First version for Paging procedures

src/amf-app/amf_app.cpp

@@ -238,39 +238,53 @@ bool amf_app::get_pdu_sessions_context(
 //------------------------------------------------------------------------------
 void amf_app::handle_itti_message(
     itti_n1n2_message_transfer_request& itti_msg) {
-  // Encode DL NAS TRANSPORT message(NAS message)
-  DLNASTransport* dl = new DLNASTransport();
-  dl->setHeader(PLAIN_5GS_MSG);
-  dl->setPayload_Container_Type(N1_SM_INFORMATION);
-  dl->setPayload_Container(
-      (uint8_t*) bdata(itti_msg.n1sm), blength(itti_msg.n1sm));
-  dl->setPDUSessionId(itti_msg.pdu_session_id);
-
-  uint8_t nas[1024];
-  int encoded_size = dl->encode2buffer(nas, 1024);
-  print_buffer("amf_app", "n1n2 transfer", nas, encoded_size);
-  bstring dl_nas = blk2bstr(nas, encoded_size);
-
-  itti_downlink_nas_transfer* dl_msg =
-      new itti_downlink_nas_transfer(TASK_AMF_APP, TASK_AMF_N1);
-  dl_msg->dl_nas = dl_nas;
-  if (!itti_msg.is_n2sm_set) {
-    dl_msg->is_n2sm_set = false;
+  if (itti_msg.is_ppi_set) {  // Paging procedure
+    std::shared_ptr<itti_paging> i =
+        std::make_shared<itti_paging>(TASK_AMF_APP, TASK_AMF_N2);
+    i.get()->amf_ue_ngap_id = amf_n1_inst->supi2amfId.at(itti_msg.supi);
+    i.get()->ran_ue_ngap_id = amf_n1_inst->supi2ranId.at(itti_msg.supi);
+
+    int ret = itti_inst->send_msg(i);
+    if (0 != ret) {
+      Logger::amf_app().error(
+          "Could not send ITTI message %s to task TASK_AMF_N2",
+          i->get_msg_name());
+    }
   } else {
-    dl_msg->n2sm           = itti_msg.n2sm;
-    dl_msg->pdu_session_id = itti_msg.pdu_session_id;
-    dl_msg->is_n2sm_set    = true;
-    dl_msg->n2sm_info_type = itti_msg.n2sm_info_type;
-  }
-  dl_msg->amf_ue_ngap_id = amf_n1_inst->supi2amfId.at(itti_msg.supi);
-  dl_msg->ran_ue_ngap_id = amf_n1_inst->supi2ranId.at(itti_msg.supi);
-  std::shared_ptr<itti_downlink_nas_transfer> i =
-      std::shared_ptr<itti_downlink_nas_transfer>(dl_msg);
-  int ret = itti_inst->send_msg(i);
-  if (0 != ret) {
-    Logger::amf_app().error(
-        "Could not send ITTI message %s to task TASK_AMF_N1",
-        i->get_msg_name());
+    // Encode DL NAS TRANSPORT message(NAS message)
+    DLNASTransport* dl = new DLNASTransport();
+    dl->setHeader(PLAIN_5GS_MSG);
+    dl->setPayload_Container_Type(N1_SM_INFORMATION);
+    dl->setPayload_Container(
+        (uint8_t*) bdata(itti_msg.n1sm), blength(itti_msg.n1sm));
+    dl->setPDUSessionId(itti_msg.pdu_session_id);
+
+    uint8_t nas[BUFFER_SIZE_1024];
+    int encoded_size = dl->encode2buffer(nas, BUFFER_SIZE_1024);
+    print_buffer("amf_app", "n1n2 transfer", nas, encoded_size);
+    bstring dl_nas = blk2bstr(nas, encoded_size);
+
+    itti_downlink_nas_transfer* dl_msg =
+        new itti_downlink_nas_transfer(TASK_AMF_APP, TASK_AMF_N1);
+    dl_msg->dl_nas = dl_nas;
+    if (!itti_msg.is_n2sm_set) {
+      dl_msg->is_n2sm_set = false;
+    } else {
+      dl_msg->n2sm           = itti_msg.n2sm;
+      dl_msg->pdu_session_id = itti_msg.pdu_session_id;
+      dl_msg->is_n2sm_set    = true;
+      dl_msg->n2sm_info_type = itti_msg.n2sm_info_type;
+    }
+    dl_msg->amf_ue_ngap_id = amf_n1_inst->supi2amfId.at(itti_msg.supi);
+    dl_msg->ran_ue_ngap_id = amf_n1_inst->supi2ranId.at(itti_msg.supi);
+    std::shared_ptr<itti_downlink_nas_transfer> i =
+        std::shared_ptr<itti_downlink_nas_transfer>(dl_msg);
+    int ret = itti_inst->send_msg(i);
+    if (0 != ret) {
+      Logger::amf_app().error(
+          "Could not send ITTI message %s to task TASK_AMF_N1",
+          i->get_msg_name());
+    }
   }
 }
 

src/amf-app/amf_n1.cpp

@@ -412,7 +412,7 @@ void amf_n1::nas_signalling_establishment_request_handle(
     set_amf_ue_ngap_id_2_nas_context(amf_ue_ngap_id, nc);
     nc.get()->ctx_avaliability_ind = false;
     // change UE connection status CM-IDLE -> CM-CONNECTED
-    nc.get()->nas_status      = "CM-CONNECTED";
+    nc.get()->nas_status      = CM_CONNECTED;
     nc.get()->amf_ue_ngap_id  = amf_ue_ngap_id;
     nc.get()->ran_ue_ngap_id  = ran_ue_ngap_id;
     nc.get()->serving_network = snn;
@@ -582,7 +582,7 @@ void amf_n1::identity_response_handle(
     nc.get()->ctx_avaliability_ind = false;
   }
   nc.get()->ctx_avaliability_ind         = true;
-  nc.get()->nas_status                   = "CM-CONNECTED";
+  nc.get()->nas_status                   = CM_CONNECTED;
   nc.get()->amf_ue_ngap_id               = amf_ue_ngap_id;
   nc.get()->ran_ue_ngap_id               = ran_ue_ngap_id;
   nc.get()->is_imsi_present              = true;
@@ -847,7 +847,7 @@ void amf_n1::registration_request_handle(
           set_amf_ue_ngap_id_2_nas_context(amf_ue_ngap_id, nc);
           nc.get()->ctx_avaliability_ind = false;
           // change UE connection status CM-IDLE -> CM-CONNECTED
-          nc.get()->nas_status      = "CM-CONNECTED";
+          nc.get()->nas_status      = CM_CONNECTED;
           nc.get()->amf_ue_ngap_id  = amf_ue_ngap_id;
           nc.get()->ran_ue_ngap_id  = ran_ue_ngap_id;
           nc.get()->serving_network = snn;
@@ -925,7 +925,7 @@ void amf_n1::registration_request_handle(
         set_amf_ue_ngap_id_2_nas_context(amf_ue_ngap_id, nc);
         nc.get()->ctx_avaliability_ind = false;
         // change UE connection status CM-IDLE -> CM-CONNECTED
-        nc.get()->nas_status                 = "CM-CONNECTED";
+        nc.get()->nas_status                 = CM_CONNECTED;
         nc.get()->amf_ue_ngap_id             = amf_ue_ngap_id;
         nc.get()->ran_ue_ngap_id             = ran_ue_ngap_id;
         nc.get()->serving_network            = snn;

src/amf-app/amf_n11.cpp

@@ -494,6 +494,7 @@ void amf_n11::handle_post_sm_context_response_error(
   itti_msg->is_n2sm_set    = false;
   itti_msg->supi           = supi;
   itti_msg->pdu_session_id = pdu_session_id;
+  itti_msg->is_ppi_set     = false;
   std::shared_ptr<itti_n1n2_message_transfer_request> i =
       std::shared_ptr<itti_n1n2_message_transfer_request>(itti_msg);
   int ret = itti_inst->send_msg(i);
@@ -718,6 +719,8 @@ void amf_n11::curl_http_client(
 
         itti_msg->is_n1sm_set = false;
         itti_msg->is_n2sm_set = false;
+        itti_msg->is_ppi_set  = false;
+
         if (n1sm.size() > 0) {
           msg_str_2_msg_hex(n1sm, n1sm_hex);
           print_buffer(

src/amf-app/amf_n2.cpp

@@ -243,10 +243,7 @@ void amf_n2::handle_itti_message(itti_paging& itti_msg) {
         itti_msg.amf_ue_ngap_id, unc.get()->amf_ue_ngap_id);
   }
 
-  if (unc.get()->ng_ue_state == NGAP_UE_CONNECTED) {
-    Logger::amf_n2().warn("Received NGAP PAGING while UE in CONNECTED MODE");
-    // return;
-  }
+  // TODO: check UE reachability status
 
   PagingMsg paging_msg = {};
   paging_msg.setMessageType();
@@ -746,15 +743,15 @@ void amf_n2::handle_itti_message(itti_dl_nas_transport& dl_nas_transport) {
 
 //------------------------------------------------------------------------------
 void amf_n2::handle_itti_message(itti_initial_context_setup_request& itti_msg) {
-  std::shared_ptr<ue_ngap_context> unc;
+  std::shared_ptr<ue_ngap_context> unc = {};
   unc = ran_ue_id_2_ue_ngap_context(itti_msg.ran_ue_ngap_id);
   if (unc.get() == nullptr) {
     Logger::amf_n2().error(
         "Illegal UE with ran_ue_ngap_id (0x%x)", itti_msg.ran_ue_ngap_id);
     return;
   }
-  unc.get()->ncc = 1;
-  std::shared_ptr<gnb_context> gc;
+  unc.get()->ncc                  = 1;
+  std::shared_ptr<gnb_context> gc = {};
   gc = assoc_id_2_gnb_context(unc.get()->gnb_assoc_id);
   if (gc.get() == nullptr) {
     Logger::amf_n2().error(
@@ -866,8 +863,8 @@ void amf_n2::handle_itti_message(itti_initial_context_setup_request& itti_msg) {
     }
   }
 
-  uint8_t buffer[20000];  // TODO: remove hardcoded value
-  int encoded_size = msg->encode2buffer(buffer, 10000);
+  uint8_t buffer[BUFFER_SIZE_2048];
+  int encoded_size = msg->encode2buffer(buffer, BUFFER_SIZE_2048);
   bstring b        = blk2bstr(buffer, encoded_size);
   sctp_s_38412.sctp_send_msg(
       gc.get()->sctp_assoc_id, unc.get()->sctp_stream_send, &b);

src/contexts/gNB_context.cpp → src/common/3gpp_29.518.h

@@ -4,8 +4,8 @@
  * this work for additional information regarding copyright ownership.
  * The OpenAirInterface Software Alliance licenses this file to You under
  * the OAI Public License, Version 1.1  (the "License"); you may not use this
- * file except in compliance with the License. You may obtain a copy of the
- * License at
+ *file except in compliance with the License. You may obtain a copy of the
+ *License at
  *
  *      http://www.openairinterface.org/?page_id=698
  *
@@ -19,11 +19,27 @@
  *      contact@openairinterface.org
  */
 
-/*! \file gNB_context.cpp
- \brief
- \author  Keliang DU, BUPT
- \date 2020
- \email: contact@openairinterface.org
- */
+#ifndef FILE_3GPP_29_518_SEEN
+#define FILE_3GPP_29_518_SEEN
+
+#include <vector>
+
+enum n1_n2_message_transfer_cause_e {
+  ATTEMPTING_TO_REACH_UE            = 1,
+  N1_N2_TRANSFER_INITIATED          = 2,
+  WAITING_FOR_ASYNCHRONOUS_TRANSFER = 3,
+  UE_NOT_RESPONDING                 = 4,
+  N1_MSG_NOT_TRANSFERRED            = 5,
+  UE_NOT_REACHABLE_FOR_SESSION      = 6
+};
+
+static const std::vector<std::string> n1_n2_message_transfer_cause_e2str = {
+    "UNKNOWN ERROR",
+    "ATTEMPTING_TO_REACH_UE",
+    "N1_N2_TRANSFER_INITIATED",
+    "WAITING_FOR_ASYNCHRONOUS_TRANSFER",
+    "UE_NOT_RESPONDING",
+    "N1_MSG_NOT_TRANSFERRED",
+    "UE_NOT_REACHABLE_FOR_SESSION"};
 
-#include "gNB_context.hpp"
+#endif

src/common/amf.hpp

@@ -29,6 +29,8 @@
 #define __AMF_HPP
 
 #include "3gpp_23.003.h"
+#include "3gpp_29.518.h"
+
 /*
 typedef struct {
   std::string mcc;

src/contexts/CMakeLists.txt

@@ -37,7 +37,6 @@ include_directories(${SRC_TOP_DIR}/utils)
 include_directories(${SRC_TOP_DIR}/utils/bstr)
 
 add_library (CONTEXTS STATIC
-  ${CMAKE_CURRENT_SOURCE_DIR}/gNB_context.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/nas_context.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/pdu_session_context.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/ue_context.cpp

src/contexts/gNB_context.hpp

@@ -45,10 +45,15 @@ extern "C" {
 using namespace sctp;
 using namespace ngap;
 
-enum amf_ng_gnb_state_s { NGAP_INIT, NGAP_RESETING, NGAP_READY, NGAP_SHUTDOWN };
+typedef enum {
+  NGAP_INIT,
+  NGAP_RESETING,
+  NGAP_READY,
+  NGAP_SHUTDOWN
+} amf_ng_gnb_state_t;
 class gnb_context {
  public:
-  enum amf_ng_gnb_state_s ng_state;
+  amf_ng_gnb_state_t ng_state;
 
   std::string gnb_name;
   long globalRanNodeId;

src/contexts/nas_context.hpp

@@ -56,6 +56,11 @@ static const std::vector<std::string> _5gmm_state_e2str = {
     "_5GMM_COMMON_PROCEDURE_INITIATED",
     "_5GMM_STATE_MAX"};
 
+typedef enum { CM_IDLE = 0, CM_CONNECTED } cm_state_t;
+
+static const std::vector<std::string> cm_state_e2str = {"CM_IDLE",
+                                                        "CM_CONNECTED"};
+
 class nas_context {
  public:
   nas_context();
@@ -64,7 +69,7 @@ class nas_context {
   bool is_stacs_available;
   long amf_ue_ngap_id;
   uint32_t ran_ue_ngap_id;
-  std::string nas_status;
+  cm_state_t nas_status;
   _5gmm_state_t _5gmm_state;
 
   // parameters from Registration request

src/itti/msgs/itti_msg_amf_app.hpp

@@ -86,9 +86,11 @@ class itti_n1n2_message_transfer_request : public itti_msg_amf_app {
       : itti_msg_amf_app(N1N2_MESSAGE_TRANSFER_REQ, origin, destination),
         supi(),
         pdu_session_id(0),
-        n2sm_info_type() {
+        n2sm_info_type(),
+        ppi(0) {
     is_n2sm_set = false;
     is_n1sm_set = false;
+    is_ppi_set  = false;
   }
   itti_n1n2_message_transfer_request(
       const itti_n1n2_message_transfer_request& i)
@@ -100,6 +102,8 @@ class itti_n1n2_message_transfer_request : public itti_msg_amf_app {
     is_n1sm_set    = i.is_n1sm_set;
     pdu_session_id = i.pdu_session_id;
     n2sm_info_type = i.n2sm_info_type;
+    ppi            = i.ppi;
+    is_ppi_set     = i.is_ppi_set;
   }
 
   std::string supi;
@@ -109,6 +113,8 @@ class itti_n1n2_message_transfer_request : public itti_msg_amf_app {
   bool is_n1sm_set;
   uint8_t pdu_session_id;
   std::string n2sm_info_type;
+  bool is_ppi_set;
+  uint8_t ppi;
   // other parameters
 };
 

src/sbi/amf_server/impl/N1N2MessageCollectionDocumentApiImpl.cpp

@@ -72,7 +72,11 @@ void N1N2MessageCollectionDocumentApiImpl::n1_n2_message_transfer(
     Pistache::Http::ResponseWriter& response) {
   Logger::amf_server().debug(
       "Receive N1N2MessageTransfer Request, handling...");
-  response.send(Pistache::Http::Code::Ok, "OK");
+
+  nlohmann::json response_json = {};
+  response_json["cause"] =
+      n1_n2_message_transfer_cause_e2str[N1_N2_TRANSFER_INITIATED];
+  Pistache::Http::Code code = Pistache::Http::Code::Ok;
 
   std::string supi = ueContextId;
   Logger::amf_server().debug(
@@ -108,6 +112,20 @@ void N1N2MessageCollectionDocumentApiImpl::n1_n2_message_transfer(
   itti_msg->is_n2sm_set = true;
   itti_msg->pdu_session_id =
       (uint8_t) n1N2MessageTransferReqData.getPduSessionId();
+
+  // For Paging
+  if (n1N2MessageTransferReqData.ppiIsSet()) {
+    itti_msg->is_ppi_set = true;
+    itti_msg->ppi        = n1N2MessageTransferReqData.getPpi();
+    response_json["cause"] =
+        n1_n2_message_transfer_cause_e2str[ATTEMPTING_TO_REACH_UE];
+    code = Pistache::Http::Code::Accepted;
+  }
+
+  // Send response to the NF Service Consumer (e.g., SMF)
+  response.send(code, response_json.dump().c_str());
+
+  // Process N1N2 Message Transfer Request
   std::shared_ptr<itti_n1n2_message_transfer_request> i =
       std::shared_ptr<itti_n1n2_message_transfer_request>(itti_msg);
   int ret = itti_inst->send_msg(i);