbsc/openbsc/ $ autoreconf --install --force $ ./configure --prefix=/opt/openbsc $ make $ sudo make install }}} After that we're going for LCR: {{{ $ cd ../../lcr }}} First of all, we have to link the source directory of OpenBSC and !LibOsmocore in the lcr-Directory: {{{ $ ln -s ../libosmocore/ . $ ln -s ../openbsc/openbsc/ . }}} Now we can go on with compiling LCR. Unfortunately, due to changes in OpenBSC, we have to install a patch for LCR, until the programmer of LCR will include this patch in the current version. The patch is attached to this document. {{{ $ sh autogen.sh $ git-apply --verbose lcrOpenBSC.patch $ ./configure --prefix=/opt/lcr --with-asterisk --with-gsm-bs $ make $ sudo make install }}} and now we can copy the module into the modules' directory of Asterisk: {{{ $ sudo cp chan_lcr.so /usr/lib/asterisk/modules/ }}} === LCR configuration === '''1. gsm in options.conf'''[[BR]] The gsm option in /usr/local/lcr/options.conf needs to be activated. This can be simply done by adding 'gsm' as a single line to the file.[[BR]] Because it is a good idea to start Asterisk without root's privileges, we want to add these lines, too: {{{ socketuser asterisk socketgroup asterisk }}} '''2. GSM interface in interface.conf'''[[BR]] /usr/local/lcr/interface.conf holds an example for a GSM interface. Remove the comments and use the example as is. '''3. gsm.conf'''[[BR]] Enable the debugging option in /usr/local/lcr/gsm.conf. We also need 2 mISDN loopback interfaces. Create them with {{{ $ sudo modprobe mISDN_l1loop pri=1 nchannel=30 }}} You can check for the interfaces names with the misdn_info tool. All the default settings should work in a BS11 setup. You have just to give a value for 'config' and 'hlr', with the full path of your OpenBSC configuration file and HLR-!DataBase. '''4. Routing'''[[BR]] We route all our calls to to asterisk at the moment, as we only have outgoing connectivity via IAX/SIP in our setup. {{{ [main] interface=GSM : remote application=asterisk context=btsctrl }}} Calls will go to the context btsctrl in Asterisk. === Asterisk configuration === Our setup connects to an external Asterisk via SIP - as we don't have a second ISDN interface. chan_lcr for Asterisk comes with LCR (compiled with --with-asterisk). You only need to load the channel driver and maybe check the permissions of the LCR socket (/var/tmp/lcr.socket) - Asterisk on Debian uses a Set UID wrapper. To load chan_lcr automagically on startup add the following to your modules.conf: {{{ load => chan_lcr.so }}} We've created an exclusive context in extensions.conf for OpenBSC/LCR: {{{ [btsctrl] exten => _02X.,1,GotoIf($[${CALLERID(name)} != ""]?4) exten => _02X.,2,Set(CALLIDORIG=${CALLERID(num)}) exten => _02X.,3,Set(CALLERID(num)=02${CALLIDORIG}) exten => _02X.,4,Dial(LCR/GSM/${EXTEN:2},120) }}} === Running OpenBSC/LCR and Asterisk === Now we're ready to start with our GSM network. Boot up the BS11 and start LCR with {{{ $ sudo /opt/lcr/sbin/lcr start }}} You can also use 'fork' instead of 'start' to run LCR in daemon mode, but I'd rather go with fork AFTER you made you first successful call. (; Now start Asterisk. It should connect to LCR right after startup. You can check this by running {{{ $ sudo /opt/lcr/bin/lcradmin state }}} The UI should show {{{ Remote: asterisk }}} in the upper left part. Connect your phone and make your call(s). === Troubleshooting === ==== Phones unable to connect ==== On the first run I had some problems with connecting my phones as the registration just timed out. I fixed this by starting over with a fresh HLR. ==== The call routing fails (somewhere) ==== Most problems occured within Asterisk for me as neither IAX2 or SIP was working. This was just some kind of problem within the configuration. I can provide a working dialplan and SIP configuration if you need it. ==== Can't see the network ==== This was either related to the phone (a restart fixed it) or the BS11. After the first start I sometimes had to hardreset (as in reboot) the BS11.