OpenBSC March 2014

openbsc@lists.osmocom.org

27 participants
71 discussions

3 OpenBSC moderator request(s) waiting
by openbsc-bounces＠lists.osmocom.org 26 Mar '14

26 Mar '14

The OpenBSC(a)lists.osmocom.org mailing list has 3 request(s) waiting for your consideration at: https://lists.osmocom.org/mailman/admindb/openbsc Please attend to this at your earliest convenience. This notice of pending requests, if any, will be sent out daily. Pending posts: From: tlab.tester(a)googlemail.com on Mon Mar 3 13:01:09 2014 Subject: Unsubscribe Cause: Message may contain administrivia From: zielonka.markus(a)googlemail.com on Mon Mar 3 15:16:07 2014 Subject: unsubscribe Cause: Message may contain administrivia From: holger(a)freyther.de on Thu Mar 20 21:44:00 2014 Subject: DRAFT for a 30C3 report. Care to review? Cause: Message body is too big: 1033152 bytes with a limit of 400 KB

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3 OpenBSC moderator request(s) waiting
by openbsc-bounces＠lists.osmocom.org 25 Mar '14

25 Mar '14

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[libosmocore PATCH] src/socket: Added support for using socket unix
by Alvaro Neira 24 Mar '14

24 Mar '14

From: Álvaro Neira Ayuso <anayuso(a)sysmocom.de> Added some function for adding socket unix support. Signed-off-by: Alvaro Neira Ayuso <anayuso(a)sysmocom.de> --- include/osmocom/core/socket.h | 6 +++ src/socket.c | 92 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 98 insertions(+) diff --git a/include/osmocom/core/socket.h b/include/osmocom/core/socket.h index f15a03a..cb1b7a8 100644 --- a/include/osmocom/core/socket.h +++ b/include/osmocom/core/socket.h @@ -30,6 +30,12 @@ int osmo_sock_init_sa(struct sockaddr *ss, uint16_t type, int osmo_sockaddr_is_local(struct sockaddr *addr, unsigned int addrlen); +int osmo_sock_unix_init(uint16_t type, uint8_t proto, + const char *socket_path, unsigned int flags); + +int osmo_sock_unix_init_ofd(struct osmo_fd *ofd, uint16_t type, uint8_t proto, + const char *socket_path, unsigned int flags); + /*! @} */ #endif /* _OSMOCORE_SOCKET_H */ diff --git a/src/socket.c b/src/socket.c index 6ff00f0..6d4eddf 100644 --- a/src/socket.c +++ b/src/socket.c @@ -17,6 +17,7 @@ #include <sys/ioctl.h> #include <sys/socket.h> #include <sys/types.h> +#include <sys/un.h> #include <netinet/in.h> @@ -257,6 +258,97 @@ int osmo_sockaddr_is_local(struct sockaddr *addr, unsigned int addrlen) return 0; } +/*! \brief Initialize a socket unix(including bind/connect) + * \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM + * \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP + * \param[in] socket_path path to identify the socket + * \param[in] flags flags like \ref OSMO_SOCK_F_CONNECT + * + * This function creates a new socket unix, \a + * type and \a proto and optionally binds or connects it, depending on + * the value of \a flags parameter. + */ +int osmo_sock_unix_init(uint16_t type, uint8_t proto, + const char *socket_path, unsigned int flags) +{ + struct sockaddr_un addr; + int sfd, rc, on = 1; + + if ((flags & (OSMO_SOCK_F_BIND | OSMO_SOCK_F_CONNECT)) == + (OSMO_SOCK_F_BIND | OSMO_SOCK_F_CONNECT)) + return -EINVAL; + + memset(&addr, 0, sizeof(addr)); + addr.sun_family = AF_UNIX; + strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path)-1); + + if (type == SOCK_RAW) { + sfd = socket(AF_UNIX, SOCK_DGRAM, 0); + } else { + sfd = socket(AF_UNIX, type, proto); + } + + if (sfd < 0) + return -1; + + if (flags & OSMO_SOCK_F_NONBLOCK) { + if (ioctl(sfd, FIONBIO, (unsigned char *)&on) < 0) { + perror("cannot set this socket unblocking"); + close(sfd); + return -EINVAL; + } + } + if (flags & OSMO_SOCK_F_CONNECT) { + rc = connect(sfd, (struct sockaddr*)&addr, sizeof(addr)); + if (rc < 0) { + close(sfd); + return -1; + } + } else { + rc = bind(sfd, (struct sockaddr*)&addr, sizeof(addr)); + if (rc < 0) { + close(sfd); + return -1; + } + } + + if (flags & OSMO_SOCK_F_BIND) + listen(sfd, 10); + + return sfd; +} + +/*! \brief Initialize a socket unix and fill \ref osmo_fd + * \param[out] ofd file descriptor (will be filled in) + * \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM + * \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP + * \param[in] socket_path path to identify the socket + * \param[in] flags flags like \ref OSMO_SOCK_F_CONNECT + * + * This function creates (and optionall binds/connects) a socket using + * \ref osmo_sock_unix_init, but also fills the \a ofd structure. + */ +int osmo_sock_unix_init_ofd(struct osmo_fd *ofd, uint16_t type, uint8_t proto, + const char *socket_path, unsigned int flags) +{ + int sfd, rc; + + sfd = osmo_sock_unix_init(type, proto, socket_path, flags); + if (sfd < 0) + return sfd; + + ofd->fd = sfd; + ofd->when = BSC_FD_READ; + + rc = osmo_fd_register(ofd); + if (rc < 0) { + close(sfd); + return rc; + } + + return sfd; +} + #endif /* HAVE_SYS_SOCKET_H */ /*! @} */

3 3

[PATCH 1/2] ipa/test: Add test program for IPA message reception
by Jacob Erlbeck 24 Mar '14

24 Mar '14

This patch adds tests for ipa_msg_recv(), where messages are sent either complete or partitioned. Sponsored-by: On-Waves ehf --- tests/Makefile.am | 11 +- tests/ipa_recv/ipa_recv_test.c | 247 +++++++++++++++++++++++++++++++++++++++ tests/ipa_recv/ipa_recv_test.ok | 12 ++ tests/testsuite.at | 7 ++ 4 files changed, 275 insertions(+), 2 deletions(-) create mode 100644 tests/ipa_recv/ipa_recv_test.c create mode 100644 tests/ipa_recv/ipa_recv_test.ok diff --git a/tests/Makefile.am b/tests/Makefile.am index af8a9cf..c8b8996 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -5,7 +5,8 @@ AM_LDFLAGS = $(COVERAGE_LDFLAGS) check_PROGRAMS = e1inp_ipa_bsc_test \ e1inp_ipa_bts_test \ ipa_proxy_test \ - subchan_demux/subchan_demux_test + subchan_demux/subchan_demux_test \ + ipa_recv/ipa_recv_test e1inp_ipa_bsc_test_SOURCES = e1inp_ipa_bsc_test.c e1inp_ipa_bsc_test_LDADD = $(top_builddir)/src/libosmoabis.la \ @@ -25,6 +26,11 @@ subchan_demux_subchan_demux_test_LDADD = $(top_builddir)/src/libosmoabis.la \ $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) \ $(LIBOSMOVTY_LIBS) +ipa_recv_ipa_recv_test_SOURCES = ipa_recv/ipa_recv_test.c +ipa_recv_ipa_recv_test_LDADD = $(top_builddir)/src/libosmoabis.la \ + $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) \ + $(LIBOSMOVTY_LIBS) + # boilerplate for the tests # The `:;' works around a Bash 3.2 bug when the output is not writeable. $(srcdir)/package.m4: $(top_srcdir)/configure.ac @@ -45,7 +51,8 @@ $(srcdir)/package.m4: $(top_srcdir)/configure.ac } >'$(srcdir)/package.m4' EXTRA_DIST = testsuite.at $(srcdir)/package.m4 $(TESTSUITE) \ - subchan_demux/subchan_demux_test.ok + subchan_demux/subchan_demux_test.ok \ + ipa_recv/ipa_recv_test.ok TESTSUITE = $(srcdir)/testsuite diff --git a/tests/ipa_recv/ipa_recv_test.c b/tests/ipa_recv/ipa_recv_test.c new file mode 100644 index 0000000..7b26259 --- /dev/null +++ b/tests/ipa_recv/ipa_recv_test.c @@ -0,0 +1,247 @@ +/* IPA receive test */ + +/* (C) 2014 by On-Waves + * + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +#include <osmocom/abis/e1_input.h> + +#include <osmocom/abis/ipa.h> +#include <osmocom/core/utils.h> +#include <osmocom/core/msgb.h> +#include <osmocom/core/logging.h> +#include <osmocom/core/application.h> + +#include <stdio.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> +#include <err.h> + +#if 0 +/* IPA protocol ip.access, type: RSL */ +static const unsigned char gsm_ipa_chanrqd[13] = { + 0x00, 0x0a, 0x00, 0x0c, 0x13, 0x01, 0x88, 0x13, + 0x4e, 0x42, 0x93, 0x11, 0x00 +}; + +/* IPA protocol ip.access, type: RSL */ +static const unsigned char gsm_ipa_chanactivack[10] = { + 0x00, 0x07, 0x00, 0x08, 0x22, 0x01, 0x12, 0x08, + 0x43, 0x81 +}; + +/* IPA protocol ip.access, type: RSL */ +static const unsigned char gsm_ipa_data[40] = { + 0x00, 0x25, 0x00, 0x08, 0x28, 0x01, 0x12, 0x1b, + 0x00, 0x19, 0x03, 0x3b, 0x3b, 0x00, 0x04, 0x00, + 0x0a, 0x38, 0x00, 0x0b, 0x00, 0x12, 0x06, 0x15, + 0x35, 0x40, 0x7e, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 +}; +#endif + +static const char *ipa_test_messages[] = { + "Hello IPA", + "A longer test message. ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz", + "Hello again IPA", + "", + "Next is empty", + NULL, + "Bye", + "Bye", +}; + +static void append_ipa_message(struct msgb *msg, int proto, const char *text) +{ + int len = 0; + unsigned char *l2; + + if (text) + len = strlen(text) + 1; + + msgb_put_u16(msg, len); + msgb_put_u8(msg, proto); + + l2 = msgb_put(msg, len); + if (text) + strcpy((char *)l2, text); +} + +static int receive_messages(int fd) +{ + struct msgb *msg; + char dummy; + int rc; + while (1) { + if (recv(fd, &dummy, 1, MSG_PEEK) < 1) { + rc = -EAGAIN; + break; + } + msg = NULL; + rc = ipa_msg_recv(fd, &msg); + if (rc == -1) + rc = -errno; + fprintf(stderr, + "ipa_msg_recv: %d, msg %s NULL\n", + rc, msg ? "!=" : "=="); + if (rc == -EAGAIN) + printf( "got msg %s NULL, " + "returned: %s\n", + msg ? "!=" : "==", + rc == 0 ? "EOF" : + rc > 0 ? "OK" : + strerror(-rc)); + if (rc == 0) + return 0; + if (rc == -EAGAIN) + break; + if (rc < 0) { + printf("ipa_msg_recv failed with: %s\n", strerror(-rc)); + return rc; + } + printf("got IPA message, size=%d, proto=%d, text=\"%s\"\n", + rc, msg->data[2], msg->l2h); + msgb_free(msg); + }; + + return rc; +} + +static int slurp_data(int fd) { + int rc; + char buf[256]; + int count = 0; + + do { + rc = recv(fd, buf, sizeof(buf), 0); + if (rc <= 0) + break; + + count += rc; + } while (1); + + return count; +}; + +static void test_complete_recv(void) +{ + int sv[2]; + struct msgb *msg_out = msgb_alloc(4096, "msg_out"); + int rc, i; + + printf("Testing IPA recv with complete messages.\n"); + + if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1) + err(1, "socketpair"); + + fcntl(sv[0], F_SETFL, O_NONBLOCK); + + for (i=0; i < ARRAY_SIZE(ipa_test_messages); i++) + append_ipa_message(msg_out, 200, ipa_test_messages[i]); + + while (msg_out->len > 0) { + rc = write(sv[1], msg_out->data, msg_out->len); + if (rc == -1) + err(1, "write"); + msgb_pull(msg_out, rc); + } + + for (i=0; i < ARRAY_SIZE(ipa_test_messages); i++) { + rc = receive_messages(sv[0]); + if (rc == 0) + break; + + if (rc < 0 && rc != -EAGAIN) + break; + } + + rc = slurp_data(sv[0]); + printf("done: unread %d, unsent %d\n", rc, msg_out->len); + + close(sv[1]); + close(sv[0]); + + msgb_free(msg_out); +} + + +static void test_partial_recv(void) +{ + int sv[2]; + struct msgb *msg_out = msgb_alloc(4096, "msg_out"); + int rc, i; + + printf("Testing IPA recv with partitioned messages.\n"); + + if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1) + err(1, "socketpair"); + + fcntl(sv[0], F_SETFL, O_NONBLOCK); + + for (i=0; i < ARRAY_SIZE(ipa_test_messages); i++) + append_ipa_message(msg_out, 200, ipa_test_messages[i]); + + while (msg_out->len > 0) { + int len = 5; + if (len > msg_out->len) + len = msg_out->len; + if (write(sv[1], msg_out->data, len) == -1) + err(1, "write"); + msgb_pull(msg_out, len); + + if (msg_out->len == 0) + shutdown(sv[1], SHUT_WR); + + rc = receive_messages(sv[0]); + + if (rc == 0) + break; + + if (rc < 0 && rc != -EAGAIN) + break; + } + rc = slurp_data(sv[0]); + printf("done: unread %d, unsent %d\n", rc, msg_out->len); + + close(sv[1]); + close(sv[0]); + + msgb_free(msg_out); +} + +static struct log_info info = {}; + +int main(int argc, char **argv) +{ + osmo_init_logging(&info); + log_set_all_filter(osmo_stderr_target, 1); + log_set_log_level(osmo_stderr_target, LOGL_INFO); + + printf("Testing the IPA layer.\n"); + + /* run the tests */ + test_complete_recv(); + test_partial_recv(); + + printf("No crashes.\n"); + return 0; +} diff --git a/tests/ipa_recv/ipa_recv_test.ok b/tests/ipa_recv/ipa_recv_test.ok new file mode 100644 index 0000000..4144d47 --- /dev/null +++ b/tests/ipa_recv/ipa_recv_test.ok @@ -0,0 +1,12 @@ +Testing the IPA layer. +Testing IPA recv with complete messages. +got IPA message, size=10, proto=200, text="Hello IPA" +got IPA message, size=86, proto=200, text="A longer test message. ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz" +got IPA message, size=16, proto=200, text="Hello again IPA" +got IPA message, size=1, proto=200, text="" +got IPA message, size=14, proto=200, text="Next is empty" +done: unread 14, unsent 0 +Testing IPA recv with partitioned messages. +ipa_msg_recv failed with: Input/output error +done: unread 0, unsent 154 +No crashes. diff --git a/tests/testsuite.at b/tests/testsuite.at index 04193c5..ff550b0 100644 --- a/tests/testsuite.at +++ b/tests/testsuite.at @@ -11,8 +11,15 @@ AT_BANNER([Regression tests.]) # AT_CHECK([$abs_top_builddir/tests/NAME/NAME_test], [], [expout]) # AT_CLEANUP +AT_SETUP([ipa_recv]) +AT_KEYWORDS([ipa_recv]) +cat $abs_srcdir/ipa_recv/ipa_recv_test.ok > expout +AT_CHECK([$abs_top_builddir/tests/ipa_recv/ipa_recv_test], [], [expout],[ignore]) +AT_CLEANUP + AT_SETUP([subchan_demux]) AT_KEYWORDS([subchan_demux]) cat $abs_srcdir/subchan_demux/subchan_demux_test.ok > expout AT_CHECK([$abs_top_builddir/tests/subchan_demux/subchan_demux_test], [], [expout]) AT_CLEANUP + -- 1.7.9.5

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3 OpenBSC moderator request(s) waiting
by openbsc-bounces＠lists.osmocom.org 24 Mar '14

24 Mar '14

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[PATCH openggsn v2] gtp: fix endianness in teid field of GTPv0 header
by pablo＠gnumonks.org 23 Mar '14

23 Mar '14

From: Pablo Neira Ayuso <pablo(a)gnumonks.org> This field needs to be in network byte order as well. This problem may manifest if you use ggsn and sgsn with different endianness. It also show up when using the gtp kernel mode since the downlink packets are using network byte order in the 64-bits teid field, which osmo-sgsn / libgtp doesn't expect. --- v2: Add function to encapsulate the code to access and to build the teid as Holger suggested. Tested with and without gtp kernel support. If no objections, I'll push this to master. gtp/gtp.c | 34 +++++++++++++--------------------- gtp/pdp.c | 6 ++++++ gtp/pdp.h | 2 ++ 3 files changed, 21 insertions(+), 21 deletions(-) diff --git a/gtp/gtp.c b/gtp/gtp.c index 3cc0c0b..6185634 100644 --- a/gtp/gtp.c +++ b/gtp/gtp.c @@ -250,7 +250,7 @@ static uint64_t get_tid(void *pack) union gtp_packet *packet = (union gtp_packet *)pack; if ((packet->flags & 0xe0) == 0x00) { /* Version 0 */ - return packet->gtp0.h.tid; + return be64toh(packet->gtp0.h.tid); } return 0; } @@ -425,10 +425,10 @@ int gtp_req(struct gsn_t *gsn, int version, struct pdp_t *pdp, addr.sin_port = htons(GTP0_PORT); packet->gtp0.h.length = hton16(len - GTP0_HEADER_SIZE); packet->gtp0.h.seq = hton16(gsn->seq_next); - if (pdp) + if (pdp) { packet->gtp0.h.tid = - (pdp->imsi & 0x0fffffffffffffffull) + - ((uint64_t) pdp->nsapi << 60); + htobe64(pdp_gettid(pdp->imsi, pdp->nsapi)); + } if (pdp && ((packet->gtp0.h.type == GTP_GPDU) || (packet->gtp0.h.type == GTP_ERROR))) packet->gtp0.h.flow = hton16(pdp->flru); @@ -581,7 +581,7 @@ int gtp_resp(int version, struct gsn_t *gsn, struct pdp_t *pdp, if ((packet->flags & 0xe0) == 0x00) { /* Version 0 */ packet->gtp0.h.length = hton16(len - GTP0_HEADER_SIZE); packet->gtp0.h.seq = hton16(seq); - packet->gtp0.h.tid = tid; + packet->gtp0.h.tid = htobe64(tid); if (pdp && ((packet->gtp0.h.type == GTP_GPDU) || (packet->gtp0.h.type == GTP_ERROR))) packet->gtp0.h.flow = hton16(pdp->flru); @@ -1329,12 +1329,9 @@ int gtp_create_pdp_ind(struct gsn_t *gsn, int version, memset(pdp, 0, sizeof(struct pdp_t)); if (version == 0) { - pdp->imsi = - ((union gtp_packet *)pack)->gtp0. - h.tid & 0x0fffffffffffffffull; - pdp->nsapi = - (((union gtp_packet *)pack)->gtp0. - h.tid & 0xf000000000000000ull) >> 60; + uint64_t tid = be64toh(((union gtp_packet *)pack)->gtp0.h.tid); + + pdp_set_imsi_nsapi(pdp, tid); } pdp->seq = seq; @@ -2051,12 +2048,9 @@ int gtp_update_pdp_ind(struct gsn_t *gsn, int version, /* For GTP1 we must use imsi and nsapi if imsi is present. Otherwise */ /* we have to use the tunnel endpoint identifier */ if (version == 0) { - imsi = - ((union gtp_packet *)pack)->gtp0. - h.tid & 0x0fffffffffffffffull; - nsapi = - (((union gtp_packet *)pack)->gtp0. - h.tid & 0xf000000000000000ull) >> 60; + uint64_t tid = be64toh(((union gtp_packet *)pack)->gtp0.h.tid); + + pdp_set_imsi_nsapi(pdp, tid); /* Find the context in question */ if (pdp_getimsi(&pdp, imsi, nsapi)) { @@ -2645,7 +2639,7 @@ int gtp_error_ind_conf(struct gsn_t *gsn, int version, struct pdp_t *pdp; /* Find the context in question */ - if (pdp_tidget(&pdp, ((union gtp_packet *)pack)->gtp0.h.tid)) { + if (pdp_tidget(&pdp, be64toh(((union gtp_packet *)pack)->gtp0.h.tid))) { gsn->err_unknownpdp++; gtp_errpack(LOG_ERR, __FILE__, __LINE__, peer, pack, len, "Unknown PDP context"); @@ -3196,9 +3190,7 @@ int gtp_data_req(struct gsn_t *gsn, struct pdp_t *pdp, void *pack, unsigned len) packet.gtp0.h.length = hton16(len); packet.gtp0.h.seq = hton16(pdp->gtpsntx++); packet.gtp0.h.flow = hton16(pdp->flru); - packet.gtp0.h.tid = - (pdp->imsi & 0x0fffffffffffffffull) + - ((uint64_t) pdp->nsapi << 60); + packet.gtp0.h.tid = htobe64(pdp_gettid(pdp->imsi, pdp->nsapi)); if (len > sizeof(union gtp_packet) - sizeof(struct gtp0_header)) { gsn->err_memcpy++; diff --git a/gtp/pdp.c b/gtp/pdp.c index dfb91ea..dc21bf8 100644 --- a/gtp/pdp.c +++ b/gtp/pdp.c @@ -370,6 +370,12 @@ uint64_t pdp_gettid(uint64_t imsi, uint8_t nsapi) return (imsi & 0x0fffffffffffffffull) + ((uint64_t) nsapi << 60); } +void pdp_set_imsi_nsapi(struct pdp_t *pdp, uint64_t teid) +{ + pdp->imsi = teid & 0x0fffffffffffffffull; + pdp->nsapi = (teid & 0xf000000000000000ull) >> 60; +} + int ulcpy(void *dst, void *src, size_t size) { if (((struct ul255_t *)src)->l <= size) { diff --git a/gtp/pdp.h b/gtp/pdp.h index b069a6f..6e30467 100644 --- a/gtp/pdp.h +++ b/gtp/pdp.h @@ -242,6 +242,8 @@ int pdp_tidset(struct pdp_t *pdp, uint64_t tid); int pdp_tiddel(struct pdp_t *pdp); int pdp_tidget(struct pdp_t **pdp, uint64_t tid); +void pdp_set_imsi_nsapi(struct pdp_t *pdp, uint64_t teid); + /* int pdp_iphash(void* ipif, struct ul66_t *eua); int pdp_ipset(struct pdp_t *pdp, void* ipif, struct ul66_t *eua); -- 1.7.10.4

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3 OpenBSC moderator request(s) waiting
by openbsc-bounces＠lists.osmocom.org 23 Mar '14

23 Mar '14

1 0

3 OpenBSC moderator request(s) waiting
by openbsc-bounces＠lists.osmocom.org 22 Mar '14

22 Mar '14

1 0

Re: Location Area Updates missed during calls
by Luca Valtulina 21 Mar '14

21 Mar '14

Indeed the problem has been already solved in the master branch by adding the "expire_timer_stopped" attributes to a gsm_subscriber_connection and then checking it upon expiration of the expire_lu timer for an active subscriber. Sorry to have re-raised the issue. luca

1 0

Fwd: Location Area Updates missed during calls
by Luca Valtulina 21 Mar '14

21 Mar '14

Hi holger, What is a network-initiated Location Area Update? Do you talk about > the NITB/BSC advertizing periodic updating? With Location Area Update I refer to the Location Update procedure (I made confusion with the UMTS protocol where "Area" has been added in-between). I also have to apologies about that "network-initiated" which is clearly wrong since is the MS which triggers the procedure by sending a location update request signal (what I meant is that the T3212 timer is provided to the MS by the network). > > I find this behavior annoying mostly in scenarios where the T3212 (LAU > > timer) has been setup to a low value. > > About which software and which versions do you talk? mmm, I didn't quite get your question here. After performing further testing I can wrap up the issue as following: when a MS ends a call after the expire_lu time, it will be considered expired in the HLR (because two LUs were missed by the network). When the (now expired) MS initiates a call, the CM service will be rejected by the network with cause 4 (GSM48_REJECT_IMSI_UNKNOWN_IN_VLR). Needless to say that when a different MS tries to establish a call towards the (now expired) MS, this call will also be dropped because the destination MS is (seen as) detached from the BTS. Now I think that if we want to have a more precise location management, a lower expiration interval is a possibilities: this can be achieved by either lowering down the t3212 value and keeping the same expire_lu calculation (2 times t3212 + 1 minute) or by modifying the expire_lu calculation. In this scenarios the issue described above is more likely to happen (higher probability of having ~10 minutes calls than > 60 minutes). So indeed, is this behavior expected by the GSM protocol? I think that update the HLR whenever an MS exits a call will be a costless procedure which can avoid the annoyance of having the first next call dropped if this happens prior to the triggering of the LU by the interested MS. luca

1 0

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OpenBSC March 2014