Libgtp is included in the openggsn source tree. You'll have to install OpenGGSN first then recompile openbsc. Binaries will be generated automatically if libgtp is found. Osmo-sgsn, osmo-nitb and openggsn are separate binaries, you need to configure and start each of them separately. Regards, Pierre From: openbsc-bounces(a)lists.osmocom.org [mailto:openbsc-bounces@lists.osmocom.org] On Behalf Of Dai H. Tran Sent: Monday, September 23, 2013 2:56 PM To: openbsc(a)lists.osmocom.org Subject: how gprs is called in openbsc, where to find the libgtb? Hello everyone, I just recently learn about openbsc, and still in the phase of compiling and try to run the osmo-nitb app. 1st problem The problem is one of my teammate said the osmo-nitb will also started/call the osmo-sgsn program, but after examine the code, I still don't know how the osmo-sgsn is called from osmp-nitb, may be I was wrong, anyone can help me with this, how can I activate osmo-sgsn from osmo-nitb, with extra arguments? 2nd problem Another question, when I try to compile osmo-sgsn, the gtp lib is missing, as define in the makefile: if HAVE_LIBGTP bin_PROGRAMS = osmo-gbproxy osmo-sgsn else bin_PROGRAMS = osmo-gbproxy endif I don't know where to get this lib, so I modified by adding osmo-sgsn to the else clause as-well to have osmo-sgsn compiled. I still can run osmo-sgsn, but it show error about the gtp socket, i think the configuration is not correct, but not because of missing gtp lib, should this be a problem? Best regards, Dai