diff --git a/lib/include/srslte/upper/rlc.h b/lib/include/srslte/upper/rlc.h
index 6f0f2d21f..642d59fac 100644
--- a/lib/include/srslte/upper/rlc.h
+++ b/lib/include/srslte/upper/rlc.h
@@ -50,13 +50,12 @@ class rlc
 public:
   rlc();
   virtual ~rlc();
-  void init(srsue::pdcp_interface_rlc *pdcp_,
-            srsue::rrc_interface_rlc  *rrc_,
-            srsue::ue_interface       *ue_,
-            log                       *rlc_log_,
-            mac_interface_timers      *mac_timers_,
-            uint32_t                   lcid_,
-            int                        buffer_size_ = -1); // -1 to use default buffer sizes
+  void init(srsue::pdcp_interface_rlc* pdcp_,
+            srsue::rrc_interface_rlc*  rrc_,
+            srsue::ue_interface*       ue_,
+            log*                       rlc_log_,
+            mac_interface_timers*      mac_timers_,
+            uint32_t                   lcid_);
   void stop();
 
   void get_metrics(rlc_metrics_t &m);
@@ -109,7 +108,6 @@ private:
   pthread_rwlock_t rwlock;
 
   uint32_t                     default_lcid;
-  int                          buffer_size;
 
   // Timer needed for metrics calculation
   struct timeval      metrics_time[3];
diff --git a/lib/include/srslte/upper/rlc_am.h b/lib/include/srslte/upper/rlc_am.h
index 29d44a2a4..d67dbb53b 100644
--- a/lib/include/srslte/upper/rlc_am.h
+++ b/lib/include/srslte/upper/rlc_am.h
@@ -69,7 +69,7 @@ struct rlc_amd_retx_t{
 class rlc_am : public rlc_common
 {
 public:
-  rlc_am(uint32_t queue_len = 128);
+  rlc_am();
   ~rlc_am();
   void init(log                   *log_,
             uint32_t              lcid_,
@@ -104,11 +104,11 @@ private:
   class rlc_am_tx : public timer_callback
   {
   public:
-    rlc_am_tx(rlc_am *parent_, uint32_t queue_len_);
+    rlc_am_tx(rlc_am* parent_);
     ~rlc_am_tx();
 
     void init();
-    bool configure(srslte_rlc_am_config_t cfg_);
+    bool configure(srslte_rlc_config_t cfg_);
 
     void empty_queue();
     void reestablish();
diff --git a/lib/include/srslte/upper/rlc_interface.h b/lib/include/srslte/upper/rlc_interface.h
index 6a0869b52..9549cdd38 100644
--- a/lib/include/srslte/upper/rlc_interface.h
+++ b/lib/include/srslte/upper/rlc_interface.h
@@ -30,6 +30,8 @@
 // for custom constructors
 #include "srslte/asn1/rrc_asn1.h"
 
+#define RLC_TX_QUEUE_LEN (128)
+
 namespace srslte {
 
 typedef enum{
@@ -86,12 +88,13 @@ typedef struct {
 class srslte_rlc_config_t
 {
 public:
-  rlc_mode_t               rlc_mode;
-  srslte_rlc_am_config_t    am;
-  srslte_rlc_um_config_t    um;
+  rlc_mode_t             rlc_mode;
+  srslte_rlc_am_config_t am;
+  srslte_rlc_um_config_t um;
+  uint32_t               tx_queue_length;
 
   // Default ctor
-  srslte_rlc_config_t(): rlc_mode(RLC_MODE_TM), am(), um() {};
+  srslte_rlc_config_t() : rlc_mode(RLC_MODE_TM), am(), um(), tx_queue_length(RLC_TX_QUEUE_LEN){};
 
   // Constructor based on rrc_asn1's RLC config
   srslte_rlc_config_t(asn1::rrc::rlc_cfg_c* cnfg) : rlc_mode(RLC_MODE_AM), am(), um()
@@ -131,6 +134,8 @@ public:
         // Handle default case
         break;
     }
+
+    tx_queue_length = RLC_TX_QUEUE_LEN;
   }
 
   // Factory for MCH
@@ -145,6 +150,7 @@ public:
     cfg.um.tx_sn_field_length  = RLC_UMD_SN_SIZE_5_BITS;
     cfg.um.tx_mod              = 32;
     cfg.um.is_mrb              = true;
+    cfg.tx_queue_length        = 512;
     return cfg;
   }
 };
diff --git a/lib/include/srslte/upper/rlc_um.h b/lib/include/srslte/upper/rlc_um.h
index 48ad0da17..7f947b94f 100644
--- a/lib/include/srslte/upper/rlc_um.h
+++ b/lib/include/srslte/upper/rlc_um.h
@@ -48,7 +48,7 @@ class rlc_um
     :public rlc_common
 {
 public:
-  rlc_um(uint32_t queue_len = 128);
+  rlc_um();
   ~rlc_um();
   void init(log                       *rlc_entity_log_,
             uint32_t                   lcid_,
@@ -84,7 +84,7 @@ private:
   class rlc_um_tx
   {
   public:
-    rlc_um_tx(uint32_t queue_len);
+    rlc_um_tx();
     ~rlc_um_tx();
     void init(srslte::log *log_);
     bool configure(srslte_rlc_config_t cfg, std::string rb_name);
diff --git a/lib/src/upper/rlc.cc b/lib/src/upper/rlc.cc
index 4111c5b5b..c8516ac3a 100644
--- a/lib/src/upper/rlc.cc
+++ b/lib/src/upper/rlc.cc
@@ -42,8 +42,6 @@ rlc::rlc()
   rrc = NULL;
   mac_timers = NULL;
   ue = NULL;
-  default_lcid = 0;
-  buffer_size = 0;
   bzero(metrics_time, sizeof(metrics_time));
   pthread_rwlock_init(&rwlock, NULL);
 }
@@ -66,13 +64,12 @@ rlc::~rlc()
   pthread_rwlock_destroy(&rwlock);
 }
 
-void rlc::init(srsue::pdcp_interface_rlc *pdcp_,
-               srsue::rrc_interface_rlc  *rrc_,
-               srsue::ue_interface       *ue_,
-               log                       *rlc_log_, 
-               mac_interface_timers      *mac_timers_,
-               uint32_t                  lcid_,
-               int                       buffer_size_)
+void rlc::init(srsue::pdcp_interface_rlc* pdcp_,
+               srsue::rrc_interface_rlc*  rrc_,
+               srsue::ue_interface*       ue_,
+               log*                       rlc_log_,
+               mac_interface_timers*      mac_timers_,
+               uint32_t                   lcid_)
 {
   pdcp    = pdcp_;
   rrc     = rrc_;
@@ -80,7 +77,6 @@ void rlc::init(srsue::pdcp_interface_rlc *pdcp_,
   rlc_log = rlc_log_;
   mac_timers = mac_timers_;
   default_lcid = lcid_;
-  buffer_size  = buffer_size_;
 
   gettimeofday(&metrics_time[1], NULL);
   reset_metrics();
diff --git a/lib/src/upper/rlc_am.cc b/lib/src/upper/rlc_am.cc
index 6d34ee8e9..9cff3ad87 100644
--- a/lib/src/upper/rlc_am.cc
+++ b/lib/src/upper/rlc_am.cc
@@ -38,16 +38,7 @@
 
 namespace srslte {
 
-rlc_am::rlc_am(uint32_t queue_len)
-  :tx(this, queue_len)
-  ,rx(this)
-  ,log(NULL)
-  ,rrc(NULL)
-  ,pdcp(NULL)
-  ,mac_timers(NULL)
-  ,lcid(0)
-  ,rb_name("")
-  ,cfg()
+rlc_am::rlc_am() : tx(this), rx(this), log(NULL), rrc(NULL), pdcp(NULL), mac_timers(NULL), lcid(0), rb_name(""), cfg()
 {
 }
 
@@ -80,7 +71,7 @@ bool rlc_am::configure(srslte_rlc_config_t cfg_)
     return false;
   }
 
-  if (not tx.configure(cfg_.am)) {
+  if (not tx.configure(cfg_)) {
     return false;
   }
 
@@ -176,26 +167,25 @@ void rlc_am::write_pdu(uint8_t *payload, uint32_t nof_bytes)
  * Tx subclass implementation
  ***************************************************************************/
 
-rlc_am::rlc_am_tx::rlc_am_tx(rlc_am* parent_, uint32_t queue_len_)
-  :parent(parent_)
-  ,poll_retx_timer(NULL)
-  ,poll_retx_timer_id(0)
-  ,status_prohibit_timer(NULL)
-  ,status_prohibit_timer_id(0)
-  ,vt_a(0)
-  ,vt_ms(RLC_AM_WINDOW_SIZE)
-  ,vt_s(0)
-  ,status_prohibited(false)
-  ,poll_sn(0)
-  ,num_tx_bytes(0)
-  ,pdu_without_poll(0)
-  ,byte_without_poll(0)
-  ,tx_sdu(NULL)
-  ,tx_sdu_queue(queue_len_)
-  ,log(NULL)
-  ,cfg()
-  ,pool(byte_buffer_pool::get_instance())
-  ,tx_enabled(false)
+rlc_am::rlc_am_tx::rlc_am_tx(rlc_am* parent_) :
+  parent(parent_),
+  poll_retx_timer(NULL),
+  poll_retx_timer_id(0),
+  status_prohibit_timer(NULL),
+  status_prohibit_timer_id(0),
+  vt_a(0),
+  vt_ms(RLC_AM_WINDOW_SIZE),
+  vt_s(0),
+  status_prohibited(false),
+  poll_sn(0),
+  num_tx_bytes(0),
+  pdu_without_poll(0),
+  byte_without_poll(0),
+  tx_sdu(NULL),
+  log(NULL),
+  cfg(),
+  pool(byte_buffer_pool::get_instance()),
+  tx_enabled(false)
 {
   pthread_mutex_init(&mutex, NULL);
   ZERO_OBJECT(tx_status);
@@ -219,10 +209,10 @@ void rlc_am::rlc_am_tx::init()
   }
 }
 
-bool rlc_am::rlc_am_tx::configure(srslte_rlc_am_config_t cfg_)
+bool rlc_am::rlc_am_tx::configure(srslte_rlc_config_t cfg_)
 {
   // TODO: add config checks
-  cfg = cfg_;
+  cfg = cfg_.am;
 
   // check timers
   if (poll_retx_timer == NULL or status_prohibit_timer == NULL) {
@@ -238,6 +228,8 @@ bool rlc_am::rlc_am_tx::configure(srslte_rlc_am_config_t cfg_)
     poll_retx_timer->set(this, static_cast<uint32_t>(cfg.t_poll_retx));
   }
 
+  tx_sdu_queue.resize(cfg_.tx_queue_length);
+
   tx_enabled = true;
 
   return true;
diff --git a/lib/src/upper/rlc_um.cc b/lib/src/upper/rlc_um.cc
index 55b61f008..2c1858661 100644
--- a/lib/src/upper/rlc_um.cc
+++ b/lib/src/upper/rlc_um.cc
@@ -36,12 +36,7 @@ using namespace asn1::rrc;
 
 namespace srslte {
 
-rlc_um::rlc_um(uint32_t queue_len)
-    :lcid(0)
-    ,tx(queue_len)
-    ,pool(byte_buffer_pool::get_instance())
-    ,rrc(NULL)
-    ,log(NULL)
+rlc_um::rlc_um() : lcid(0), tx(), pool(byte_buffer_pool::get_instance()), rrc(NULL), log(NULL)
 {
   bzero(&cfg, sizeof(srslte_rlc_um_config_t));
 }
@@ -221,14 +216,13 @@ std::string rlc_um::get_rb_name(srsue::rrc_interface_rlc *rrc, uint32_t lcid, bo
  * Tx subclass implementation
  ***************************************************************************/
 
-rlc_um::rlc_um_tx::rlc_um_tx(uint32_t queue_len)
-    :tx_sdu_queue(queue_len)
-    ,pool(byte_buffer_pool::get_instance())
-    ,log(NULL)
-    ,tx_sdu(NULL)
-    ,vt_us(0)
-    ,tx_enabled(false)
-    ,num_tx_bytes(0)
+rlc_um::rlc_um_tx::rlc_um_tx() :
+  pool(byte_buffer_pool::get_instance()),
+  log(NULL),
+  tx_sdu(NULL),
+  vt_us(0),
+  tx_enabled(false),
+  num_tx_bytes(0)
 {
   pthread_mutex_init(&mutex, NULL);
 }
@@ -255,9 +249,7 @@ bool rlc_um::rlc_um_tx::configure(srslte_rlc_config_t cnfg_, std::string rb_name
     return false;
   }
 
-  if(cfg.is_mrb){
-    tx_sdu_queue.resize(512);
-  }
+  tx_sdu_queue.resize(cnfg_.tx_queue_length);
 
   rb_name = rb_name_;
   tx_enabled = true;
diff --git a/srsenb/hdr/upper/rlc.h b/srsenb/hdr/upper/rlc.h
index 05d4681f1..6ca7ee195 100644
--- a/srsenb/hdr/upper/rlc.h
+++ b/srsenb/hdr/upper/rlc.h
@@ -94,8 +94,6 @@ private:
 
   void clear_user(user_interface *ue);
 
-  const static int RLC_TX_QUEUE_LEN = 512;
-
   pthread_rwlock_t rwlock;
 
   std::map<uint32_t,user_interface> users;