Merge branch 'bssgp_fc'
diff --git a/include/osmocom/gprs/gprs_bssgp.h b/include/osmocom/gprs/gprs_bssgp.h
index 8ca42bf..eb4e721 100644
--- a/include/osmocom/gprs/gprs_bssgp.h
+++ b/include/osmocom/gprs/gprs_bssgp.h
@@ -2,6 +2,8 @@
#define _GPRS_BSSGP_H
#include <stdint.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/linuxlist.h>
#include <osmocom/gsm/gsm48.h>
#include <osmocom/gsm/prim.h>
@@ -54,6 +56,25 @@
/* gprs_bssgp.c */
+/*! \brief BSSGP flow control (SGSN side) According to Section 8.2 */
+struct bssgp_flow_control {
+ uint32_t bucket_size_max; /*!< maximum size of the bucket (octets) */
+ uint32_t bucket_leak_rate; /*!< leak rate of the bucket (octets/sec) */
+
+ uint32_t bucket_counter; /*!< number of tokens in the bucket */
+ struct timeval time_last_pdu; /*!< timestamp of last PDU sent */
+
+ /* the built-in queue */
+ uint32_t max_queue_depth; /*!< how many packets to queue (mgs) */
+ uint32_t queue_depth; /*!< current length of queue (msgs) */
+ struct llist_head queue; /*!< linked list of msgb's */
+ struct osmo_timer_list timer; /*!< timer-based dequeueing */
+
+ /*! callback to be called at output of flow control */
+ int (*out_cb)(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv);
+};
+
#define BVC_S_BLOCKED 0x0001
/* The per-BTS context that we keep on the SGSN side of the BSSGP link */
@@ -72,6 +93,12 @@
struct rate_ctr_group *ctrg;
+ struct bssgp_flow_control *fc;
+ /*! default maximum size of per-MS bucket in octets */
+ uint32_t bmax_default_ms;
+ /*! default bucket leak rate of per-MS bucket in octests/s */
+ uint32_t r_default_ms;
+
/* we might want to add this as a shortcut later, avoiding the NSVC
* lookup for every packet, similar to a routing cache */
//struct gprs_nsvc *nsvc;
@@ -109,6 +136,7 @@
struct bssgp_dl_ud_par {
uint32_t *tlli;
char *imsi;
+ struct bssgp_flow_control *fc;
uint16_t drx_parms;
/* FIXME: priority */
struct bssgp_lv ms_ra_cap;
@@ -157,6 +185,23 @@
int bssgp_tx_paging(uint16_t nsei, uint16_t ns_bvci,
struct bssgp_paging_info *pinfo);
+void bssgp_fc_init(struct bssgp_flow_control *fc,
+ uint32_t bucket_size_max, uint32_t bucket_leak_rate,
+ uint32_t max_queue_depth,
+ int (*out_cb)(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv));
+
+/* input function of the flow control implementation, called first
+ * for the MM flow control, and then as the MM flow control output
+ * callback in order to perform BVC flow control */
+int bssgp_fc_in(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv);
+
+/* Initialize the Flow Control parameters for a new MS according to
+ * default values for the BVC specified by BVCI and NSEI */
+int bssgp_fc_ms_init(struct bssgp_flow_control *fc_ms, uint16_t bvci,
+ uint16_t nsei, uint32_t max_queue_depth);
+
/* gprs_bssgp_vty.c */
int bssgp_vty_init(void);
void bssgp_set_log_ss(int ss);
diff --git a/src/gb/gprs_bssgp.c b/src/gb/gprs_bssgp.c
index 142e69b..e41c7ef 100644
--- a/src/gb/gprs_bssgp.c
+++ b/src/gb/gprs_bssgp.c
@@ -57,6 +57,9 @@
LLIST_HEAD(bssgp_bvc_ctxts);
+static int _bssgp_tx_dl_ud(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv);
+
/* Find a BTS Context based on parsed RA ID and Cell ID */
struct bssgp_bvc_ctx *btsctx_by_raid_cid(const struct gprs_ra_id *raid, uint16_t cid)
{
@@ -93,6 +96,9 @@
ctx->nsei = nsei;
/* FIXME: BVCI is not unique, only BVCI+NSEI ?!? */
ctx->ctrg = rate_ctr_group_alloc(ctx, &bssgp_ctrg_desc, bvci);
+ ctx->fc = talloc_zero(ctx, struct bssgp_flow_control);
+ /* cofigure for 2Mbit, 30 packets in queue */
+ bssgp_fc_init(ctx->fc, 100000, 2*1024*1024/8, 30, &_bssgp_tx_dl_ud);
llist_add(&ctx->list, &bssgp_bvc_ctxts);
@@ -510,6 +516,229 @@
return bssgp_prim_cb(&nmp.oph, NULL);
}
+/* One element (msgb) in a BSSGP Flow Control queue */
+struct bssgp_fc_queue_element {
+ /* linked list of queue elements */
+ struct llist_head list;
+ /* The message that we have enqueued */
+ struct msgb *msg;
+ /* Length of the LLC PDU part of the contained message */
+ uint32_t llc_pdu_len;
+ /* private pointer passed to the flow control out_cb function */
+ void *priv;
+};
+
+static int fc_queue_timer_cfg(struct bssgp_flow_control *fc);
+static int bssgp_fc_needs_queueing(struct bssgp_flow_control *fc, uint32_t pdu_len);
+
+static void fc_timer_cb(void *data)
+{
+ struct bssgp_flow_control *fc = data;
+ struct bssgp_fc_queue_element *fcqe;
+ struct timeval time_now;
+
+ /* if the queue is empty, we return without sending something
+ * and without re-starting the timer */
+ if (llist_empty(&fc->queue))
+ return;
+
+ /* get the first entry from the queue */
+ fcqe = llist_entry(fc->queue.next, struct bssgp_fc_queue_element,
+ list);
+
+ if (bssgp_fc_needs_queueing(fc, fcqe->llc_pdu_len)) {
+ LOGP(DBSSGP, LOGL_NOTICE, "BSSGP-FC: fc_timer_cb() but still "
+ "not able to send PDU of %u bytes\n", fcqe->llc_pdu_len);
+ /* make sure we re-start the timer */
+ fc_queue_timer_cfg(fc);
+ return;
+ }
+
+ /* remove from the queue */
+ llist_del(&fcqe->list);
+
+ fc->queue_depth--;
+
+ /* record the time we transmitted this PDU */
+ gettimeofday(&time_now, NULL);
+ fc->time_last_pdu = time_now;
+
+ /* call the output callback for this FC instance */
+ fc->out_cb(fcqe->priv, fcqe->msg, fcqe->llc_pdu_len, NULL);
+
+ /* we expect that out_cb will in the end free the msgb once
+ * it is no longer needed */
+
+ /* but we have to free the queue element ourselves */
+ talloc_free(fcqe);
+
+ /* re-configure the timer for the next PDU */
+ fc_queue_timer_cfg(fc);
+}
+
+/* configure/schedule the flow control timer to expire once the bucket
+ * will have leaked a sufficient number of bytes to transmit the next
+ * PDU in the queue */
+static int fc_queue_timer_cfg(struct bssgp_flow_control *fc)
+{
+ struct bssgp_fc_queue_element *fcqe;
+ uint32_t msecs;
+
+ if (llist_empty(&fc->queue))
+ return 0;
+
+ fcqe = llist_entry(&fc->queue.next, struct bssgp_fc_queue_element,
+ list);
+
+ /* Calculate the point in time at which we will have leaked
+ * a sufficient number of bytes from the bucket to transmit
+ * the first PDU in the queue */
+ msecs = (fcqe->llc_pdu_len * 1000) / fc->bucket_leak_rate;
+ /* FIXME: add that time to fc->time_last_pdu and subtract it from
+ * current time */
+
+ fc->timer.data = fc;
+ fc->timer.cb = &fc_timer_cb;
+ osmo_timer_schedule(&fc->timer, msecs / 1000, (msecs % 1000) * 1000);
+
+ return 0;
+}
+
+/* Enqueue a PDU in the flow control queue for delayed transmission */
+static int fc_enqueue(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv)
+{
+ struct bssgp_fc_queue_element *fcqe;
+
+ if (fc->queue_depth >= fc->max_queue_depth)
+ return -ENOSPC;
+
+ fcqe = talloc_zero(fc, struct bssgp_fc_queue_element);
+ if (!fcqe)
+ return -ENOMEM;
+ fcqe->msg = msg;
+ fcqe->llc_pdu_len = llc_pdu_len;
+ fcqe->priv = priv;
+
+ llist_add_tail(&fcqe->list, &fc->queue);
+
+ fc->queue_depth++;
+
+ /* re-configure the timer for dequeueing the pdu */
+ fc_queue_timer_cfg(fc);
+
+ return 0;
+}
+
+/* According to Section 8.2 */
+static int bssgp_fc_needs_queueing(struct bssgp_flow_control *fc, uint32_t pdu_len)
+{
+ struct timeval time_now, time_diff;
+ int64_t bucket_predicted;
+ uint32_t csecs_elapsed, leaked;
+
+ /* B' = B + L(p) - (Tc - Tp)*R */
+
+ /* compute number of centi-seconds that have elapsed since transmitting
+ * the last PDU (Tc - Tp) */
+ gettimeofday(&time_now, NULL);
+ timersub(&time_now, &fc->time_last_pdu, &time_diff);
+ csecs_elapsed = time_diff.tv_sec*100 + time_diff.tv_usec/10000;
+
+ /* compute number of bytes that have leaked in the elapsed number
+ * of centi-seconds */
+ leaked = csecs_elapsed * (fc->bucket_leak_rate / 100);
+ /* add the current PDU length to the last bucket level */
+ bucket_predicted = fc->bucket_counter + pdu_len;
+ /* ... and subtract the number of leaked bytes */
+ bucket_predicted -= leaked;
+
+ if (bucket_predicted < pdu_len) {
+ /* this is just to make sure the bucket doesn't underflow */
+ bucket_predicted = pdu_len;
+ goto pass;
+ }
+
+ if (bucket_predicted <= fc->bucket_size_max) {
+ /* the bucket is not full yet, we can pass the packet */
+ fc->bucket_counter = bucket_predicted;
+ goto pass;
+ }
+
+ /* bucket is full, PDU needs to be delayed */
+ return 1;
+
+pass:
+ /* if we reach here, the PDU can pass */
+ return 0;
+}
+
+/* output callback for BVC flow control */
+static int _bssgp_tx_dl_ud(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv)
+{
+ return gprs_ns_sendmsg(bssgp_nsi, msg);
+}
+
+/* input function of the flow control implementation, called first
+ * for the MM flow control, and then as the MM flow control output
+ * callback in order to perform BVC flow control */
+int bssgp_fc_in(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv)
+{
+ struct timeval time_now;
+
+ if (llc_pdu_len > fc->bucket_size_max) {
+ LOGP(DBSSGP, LOGL_NOTICE, "Single PDU (size=%u) is larger "
+ "than maximum bucket size (%u)!\n", llc_pdu_len,
+ fc->bucket_size_max);
+ return -EIO;
+ }
+
+ if (bssgp_fc_needs_queueing(fc, llc_pdu_len)) {
+ return fc_enqueue(fc, msg, llc_pdu_len, priv);
+ } else {
+ /* record the time we transmitted this PDU */
+ gettimeofday(&time_now, NULL);
+ fc->time_last_pdu = time_now;
+ return fc->out_cb(priv, msg, llc_pdu_len, NULL);
+ }
+}
+
+
+/* Initialize the Flow Control structure */
+void bssgp_fc_init(struct bssgp_flow_control *fc,
+ uint32_t bucket_size_max, uint32_t bucket_leak_rate,
+ uint32_t max_queue_depth,
+ int (*out_cb)(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv))
+{
+ fc->out_cb = out_cb;
+ fc->bucket_size_max = bucket_size_max;
+ fc->bucket_leak_rate = bucket_leak_rate;
+ fc->max_queue_depth = max_queue_depth;
+ INIT_LLIST_HEAD(&fc->queue);
+ gettimeofday(&fc->time_last_pdu, NULL);
+}
+
+/* Initialize the Flow Control parameters for a new MS according to
+ * default values for the BVC specified by BVCI and NSEI */
+int bssgp_fc_ms_init(struct bssgp_flow_control *fc_ms, uint16_t bvci,
+ uint16_t nsei, uint32_t max_queue_depth)
+{
+ struct bssgp_bvc_ctx *ctx;
+
+ ctx = btsctx_by_bvci_nsei(bvci, nsei);
+ if (!ctx)
+ return -ENODEV;
+
+ /* output call-back of per-MS FC is per-CTX FC */
+ bssgp_fc_init(fc_ms, ctx->bmax_default_ms, ctx->r_default_ms,
+ max_queue_depth, bssgp_fc_in);
+
+ return 0;
+}
+
static int bssgp_rx_fc_bvc(struct msgb *msg, struct tlv_parsed *tp,
struct bssgp_bvc_ctx *bctx)
{
@@ -527,7 +756,18 @@
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
}
- /* FIXME: actually implement flow control */
+ /* 11.3.5 Bucket Size in 100 octets unit */
+ bctx->fc->bucket_size_max = 100 *
+ ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_BVC_BUCKET_SIZE));
+ /* 11.3.4 Bucket Leak Rate in 100 bits/sec unit */
+ bctx->fc->bucket_leak_rate = 100 *
+ ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_BUCKET_LEAK_RATE)) / 8;
+ /* 11.3.2 in octets */
+ bctx->bmax_default_ms =
+ ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_BMAX_DEFAULT_MS));
+ /* 11.3.32 Bucket Leak rate in 100bits/sec unit */
+ bctx->r_default_ms = 100 *
+ ntohs(*(uint16_t *)TLVP_VAL(tp, BSSGP_IE_R_DEFAULT_MS)) / 8;
/* Send FLOW_CONTROL_BVC_ACK */
return bssgp_tx_fc_bvc_ack(msgb_nsei(msg), *TLVP_VAL(tp, BSSGP_IE_TAG),
@@ -777,8 +1017,9 @@
bctx = btsctx_by_bvci_nsei(bvci, nsei);
if (!bctx) {
- /* FIXME: don't simply create missing context, but reject message */
- bctx = btsctx_alloc(bvci, nsei);
+ LOGP(DBSSGP, LOGL_ERROR, "Cannot send DL-UD to unknown BVCI %u\n",
+ bvci);
+ return -ENODEV;
}
if (msg->len > TVLV_MAX_ONEBYTE)
@@ -841,7 +1082,12 @@
/* Identifiers down: BVCI, NSEI (in msgb->cb) */
- return gprs_ns_sendmsg(bssgp_nsi, msg);
+ /* check if we have to go through per-ms flow control or can go
+ * directly to the per-BSS flow control */
+ if (dup->fc)
+ return bssgp_fc_in(dup->fc, msg, msg_len, bctx->fc);
+ else
+ return bssgp_fc_in(bctx->fc, msg, msg_len, NULL);
}
/* Send a single GMM-PAGING.req to a given NSEI/NS-BVCI */
diff --git a/src/gb/gprs_bssgp_vty.c b/src/gb/gprs_bssgp_vty.c
index aa1f106..d8e1d32 100644
--- a/src/gb/gprs_bssgp_vty.c
+++ b/src/gb/gprs_bssgp_vty.c
@@ -88,8 +88,19 @@
bvc->ra_id.mnc, bvc->ra_id.lac, bvc->ra_id.rac, bvc->cell_id,
bvc->state & BVC_S_BLOCKED ? "BLOCKED" : "UNBLOCKED",
VTY_NEWLINE);
- if (stats)
+
+ if (stats) {
+ struct bssgp_flow_control *fc = bvc->fc;
+
vty_out_rate_ctr_group(vty, " ", bvc->ctrg);
+
+ if (fc)
+ vty_out(vty, "FC-BVC(bucket_max: %uoct, leak_rate: "
+ "%uoct/s, cur_tokens: %uoct, max_q_d: %u, "
+ "cur_q_d: %u)\n", fc->bucket_size_max,
+ fc->bucket_leak_rate, fc->bucket_counter,
+ fc->max_queue_depth, fc->queue_depth);
+ }
}
static void dump_bssgp(struct vty *vty, int stats)
diff --git a/src/gb/libosmogb.map b/src/gb/libosmogb.map
index a41a91a..d0f76f8 100644
--- a/src/gb/libosmogb.map
+++ b/src/gb/libosmogb.map
@@ -2,6 +2,9 @@
global:
bssgp_cause_str;
bssgp_create_cell_id;
+bssgp_fc_in;
+bssgp_fc_init;
+bssgp_fc_ms_init;
bssgp_msgb_alloc;
bssgp_msgb_tlli_put;
bssgp_parse_cell_id;
diff --git a/tests/Makefile.am b/tests/Makefile.am
index ce5fefb..b489b3b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -3,7 +3,8 @@
check_PROGRAMS = timer/timer_test sms/sms_test ussd/ussd_test \
smscb/smscb_test bits/bitrev_test a5/a5_test \
conv/conv_test auth/milenage_test lapd/lapd_test \
- gsm0808/gsm0808_test gsm0408/gsm0408_test
+ gsm0808/gsm0808_test gsm0408/gsm0408_test \
+ gb/bssgp_fc_test
if ENABLE_MSGFILE
check_PROGRAMS += msgfile/msgfile_test
endif
@@ -44,6 +45,9 @@
ussd_ussd_test_SOURCES = ussd/ussd_test.c
ussd_ussd_test_LDADD = $(top_builddir)/src/libosmocore.la $(top_builddir)/src/gsm/libosmogsm.la
+gb_bssgp_fc_test_SOURCES = gb/bssgp_fc_test.c
+gb_bssgp_fc_test_LDADD = $(top_builddir)/src/libosmocore.la $(top_builddir)/src/gb/libosmogb.la
+
# The `:;' works around a Bash 3.2 bug when the output is not writeable.
$(srcdir)/package.m4: $(top_srcdir)/configure.ac
:;{ \
diff --git a/tests/gb/bssgp_fc_test.c b/tests/gb/bssgp_fc_test.c
new file mode 100644
index 0000000..c5e864d
--- /dev/null
+++ b/tests/gb/bssgp_fc_test.c
@@ -0,0 +1,167 @@
+/* test routines for BSSGP flow control implementation in libosmogb
+ * (C) 2012 by Harald Welte <laforge@gnumonks.org>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <getopt.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/gprs/gprs_bssgp.h>
+
+static unsigned long in_ctr = 1;
+static struct timeval tv_start;
+
+int get_centisec_diff(void)
+{
+ struct timeval tv;
+ struct timeval now;
+ gettimeofday(&now, NULL);
+
+ timersub(&now, &tv_start, &tv);
+
+ return tv.tv_sec * 100 + tv.tv_usec/10000;
+}
+
+/* round to deciseconds to make sure test output is always consistent */
+int round_decisec(int csec_in)
+{
+ int tmp = csec_in / 10;
+
+ return tmp * 10;
+}
+
+static int fc_out_cb(struct bssgp_flow_control *fc, struct msgb *msg,
+ uint32_t llc_pdu_len, void *priv)
+{
+ unsigned int csecs = get_centisec_diff();
+ csecs = round_decisec(csecs);
+
+ printf("%u: FC OUT Nr %lu\n", csecs, (unsigned long) msg);
+}
+
+static int fc_in(struct bssgp_flow_control *fc, unsigned int pdu_len)
+{
+ unsigned int csecs = get_centisec_diff();
+ csecs = round_decisec(csecs);
+
+ printf("%u: FC IN Nr %lu\n", csecs, in_ctr);
+ bssgp_fc_in(fc, (struct msgb *) in_ctr, pdu_len, NULL);
+ in_ctr++;
+}
+
+
+static void test_fc(uint32_t bucket_size_max, uint32_t bucket_leak_rate,
+ uint32_t max_queue_depth, uint32_t pdu_len,
+ uint32_t pdu_count)
+{
+ struct bssgp_flow_control *fc = talloc_zero(NULL, struct bssgp_flow_control);
+ int i;
+
+ bssgp_fc_init(fc, bucket_size_max, bucket_leak_rate, max_queue_depth,
+ fc_out_cb);
+
+ gettimeofday(&tv_start, NULL);
+
+ for (i = 0; i < pdu_count; i++) {
+ fc_in(fc, pdu_len);
+ osmo_timers_check();
+ osmo_timers_prepare();
+ osmo_timers_update();
+ }
+
+ while (1) {
+ usleep(100000);
+ osmo_timers_check();
+ osmo_timers_prepare();
+ osmo_timers_update();
+
+ if (llist_empty(&fc->queue))
+ break;
+ }
+}
+
+static void help(void)
+{
+ printf(" -h --help This help message\n");
+ printf(" -s --bucket-size-max N Maximum size of bucket in octets\n");
+ printf(" -r --bucket-leak-rate N Bucket leak rate in octets/sec\n");
+ printf(" -d --max-queue-depth N Maximum length of pending PDU queue (msgs)\n");
+ printf(" -l --pdu-length N Length of each PDU in octets\n");
+}
+
+int bssgp_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
+{
+ return -1;
+}
+
+static struct log_info info = {};
+
+int main(int argc, char **argv)
+{
+ uint32_t bucket_size_max = 100; /* octets */
+ uint32_t bucket_leak_rate = 100; /* octets / second */
+ uint32_t max_queue_depth = 5; /* messages */
+ uint32_t pdu_length = 10; /* octets */
+ uint32_t pdu_count = 20; /* messages */
+ int c;
+
+ static const struct option long_options[] = {
+ { "bucket-size-max", 1, 0, 's' },
+ { "bucket-leak-rate", 1, 0, 'r' },
+ { "max-queue-depth", 1, 0, 'd' },
+ { "pdu-length", 1, 0, 'l' },
+ { "pdu-count", 1, 0, 'c' },
+ { "help", 0, 0, 'h' },
+ { 0, 0, 0, 0 }
+ };
+
+ osmo_init_logging(&info);
+
+ while ((c = getopt_long(argc, argv, "s:r:d:l:c:",
+ long_options, NULL)) != -1) {
+ switch (c) {
+ case 's':
+ bucket_size_max = atoi(optarg);
+ break;
+ case 'r':
+ bucket_leak_rate = atoi(optarg);
+ break;
+ case 'd':
+ max_queue_depth = atoi(optarg);
+ break;
+ case 'l':
+ pdu_length = atoi(optarg);
+ break;
+ case 'c':
+ pdu_count = atoi(optarg);
+ break;
+ case 'h':
+ help();
+ exit(EXIT_SUCCESS);
+ break;
+ default:
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ /* bucket leak rate less than 100 not supported! */
+ if (bucket_leak_rate < 100) {
+ fprintf(stderr, "Bucket leak rate < 100 not supported!\n");
+ exit(EXIT_FAILURE);
+ }
+
+ printf("===== BSSGP flow-control test START\n");
+ printf("size-max=%u oct, leak-rate=%u oct/s, "
+ "queue-len=%u msgs, pdu_len=%u oct, pdu_cnt=%u\n\n", bucket_size_max,
+ bucket_leak_rate, max_queue_depth, pdu_length, pdu_count);
+ test_fc(bucket_size_max, bucket_leak_rate, max_queue_depth,
+ pdu_length, pdu_count);
+ printf("===== BSSGP flow-control test END\n\n");
+
+ exit(EXIT_SUCCESS);
+}
diff --git a/tests/gb/bssgp_fc_tests.err b/tests/gb/bssgp_fc_tests.err
new file mode 100644
index 0000000..ae5d6f6
--- /dev/null
+++ b/tests/gb/bssgp_fc_tests.err
@@ -0,0 +1,51 @@
+<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:699 Single PDU (size=1000) is larger than maximum bucket size (100)!
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m<0000> gprs_bssgp.c:556 BSSGP-FC: fc_timer_cb() but still not able to send PDU of 10 bytes
+[0;m
\ No newline at end of file
diff --git a/tests/gb/bssgp_fc_tests.ok b/tests/gb/bssgp_fc_tests.ok
new file mode 100644
index 0000000..fda96f3
--- /dev/null
+++ b/tests/gb/bssgp_fc_tests.ok
@@ -0,0 +1,150 @@
+===== BSSGP flow-control test START
+size-max=100 oct, leak-rate=100 oct/s, queue-len=5 msgs, pdu_len=10 oct, pdu_cnt=20
+
+0: FC IN Nr 1
+0: FC OUT Nr 1
+0: FC IN Nr 2
+0: FC OUT Nr 2
+0: FC IN Nr 3
+0: FC OUT Nr 3
+0: FC IN Nr 4
+0: FC OUT Nr 4
+0: FC IN Nr 5
+0: FC OUT Nr 5
+0: FC IN Nr 6
+0: FC OUT Nr 6
+0: FC IN Nr 7
+0: FC OUT Nr 7
+0: FC IN Nr 8
+0: FC OUT Nr 8
+0: FC IN Nr 9
+0: FC OUT Nr 9
+0: FC IN Nr 10
+0: FC OUT Nr 10
+0: FC IN Nr 11
+0: FC IN Nr 12
+0: FC IN Nr 13
+0: FC IN Nr 14
+0: FC IN Nr 15
+0: FC IN Nr 16
+0: FC IN Nr 17
+0: FC IN Nr 18
+0: FC IN Nr 19
+0: FC IN Nr 20
+10: FC OUT Nr 11
+20: FC OUT Nr 12
+30: FC OUT Nr 13
+40: FC OUT Nr 14
+50: FC OUT Nr 15
+===== BSSGP flow-control test END
+
+===== BSSGP flow-control test START
+size-max=100 oct, leak-rate=100 oct/s, queue-len=100 msgs, pdu_len=10 oct, pdu_cnt=20
+
+0: FC IN Nr 1
+0: FC OUT Nr 1
+0: FC IN Nr 2
+0: FC OUT Nr 2
+0: FC IN Nr 3
+0: FC OUT Nr 3
+0: FC IN Nr 4
+0: FC OUT Nr 4
+0: FC IN Nr 5
+0: FC OUT Nr 5
+0: FC IN Nr 6
+0: FC OUT Nr 6
+0: FC IN Nr 7
+0: FC OUT Nr 7
+0: FC IN Nr 8
+0: FC OUT Nr 8
+0: FC IN Nr 9
+0: FC OUT Nr 9
+0: FC IN Nr 10
+0: FC OUT Nr 10
+0: FC IN Nr 11
+0: FC IN Nr 12
+0: FC IN Nr 13
+0: FC IN Nr 14
+0: FC IN Nr 15
+0: FC IN Nr 16
+0: FC IN Nr 17
+0: FC IN Nr 18
+0: FC IN Nr 19
+0: FC IN Nr 20
+10: FC OUT Nr 11
+20: FC OUT Nr 12
+30: FC OUT Nr 13
+40: FC OUT Nr 14
+50: FC OUT Nr 15
+60: FC OUT Nr 16
+70: FC OUT Nr 17
+80: FC OUT Nr 18
+90: FC OUT Nr 19
+100: FC OUT Nr 20
+===== BSSGP flow-control test END
+
+===== BSSGP flow-control test START
+size-max=100 oct, leak-rate=100 oct/s, queue-len=5 msgs, pdu_len=1000 oct, pdu_cnt=20
+
+0: FC IN Nr 1
+0: FC IN Nr 2
+0: FC IN Nr 3
+0: FC IN Nr 4
+0: FC IN Nr 5
+0: FC IN Nr 6
+0: FC IN Nr 7
+0: FC IN Nr 8
+0: FC IN Nr 9
+0: FC IN Nr 10
+0: FC IN Nr 11
+0: FC IN Nr 12
+0: FC IN Nr 13
+0: FC IN Nr 14
+0: FC IN Nr 15
+0: FC IN Nr 16
+0: FC IN Nr 17
+0: FC IN Nr 18
+0: FC IN Nr 19
+0: FC IN Nr 20
+===== BSSGP flow-control test END
+
+===== BSSGP flow-control test START
+size-max=100 oct, leak-rate=100 oct/s, queue-len=5 msgs, pdu_len=10 oct, pdu_cnt=20
+
+0: FC IN Nr 1
+0: FC OUT Nr 1
+0: FC IN Nr 2
+0: FC OUT Nr 2
+0: FC IN Nr 3
+0: FC OUT Nr 3
+0: FC IN Nr 4
+0: FC OUT Nr 4
+0: FC IN Nr 5
+0: FC OUT Nr 5
+0: FC IN Nr 6
+0: FC OUT Nr 6
+0: FC IN Nr 7
+0: FC OUT Nr 7
+0: FC IN Nr 8
+0: FC OUT Nr 8
+0: FC IN Nr 9
+0: FC OUT Nr 9
+0: FC IN Nr 10
+0: FC OUT Nr 10
+0: FC IN Nr 11
+0: FC IN Nr 12
+0: FC IN Nr 13
+0: FC IN Nr 14
+0: FC IN Nr 15
+0: FC IN Nr 16
+0: FC IN Nr 17
+0: FC IN Nr 18
+0: FC IN Nr 19
+0: FC IN Nr 20
+10: FC OUT Nr 11
+20: FC OUT Nr 12
+30: FC OUT Nr 13
+40: FC OUT Nr 14
+50: FC OUT Nr 15
+===== BSSGP flow-control test END
+
diff --git a/tests/gb/bssgp_fc_tests.sh b/tests/gb/bssgp_fc_tests.sh
new file mode 100755
index 0000000..38659bb
--- /dev/null
+++ b/tests/gb/bssgp_fc_tests.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+T=$1/bssgp_fc_test
+
+# default test (1 second, insufficient queue depth)
+$T
+
+# default test (1 second, sufficient queue depth)
+$T -d 100
+
+# test with PDU too large for bucket max
+$T -l 1000
+
+# test with 100 byte PDUs (10 second)
+$T -s 100
+
diff --git a/tests/testsuite.at b/tests/testsuite.at
index 2154269..dd22c32 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -9,6 +9,13 @@
AT_CHECK([$abs_top_builddir/tests/a5/a5_test], [], [expout])
AT_CLEANUP
+AT_SETUP([bssgp-fc])
+AT_KEYWORDS([bssgp-fc])
+cat $abs_srcdir/gb/bssgp_fc_tests.ok > expout
+cat $abs_srcdir/gb/bssgp_fc_tests.err > experr
+AT_CHECK([$abs_top_builddir/tests/gb/bssgp_fc_tests.sh $abs_top_builddir/tests/gb], [], [expout], [experr])
+AT_CLEANUP
+
AT_SETUP([bits])
AT_KEYWORDS([bits])
cat $abs_srcdir/bits/bitrev_test.ok > expout