Problem with running OsmoSGSN and OsmoNITB

Hi, I have a problem with running 2 software programs OpenBSC (osmo-nitb and osmo-sgsn). When I run osmo-nitb: ROOT: /media/obsc_gprs/gitrep/openbsc/openbsc/src/osmo-nitb# ./osmo-nitb There is no such command. Error occurred during reading below line: logging level mi notice <0005> bsc_init.c:496 Failed to parse the config file: 'openbsc.cfg' ______________________________________________________________ However, when I run osmo-sgsn: ROOT: /media/obsc_gprs/gitrep/openbsc/openbsc/src/gprs# ./osmo-sgsn <0011> gprs_ns.c:171 NSVCI=65534 Creating NS-VC <0010> sgsn_libgtp.c:571 Failed to create GTP: -1 <0010> sgsn_main.c:348 Cannot bind/listen on GTP socket Anybody help?