diff --git a/lib/include/srslte/interfaces/enb_interfaces.h b/lib/include/srslte/interfaces/enb_interfaces.h
index 601c9a12d..74b218dbc 100644
--- a/lib/include/srslte/interfaces/enb_interfaces.h
+++ b/lib/include/srslte/interfaces/enb_interfaces.h
@@ -551,6 +551,7 @@ typedef struct {
   uint32_t                      nof_prb; ///< Needed to dimension MAC softbuffers for all cells
   sched_interface::sched_args_t sched;
   int                           nr_tb_size = -1;
+  uint32_t                      max_nof_ues;
 } mac_args_t;
 
 class stack_interface_s1ap_lte
diff --git a/lib/include/srslte/interfaces/enb_metrics_interface.h b/lib/include/srslte/interfaces/enb_metrics_interface.h
index 9e70ae6dd..b8138ab0e 100644
--- a/lib/include/srslte/interfaces/enb_metrics_interface.h
+++ b/lib/include/srslte/interfaces/enb_metrics_interface.h
@@ -37,17 +37,17 @@
 namespace srsenb {
 
 struct stack_metrics_t {
-  mac_metrics_t  mac[ENB_METRICS_MAX_USERS];
-  rrc_metrics_t  rrc;
-  s1ap_metrics_t s1ap;
+  std::vector<mac_metrics_t> mac;
+  rrc_metrics_t              rrc;
+  s1ap_metrics_t             s1ap;
 };
 
-typedef struct {
-  srslte::rf_metrics_t rf;
-  phy_metrics_t        phy[ENB_METRICS_MAX_USERS];
-  stack_metrics_t      stack;
-  bool                 running;
-} enb_metrics_t;
+struct enb_metrics_t {
+  srslte::rf_metrics_t       rf;
+  std::vector<phy_metrics_t> phy;
+  stack_metrics_t            stack;
+  bool                       running;
+};
 
 // ENB interface
 class enb_metrics_interface : public srslte::metrics_interface<enb_metrics_t>
diff --git a/srsenb/hdr/phy/cc_worker.h b/srsenb/hdr/phy/cc_worker.h
index b9b56e87c..afa57fc2f 100644
--- a/srsenb/hdr/phy/cc_worker.h
+++ b/srsenb/hdr/phy/cc_worker.h
@@ -60,7 +60,7 @@ public:
                stack_interface_phy_lte::ul_sched_t& ul_grants,
                srslte_mbsfn_cfg_t*                  mbsfn_cfg);
 
-  uint32_t get_metrics(phy_metrics_t metrics[ENB_METRICS_MAX_USERS]);
+  uint32_t get_metrics(std::vector<phy_metrics_t>& metrics);
 
 private:
   constexpr static float PUSCH_RL_SNR_DB_TH = 1.0f;
diff --git a/srsenb/hdr/phy/enb_phy_base.h b/srsenb/hdr/phy/enb_phy_base.h
index 3daf32965..ac2b99669 100644
--- a/srsenb/hdr/phy/enb_phy_base.h
+++ b/srsenb/hdr/phy/enb_phy_base.h
@@ -28,6 +28,7 @@
 #define SRSENB_PHY_BASE_H
 
 #include "srsenb/hdr/phy/phy_metrics.h"
+#include <vector>
 
 namespace srsenb {
 
@@ -43,7 +44,7 @@ public:
 
   virtual void start_plot() = 0;
 
-  virtual void get_metrics(phy_metrics_t* m) = 0;
+  virtual void get_metrics(std::vector<phy_metrics_t>& m) = 0;
 
   virtual void cmd_cell_gain(uint32_t cell_idx, float gain_db) = 0;
 };
diff --git a/srsenb/hdr/phy/phy.h b/srsenb/hdr/phy/phy.h
index 8ca9e3dec..efed33db7 100644
--- a/srsenb/hdr/phy/phy.h
+++ b/srsenb/hdr/phy/phy.h
@@ -64,7 +64,7 @@ public:
   void set_config(uint16_t rnti, const phy_rrc_cfg_list_t& phy_cfg_list) override;
   void complete_config(uint16_t rnti) override;
 
-  void get_metrics(phy_metrics_t metrics[ENB_METRICS_MAX_USERS]) override;
+  void get_metrics(std::vector<phy_metrics_t>& metrics) override;
 
   void cmd_cell_gain(uint32_t cell_id, float gain_db) override;
 
diff --git a/srsenb/hdr/phy/sf_worker.h b/srsenb/hdr/phy/sf_worker.h
index ffc721b71..c8ac8e6b7 100644
--- a/srsenb/hdr/phy/sf_worker.h
+++ b/srsenb/hdr/phy/sf_worker.h
@@ -55,7 +55,7 @@ public:
   int      read_pucch_d(uint32_t cc_idx, cf_t* pusch_d);
   void start_plot();
 
-  uint32_t get_metrics(phy_metrics_t metrics[ENB_METRICS_MAX_USERS]);
+  uint32_t get_metrics(std::vector<phy_metrics_t>& metrics);
 
 private:
   void work_imp() final;
diff --git a/srsenb/hdr/phy/vnf_phy_nr.h b/srsenb/hdr/phy/vnf_phy_nr.h
index d225d5b92..11fbe9324 100644
--- a/srsenb/hdr/phy/vnf_phy_nr.h
+++ b/srsenb/hdr/phy/vnf_phy_nr.h
@@ -50,7 +50,7 @@ public:
 
   void start_plot() override;
 
-  void get_metrics(srsenb::phy_metrics_t metrics[ENB_METRICS_MAX_USERS]) override;
+  void get_metrics(std::vector<srsenb::phy_metrics_t>& metrics) override;
 
   // MAC interface
   int dl_config_request(const dl_config_request_t& request) override;
diff --git a/srsenb/hdr/stack/mac/mac.h b/srsenb/hdr/stack/mac/mac.h
index 81712c57e..792291a00 100644
--- a/srsenb/hdr/stack/mac/mac.h
+++ b/srsenb/hdr/stack/mac/mac.h
@@ -98,7 +98,7 @@ public:
 
   bool process_pdus();
 
-  void get_metrics(mac_metrics_t metrics[ENB_METRICS_MAX_USERS]);
+  void get_metrics(std::vector<mac_metrics_t>& metrics);
   void write_mcch(const srslte::sib2_mbms_t* sib2_,
                   const srslte::sib13_t*     sib13_,
                   const srslte::mcch_msg_t*  mcch_,
@@ -110,6 +110,7 @@ private:
 
   bool     check_ue_exists(uint16_t rnti);
   uint16_t allocate_rnti();
+  uint16_t allocate_ue();
 
   std::mutex rnti_mutex;
 
diff --git a/srsenb/hdr/stack/mac/mac_nr.h b/srsenb/hdr/stack/mac/mac_nr.h
index 91d39aa1d..eaab92fce 100644
--- a/srsenb/hdr/stack/mac/mac_nr.h
+++ b/srsenb/hdr/stack/mac/mac_nr.h
@@ -60,7 +60,7 @@ public:
             rrc_interface_mac_nr*   rrc_);
   void stop();
 
-  void get_metrics(srsenb::mac_metrics_t* metrics);
+  void get_metrics(std::vector<srsenb::mac_metrics_t>& metrics);
 
   // MAC interface for RRC
   int cell_cfg(srsenb::sched_interface::cell_cfg_t* cell_cfg);
diff --git a/srsenb/hdr/stack/rrc/rrc_metrics.h b/srsenb/hdr/stack/rrc/rrc_metrics.h
index f720c6fe5..080c2dddd 100644
--- a/srsenb/hdr/stack/rrc/rrc_metrics.h
+++ b/srsenb/hdr/stack/rrc/rrc_metrics.h
@@ -23,6 +23,7 @@
 #define SRSENB_RRC_METRICS_H
 
 #include "srsenb/hdr/stack/upper/common_enb.h"
+#include <vector>
 
 namespace srsenb {
 
@@ -44,8 +45,7 @@ struct rrc_ue_metrics_t {
 };
 
 struct rrc_metrics_t {
-  uint16_t         n_ues;
-  rrc_ue_metrics_t ues[ENB_METRICS_MAX_USERS];
+  std::vector<rrc_ue_metrics_t> ues;
 };
 
 } // namespace srsenb
diff --git a/srsenb/hdr/stack/upper/common_enb.h b/srsenb/hdr/stack/upper/common_enb.h
index 36828a9ba..b82ffce21 100644
--- a/srsenb/hdr/stack/upper/common_enb.h
+++ b/srsenb/hdr/stack/upper/common_enb.h
@@ -30,7 +30,6 @@
 
 namespace srsenb {
 
-#define ENB_METRICS_MAX_USERS 64
 #define SRSENB_RRC_MAX_N_PLMN_IDENTITIES 6
 
 #define SRSENB_N_SRB 3
diff --git a/srsenb/src/main.cc b/srsenb/src/main.cc
index 26191da78..be8433e5f 100644
--- a/srsenb/src/main.cc
+++ b/srsenb/src/main.cc
@@ -204,6 +204,7 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("expert.print_buffer_state", bpo::value<bool>(&args->general.print_buffer_state)->default_value(false), "Prints on the console the buffer state every 10 seconds")
     ("expert.eea_pref_list", bpo::value<string>(&args->general.eea_pref_list)->default_value("EEA0, EEA2, EEA1"), "Ordered preference list for the selection of encryption algorithm (EEA) (default: EEA0, EEA2, EEA1).")
     ("expert.eia_pref_list", bpo::value<string>(&args->general.eia_pref_list)->default_value("EIA2, EIA1, EIA0"), "Ordered preference list for the selection of integrity algorithm (EIA) (default: EIA2, EIA1, EIA0).")
+    ("expert.max_nof_ues", bpo::value<uint32_t>(&args->stack.mac.max_nof_ues)->default_value(64), "Maximum number of connected UEs")
 
     // eMBMS section
     ("embms.enable", bpo::value<bool>(&args->stack.embms.enable)->default_value(false), "Enables MBMS in the eNB")
diff --git a/srsenb/src/metrics_csv.cc b/srsenb/src/metrics_csv.cc
index 443c9a955..2cddc342c 100644
--- a/srsenb/src/metrics_csv.cc
+++ b/srsenb/src/metrics_csv.cc
@@ -70,11 +70,11 @@ void metrics_csv::set_metrics(const enb_metrics_t& metrics, const uint32_t perio
     file << (metrics_report_period * n_reports) << ";";
 
     // UEs
-    file << (metrics.stack.rrc.n_ues) << ";";
+    file << (metrics.stack.rrc.ues.size()) << ";";
 
     // Sum up rates for all UEs
     float dl_rate_sum = 0.0, ul_rate_sum = 0.0;
-    for (int i = 0; i < metrics.stack.rrc.n_ues; i++) {
+    for (size_t i = 0; i < metrics.stack.rrc.ues.size(); i++) {
       dl_rate_sum += metrics.stack.mac[i].tx_brate / (metrics.stack.mac[i].nof_tti * 1e-3);
       ul_rate_sum += metrics.stack.mac[i].rx_brate / (metrics.stack.mac[i].nof_tti * 1e-3);
     }
diff --git a/srsenb/src/metrics_stdout.cc b/srsenb/src/metrics_stdout.cc
index 677807d3c..4ab54aa85 100644
--- a/srsenb/src/metrics_stdout.cc
+++ b/srsenb/src/metrics_stdout.cc
@@ -83,7 +83,7 @@ void metrics_stdout::set_metrics(const enb_metrics_t& metrics, const uint32_t pe
     printf("RF status: O=%d, U=%d, L=%d\n", metrics.rf.rf_o, metrics.rf.rf_u, metrics.rf.rf_l);
   }
 
-  if (metrics.stack.rrc.n_ues == 0) {
+  if (metrics.stack.rrc.ues.size() == 0) {
     return;
   }
 
@@ -96,7 +96,7 @@ void metrics_stdout::set_metrics(const enb_metrics_t& metrics, const uint32_t pe
     cout << "rnti cqi  ri mcs brate   ok  nok  (%)  snr  phr mcs brate   ok  nok  (%)   bsr" << endl;
   }
 
-  for (int i = 0; i < metrics.stack.rrc.n_ues; i++) {
+  for (size_t i = 0; i < metrics.stack.rrc.ues.size(); i++) {
     if (metrics.stack.mac[i].tx_errors > metrics.stack.mac[i].tx_pkts) {
       printf("tx caution errors %d > %d\n", metrics.stack.mac[i].tx_errors, metrics.stack.mac[i].tx_pkts);
     }
diff --git a/srsenb/src/phy/cc_worker.cc b/srsenb/src/phy/cc_worker.cc
index 7ec3e8fb2..8cdee6ee1 100644
--- a/srsenb/src/phy/cc_worker.cc
+++ b/srsenb/src/phy/cc_worker.cc
@@ -314,7 +314,7 @@ void cc_worker::decode_pusch_rnti(stack_interface_phy_lte::ul_sched_grant_t& ul_
   // Use last TBS for this TB in case of mcs>28
   if (ul_grant.dci.tb.mcs_idx > 28) {
     int rv_idx  = grant.tb.rv;
-    grant.tb = phy->ue_db.get_last_ul_tb(rnti, cc_idx, ul_pid);
+    grant.tb    = phy->ue_db.get_last_ul_tb(rnti, cc_idx, ul_pid);
     grant.tb.rv = rv_idx;
     Info("Adaptive retx: rnti=0x%x, pid=%d, rv_idx=%d, mcs=%d, old_tbs=%d\n",
          rnti,
@@ -591,16 +591,17 @@ int cc_worker::encode_pdsch(stack_interface_phy_lte::dl_sched_grant_t* grants, u
 }
 
 /************ METRICS interface ********************/
-uint32_t cc_worker::get_metrics(phy_metrics_t metrics[ENB_METRICS_MAX_USERS])
+uint32_t cc_worker::get_metrics(std::vector<phy_metrics_t>& metrics)
 {
   std::lock_guard<std::mutex> lock(mutex);
   uint32_t                    cnt = 0;
+  metrics.resize(ue_db.size());
   for (auto& ue : ue_db) {
-    if ((SRSLTE_RNTI_ISUSER(ue.first) || ue.first == SRSLTE_MRNTI) && cnt < ENB_METRICS_MAX_USERS) {
-      ue.second->metrics_read(&metrics[cnt]);
-      cnt++;
+    if ((SRSLTE_RNTI_ISUSER(ue.first) || ue.first == SRSLTE_MRNTI)) {
+      ue.second->metrics_read(&metrics[cnt++]);
     }
   }
+  metrics.resize(cnt);
   return cnt;
 }
 
diff --git a/srsenb/src/phy/phy.cc b/srsenb/src/phy/phy.cc
index 00d405008..16291bb4f 100644
--- a/srsenb/src/phy/phy.cc
+++ b/srsenb/src/phy/phy.cc
@@ -51,8 +51,7 @@ namespace srsenb {
 
 phy::phy(srslte::logger* logger_) :
   logger(logger_), workers_pool(MAX_WORKERS), workers(MAX_WORKERS), workers_common(), nof_workers(0)
-{
-}
+{}
 
 phy::~phy()
 {
@@ -190,14 +189,13 @@ void phy::set_activation_deactivation_scell(uint16_t rnti, const std::array<bool
   }
 }
 
-void phy::get_metrics(phy_metrics_t metrics[ENB_METRICS_MAX_USERS])
+void phy::get_metrics(std::vector<phy_metrics_t>& metrics)
 {
-  phy_metrics_t metrics_tmp[ENB_METRICS_MAX_USERS] = {};
-
-  uint32_t nof_users = workers[0].get_nof_rnti();
-  bzero(metrics, sizeof(phy_metrics_t) * ENB_METRICS_MAX_USERS);
+  uint32_t                   nof_users = workers[0].get_nof_rnti();
+  std::vector<phy_metrics_t> metrics_tmp;
   for (uint32_t i = 0; i < nof_workers; i++) {
     workers[i].get_metrics(metrics_tmp);
+    metrics.resize(std::max(metrics_tmp.size(), metrics.size()));
     for (uint32_t j = 0; j < nof_users; j++) {
       metrics[j].dl.n_samples += metrics_tmp[j].dl.n_samples;
       metrics[j].dl.mcs += metrics_tmp[j].dl.n_samples * metrics_tmp[j].dl.mcs;
diff --git a/srsenb/src/phy/sf_worker.cc b/srsenb/src/phy/sf_worker.cc
index 82e65fe54..baf46684a 100644
--- a/srsenb/src/phy/sf_worker.cc
+++ b/srsenb/src/phy/sf_worker.cc
@@ -280,23 +280,24 @@ void sf_worker::work_imp()
 }
 
 /************ METRICS interface ********************/
-uint32_t sf_worker::get_metrics(phy_metrics_t metrics[ENB_METRICS_MAX_USERS])
+uint32_t sf_worker::get_metrics(std::vector<phy_metrics_t>& metrics)
 {
-  uint32_t      cnt                             = 0;
-  phy_metrics_t _metrics[ENB_METRICS_MAX_USERS] = {};
+  uint32_t                   cnt = 0;
+  std::vector<phy_metrics_t> metrics_;
   for (uint32_t cc = 0; cc < phy->get_nof_carriers(); cc++) {
-    cnt = cc_workers[cc]->get_metrics(_metrics);
+    cnt = cc_workers[cc]->get_metrics(metrics_);
+    metrics.resize(std::max(metrics_.size(), metrics.size()));
     for (uint32_t r = 0; r < cnt; r++) {
       phy_metrics_t* m  = &metrics[r];
-      phy_metrics_t* _m = &_metrics[r];
-      m->dl.mcs         = SRSLTE_VEC_PMA(m->dl.mcs, m->dl.n_samples, _m->dl.mcs, _m->dl.n_samples);
-      m->dl.n_samples += _m->dl.n_samples;
-      m->ul.n           = SRSLTE_VEC_PMA(m->ul.n, m->ul.n_samples, _m->ul.n, _m->ul.n_samples);
-      m->ul.sinr        = SRSLTE_VEC_PMA(m->ul.sinr, m->ul.n_samples, _m->ul.sinr, _m->ul.n_samples);
-      m->ul.mcs         = SRSLTE_VEC_PMA(m->ul.mcs, m->ul.n_samples, _m->ul.mcs, _m->ul.n_samples);
-      m->ul.rssi        = SRSLTE_VEC_PMA(m->ul.rssi, m->ul.n_samples, _m->ul.rssi, _m->ul.n_samples);
-      m->ul.turbo_iters = SRSLTE_VEC_PMA(m->ul.turbo_iters, m->ul.n_samples, _m->ul.turbo_iters, _m->ul.n_samples);
-      m->ul.n_samples += _m->ul.n_samples;
+      phy_metrics_t* m_ = &metrics_[r];
+      m->dl.mcs         = SRSLTE_VEC_PMA(m->dl.mcs, m->dl.n_samples, m_->dl.mcs, m_->dl.n_samples);
+      m->dl.n_samples += m_->dl.n_samples;
+      m->ul.n           = SRSLTE_VEC_PMA(m->ul.n, m->ul.n_samples, m_->ul.n, m_->ul.n_samples);
+      m->ul.sinr        = SRSLTE_VEC_PMA(m->ul.sinr, m->ul.n_samples, m_->ul.sinr, m_->ul.n_samples);
+      m->ul.mcs         = SRSLTE_VEC_PMA(m->ul.mcs, m->ul.n_samples, m_->ul.mcs, m_->ul.n_samples);
+      m->ul.rssi        = SRSLTE_VEC_PMA(m->ul.rssi, m->ul.n_samples, m_->ul.rssi, m_->ul.n_samples);
+      m->ul.turbo_iters = SRSLTE_VEC_PMA(m->ul.turbo_iters, m->ul.n_samples, m_->ul.turbo_iters, m_->ul.n_samples);
+      m->ul.n_samples += m_->ul.n_samples;
     }
   }
   return cnt;
diff --git a/srsenb/src/phy/vnf_phy_nr.cc b/srsenb/src/phy/vnf_phy_nr.cc
index 0d1c833e9..a187cb7df 100644
--- a/srsenb/src/phy/vnf_phy_nr.cc
+++ b/srsenb/src/phy/vnf_phy_nr.cc
@@ -69,7 +69,7 @@ void vnf_phy_nr::stop()
 // Start GUI
 void vnf_phy_nr::start_plot() {}
 
-void vnf_phy_nr::get_metrics(srsenb::phy_metrics_t metrics[ENB_METRICS_MAX_USERS]) {}
+void vnf_phy_nr::get_metrics(std::vector<srsenb::phy_metrics_t>& metrics) {}
 
 int vnf_phy_nr::dl_config_request(const dl_config_request_t& request)
 {
diff --git a/srsenb/src/stack/mac/mac.cc b/srsenb/src/stack/mac/mac.cc
index d1345ac51..18f2e8245 100644
--- a/srsenb/src/stack/mac/mac.cc
+++ b/srsenb/src/stack/mac/mac.cc
@@ -276,10 +276,11 @@ int mac::cell_cfg(const std::vector<sched_interface::cell_cfg_t>& cell_cfg_)
   return scheduler.cell_cfg(cell_config);
 }
 
-void mac::get_metrics(mac_metrics_t metrics[ENB_METRICS_MAX_USERS])
+void mac::get_metrics(std::vector<mac_metrics_t>& metrics)
 {
   srslte::rwlock_read_guard lock(rwlock);
   int                       cnt = 0;
+  metrics.resize(ue_db.size());
   for (auto& u : ue_db) {
     u.second->metrics_read(&metrics[cnt]);
     cnt++;
@@ -443,15 +444,23 @@ uint16_t mac::allocate_rnti()
   return rnti;
 }
 
-uint16_t mac::reserve_new_crnti(const sched_interface::ue_cfg_t& ue_cfg)
+uint16_t mac::allocate_ue()
 {
+  {
+    srslte::rwlock_read_guard lock(rwlock);
+    if (ue_db.size() >= args.max_nof_ues) {
+      Warning("Maximum number of connected UEs %d reached. Ignoring PRACH\n", args.max_nof_ues);
+      return SRSLTE_INVALID_RNTI;
+    }
+  }
+
   // Get pre-allocated UE object
   if (ue_pool.empty()) {
     Error("Ignoring RACH attempt. UE pool empty.\n");
     return SRSLTE_INVALID_RNTI;
   }
-  auto     ue_ptr = ue_pool.wait_pop();
-  uint16_t rnti   = ue_ptr->get_rnti();
+  std::unique_ptr<ue> ue_ptr = ue_pool.wait_pop();
+  uint16_t            rnti   = ue_ptr->get_rnti();
 
   // Set PCAP if available
   if (pcap != nullptr) {
@@ -463,14 +472,27 @@ uint16_t mac::reserve_new_crnti(const sched_interface::ue_cfg_t& ue_cfg)
     ue_db[rnti] = std::move(ue_ptr);
   }
 
+  return rnti;
+}
+
+uint16_t mac::reserve_new_crnti(const sched_interface::ue_cfg_t& ue_cfg)
+{
+  uint16_t rnti = allocate_ue();
+  if (rnti == SRSLTE_INVALID_RNTI) {
+    return rnti;
+  }
+
+  task_sched.enqueue_background_task([this](uint32_t wid) {
+    // Allocate one new UE object in advance
+    prealloc_ue(1);
+  });
+
   // Add new user to the scheduler so that it can RX/TX SRB0
   if (scheduler.ue_cfg(rnti, ue_cfg) != SRSLTE_SUCCESS) {
     Error("Registering new user rnti=0x%x to SCHED\n", rnti);
     return SRSLTE_INVALID_RNTI;
   }
 
-  // Allocate one new UE object in advance
-  prealloc_ue(1);
   return rnti;
 }
 
@@ -480,21 +502,9 @@ void mac::rach_detected(uint32_t tti, uint32_t enb_cc_idx, uint32_t preamble_idx
   log_h->step(tti);
   auto rach_tprof_meas = rach_tprof.start();
 
-  // Get pre-allocated UE object
-  if (ue_pool.empty()) {
-    Error("Ignoring RACH attempt. UE pool empty.\n");
-  }
-  auto     ue_ptr = ue_pool.wait_pop();
-  uint16_t rnti   = ue_ptr->get_rnti();
-
-  // Set PCAP if available
-  if (pcap != nullptr) {
-    ue_ptr->start_pcap(pcap);
-  }
-
-  {
-    srslte::rwlock_write_guard lock(rwlock);
-    ue_db[rnti] = std::move(ue_ptr);
+  uint16_t rnti = allocate_ue();
+  if (rnti == SRSLTE_INVALID_RNTI) {
+    return;
   }
 
   stack_task_queue.push([this, rnti, tti, enb_cc_idx, preamble_idx, time_adv, rach_tprof_meas]() mutable {
@@ -532,11 +542,11 @@ void mac::rach_detected(uint32_t tti, uint32_t enb_cc_idx, uint32_t preamble_idx
                 time_adv,
                 rnti);
     srslte::console("RACH:  tti=%d, cc=%d, preamble=%d, offset=%d, temp_crnti=0x%x\n",
-                       tti,
-                       enb_cc_idx,
-                       preamble_idx,
-                       time_adv,
-                       rnti);
+                    tti,
+                    enb_cc_idx,
+                    preamble_idx,
+                    time_adv,
+                    rnti);
   });
 
   // Allocate one new UE object in advance
diff --git a/srsenb/src/stack/mac/mac_nr.cc b/srsenb/src/stack/mac/mac_nr.cc
index 5db5e0721..92e58790d 100644
--- a/srsenb/src/stack/mac/mac_nr.cc
+++ b/srsenb/src/stack/mac/mac_nr.cc
@@ -85,7 +85,7 @@ void mac_nr::stop()
   }
 }
 
-void mac_nr::get_metrics(srsenb::mac_metrics_t* metrics) {}
+void mac_nr::get_metrics(std::vector<srsenb::mac_metrics_t>& metrics) {}
 
 // Fills both, DL_CONFIG.request and TX.request structs
 void mac_nr::get_dl_config(const uint32_t                               tti,
diff --git a/srsenb/src/stack/rrc/rrc.cc b/srsenb/src/stack/rrc/rrc.cc
index 970938630..013601984 100644
--- a/srsenb/src/stack/rrc/rrc.cc
+++ b/srsenb/src/stack/rrc/rrc.cc
@@ -109,10 +109,10 @@ void rrc::stop()
 void rrc::get_metrics(rrc_metrics_t& m)
 {
   if (running) {
-    m.n_ues = 0;
-    for (auto iter = users.begin(); m.n_ues < ENB_METRICS_MAX_USERS && iter != users.end(); ++iter) {
-      ue* u                  = iter->second.get();
-      m.ues[m.n_ues++].state = u->get_state();
+    m.ues.resize(users.size());
+    size_t count = 0;
+    for (auto& ue : users) {
+      m.ues[count++].state = ue.second->get_state();
     }
   }
 }
diff --git a/srsenb/test/enb_metrics_test.cc b/srsenb/test/enb_metrics_test.cc
index e330c7657..b627c4866 100644
--- a/srsenb/test/enb_metrics_test.cc
+++ b/srsenb/test/enb_metrics_test.cc
@@ -45,8 +45,9 @@ public:
   enb_dummy()
   {
     // first entry
-    metrics[0].rf.rf_o                = 10;
-    metrics[0].stack.rrc.n_ues        = 1;
+    metrics[0].rf.rf_o = 10;
+    metrics[0].stack.rrc.ues.resize(1);
+    metrics[0].stack.mac.resize(metrics[0].stack.rrc.ues.size());
     metrics[0].stack.mac[0].rnti      = 0x46;
     metrics[0].stack.mac[0].tx_pkts   = 1000;
     metrics[0].stack.mac[0].tx_errors = 1000;
@@ -60,13 +61,15 @@ public:
     metrics[0].stack.mac[0].dl_ri     = 1.5;
     metrics[0].stack.mac[0].dl_pmi    = 1.0;
     metrics[0].stack.mac[0].phr       = 12.0;
-    metrics[0].phy->dl.mcs            = 28.0;
-    metrics[0].phy->ul.mcs            = 20.2;
-    metrics[0].phy->ul.sinr           = 14.2;
+    metrics[0].phy.resize(1);
+    metrics[0].phy[0].dl.mcs  = 28.0;
+    metrics[0].phy[0].ul.mcs  = 20.2;
+    metrics[0].phy[0].ul.sinr = 14.2;
 
     // second
-    metrics[1].rf.rf_o                = 10;
-    metrics[1].stack.rrc.n_ues        = 1;
+    metrics[1].rf.rf_o = 10;
+    metrics[1].stack.rrc.ues.resize(1);
+    metrics[1].stack.mac.resize(metrics[1].stack.rrc.ues.size());
     metrics[1].stack.mac[0].rnti      = 0xffff;
     metrics[1].stack.mac[0].tx_pkts   = 100;
     metrics[1].stack.mac[0].tx_errors = 0;
@@ -80,13 +83,15 @@ public:
     metrics[1].stack.mac[0].dl_ri     = 1.5;
     metrics[1].stack.mac[0].dl_pmi    = 1.0;
     metrics[1].stack.mac[0].phr       = 99.1;
-    metrics[1].phy->dl.mcs            = 6.2;
-    metrics[1].phy->ul.mcs            = 28.0;
-    metrics[1].phy->ul.sinr           = 22.2;
+    metrics[1].phy.resize(1);
+    metrics[1].phy[0].dl.mcs  = 6.2;
+    metrics[1].phy[0].ul.mcs  = 28.0;
+    metrics[1].phy[0].ul.sinr = 22.2;
 
     // third entry
-    metrics[2].rf.rf_o                = 10;
-    metrics[2].stack.rrc.n_ues        = 1;
+    metrics[2].rf.rf_o = 10;
+    metrics[2].stack.rrc.ues.resize(1);
+    metrics[2].stack.mac.resize(metrics[2].stack.rrc.ues.size());
     metrics[2].stack.mac[0].rnti      = 0x1;
     metrics[2].stack.mac[0].tx_pkts   = 9999;
     metrics[2].stack.mac[0].tx_errors = 1;
@@ -100,15 +105,16 @@ public:
     metrics[2].stack.mac[0].dl_ri     = 1.5;
     metrics[2].stack.mac[0].dl_pmi    = 1.0;
     metrics[2].stack.mac[0].phr       = 12.0;
-    metrics[2].phy->dl.mcs            = 28.0;
-    metrics[2].phy->ul.mcs            = 20.2;
-    metrics[2].phy->ul.sinr           = 14.2;
+    metrics[2].phy.resize(1);
+    metrics[2].phy[0].dl.mcs  = 28.0;
+    metrics[2].phy[0].ul.mcs  = 20.2;
+    metrics[2].phy[0].ul.sinr = 14.2;
   }
 
   bool get_metrics(enb_metrics_t* m)
   {
     // fill dummy values
-    memcpy(m, &metrics[counter % NUM_METRICS], sizeof(enb_metrics_t));
+    *m = metrics[counter % NUM_METRICS];
     counter++;
     return true;
   }