Merge remote-tracking branch 'origin/add-support-eth-pdu-sess' into integration_2026_w05 (!3769)

Add Ethernet PDU session support and make PDU session request configurable This MR adds support for Ethernet PDU sessions, and makes PDU sessions configurable: per-PDU session ID, type (IPv4/IPv4v6/IPv6/Ethernet [1]), DNN, NSSAI. Concretely, it adds a new configuration file section pdu_sessions below uicc0 that looks like this if everything is specified (default values are shown): uicc0: [...] pdu_sessions: - id: 1 type: "IPv4" nssai_sst: 1 nssai_sd: 0xffffff dnn: "oai" It is possible to list multiple PDU sessions (add new line - id: 2 to request a second PDU session). It is backwards-compatible to the current PDU session configuration (uicc0.dnn/nssai_sst/etc), the idea being that either legacy or new configuration could be used, but (1) if pdu_sessions exist, it will overwrite the legacy configuration, and (2) multiple PDU sessions, and type, can only be configured using the new config. The old parameters --extra-pdu-id and --default-pdu-id are not accepted anymore. Documentation has been added to the UE tutorial. It is possible to test an Ethernet PDU session [1]. It is possible to test the PDU session inside the UE by verifying it has an TAP interface oaitap_ue1, and ARPing the data network (arping has been added to oai-nr-ue container for that purpose): ip addr add 192.168.72.140/26 dev oaitap_ue1 # same subnet as data network! ip link set dev oaitap_ue1 up arping -c 20 -I oaitap_ue1 192.168.72.135 # will send ARP request in Ethernet frame to get IP address of data network [1] See description MR !3769 for more information. On the UE side, only the type has to be changed to "Ethernet".
2026-01-29 07:52:48 +01:00
parent e1a327ca4f 780a2467aa
commit 0eb33e69c7
49 changed files with 483 additions and 190 deletions
@@ -12,8 +12,7 @@ uicc0 = {
 imsi = "208990100001100";
 key = "fec86ba6eb707ed08905757b1bb44b8f";
 opc= "C42449363BBAD02B66D16BC975D77CC1";
-dnn= "oai";
-nssai_sst=1;
+pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }

 MACRLCs = (
@@ -0,0 +1,11 @@
+uicc0 = {
+  imsi = "208990100001100";
+  key = "fec86ba6eb707ed08905757b1bb44b8f";
+  opc= "C42449363BBAD02B66D16BC975D77CC1";
+  pdu_sessions = (
+    { id = 1; dnn = "oai"; nssai_sst = 1; },
+    { id = 2; dnn = "oai"; nssai_sst = 1; }
+  )
+}
+
+thread-pool = "-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1"
@@ -2,8 +2,7 @@ uicc0 = {
  imsi = "208990100001100";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }

 position0 = {
@@ -2,8 +2,7 @@ uicc0 = {
  imsi = "208990100001100";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }

 position0 = {
@@ -2,8 +2,9 @@ uicc0:
  imsi: 208990100001100
  key: fec86ba6eb707ed08905757b1bb44b8f
  opc: C42449363BBAD02B66D16BC975D77CC1
-  dnn: oai
-  nssai_sst: 1
+  pdu_sessions:
+    - dnn: oai
+      nssai_sst: 1

 thread-pool: "-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1"

@@ -2,8 +2,9 @@ uicc0:
  imsi: 208990100001100
  key: fec86ba6eb707ed08905757b1bb44b8f
  opc: C42449363BBAD02B66D16BC975D77CC1
-  dnn: oai
-  nssai_sst: 1
+  pdu_sessions:
+    - dnn: oai
+      nssai_sst: 1

 thread-pool: "-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1"

@@ -2,8 +2,7 @@ uicc0 = {
  imsi = "208970100001127";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "c42449363bbad02b66d16bc975d77cc1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }

 thread-pool = "-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1"
@@ -12,9 +12,7 @@ uicc0 = {
 imsi = "208950000000031";
 key = "0c0a34601d4f07677303652c0462535b";
 opc= "63bfa50ee6523365ff14c1f45f88737d";
-dnn= "oai";
-nssai_sst=222;
-nssai_sd=123;
+pdu_sessions = ({ dnn = "oai"; nssai_sst = 222; nssai_sd = 123; });
 }

 MACRLCs = (
@@ -12,9 +12,7 @@ uicc0 = {
 imsi = "2089900007487";
 key = "fec86ba6eb707ed08905757b1bb44b8f";
 opc= "C42449363BBAD02B66D16BC975D77CC1";
-dnn= "oai";
-nssai_sst=1;
-nssai_sd=1;
+pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; nssai_sd = 1; });
 }

 MACRLCs = (
@@ -518,8 +518,7 @@ uicc0 = {
  imsi = "208990100001100";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 ```

@@ -338,7 +338,7 @@ services:
        environment:
            USE_ADDITIONAL_OPTIONS: --rfsim --log_config.global_log_options level,nocolor,time
                                    -r 106 --numerology 1 -C 3619200000
-                                    --uicc0.imsi 208990100001101 --uicc0.nssai_sst 2
+                                    --uicc0.imsi 208990100001101 --uicc0.pdu_sessions.[0].nssai_sst 2
                                    --rfsimulator.[0].serveraddr 192.168.78.3
        depends_on:
            - oai-du2
@@ -368,7 +368,7 @@ services:
        environment:
            USE_ADDITIONAL_OPTIONS: --rfsim --log_config.global_log_options level,nocolor,time
                                    -r 106 --numerology 1 -C 3619200000
-                                    --uicc0.imsi 208990100001102 --uicc0.nssai_sst 3
+                                    --uicc0.imsi 208990100001102 --uicc0.pdu_sessions.[0].nssai_sst 3
                                    --rfsimulator.[0].serveraddr 192.168.78.4
            ASAN_OPTIONS: detect_leaks=0
        depends_on:
@@ -2,71 +2,61 @@ uicc0 = {
  imsi = "208990100001100";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc1 = {
  imsi = "208990100001101";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc2 = {
  imsi = "208990100001102";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc3 = {
  imsi = "208990100001103";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc4 = {
  imsi = "208990100001104";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc5 = {
  imsi = "208990100001105";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc6 = {
  imsi = "208990100001106";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc7 = {
  imsi = "208990100001107";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc8 = {
  imsi = "208990100001108";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 uicc9 = {
  imsi = "208990100001109";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc= "C42449363BBAD02B66D16BC975D77CC1";
-  dnn= "oai";
-  nssai_sst=1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }

 thread-pool: "-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1"
@@ -149,7 +149,7 @@ services:
            - NET_RAW    # for ping
        environment:
            USE_ADDITIONAL_OPTIONS: --rfsim -r 25 --numerology 0 --uicc0.imsi 208990100001100 --band 66 -C 2152680000 --CO -400000000 --ssb 48
-                                    --rfsimulator.[0].serveraddr 192.168.71.141 --extra-pdu-id 2 --log_config.global_log_options level,nocolor,time
+                                    --rfsimulator.[0].serveraddr 192.168.71.141 --log_config.global_log_options level,nocolor,time
                                    --telnetsrv --telnetsrv.shrmod ciUE --telnetsrv.listenaddr 192.168.71.150 --telnetsrv.listenport 8091
            ASAN_OPTIONS: detect_leaks=0:detect_odr_violation=0
        depends_on:
@@ -160,7 +160,7 @@ services:
        devices:
             - /dev/net/tun:/dev/net/tun
        volumes:
-            - ../../conf_files/nrue.uicc.conf:/opt/oai-nr-ue/etc/nr-ue.conf
+            - ../../conf_files/nrue.uicc.2pdu.conf:/opt/oai-nr-ue/etc/nr-ue.conf
        healthcheck:
            test: /bin/bash -c "pgrep nr-uesoftmodem"
            start_period: 10s
@@ -144,7 +144,7 @@ int config_cmdlineonly_getlist(configmodule_interface_t *cfg,
                               paramlist_def_t *ParamList,
                               paramdef_t *params,
                               int numparams,
-                               char *prefix)
+                               const char *prefix)
 {
  ParamList->numelt = 0;
  return 0;
@@ -61,7 +61,7 @@
 struct configmodule_interface;
 typedef int (*configmodule_getfunc_t)(struct configmodule_interface *, paramdef_t *, int numparams, const char *prefix);
 typedef int (
-    *configmodule_getlistfunc_t)(struct configmodule_interface *, paramlist_def_t *, paramdef_t *, int numparams, char *prefix);
+    *configmodule_getlistfunc_t)(struct configmodule_interface *, paramlist_def_t *, paramdef_t *, int numparams, const char *prefix);
 typedef int (*configmodule_setfunc_t)(paramdef_t *cfgoptions, int numoptions, const char *prefix);
 typedef void (*configmodule_endfunc_t)(struct configmodule_interface *cfg);

@@ -142,7 +142,7 @@ int config_get(configmodule_interface_t *cfgif, paramdef_t *params, int numparam
  return ret;
 }

-int config_getlist(configmodule_interface_t *cfg, paramlist_def_t *ParamList, paramdef_t *params, int numparams, char *prefix)
+int config_getlist(configmodule_interface_t *cfg, paramlist_def_t *ParamList, paramdef_t *params, int numparams, const char *prefix)
 {
  if (CONFIG_ISFLAGSET(CONFIG_ABORT)) {
    fprintf(stderr,"[CONFIG] config_get skipped, config module not properly initialized\n");
@@ -62,7 +62,7 @@ int config_assign_ipv4addr(configmodule_interface_t *cfg, paramdef_t *cfgoptions
 #define CONFIG_CHECKALLSECTIONS "ALLSECTIONS"
 int config_check_unknown_cmdlineopt(configmodule_interface_t *cfg, char *prefix);
 int config_get(configmodule_interface_t *cfg, paramdef_t *params, int numparams, const char *prefix);
-int config_getlist(configmodule_interface_t *cfg, paramlist_def_t *ParamList, paramdef_t *params, int numparams, char *prefix);
+int config_getlist(configmodule_interface_t *cfg, paramlist_def_t *ParamList, paramdef_t *params, int numparams, const char *prefix);

 /* apis to set some of the paramdef_t fields before using the get/getlist api's */
 void config_set_checkfunctions(paramdef_t *params, checkedparam_t *checkfunctions, int numparams);
@@ -100,5 +100,8 @@
 // SDAP
 #define MAX_QOS_FLOWS 64

+// SDAP/5G NAS NOS1
+#define DEFAULT_NOS1_PDU_ID 10
+
 #define SPEED_OF_LIGHT 299792458 // in m/s
 #endif /* __PLATFORM_CONSTANTS_H__ */
@@ -14,7 +14,7 @@ add_subdirectory(nr)
 add_subdirectory(LOG)
 add_subdirectory(threadPool)
 add_subdirectory(time_manager)
-add_library(utils utils.c system.c time_meas.c time_stat.c tun_if.c)
+add_library(utils utils.c system.c time_meas.c time_stat.c tuntap_if.c)
 target_include_directories(utils PUBLIC .)
 target_link_libraries(utils PRIVATE ${T_LIB})
 if (ENABLE_TESTS)
@@ -172,7 +172,11 @@ static int add_pdu_session(char *buf, int debug, telnet_printfunc_t prnt)
  if (!nas)
    ERROR_MSG_RET("No NAS context found for UE_ID %d\n", ue_id);

-  request_pdusession(nas, pdusession_id);
+  DevAssert(nas->uicc);
+  nssai_t nssai = {nas->uicc->nssai_sst, nas->uicc->nssai_sd};
+  pdu_session_config_t c = {pdusession_id, 1 /* = PDU_SESSION_TYPE_IPV4 */, nssai, nas->uicc->dnnStr};
+  nas->uicc->pdu_sessions[nas->uicc->n_pdu_sessions++] = c;
+  request_pdusession(nas, &c);
  prnt("Triggered PDU session request for UE %d with ID %d\n", ue_id, pdusession_id);
  return 0;
 }
@@ -27,10 +27,9 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <linux/ipv6.h>
-#include <linux/if_tun.h>
 #include <linux/netlink.h>

-#include "tun_if.h"
+#include "tuntap_if.h"
 #include "common/platform_constants.h"
 #include "common/utils/LOG/log.h"
 #include "common/utils/system.h"
@@ -38,7 +37,7 @@
 int nas_sock_fd[MAX_MOBILES_PER_ENB * 2]; // Allocated for both LTE UE and NR UE.
 int nas_sock_mbms_fd;

-int tun_alloc(const char *dev)
+int tuntap_alloc(int flag, const char *dev)
 {
  struct ifreq ifr;
  int fd, err;
@@ -54,7 +53,8 @@ int tun_alloc(const char *dev)
   *
   *        IFF_NO_PI - Do not provide packet information
   */
-  ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
+  DevAssert(flag == IFF_TUN || flag == IFF_TAP);
+  ifr.ifr_flags = flag | IFF_NO_PI;
  strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name) - 1);
  if ((err = ioctl(fd, TUNSETIFF, (void *)&ifr)) < 0) {
    close(fd);
@@ -76,7 +76,7 @@ int tun_alloc(const char *dev)

 int tun_init_mbms(char *ifname)
 {
-  nas_sock_mbms_fd = tun_alloc(ifname);
+  nas_sock_mbms_fd = tuntap_alloc(IFF_TUN, ifname);

  if (nas_sock_mbms_fd == -1) {
    LOG_E(UTIL, "Error opening mbms socket %s (%d:%s)\n", ifname, errno, strerror(errno));
@@ -96,7 +96,7 @@ int tun_init_mbms(char *ifname)

 int tun_init(const char *ifname, int instance_id)
 {
-  nas_sock_fd[instance_id] = tun_alloc(ifname);
+  nas_sock_fd[instance_id] = tuntap_alloc(IFF_TUN, ifname);

  if (nas_sock_fd[instance_id] == -1) {
    LOG_E(UTIL, "Error opening socket %s (%d:%s)\n", ifname, errno, strerror(errno));
@@ -158,42 +158,47 @@ static bool setInterfaceParameter(int sock_fd, const char *ifn, int af, const ch
 }


-typedef enum { INTERFACE_DOWN, INTERFACE_UP } if_action_t;
 /*
-* \brief bring interface up (up != 0) or down (up == 0)
+* \brief Get an interface's flags.
+* \param[in]  sock_fd socket to use for getting the flags
+* \param[in]  ifn the interface name for which to get flags
+* \param[out] flags the flags of the interface
+* \return true on success, false otherwise
 */
-static bool change_interface_state(int sock_fd, const char *ifn, if_action_t if_action)
+static bool get_if_flags(int sock_fd, const char *ifn, short *flags)
 {
-  const char *action = if_action == INTERFACE_DOWN ? "DOWN" : "UP";
-
  struct ifreq ifr = {0};
  strncpy(ifr.ifr_name, ifn, sizeof(ifr.ifr_name) - 1);

  /* get flags of this interface: see netdevice(7) */
-  bool success = ioctl(sock_fd, SIOCGIFFLAGS, (caddr_t)&ifr) == 0;
-  if (!success && if_action == INTERFACE_DOWN && errno == ENODEV) {
-    LOG_W(OIP, "trying to remove non-existant device %s\n", ifn);
-    return true;
+  int success = ioctl(sock_fd, SIOCGIFFLAGS, (caddr_t)&ifr) == 0;
+  if (!success) {
+    LOG_W(OIP, "On interface %s: ioctl() failed: %d, %s\n", ifn, errno, strerror(errno));
+    return false;
  }
-  LOG_D(OIP, "Got flags for %s: 0x%x (action: %s)\n", ifn, ifr.ifr_flags, action);
-
-  if (if_action == INTERFACE_UP) {
-    ifr.ifr_flags |= IFF_UP | IFF_NOARP | IFF_POINTOPOINT;
-    ifr.ifr_flags &= ~IFF_MULTICAST;
-  } else {
-    ifr.ifr_flags &= ~IFF_UP;
-  }
-
-  success = ioctl(sock_fd, SIOCSIFFLAGS, (caddr_t)&ifr) == 0;
-  if (!success)
-    goto fail_interface_state;
-  LOG_D(OIP, "Interface %s successfully set %s\n", ifn, action);
-
+  *flags = ifr.ifr_flags;
  return true;
+}

-fail_interface_state:
-  LOG_E(OIP, "Bringing interface %s for %s: ioctl call failed: %d, %s\n", action, ifn, errno, strerror(errno));
-  return false;
+/*
+ * \brief Set an interface's flags.
+* \param[in]  sock_fd socket to use for setting the flags
+* \param[in]  ifn the interface name for which to set flags
+* \param[in]  flags the flags to set for the interface
+* \return true on success, false otherwise
+ */
+static bool set_if_flags(int sock_fd, const char *ifn, short flags)
+{
+  struct ifreq ifr = {0};
+  strncpy(ifr.ifr_name, ifn, sizeof(ifr.ifr_name) - 1);
+  ifr.ifr_flags = flags;
+
+  int success = ioctl(sock_fd, SIOCSIFFLAGS, (caddr_t)&ifr) == 0;
+  if (!success) {
+    LOG_W(OIP, "On interface %s: ioctl() failed: %d, %s\n", ifn, errno, strerror(errno));
+    return false;
+  }
+  return true;
 }


@@ -227,11 +232,13 @@ bool tun_config(const char* ifname, const char *ipv4, const char *ipv6)
    close(sock_fd);
  }

+  // if successfully set IP addresses: set iterface up, disable ARP, no
+  // multicast, point-to-point
  if (success)
-    success = change_interface_state(sock_fd, ifname, INTERFACE_UP);
+    success = set_if_flags(sock_fd, ifname, (IFF_UP | IFF_NOARP | IFF_POINTOPOINT) & ~IFF_MULTICAST);

  if (success)
-    LOG_I(OIP, "Interface %s successfully configured, IPv4 %s, IPv6 %s\n", ifname, ipv4, ipv6);
+    LOG_A(OIP, "TUN Interface %s successfully configured, IPv4 %s, IPv6 %s\n", ifname, ipv4, ipv6);
  else
    LOG_E(OIP, "Interface %s couldn't be configured (IPv4 %s, IPv6 %s)\n", ifname, ipv4, ipv6);

@@ -239,6 +246,25 @@ bool tun_config(const char* ifname, const char *ipv4, const char *ipv6)
  return success;
 }

+bool tap_config(const char* ifname)
+{
+  int sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sock_fd < 0) {
+    LOG_E(UTIL, "Failed creating socket for interface management: %d, %s\n", errno, strerror(errno));
+    return false;
+  }
+
+  bool success = set_if_flags(sock_fd, ifname, IFF_UP);
+
+  if (success)
+    LOG_A(OIP, "TAP interface %s successfully configured\n", ifname);
+  else
+    LOG_E(OIP, "Tap interface %s couldn't be configured\n", ifname);
+
+  close(sock_fd);
+  return success;
+}
+
 void setup_ue_ipv4_route(const char* ifname, int instance_id, const char *ipv4)
 {
  int table_id = instance_id - 1 + 10000;
@@ -267,14 +293,16 @@ int tun_generate_ifname(char *ifname, const char *ifprefix, int instance_id)
  return snprintf(ifname, IFNAMSIZ, "%s%d", ifprefix, instance_id + 1);
 }

-int tun_generate_ue_ifname(char *ifname, int instance_id, int pdu_session_id)
+int tuntap_generate_ue_ifname(char *ifname, int flag, int instance_id, int pdu_session_id)
 {
+  DevAssert(flag == IFF_TUN || flag == IFF_TAP);
  char pdu_session_string[10];
  snprintf(pdu_session_string, sizeof(pdu_session_string), "p%d", pdu_session_id);
-  return snprintf(ifname, IFNAMSIZ, "%s%d%s", "oaitun_ue", instance_id + 1, pdu_session_id == -1 ? "" : pdu_session_string);
+  const char *basename = flag == IFF_TUN ? "oaitun_ue" : "oaitap_ue";
+  return snprintf(ifname, IFNAMSIZ, "%s%d%s", basename, instance_id + 1, pdu_session_id == -1 ? "" : pdu_session_string);
 }

-void tun_destroy(const char *dev)
+void tuntap_destroy(const char *dev)
 {
  // Use a new socket for ioctl operations
  int fd = socket(AF_INET, SOCK_DGRAM, 0);
@@ -283,11 +311,12 @@ void tun_destroy(const char *dev)
    return;
  }

-  bool success = change_interface_state(fd, dev, INTERFACE_DOWN);
+  // interface not up => down
+  short flags;
+  bool success = get_if_flags(fd, dev, &flags);
+  success = success && set_if_flags(fd, dev, flags & ~IFF_UP);
  if (success) {
    LOG_I(UTIL, "Interface %s is now down.\n", dev);
-  } else {
-    LOG_E(UTIL, "Could not bring interface %s down.\n", dev);
-  }
+  } // no else: get_if_flags()/set_if_flags() should have printed error
  close(fd);
 }
@@ -24,6 +24,7 @@

 #include <stdbool.h>
 #include <net/if.h>
+#include <linux/if_tun.h>

 /*!
 * \brief This function generates the name of the interface based on the prefix and
@@ -34,7 +35,17 @@
 * \param[in] instance_id unique instance number
 */
 int tun_generate_ifname(char *ifname, const char *ifprefix, int instance_id);
-int tun_generate_ue_ifname(char *ifname, int instance_id, int pdu_session_id);
+
+/*!
+ * \brief This function generates the name of the interface based on the prefix and
+ * the instance id for a UE.
+ *
+ * \param[in,out] ifname name of the interface
+ * \param[in] flag IFF_TUN (for TUN device) or IFF_TAP (for TAP device)
+ * \param[in] ifprefix prefix of the interface
+ * \param[in] instance_id unique instance number
+ */
+int tuntap_generate_ue_ifname(char *ifname, int flag, int instance_id, int pdu_session_id);

 /*!
 * \brief This function initializes the TUN interface
@@ -50,9 +61,8 @@ int tun_init(const char *ifname, int instance_id);
 int tun_init_mbms(char *ifname);

 /*!
- * \brief This function initializes the nasmesh interface using the basic values,
- * basic address, network mask and broadcast address, as the default configured
- * ones
+ * \brief Initializes the TUN interface with an IPv4 or IPv6 address and
+ * activates the interface.
 * \param[in] ifname name of the interface
 * \param[in] ipv4 IPv4 address of this interface as a string
 * \param[in] ipv6 IPv6 address of this interface as a string
@@ -62,6 +72,15 @@ int tun_init_mbms(char *ifname);
 */
 bool tun_config(const char* ifname, const char *ipv4, const char *ipv6);

+/*!
+ * \brief Initializes and activates the TAP interface.
+ * \param[in] ifname name of the interface
+ * \return true on success, otherwise false
+ * \note
+ * @ingroup  _nas
+ */
+bool tap_config(const char* ifname);
+
 /*!
 * \brief Setup a IPv4 rule in table (interface_id - 1 + 10000) and route to
 * force packets coming into interface back through it, and workaround
@@ -75,16 +94,17 @@ bool tun_config(const char* ifname, const char *ipv4, const char *ipv6);
 void setup_ue_ipv4_route(const char* ifname, int instance_id, const char *ipv4);

 /*!
- * \brief This function allocates a TUN interface
+ * \brief This function allocates a TUN or TAP interface
+ * \param[in] flag IFF_TUN (for TUN device) or IFF_TAP (for TAP device)
 * \param[in] dev name of the interface
 * \return file descriptor of the allocated interface
 */
-int tun_alloc(const char *dev);
+int tuntap_alloc(int flag, const char *dev);

 /*!
- * \brief This function destroys the TUN interface
+ * \brief This function destroys the TUN or TAP interface
 * \param[in] dev name of the interface
 */
-void tun_destroy(const char *dev);
+void tuntap_destroy(const char *dev);

 #endif /*TUN_IF_H_*/
@@ -866,8 +866,8 @@ INPUT                  = \
@CMAKE_CURRENT_SOURCE_DIR@/../common/config/config_cmdline.c \
@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/time_meas.c \
@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/time_meas.h \
-@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/tun_if.h \
-@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/tun_if.c \
+@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/tuntap_if.h \
+@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/tuntap_if.c \
@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/utils.c \
@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/oai_asn1.h \
@CMAKE_CURRENT_SOURCE_DIR@/../common/utils/system.h \
@@ -173,8 +173,7 @@ uicc0 = {
  imsi = "001010000000001";
  key = "fec86ba6eb707ed08905757b1bb44b8f";
  opc = "C42449363BBAD02B66D16BC975D77CC1";
-  dnn = "oai";
-  nssai_sst = 1;
+  pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; });
 }
 ```

@@ -183,8 +182,23 @@ uicc0 = {
 | **IMSI** | Unique identifier for the UE within the mobile network. Used by the network to identify the UE during authentication. It ensures that the UE is correctly identified by the network. | 001010000000001 |
 | **key** | Cryptographic key shared between the UE and the network, used for encryption during the authentication process. | `fec86ba6eb707ed08905757b1bb44b8f` |
 | **OPC** | Operator key for the Milenage Authentication and Key Agreement algorithm used for encryption during the authentication process. | Ensures secure communication between the UE and the network by matching the encryption keys. | `C42449363BBAD02B66D16BC975D77CC1` |
-| **DNN** | Specifies the name of the data network the UE wishes to connect to, similar to an APN in 4G networks. | `oai` |
-| **NSSAI** | Allows the UE to select the appropriate network slice, which provides different QoS. | `1` |
+| **DNN** | _Deprecated_: Specifies the name of the data network the UE wishes to connect to, similar to an APN in 4G networks. | `oai` |
+| **NSSAI** | _Deprecated_: Allows the UE to select the appropriate network slice, which provides different QoS. | `1` |
+| **pdu_sessions** | list of PDU sessions to request | empty array (no PDU session) |
+
+Note that DNN and NSSAI parameters are deprecated, and `pdu_sessions` should be
+used. If the `pdu_sessions` array is present, DNN and NSSAI are ignored.
+
+Each element within the `pdu_sessions` array takes the following parameters.
+Multiple PDU sessions can be requested.
+
+| **Parameter** | **Description** | **Default Value** |
+|---------------|-----------------|-------------------|
+| `id`          | ID of the PDU session to request | index of the current element (1..16) |
+| `type`        | Type of the PDU session to request (allowed: `IPv4`, `IPv6`, `IPv4v6`, `Ethernet` | `IPv4` |
+| `dnn`         | Specifies the name of the data network the UE wishes to connect to | `oai` |
+| `nssai_sst`   | Slice Service Type to request (1=eMBB, 2=URLLC, 3=mMTC) | `1` |
+| `nssai_sd`   | Slice Differentiator to request | `0xffffff` (meaning "no SD") |

 The UE configuration must match the one of the network's AMF. The nrUE can connect by default to OAI CN5G with no need to provide the configuration file.

@@ -39,6 +39,7 @@ ENV TZ=Europe/Paris
 RUN apt-get update && \
    apt-get upgrade --yes && \
    apt-get install --yes \
+        arping \
        software-properties-common \
        procps \
        libsctp1 \
@@ -168,10 +168,8 @@ static void get_options(configmodule_interface_t *cfg)
  config_get(cfg, cmdline_params, numparams, NULL);
  if (nrUE_params.vcdflag > 0)
    ouput_vcd = 1;
-  AssertFatal(nrUE_params.extra_pdu_id != get_softmodem_params()->default_pdu_session_id,
-              "Default PDU ID (%d) and Extra PDU ID (%d) must be different!\n",
-              get_softmodem_params()->default_pdu_session_id,
-              nrUE_params.extra_pdu_id);
+  AssertFatal(nrUE_params.extra_pdu_id == -1,
+              "Add additional PDU sessions in uicc.pdu_sessions array instead\n");
 }

 // set PHY vars from command line
@@ -156,6 +156,10 @@ void get_common_options(configmodule_interface_t *cfg)
  nfapi_setmode(nfapi_mode);
  if (stats_disabled)
    IS_SOFTMODEM_NOSTATS = true;
+
+  // To be removed in a future release (after 1 month)
+  AssertFatal(get_softmodem_params()->default_pdu_session_id == -1,
+              "Use uicc0.pdu_sessions.[0].id to change the requested PDU session ID (is %d)\n", get_softmodem_params()->default_pdu_session_id);
 }

 void softmodem_verify_mode(const softmodem_params_t *p)
@@ -180,7 +180,7 @@ extern int usrp_tx_thread;
  {"E" ,                    CONFIG_HLP_TQFS,          PARAMFLAG_BOOL, .iptr=&softmodem_params.threequarter_fs, .defintval=0,            TYPE_INT,    0}, \
  {"imscope" ,              CONFIG_HLP_IMSCOPE,       PARAMFLAG_BOOL, .uptr=&enable_imscope,                   .defintval=0,            TYPE_UINT,   0}, \
  {"imscope-record" ,       CONFIG_HLP_IMSCOPE_RECORD,PARAMFLAG_BOOL, .uptr=&enable_imscope_record,            .defintval=0,            TYPE_UINT,   0}, \
-  {"default-pdu-id",        NULL,                     0,              .iptr=&DEFAULT_PDU_ID,                   .defintval=10,           TYPE_INT,    0}, \
+  {"default-pdu-id",        NULL,                     0,              .iptr=&DEFAULT_PDU_ID,                   .defintval=-1,           TYPE_INT,    0}, \
 }
 // clang-format on

@@ -474,6 +474,7 @@ typedef struct nas_pdu_session_req_s {
  int pdusession_type;
  int sst;
  int sd;
+  char dnn[103]; /* 24.501 §9.11.2.1A: max length 102 + 0-byte */
 } nas_pdu_session_req_t;

 /*
@@ -49,7 +49,7 @@
 #include "common/ngran_types.h"
 #include "common/openairinterface5g_limits.h"
 #include "executables/lte-softmodem.h"
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 #include "intertask_interface.h"
 #include "openair3/S1AP/s1ap_eNB.h"
 #include <pthread.h>
@@ -46,7 +46,7 @@
 #include "common/platform_constants.h"
 #include "common/ran_context.h"
 #include "common/utils/T/T.h"
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 #include "cuup_cucp_if.h"
 #include "executables/lte-softmodem.h"
 #include "executables/softmodem-common.h"
@@ -405,7 +405,7 @@ void nr_pdcp_layer_init(void)

 #include "nfapi/oai_integration/vendor_ext.h"
 #include "executables/lte-softmodem.h"
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 #include "openair2/SDAP/nr_sdap/nr_sdap.h"

 static void deliver_sdu_drb(void *_ue, nr_pdcp_entity_t *entity,
@@ -64,7 +64,7 @@
 #include "LTE_UECapabilityEnquiry.h"
 #include "LTE_UE-CapabilityRequest.h"

-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"
 #if ENABLE_RAL
  #include "rrc_UE_ral.h"
 #endif
@@ -79,7 +79,7 @@
 #include "T.h"
 #include "LTE_MeasResults.h"

-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"

 #include "rrc_eNB_S1AP.h"
 #include "rrc_eNB_GTPV1U.h"
@@ -201,7 +201,7 @@ void rrc_add_nsa_user(gNB_RRC_INST *rrc, x2ap_ENDC_sgnb_addition_req_t *m, sctp_
  byte_array_t cgci = {0};
  if (get_softmodem_params()->phy_test == 1 || get_softmodem_params()->do_ra == 1) {
    DevAssert(m == NULL);
-    UE->rb_config = get_default_rbconfig(10 /* EPS bearer ID */, 1 /* drb ID */, NR_CipheringAlgorithm_nea0, NR_SecurityConfig__keyToUse_master, &rrc->pdcp_config);
+    UE->rb_config = get_default_rbconfig(DEFAULT_NOS1_PDU_ID, 1 /* drb ID */, NR_CipheringAlgorithm_nea0, NR_SecurityConfig__keyToUse_master, &rrc->pdcp_config);
    int len = cg_config_info_from_ue_cap_file(sizeof tmp, tmp);
    DevAssert(len > 0);
    cgci = create_byte_array(len, tmp);
@@ -29,7 +29,7 @@
 #include "common/utils/LOG/log.h"
 #include "errno.h"
 #include "rlc.h"
-#include "tun_if.h"
+#include "tuntap_if.h"
 #include "system.h"

 static void reblock_tun_socket(int fd)
@@ -157,25 +157,27 @@ static void *sdap_tun_read_thread(void *arg)
  return NULL;
 }

-void start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id_t ue_id)
+void start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id_t ue_id, int pdu_session_id)
 {
-  nr_sdap_entity_t *entity = nr_sdap_get_entity(ue_id, get_softmodem_params()->default_pdu_session_id);
+  nr_sdap_entity_t *entity = nr_sdap_get_entity(ue_id, pdu_session_id);
  DevAssert(entity != NULL);
  DevAssert(entity->is_gnb);
  char *ifprefix = get_softmodem_params()->nsa ? "oaitun_gnb" : "oaitun_enb";
  char ifname[IFNAMSIZ];
  tun_generate_ifname(ifname, ifprefix, ue_id - 1);
-  entity->pdusession_sock = tun_alloc(ifname);
+  entity->pdusession_sock = tuntap_alloc(IFF_TUN, ifname);
+  entity->pdusession_if_name = strdup(ifname);
  tun_config(ifname, "10.0.1.1", NULL);
  threadCreate(&entity->pdusession_thread, sdap_tun_read_thread, entity, "gnb_tun_read_thread", -1, OAI_PRIORITY_RT_LOW);
 }

-void start_sdap_tun_ue(ue_id_t ue_id, int pdu_session_id, int sock)
+static void start_sdap_tun_ue(ue_id_t ue_id, int pdu_session_id, int sock, const char *ifname)
 {
  nr_sdap_entity_t *entity = nr_sdap_get_entity(ue_id, pdu_session_id);
  DevAssert(entity != NULL);
  DevAssert(!entity->is_gnb);
  entity->pdusession_sock = sock;
+  entity->pdusession_if_name = strdup(ifname);
  entity->stop_thread = false;
  char thread_name[64];
  snprintf(thread_name, sizeof(thread_name), "ue_tun_read_%ld_p%d", ue_id, pdu_session_id);
@@ -183,22 +185,32 @@ void start_sdap_tun_ue(ue_id_t ue_id, int pdu_session_id, int sock)
 }


-void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id)
+void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id, bool is_default)
 {
-  int default_pdu = get_softmodem_params()->default_pdu_session_id;
  char ifname[IFNAMSIZ];
-  tun_generate_ue_ifname(ifname, ue_id, pdu_session_id != default_pdu ? pdu_session_id : -1);
-  const int sock = tun_alloc(ifname);
+  tuntap_generate_ue_ifname(ifname, IFF_TUN, ue_id, is_default ? -1 : pdu_session_id);
+  const int sock = tuntap_alloc(IFF_TUN, ifname);
  tun_config(ifname, ipv4, ipv6);
  if (ipv4) {
    setup_ue_ipv4_route(ifname, ue_id, ipv4);
  }
-  start_sdap_tun_ue(ue_id, pdu_session_id, sock); // interface name suffix is ue_id+1
+  start_sdap_tun_ue(ue_id, pdu_session_id, sock, ifname); // interface name suffix is ue_id+1
+}
+
+void create_ue_eth_if(int ue_id, int pdu_session_id, bool is_default)
+{
+  char ifname[IFNAMSIZ];
+  tuntap_generate_ue_ifname(ifname, IFF_TAP, ue_id, is_default ? -1 : pdu_session_id);
+  const int sock = tuntap_alloc(IFF_TAP, ifname);
+  tap_config(ifname); // brings the interface up
+  start_sdap_tun_ue(ue_id, pdu_session_id, sock, ifname);
 }

 void remove_ip_if(nr_sdap_entity_t *entity)
 {
  DevAssert(entity != NULL);
+  DevAssert(entity->pdusession_if_name != NULL);
+
  // Stop the read thread
  entity->stop_thread = true;

@@ -208,13 +220,7 @@ void remove_ip_if(nr_sdap_entity_t *entity)
  int ret = pthread_join(entity->pdusession_thread, NULL);
  AssertFatal(ret == 0, "pthread_join() failed, errno: %d, %s\n", errno, strerror(errno));
  // Bring down the IP interface
-  int default_pdu = get_softmodem_params()->default_pdu_session_id;
-  char ifname[IFNAMSIZ];
-  if (entity->is_gnb) {
-    char *ifprefix = get_softmodem_params()->nsa ? "oaitun_gnb" : "oaitun_enb";
-    tun_generate_ifname(ifname, ifprefix, entity->ue_id - 1);
-  } else {
-    tun_generate_ue_ifname(ifname, entity->ue_id, entity->pdusession_id != default_pdu ? entity->pdusession_id : -1);
-  }
-  tun_destroy(ifname);
+  tuntap_destroy(entity->pdusession_if_name);
+  free(entity->pdusession_if_name);
+  entity->pdusession_if_name = NULL;
 }
@@ -60,8 +60,8 @@ void sdap_data_ind(int pdcp_entity,
                   char *buf,
                   int size);

-void start_sdap_tun_ue(ue_id_t ue_id, int pdu_session_id, int sock);
-void start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id_t ue_id);
-void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id);
+void start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id_t ue_id, int pdu_session_id);
+void create_ue_ip_if(const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id, bool is_default);
+void create_ue_eth_if(int ue_id, int pdu_session_id, bool is_default);

 #endif
@@ -31,7 +31,7 @@
 #include "gtpv1_u_messages_types.h"
 #include "intertask_interface.h"
 #include "rlc.h"
-#include "tun_if.h"
+#include "tuntap_if.h"
 #include "nr_sdap.h"

 #define NO_SDAP_HEADER 0
@@ -534,7 +534,7 @@ static void nr_sdap_add_entity(const int is_gnb, const ue_id_t ue_id, const sdap
  if (IS_SOFTMODEM_NOS1 && is_gnb) {
    // In NOS1 mode, terminate SDAP for the first UE on the gNB. This allows injecting/receiving
    // PDCP SDUs to/from the TUN interface.
-    start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id);
+    start_sdap_tun_gnb_first_ue_default_pdu_session(ue_id, sdap_entity->pdusession_id);
  }
 }

@@ -102,6 +102,7 @@ typedef struct nr_sdap_entity_s {
  bool enable_sdap;
  int pdusession_id;
  int pdusession_sock;
+  char *pdusession_if_name;
  pthread_t pdusession_thread;
  bool stop_thread;
  int qfi;
@@ -23,7 +23,6 @@
 #include <arpa/inet.h>
 #include "PduSessionEstablishmentAccept.h"
 #include "common/utils/LOG/log.h"
-#include "common/utils/tun_if.h"
 #include "fgs_nas_utils.h"

 /**
@@ -49,6 +49,8 @@ typedef enum { FOREACH_IEI(TO_ENUM) } pduSessionEstablishment_IEI_t;
 #define PDU_SESSION_TYPE_IPV4 0b001
 #define PDU_SESSION_TYPE_IPV6 0b010
 #define PDU_SESSION_TYPE_IPV4V6 0b011
+#define PDU_SESSION_TYPE_UNSTRUCT 0b100
+#define PDU_SESSION_TYPE_ETHER 0b101
 #define IPv4_ADDRESS_LENGTH 4 // length of the IPv4 address associated with a PDU session
 #define IPv6_INTERFACE_ID_LENGTH 8 // interface identifier for the IPv6 link local address
 #define SMF_IPv6_LLA_LENGTH 16
@@ -56,7 +56,6 @@
 #include "aka_functions.h"
 #include "assertions.h"
 #include "common/utils/ds/byte_array.h"
-#include "common/utils/tun_if.h"
 #include "commonDef.h"
 #include "intertask_interface.h"
 #include "kdf.h"
@@ -1473,7 +1472,10 @@ static int capture_ipv6_addr(const uint8_t *addr, char *ip, size_t len)
 * @brief Process PDU Session Address in PDU Session Establishment Accept message
 *        and configure the tun interface
 */
-static void process_pdu_session_addr(pdu_session_establishment_accept_msg_t *msg, int instance_id, int pdu_session_id)
+static void process_pdu_session_addr(pdu_session_establishment_accept_msg_t *msg,
+                                     int instance_id,
+                                     int pdu_session_id,
+                                     bool is_default)
 {
  uint8_t *addr = msg->pdu_addr_ie.pdu_addr_oct;

@@ -1481,13 +1483,13 @@ static void process_pdu_session_addr(pdu_session_establishment_accept_msg_t *msg
    case PDU_SESSION_TYPE_IPV4: {
      char ip[20];
      capture_ipv4_addr(&addr[0], ip, sizeof(ip));
-      create_ue_ip_if(ip, NULL, instance_id, pdu_session_id);
+      create_ue_ip_if(ip, NULL, instance_id, pdu_session_id, is_default);
    } break;

    case PDU_SESSION_TYPE_IPV6: {
      char ipv6[40];
      capture_ipv6_addr(addr, ipv6, sizeof(ipv6));
-      create_ue_ip_if(NULL, ipv6, instance_id, pdu_session_id);
+      create_ue_ip_if(NULL, ipv6, instance_id, pdu_session_id, is_default);
    } break;

    case PDU_SESSION_TYPE_IPV4V6: {
@@ -1495,7 +1497,7 @@ static void process_pdu_session_addr(pdu_session_establishment_accept_msg_t *msg
      capture_ipv6_addr(addr, ipv6, sizeof(ipv6));
      char ipv4[20];
      capture_ipv4_addr(&addr[IPv6_INTERFACE_ID_LENGTH], ipv4, sizeof(ipv4));
-      create_ue_ip_if(ipv4, ipv6, instance_id, pdu_session_id);
+      create_ue_ip_if(ipv4, ipv6, instance_id, pdu_session_id, is_default);
    } break;

    default:
@@ -1507,7 +1509,7 @@ static void process_pdu_session_addr(pdu_session_establishment_accept_msg_t *msg
 /**
 * @brief Handle PDU Session Establishment Accept and process decoded message
 */
-static void handle_pdu_session_accept(uint8_t *pdu_buffer, uint32_t msg_length, int instance)
+static void handle_pdu_session_accept(const nr_ue_nas_t *nas, uint8_t *pdu_buffer, uint32_t msg_length, int instance)
 {
  pdu_session_establishment_accept_msg_t msg = {0};
  int size = 0;
@@ -1545,22 +1547,42 @@ static void handle_pdu_session_accept(uint8_t *pdu_buffer, uint32_t msg_length,
  size += decoded;

  // decode PDU Session Establishment Accept
-  if (!decode_pdu_session_establishment_accept_msg(&msg, pdu_buffer + size, msg_length))
+  if (!decode_pdu_session_establishment_accept_msg(&msg, pdu_buffer + size, msg_length)) {
    LOG_E(NAS, "decode_pdu_session_establishment_accept_msg failure\n");
+    return;
+  }
+
+  int idx;
+  for (idx = 0; idx < nas->uicc->n_pdu_sessions; ++idx) {
+    const pdu_session_config_t *pdu = &nas->uicc->pdu_sessions[idx];
+    if (pdu->id == sm_header.pdu_session_id && pdu->type == msg.pdu_type)
+      break;
+  }
+  if (idx == nas->uicc->n_pdu_sessions) {
+    LOG_E(NAS,
+          "PDU session establishment accept for ID %d type %d not in list of configured PDU sessions, abort transaction\n",
+          sm_header.pdu_session_id,
+          msg.pdu_type);
+    return;
+  }
+
+  // process PDU Session: pass ID -1 to not append PDU ID to interface
+  bool is_default = idx == 0;
+  if (msg.pdu_type == PDU_SESSION_TYPE_ETHER) {
+    create_ue_eth_if(instance, sm_header.pdu_session_id, is_default);
+  } else if (msg.pdu_addr_ie.pdu_length) {
+    process_pdu_session_addr(&msg, instance, sm_header.pdu_session_id, is_default);
+  } else {
+    LOG_W(NAS, "Unhandled PDU session type %d, ignoring PDU session ID %d\n", msg.pdu_type, sm_header.pdu_session_id);
+  }

-  // process PDU Session
-  if (msg.pdu_addr_ie.pdu_length)
-    process_pdu_session_addr(&msg, instance, sm_header.pdu_session_id);
-  else
-    LOG_W(NAS, "Optional PDU Address IE was not provided\n");
-  
  set_qfi(msg.qos_rules.rule->qfi, sm_header.pdu_session_id, instance);
 }

 /**
 * @brief Handle DL NAS Transport and process piggybacked 5GSM messages
 */
-void handleDownlinkNASTransport(uint8_t * pdu_buffer, int pdu_length, int instance)
+void handleDownlinkNASTransport(const nr_ue_nas_t *nas, uint8_t * pdu_buffer, int pdu_length, int instance)
 {
  if (pdu_length < 17) {
    LOG_E(NAS, "Received DL NAS Transport message too short (%d)\n", pdu_length);
@@ -1569,7 +1591,7 @@ void handleDownlinkNASTransport(uint8_t * pdu_buffer, int pdu_length, int instan
  uint8_t msg_type = *(pdu_buffer + 16);
  if (msg_type == FGS_PDU_SESSION_ESTABLISHMENT_ACC) {
    LOG_A(NAS, "Received PDU Session Establishment Accept in DL NAS Transport\n");
-    handle_pdu_session_accept(pdu_buffer, pdu_length, instance);
+    handle_pdu_session_accept(nas, pdu_buffer, pdu_length, instance);
  } else {
    LOG_E(NAS, "Received unexpected message in DLinformationTransfer %d\n", msg_type);
  }
@@ -1688,19 +1710,16 @@ static void generatePduSessionEstablishRequest(nr_ue_nas_t *nas, as_nas_info_t *
  const bool has_nssai_sd = pdu_req->sd != 0xffffff; // 0xffffff means "no SD", TS 23.003
  const size_t nssai_len = has_nssai_sd ? 4 : 1;
  mm_msg->snssai.length = nssai_len;
-  // Fixme: it seems there are a lot of memory errors in this: this value was on the stack,
-  //  but pushed  in a itti message to another thread
-  //  this kind of error seems in many places in 5G NAS
  mm_msg->snssai.value = calloc(1, nssai_len);
  mm_msg->snssai.value[0] = pdu_req->sst;
  if (has_nssai_sd)
    INT24_TO_BUFFER(pdu_req->sd, &mm_msg->snssai.value[1]);
  size += 1 + 1 + nssai_len;
-  int dnnSize = strlen(nas->uicc->dnnStr);
+  int dnnSize = strlen(pdu_req->dnn);
  mm_msg->dnn.value = calloc(1, dnnSize + 1);
  mm_msg->dnn.length = dnnSize + 1;
  mm_msg->dnn.value[0] = dnnSize;
-  memcpy(mm_msg->dnn.value + 1, nas->uicc->dnnStr, dnnSize);
+  memcpy(mm_msg->dnn.value + 1, pdu_req->dnn, dnnSize);
  size += (1 + 1 + dnnSize + 1);

  // encode the message
@@ -1772,24 +1791,33 @@ static void send_nas_5gmm_ind(instance_t instance, const Guti5GSMobileIdentity_t
  itti_send_msg_to_task(TASK_RRC_NRUE, instance, msg);
 }

-void request_pdusession(nr_ue_nas_t *nas, int pdusession_id)
+void request_pdusession(nr_ue_nas_t *nas, const pdu_session_config_t *pdu)
 {
+  int t = pdu->type;
+  AssertFatal(t == PDU_SESSION_TYPE_IPV4 || t == PDU_SESSION_TYPE_IPV6 || t == PDU_SESSION_TYPE_IPV4V6
+                  || t == PDU_SESSION_TYPE_UNSTRUCT || t == PDU_SESSION_TYPE_ETHER,
+              "illegal PDU session type %d\n",
+              t);
+  AssertFatal(t != PDU_SESSION_TYPE_UNSTRUCT, "unstructured PDU sessions not handled yet\n");
  MessageDef *message_p = itti_alloc_new_message(TASK_NAS_NRUE, nas->UE_id, NAS_PDU_SESSION_REQ);
-  NAS_PDU_SESSION_REQ(message_p).pdusession_id = pdusession_id;
-  NAS_PDU_SESSION_REQ(message_p).pdusession_type = 0x91; // 0x91 = IPv4, 0x92 = IPv6, 0x93 = IPv4v6
-  NAS_PDU_SESSION_REQ(message_p).sst = nas->uicc->nssai_sst;
-  NAS_PDU_SESSION_REQ(message_p).sd = nas->uicc->nssai_sd;
+  nas_pdu_session_req_t *pdu_req = &NAS_PDU_SESSION_REQ(message_p);
+  pdu_req->pdusession_id = pdu->id;
+  // 24.501: joint PDU session type IEI (0x9-, Table 8.3.1.1.1) and type (9.11.4.11)
+  pdu_req->pdusession_type = 0x90 | t;
+  pdu_req->sst = pdu->nssai.sst;
+  pdu_req->sd = pdu->nssai.sd;
+  snprintf(pdu_req->dnn, sizeof(pdu_req->dnn), "%s", pdu->dnn);
  itti_send_msg_to_task(TASK_NAS_NRUE, nas->UE_id, message_p);
 }

-static int get_user_nssai_idx(const nr_nas_msg_snssai_t allowed_nssai[NAS_MAX_NUMBER_SLICES], const nr_ue_nas_t *nas)
+static int get_user_nssai_idx(nssai_t ch_nssai, const nr_nas_msg_snssai_t allowed_nssai[NAS_MAX_NUMBER_SLICES])
 {
  for (int i = 0; i < NAS_MAX_NUMBER_SLICES; i++) {
    const nr_nas_msg_snssai_t *nssai = allowed_nssai + i;
    /* If it was received in Registration Accept, check the SD
       in the stored Allowed N-SSAI, else, consider the SD valid */
-    bool sd_match = !nssai->sd || (nas->uicc->nssai_sd == *nssai->sd);
-    if ((nas->uicc->nssai_sst == nssai->sst) && sd_match)
+    bool sd_match = !nssai->sd || (ch_nssai.sd == *nssai->sd);
+    if ((ch_nssai.sst == nssai->sst) && sd_match)
      return i;
  }
  return -1;
@@ -1864,12 +1892,18 @@ static void handle_registration_accept(nr_ue_nas_t *nas, const uint8_t *pdu_buff
    send_nas_uplink_data_req(nas, &initialNasMsg);
    LOG_I(NAS, "Send NAS_UPLINK_DATA_REQ message(RegistrationComplete)\n");
  }
-  if (get_user_nssai_idx(msg.nas_allowed_nssai, nas) < 0) {
-    LOG_E(NAS, "NSSAI parameters not match with allowed NSSAI. Couldn't request PDU session.\n");
-  } else {
-    request_pdusession(nas, get_softmodem_params()->default_pdu_session_id);
-    if (get_nrUE_params()->extra_pdu_id != -1) {
-      request_pdusession(nas, get_nrUE_params()->extra_pdu_id);
+  if (nas->uicc->n_pdu_sessions == 0)
+    LOG_W(SIM, "no PDU sessions to request configured\n");
+  for (const pdu_session_config_t *pdu = nas->uicc->pdu_sessions; pdu < nas->uicc->pdu_sessions + nas->uicc->n_pdu_sessions; ++pdu) {
+    if (get_user_nssai_idx(pdu->nssai, msg.nas_allowed_nssai) < 0) {
+      LOG_E(NAS,
+            "PDU session ID %d NSSAI %d.%d: mismatch for allowed NSSAI. Couldn't request PDU session.\n",
+            pdu->id,
+            pdu->nssai.sst,
+            pdu->nssai.sd);
+    } else {
+      LOG_I(NAS, "requested PDU session ID %d type %d NSSAI %d.%d DNN %s\n", pdu->id, pdu->type, pdu->nssai.sst, pdu->nssai.sd, pdu->dnn);
+      request_pdusession(nas, pdu);
    }
  }
  // Free local message after processing
@@ -2017,7 +2051,7 @@ void *nas_nrue(void *args_p)
        if (msg_type == FGS_REGISTRATION_ACCEPT) {
          handle_registration_accept(nas, ba.buf, ba.len);
        } else if (msg_type == FGS_PDU_SESSION_ESTABLISHMENT_ACC) {
-          handle_pdu_session_accept(ba.buf, ba.len, nas->UE_id);
+          handle_pdu_session_accept(nas, ba.buf, ba.len, nas->UE_id);
        }

        // Free NAS buffer memory after use (coming from RRC)
@@ -2103,7 +2137,7 @@ void *nas_nrue(void *args_p)
            handle_security_mode_command(nas, &initialNasMsg, pdu_buffer, pdu_length);
            break;
          case FGS_DOWNLINK_NAS_TRANSPORT:
-            handleDownlinkNASTransport(pdu_buffer, pdu_length, nas->UE_id);
+            handleDownlinkNASTransport(nas, pdu_buffer, pdu_length, nas->UE_id);
            break;
          case FGS_REGISTRATION_ACCEPT:
            handle_registration_accept(nas, pdu_buffer, pdu_length);
@@ -2114,7 +2148,7 @@ void *nas_nrue(void *args_p)
            nas->fiveGMM_state = FGS_DEREGISTERED;
            break;
          case FGS_PDU_SESSION_ESTABLISHMENT_ACC:
-            handle_pdu_session_accept(pdu_buffer, pdu_length, nas->UE_id);
+            handle_pdu_session_accept(nas, pdu_buffer, pdu_length, nas->UE_id);
            break;
          case FGS_PDU_SESSION_ESTABLISHMENT_REJ:
            LOG_E(NAS, "Received PDU Session Establishment reject\n");
@@ -2159,10 +2193,11 @@ void *nas_nrue(void *args_p)
      } break;

      case NAS_INIT_NOS1_IF: {
-        const int pdu_session_id = get_softmodem_params()->default_pdu_session_id;
+        const int pdu_session_id = DEFAULT_NOS1_PDU_ID;
        const char *ip = "10.0.1.2";
        const int qfi = 7;
-        create_ue_ip_if(ip, NULL, nas->UE_id, pdu_session_id);
+        const bool is_default = true;
+        create_ue_ip_if(ip, NULL, nas->UE_id, pdu_session_id, is_default);
        set_qfi(qfi, pdu_session_id, nas->UE_id);
        break;
      }
@@ -32,6 +32,7 @@
 #define __NR_NAS_MSG_SIM_H__

 #include <common/utils/assertions.h>
+#include "common/5g_platform_types.h"
 #include <openair3/UICC/usim_interface.h>
 #include <stdbool.h>
 #include <stdint.h>
@@ -113,6 +114,6 @@ void *nas_nrue_task(void *args_p);
 void *nas_nrue(void *args_p);
 void nas_init_nrue(int num_ues);
 void nr_ue_create_ip_if(const char *ifnameprefix, const char *ipv4, const char *ipv6, int ue_id, int pdu_session_id);
-void request_pdusession(nr_ue_nas_t *nas, int pdusession_id);
+void request_pdusession(nr_ue_nas_t *nas, const pdu_session_config_t *pdu);

 #endif /* __NR_NAS_MSG_SIM_H__*/
@@ -45,7 +45,7 @@ Description Defines functions used to handle EPS bearer contexts.
 #include "esm_ebr.h"

 #include "esm_ebr_context.h"
-#include "common/utils/tun_if.h"
+#include "common/utils/tuntap_if.h"

 #include "emm_sap.h"
 #include "system.h"
@@ -1,3 +1,3 @@
-add_library(lib_uicc OBJECT usim_interface.c)
+add_library(lib_uicc OBJECT usim_interface.c pdu_session.c)
 target_include_directories(lib_uicc PRIVATE .)
 target_link_libraries(lib_uicc PRIVATE log_headers)
@@ -0,0 +1,116 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * 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
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#include <assert.h>
+
+#include "pdu_session.h"
+// we can't include the file for PDU session type defines, as it pulls in too
+// much. However, we only use it for mapping types to integers, which are
+// standard defined, so it should be ok.
+//#include "openair3/NAS/NR_UE/5GS/5GSM/MSG/PduSessionEstablishmentAccept.h"
+#include "common/utils/utils.h"
+#include "common/config/config_paramdesc.h"
+#include "common/config/config_userapi.h"
+
+
+// clang-format off
+// Note: Default PDU session ID 0 does not exist and will be replaced with PDU
+// session index if not set to a parameter > 0!
+#define PDU_SESS_PARAMS_DESC {                                              \
+    {"id",        "PDU session ID\n",             0, .iptr=NULL,       .defintval=0,        TYPE_INT,    0}, \
+    {"type",      "PDU session type\n",           0, .strptr=NULL,     .defstrval="IPv4",   TYPE_STRING, 0}, \
+    {"nssai_sst", "NSSAI slice type\n",           0, .u8ptr=NULL,      .defintval=1,        TYPE_UINT8,  0}, \
+    {"nssai_sd",  "NSSAI slice differentiator\n", 0, .uptr=NULL,       .defintval=0xffffff, TYPE_UINT32, 0}, \
+    {"dnn",       "PDU session DNN (APN)\n",      0, .strptr=NULL,     .defstrval="oai",    TYPE_STRING, 0}, \
+}
+
+#define PDU_SESS_PARAMS_CHECK {                      \
+    {.s2 = {config_check_intrange, {0, 255}}},       \
+    {.s3a = {config_checkstr_assign_integer,         \
+             {"IPv4", "IPv6", "IPv4v6", "Ethernet"}, \
+             {1 /*PDU_SESSION_TYPE_IPV4*/,           \
+              2 /*PDU_SESSION_TYPE_IPV6*/,           \
+              3 /*PDU_SESSION_TYPE_IPV4V6*/,         \
+              5 /*PDU_SESSION_TYPE_ETHER*/},         \
+             4}},                                    \
+    {.s2 = {config_check_intrange, {1, 4}}},         \
+    {.s2 = {config_check_intrange, {1, 0xffffff}}},  \
+    {.s4 = {config_check_dnn}},                      \
+}
+// clang-format on
+
+static int config_check_dnn(configmodule_interface_t *cfg, paramdef_t *param)
+{
+  const char *dnn = *param->strptr;
+  int dnn_len = strlen(dnn);
+  if (dnn_len > 102) {
+    printf("DNN '%s' exceeds max len of 102 (is %d) (TS 24.501 §9.11.2.1A)\n", dnn, dnn_len);
+    return -1;
+  }
+
+  // check for valid characters in the APN (TS 23.003 §9.1)
+  // we don't enforce all conditions
+  const char *allowed = "abcdefghijklmnopqrstuvwxyz"
+                        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                        "0123456789.-";
+  while (*dnn) {
+    if (!strchr(allowed, *dnn)) {
+      printf("character '%c' in DNN '%s' is not allowed (TS 23.003 §9.1)\n", *dnn, *param->strptr);
+      return -1;
+    }
+    dnn++;
+  }
+
+  return 0;
+}
+
+int get_pdu_session_configs(const char *uiccName, pdu_session_config_t *configs, int max_len)
+{
+  paramdef_t pdu_sess_params[] = PDU_SESS_PARAMS_DESC;
+  const int npsp = sizeofArray(pdu_sess_params);
+  paramlist_def_t pdu_sess_list = {"pdu_sessions"};
+  checkedparam_t pdu_sess_params_check[] = PDU_SESS_PARAMS_CHECK;
+  static_assert(sizeofArray(pdu_sess_params) == sizeofArray(pdu_sess_params_check),
+                "param_def_t array and corresponding checkedparam_t array should have the same size");
+  for (int i = 0; i < sizeofArray(pdu_sess_params); ++i)
+    pdu_sess_params[i].chkPptr = &pdu_sess_params_check[i];
+  int ret = config_getlist(config_get_if(), &pdu_sess_list, pdu_sess_params, sizeofArray(pdu_sess_params), uiccName);
+  if (ret < 0) {
+    // couldn't load configuration from pdu_sessions, caller has to handle
+    return -1;
+  }
+
+  int num = pdu_sess_list.numelt;
+  AssertFatal(num <= max_len, "cannot handle more than %d PDU sessions\n", max_len);
+
+  for (int i = 0; i < num; ++i) {
+    pdu_session_config_t *pdu = configs + i;
+    paramdef_t *p = pdu_sess_list.paramarray[i];
+    int id = *gpd(p, npsp, "id")->iptr;
+    pdu->id = id > 0 ? id : i + 1; // if not user-specified ID, use PDU session index
+    pdu->type = config_get_processedint(config_get_if(), (paramdef_t *)gpd(p, npsp, "type"));
+    pdu->nssai.sst = *gpd(p, npsp, "nssai_sst")->iptr;
+    pdu->nssai.sd = *gpd(p, npsp, "nssai_sd")->iptr;
+    pdu->dnn = strdup(*gpd(p, npsp, "dnn")->strptr);
+  }
+
+  return num;
+}
@@ -0,0 +1,36 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * 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
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#ifndef PDU_SESSION_H_
+#define PDU_SESSION_H_
+
+#include "common/5g_platform_types.h"
+
+typedef struct {
+  int id;
+  int type;
+  nssai_t nssai;
+  char *dnn; // [103]?
+} pdu_session_config_t;
+
+int get_pdu_session_configs(const char *uiccName, pdu_session_config_t *configs, int max_len);
+
+#endif /* PDU_SESSION_H_ */
@@ -22,6 +22,7 @@
 */
 #include <ctype.h>

+#include "common/platform_constants.h"
 #include <openair3/UICC/usim_interface.h>
 #include <openair3/NAS/COMMON/milenage.h>
 extern uint16_t NB_UE_INST;
@@ -76,10 +77,7 @@ uicc_t *init_uicc(char *sectionName) {
  // key, OPc, sqn, amf don't need to be read from the true USIM
  int ret = config_get(config_get_if(), uicc_params, sizeofArray(uicc_params), sectionName);
  AssertFatal(ret >= 0, "configuration couldn't be performed for uicc name: %s", sectionName);
-  LOG_I(SIM,
-        "UICC simulation: IMSI=%s, IMEISV=%s, Ki=%s, OPc=%s, DNN=%s, SST=0x%02x, SD=0x%06x\n",
-        uicc->imsiStr, uicc->imeisvStr, uicc->keyStr, uicc->opcStr,
-        uicc->dnnStr, uicc->nssai_sst, uicc->nssai_sd);
+  LOG_I(SIM, "UICC simulation: IMSI=%s, IMEISV=%s, Ki=%s, OPc=%s\n", uicc->imsiStr, uicc->imeisvStr, uicc->keyStr, uicc->opcStr);
  to_hex(uicc->keyStr,uicc->key, sizeof(uicc->key) );
  to_hex(uicc->opcStr,uicc->opc, sizeof(uicc->opc) );
  to_hex(uicc->sqnStr,uicc->sqn, sizeof(uicc->sqn) );
@@ -112,6 +110,36 @@ uicc_t * checkUicc(int Mod_id) {
    char uiccName[64];
    sprintf(uiccName,"uicc%d",  Mod_id);
    uiccArray[Mod_id]=(void*)init_uicc(uiccName);
+    uicc_t *uicc = uiccArray[Mod_id];
+    uicc->n_pdu_sessions = get_pdu_session_configs(uiccName, uicc->pdu_sessions, sizeof(uicc->pdu_sessions));
+    if (uicc->n_pdu_sessions > 0) {
+      LOG_I(SIM, "overriding potential %s.dnn/nssai_sst/nssai_sd from %s.pdu_sessions\n", uiccName, uiccName);
+    } else if (uicc->n_pdu_sessions < 0) {
+      // we could not load from "new" pdu_sessions list, so read from "legacy"
+      // config
+      LOG_W(SIM,
+            "loading PDU session parameters from legacy UICC configuration. Please update to use %s.pdu_sessions instead to make this warning disappear\n",
+            uiccName);
+      sleep(3);
+      uicc->n_pdu_sessions = 1;
+      pdu_session_config_t *pdu = &uicc->pdu_sessions[0];
+      AssertFatal(uicc->dnnStr != NULL, "no default DNN, cannot create\n");
+      pdu->id = DEFAULT_NOS1_PDU_ID; // any default would do
+      pdu->dnn = strdup(uicc->dnnStr);
+      pdu->nssai.sst = uicc->nssai_sst;
+      pdu->nssai.sd = uicc->nssai_sd;
+      pdu->type = 1; /* = PDU_SESSION_TYPE_IPV4 */
+    } // else: uicc->n_pdu_sessions == 0 => don't request a PDU session
+    for (int i = 0; i < uicc->n_pdu_sessions; ++i) {
+      const pdu_session_config_t *pdu = &uicc->pdu_sessions[i];
+      LOG_I(SIM,
+            "will request PDU session ID %d, type %d, DNN %s, NSSAI %d.%6x\n",
+            pdu->id,
+            pdu->type,
+            pdu->dnn,
+            pdu->nssai.sst,
+            pdu->nssai.sd);
+    }
  }
  return (uicc_t*) uiccArray[Mod_id];  
 }
@@ -34,6 +34,7 @@
 #include <common/utils/load_module_shlib.h>
 #include <common/config/config_userapi.h>
 #include "common_lib.h"
+#include "pdu_session.h"

 /* 3GPP glossary
 RES	RESponse
@@ -53,6 +54,8 @@ typedef struct {
  char *dnnStr;
  int  nssai_sst;
  int  nssai_sd;
+  pdu_session_config_t pdu_sessions[256];
+  int n_pdu_sessions;
  uint8_t key[16];
  uint8_t opc[16];
  uint8_t amf[2];
@@ -2,9 +2,7 @@ uicc0 = {
 imsi = "2089900007487";
 key = "fec86ba6eb707ed08905757b1bb44b8f";
 opc= "C42449363BBAD02B66D16BC975D77CC1";
-dnn= "oai";
-nssai_sst=1;
-nssai_sd=1;
+pdu_sessions = ({ dnn = "oai"; nssai_sst = 1; nssai_sd = 1; });
 }

 position0 = {