diff --git a/srsue/hdr/stack/ue_stack_base.h b/srsue/hdr/stack/ue_stack_base.h
index 2423f2e00..4cea6e6e4 100644
--- a/srsue/hdr/stack/ue_stack_base.h
+++ b/srsue/hdr/stack/ue_stack_base.h
@@ -68,6 +68,7 @@ typedef struct {
   usim_args_t      usim;
   rrc_args_t       rrc;
   std::string      ue_category_str;
+  nas_ext_args_t   nas_ext;
   nas_args_t       nas;
   gw_args_t        gw;
   uint32_t         sync_queue_size; // Max allowed difference between PHY and Stack clocks (in TTI)
diff --git a/srsue/hdr/stack/ue_stack_lte.h b/srsue/hdr/stack/ue_stack_lte.h
index b36823d63..92c72b7e6 100644
--- a/srsue/hdr/stack/ue_stack_lte.h
+++ b/srsue/hdr/stack/ue_stack_lte.h
@@ -37,6 +37,7 @@
 #include "srslte/upper/pdcp.h"
 #include "srslte/upper/rlc.h"
 #include "upper/nas.h"
+#include "upper/nas_ext.h"
 #include "upper/usim.h"
 
 #include "srslte/common/buffer_pool.h"
diff --git a/srsue/src/main.cc b/srsue/src/main.cc
index fd9495380..07e6a9467 100644
--- a/srsue/src/main.cc
+++ b/srsue/src/main.cc
@@ -139,6 +139,9 @@ static int parse_args(all_args_t* args, int argc, char* argv[])
     ("nas.eia",               bpo::value<string>(&args->stack.nas.eia)->default_value("1,2,3"),  "List of integrity algorithms included in UE capabilities")
     ("nas.eea",               bpo::value<string>(&args->stack.nas.eea)->default_value("0,1,2,3"),  "List of ciphering algorithms included in UE capabilities")
 
+    ("extnas.enable", bpo::value<bool>(&args->stack.nas_ext.enable)->default_value(false), "Disable the built-in NAS implementation, provide external interface")
+    ("extnas.sock_path", bpo::value<string>(&args->stack.nas_ext.sock_path)->default_value("/tmp/ue_extnas.sock"), "UNIX socket path of the external interface")
+
     ("pcap.enable", bpo::value<bool>(&args->stack.pcap.enable)->default_value(false), "Enable MAC packet captures for wireshark")
     ("pcap.filename", bpo::value<string>(&args->stack.pcap.filename)->default_value("ue.pcap"), "MAC layer capture filename")
     ("pcap.nas_enable",   bpo::value<bool>(&args->stack.pcap.nas_enable)->default_value(false), "Enable NAS packet captures for wireshark")
diff --git a/srsue/src/stack/ue_stack_lte.cc b/srsue/src/stack/ue_stack_lte.cc
index ed0ff2e08..5421a2951 100644
--- a/srsue/src/stack/ue_stack_lte.cc
+++ b/srsue/src/stack/ue_stack_lte.cc
@@ -106,9 +106,13 @@ int ue_stack_lte::init(const stack_args_t& args_, srslte::logger* logger_)
   extif_log->set_hex_limit(args.log.extif_hex_limit);
 
   // Should we use the built-in NAS implementation
-  // TODO: or provide an external interface (RRCTL)?
-  std::unique_ptr<srsue::nas> nas_impl(new srsue::nas(&task_sched, args.nas));
-  nas = std::move(nas_impl);
+  if (!args.nas_ext.enable) {
+    std::unique_ptr<srsue::nas> nas_impl(new srsue::nas(&task_sched, args.nas));
+    nas = std::move(nas_impl);
+  } else { // ... or provide an external interface (RRCTL)?
+    std::unique_ptr<srsue::nas_ext> nas_impl(new srsue::nas_ext(&task_sched, args.nas_ext));
+    nas = std::move(nas_impl);
+  }
 
   // Set up pcap
   if (args.pcap.enable) {
diff --git a/srsue/ue.conf.example b/srsue/ue.conf.example
index b9890f966..d1c15da18 100644
--- a/srsue/ue.conf.example
+++ b/srsue/ue.conf.example
@@ -163,6 +163,16 @@ imei = 353490069873319
 #eia = 1,2
 #eea = 0,1,2
 
+#####################################################################
+# External NAS interface configuration
+#
+# enable:               Disable the built-in NAS implementation, provide external interface
+# sock_path:            UNIX socket path of the external interface
+#####################################################################
+[extnas]
+#enable = false
+#sock_path = /tmp/ue_extnas.sock
+
 #####################################################################
 # GW configuration
 #