diff options
| -rw-r--r-- | src/bts.h | 1 | ||||
| -rw-r--r-- | src/llc.cpp | 15 | ||||
| -rw-r--r-- | src/llc.h | 1 | ||||
| -rw-r--r-- | src/pcu_utils.h | 5 | ||||
| -rw-r--r-- | src/pcu_vty.c | 34 | ||||
| -rw-r--r-- | src/tbf_dl.cpp | 50 |
6 files changed, 95 insertions, 11 deletions
@@ -118,6 +118,7 @@ struct gprs_rlcmac_bts { uint8_t initial_cs_dl, initial_cs_ul; uint8_t force_cs; /* 0=use from BTS 1=use from VTY */ uint16_t force_llc_lifetime; /* overrides lifetime from SGSN */ + uint32_t llc_discard_csec; uint8_t t3142; uint8_t t3169; uint8_t t3191; diff --git a/src/llc.cpp b/src/llc.cpp index b1609617..9c5581fb 100644 --- a/src/llc.cpp +++ b/src/llc.cpp @@ -160,3 +160,18 @@ bool gprs_llc::is_frame_expired(struct timeval *tv_now, struct timeval *tv) return timercmp(tv_now, tv, >); } + +bool gprs_llc::is_user_data_frame(uint8_t *data, size_t len) +{ + if (len < 2) + return false; + + if ((data[0] & 0x0f) == 1 /* GPRS_SAPI_GMM */) + return false; + + if ((data[0] & 0x0e) != 0xc0 /* LLC UI */) + /* It is not an LLC UI frame */ + return false; + + return true; +} @@ -29,6 +29,7 @@ struct gprs_llc { static void calc_pdu_lifetime(BTS *bts, const uint16_t pdu_delay_csec, struct timeval *tv); static bool is_frame_expired(struct timeval *now, struct timeval *tv); + static bool is_user_data_frame(uint8_t *data, size_t len); void init(); void reset(); diff --git a/src/pcu_utils.h b/src/pcu_utils.h index 84c545bb..5ca234a4 100644 --- a/src/pcu_utils.h +++ b/src/pcu_utils.h @@ -19,3 +19,8 @@ inline int msecs_to_frames(int msecs) { return (msecs * (1024 * 1000 / 4615)) / 1024; } + +inline void csecs_to_timeval(unsigned csecs, struct timeval *tv) { + tv->tv_sec = csecs / 100; + tv->tv_usec = (csecs % 100) * 10000; +} diff --git a/src/pcu_vty.c b/src/pcu_vty.c index 9b597ad1..3d9c79a3 100644 --- a/src/pcu_vty.c +++ b/src/pcu_vty.c @@ -97,6 +97,9 @@ static int config_write_pcu(struct vty *vty) else if (bts->force_llc_lifetime) vty_out(vty, " queue lifetime %d%s", bts->force_llc_lifetime, VTY_NEWLINE); + if (bts->llc_discard_csec) + vty_out(vty, " queue hysteresis %d%s", bts->llc_discard_csec, + VTY_NEWLINE); if (bts->alloc_algorithm == alloc_algorithm_a) vty_out(vty, " alloc-algorithm a%s", VTY_NEWLINE); if (bts->alloc_algorithm == alloc_algorithm_b) @@ -209,6 +212,35 @@ DEFUN(cfg_pcu_no_queue_lifetime, return CMD_SUCCESS; } +#define QUEUE_HYSTERESIS_STR "Set lifetime hysteresis of LLC frame in centi-seconds " \ + "(continue discarding until lifetime-hysteresis is reached)\n" + +DEFUN(cfg_pcu_queue_hysteresis, + cfg_pcu_queue_hysteresis_cmd, + "queue hysteresis <1-65534>", + QUEUE_STR QUEUE_HYSTERESIS_STR "Hysteresis in centi-seconds") +{ + struct gprs_rlcmac_bts *bts = bts_main_data(); + uint8_t csec = atoi(argv[0]); + + bts->llc_discard_csec = csec; + + return CMD_SUCCESS; +} + +DEFUN(cfg_pcu_no_queue_hysteresis, + cfg_pcu_no_queue_hysteresis_cmd, + "no queue hysteresis", + NO_STR QUEUE_STR QUEUE_HYSTERESIS_STR) +{ + struct gprs_rlcmac_bts *bts = bts_main_data(); + + bts->llc_discard_csec = 0; + + return CMD_SUCCESS; +} + + DEFUN(cfg_pcu_alloc, cfg_pcu_alloc_cmd, "alloc-algorithm (a|b)", @@ -366,6 +398,8 @@ int pcu_vty_init(const struct log_info *cat) install_element(PCU_NODE, &cfg_pcu_queue_lifetime_cmd); install_element(PCU_NODE, &cfg_pcu_queue_lifetime_inf_cmd); install_element(PCU_NODE, &cfg_pcu_no_queue_lifetime_cmd); + install_element(PCU_NODE, &cfg_pcu_queue_hysteresis_cmd); + install_element(PCU_NODE, &cfg_pcu_no_queue_hysteresis_cmd); install_element(PCU_NODE, &cfg_pcu_alloc_cmd); install_element(PCU_NODE, &cfg_pcu_two_phase_cmd); install_element(PCU_NODE, &cfg_pcu_fc_interval_cmd); diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp index 7e0883b5..aeec23f2 100644 --- a/src/tbf_dl.cpp +++ b/src/tbf_dl.cpp @@ -209,30 +209,58 @@ int gprs_rlcmac_dl_tbf::handle(struct gprs_rlcmac_bts *bts, struct msgb *gprs_rlcmac_dl_tbf::llc_dequeue(bssgp_bvc_ctx *bctx) { struct msgb *msg; - struct timeval *tv, tv_now; + struct timeval *tv, tv_now, tv_now2; uint32_t octets = 0, frames = 0; + struct timeval hyst_delta = {0, 0}; + const unsigned keep_small_thresh = 60; + + if (bts_data()->llc_discard_csec) + csecs_to_timeval(bts_data()->llc_discard_csec, &hyst_delta); gettimeofday(&tv_now, NULL); + timeradd(&tv_now, &hyst_delta, &tv_now2); while ((msg = m_llc.dequeue())) { tv = (struct timeval *)msg->data; msgb_pull(msg, sizeof(*tv)); msgb_pull(msg, sizeof(*tv)); - if (gprs_llc::is_frame_expired(&tv_now, tv)) { - LOGP(DRLCMACDL, LOGL_NOTICE, "%s Discarding LLC PDU " - "because lifetime limit reached. Queue size %zu\n", - tbf_name(this), m_llc.m_queue_size); - bts->llc_timedout_frame(); - frames++; - octets += msg->len; - msgb_free(msg); - continue; + /* Is the age below the low water mark? */ + if (!gprs_llc::is_frame_expired(&tv_now2, tv)) + break; + + /* Is the age below the high water mark */ + if (!gprs_llc::is_frame_expired(&tv_now, tv)) { + /* Has the previous message not been dropped? */ + if (frames == 0) + break; + + /* Hysteresis mode, try to discard LLC messages until + * the low water mark has been reached */ + + /* Check whether to abort the hysteresis mode */ + + /* Is the frame small, perhaps only a TCP ACK? */ + if (msg->len <= keep_small_thresh) + break; + + /* Is it a GMM message? */ + if (!gprs_llc::is_user_data_frame(msg->data, msg->len)) + break; } - break; + + bts->llc_timedout_frame(); + frames++; + octets += msg->len; + msgb_free(msg); + continue; } if (frames) { + LOGP(DRLCMACDL, LOGL_NOTICE, "%s Discarding LLC PDU " + "because lifetime limit reached, " + "count=%u new_queue_size=%zu\n", + tbf_name(this), frames, m_llc.m_queue_size); if (frames > 0xff) frames = 0xff; if (octets > 0xffffff) |