Add test to trigger re-establishment to RFSIM F1 CI

* trigger re-establshemnt on DU: reset RLC counters on DRB 1
  for OAI UE, since SRB 1 does not work for lack of periodic
  measurements reports
* how is the re-establishment triggered?
  * a transmission on DRB 1 occurs
  * detection of a mismatch of RLC counters at the UE side
  * max number of RLC retransmissions reached
  * RLF detection
* verify re-establishment on CU: we ping the core from the UE; this
  sends packets on DRB, and because the sequence number mismatches, will
  trigger a reestablishment. We accept in the ping that a couple of
  packets might be lost; after ping is over, reestablishment must be
  done as well (else the ping will already fail).

ci-scripts/xml_files/container_5g_f1_rfsim.xml

@@ -34,6 +34,11 @@
  030020
  030021
  030022
+ 040001
+ 020022
+ 040002
+ 030021
+ 030022
  100021
  222222
         </TestCaseRequestedList>
@@ -117,6 +122,31 @@
                 <iperf_bitrate_threshold>90</iperf_bitrate_threshold>
         </testCase>
 
+        <testCase id="040001">
+                <class>Custom_Command</class>
+                <desc>Trigger Reestablishment</desc>
+                <node>cacofonix</node>
+                <command>echo ci force_reestab | nc 192.168.71.171 9090 | grep -E 'Reset RLC counters of UE RNTI [0-9a-f]{4} to trigger reestablishment'</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
+        <testCase id="020022">
+                <class>Ping</class>
+                <desc>Ping ext-dn from all NR-UEs</desc>
+                <id>rfsim5g_ue</id>
+                <nodes>cacofonix</nodes>
+                <ping_args> -c 20 192.168.72.135 -i0.5 -w25</ping_args>
+                <ping_packetloss_threshold>80</ping_packetloss_threshold>
+        </testCase>
+
+        <testCase id="040002">
+                <class>Custom_Command</class>
+                <desc>Verify Reestablishment</desc>
+                <node>cacofonix</node>
+                <command>echo ci get_reestab_count | nc 192.168.71.150 9090 | grep -E 'UE RNTI [0-9a-f]{4} reestab 1'</command>
+                <command_fail>yes</command_fail>
+        </testCase>
+
         <testCase id="040021">
                 <class>Custom_Command</class>
                 <desc>Simulate a disruption of DL radio channel (ploss 55)(5 sec)</desc>

ci-scripts/yaml_files/5g_f1_rfsimulator/docker-compose.yaml

@@ -87,8 +87,11 @@ services:
         container_name: rfsim5g-oai-cu
         cap_drop:
             - ALL
-        environment:
+        environment: 
             USE_ADDITIONAL_OPTIONS: --log_config.global_log_options level,nocolor,time
+                                    --rfsimulator.options chanmod
+                                    --telnetsrv --telnetsrv.listenaddr 192.168.71.150
+                                    --telnetsrv.shrmod ci
             ASAN_OPTIONS: detect_leaks=0
         depends_on:
             - oai-ext-dn
@@ -113,6 +116,7 @@ services:
                                     --log_config.global_log_options level,nocolor,time
                                     --rfsimulator.options chanmod
                                     --telnetsrv --telnetsrv.listenaddr 192.168.71.171
+                                    --telnetsrv.shrmod ci
             ASAN_OPTIONS: detect_leaks=0:detect_odr_violation=0
         depends_on:
             - oai-cu

openair2/LAYER2/nr_rlc/nr_rlc_oai_api.c

@@ -1096,8 +1096,14 @@ bool nr_rlc_update_id(int from_id, int to_id)
   return true;
 }
 
-/* This function is for testing purposes. At least on a COTS UE, it will
+/**
- * trigger a reestablishment. */
+ * @brief This function is for testing purposes.
+ *        Re-establishment is triggered by resetting RLC counters of the bearer,
+ *        which leads to UE reaching maximum RLC retransmissions, RLF detection
+ *        and RRC triggering re-sync. It is assumed that there is ongoing traffic on the bearer.
+ *        - With COTS UEs, triggers re-establishment on SRB 1, where periodical measurement reports are sent.
+ *        - With OAI UE, triggers re-establishment on DRB 1, assuming there is ongoing data traffic.
+ */
 void nr_rlc_test_trigger_reestablishment(int ue_id)
 {
   nr_rlc_manager_lock(nr_rlc_ue_manager);
@@ -1111,6 +1117,9 @@ void nr_rlc_test_trigger_reestablishment(int ue_id)
    * as the UE context is created. */
   nr_rlc_entity_t *ent = ue->srb[0];
   ent->reestablishment(ent);
+  /* Trigger re-establishment on OAI UE */
+  nr_rlc_entity_t *drb = ue->drb[0];
+  drb->reestablishment(drb);
   nr_rlc_manager_unlock(nr_rlc_ue_manager);
 }