srsUE does not issue reconnect until iperf is off #1498
Description
Sorry if this is a duplicate issue, but I couldn't find it.
My setup is as follows: 2 x x310 USRP, Open5GS, srsRAN ENB, srsRAN UE and an additional custom noise generator (b210) aimed at the UE. Everything is running in docker compose.
UE connects to the setup, the connection is stable and the only significant config change I made was to change the MCS to 24 fixed. In the setup I generate DL traffic using iperf3 and add radio noise using another usrp and matlab. The goal is to see how the KPIs change during this process.
So, the process is fine until the UE disconnects. Disconnecting due to loss of radio connection is expected. But the problem is that the UE does not reconnect until iperf3 is turned off. Immediately after iperf3 is turned off, the UE immediately connects back to the ENB with the same IP address and I can restart iperf3 until the next disconnect.
Expectations:
UE restores the connection and continues to maintain the connection between the UE and the ENB without restarting the traffic generator.
I think this is either a fundamental issue or a setup issue, so I'm not sure what logs exactly I should provide, but here are the some logs of this process (it disconnects and reconnects only after i close iperf3 on UE):
ue
Opening 1 channels in RF device=uhd with args=default
Supported RF device list: UHD soapy bladeRF zmq file
[INFO] [UHD] linux; GNU C++ version 9.4.0; Boost_107100; UHD_4.8.0.0-0ubuntu1~focal1
[INFO] [LOGGING] Fastpath logging disabled at runtime.
Opening USRP channels=1, args: type=x300,master_clock_rate=184.32e6
[INFO] [UHD RF] RF UHD Generic instance constructed
[INFO] [X300] X300 initialization sequence...
[INFO] [X300] Maximum frame size: 8000 bytes.
[INFO] [X300] Radio 1x clock: 184.32 MHz
Waiting PHY to initialize ... done!
Attaching UE...
Starting plot for worker_id=0
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
.
Found Cell: Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=3.0 KHz
[ERROR] [UHD RF] std::bad_alloc
.
Found Cell: Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=3.0 KHz
[ERROR] [UHD RF] std::bad_alloc
Found PLMN: Id=00101, TAC=1
Could not find Home PLMN Id=99970, trying to connect to PLMN Id=00101
Random Access Transmission: seq=39, tti=9941, ra-rnti=0x2
RRC Connected
Random Access Complete. c-rnti=0x61, ta=1
Network attach successful. IP: 192.168.100.3
nTp) 22/8/2025 10:39:45 TZ:128
Received RRC Connection Release (releaseCause: other)
RRC IDLE
S-TMSI match in paging message
Service Request with cause mt-Access.
Random Access Transmission: seq=9, tti=2151, ra-rnti=0x2
RRC Connected
Random Access Complete. c-rnti=0x62, ta=1
Service Request successful.
Warning: Detected Radio-Link Failure
RRC Connection Reestablishment to PCI=1, EARFCN=3150 (Cause: "otherFailure")
Random Access Transmission: seq=36, tti=3871, ra-rnti=0x2
Reestablishment OK
RRC Connected
Random Access Complete. c-rnti=0x63, ta=1
Warning: Detected Radio-Link Failure
RRC Connection Reestablishment to PCI=1, EARFCN=3150 (Cause: "otherFailure")
Random Access Transmission: seq=26, tti=9061, ra-rnti=0x2
Selected cell no longer suitable: Going to RRC IDLE
RRC IDLE
[ERROR] [UHD RF] std::bad_alloc
.
Found Cell: Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=3.1 KHz
[ERROR] [UHD RF] std::bad_alloc
S-TMSI match in paging message
Service Request with cause mt-Access.
RRC connection for Service Request failed.
Service Request with cause mo-Data.
Random Access Transmission: seq=46, tti=3701, ra-rnti=0x2
RRC Connected
Random Access Complete. c-rnti=0x65, ta=1
Service Request successful.
RF status: O=0, U=1, L=0
Scheduling request failed: releasing RRC connection...
Random Access Transmission: seq=1, tti=1681, ra-rnti=0x2
Random Access Transmission: seq=42, tti=1761, ra-rnti=0x2
Random Access Transmission: seq=30, tti=1841, ra-rnti=0x2
Random Access Transmission: seq=48, tti=1921, ra-rnti=0x2
Random Access Transmission: seq=34, tti=2001, ra-rnti=0x2
Random Access Transmission: seq=29, tti=2081, ra-rnti=0x2
Random Access Transmission: seq=3, tti=2161, ra-rnti=0x2
Random Access Transmission: seq=24, tti=2241, ra-rnti=0x2
Random Access Transmission: seq=4, tti=2321, ra-rnti=0x2
Random Access Transmission: seq=17, tti=2401, ra-rnti=0x2
Warning: Detected Radio-Link Failure
RRC Connection Reestablishment to PCI=1, EARFCN=3150 (Cause: "otherFailure")
Random Access Transmission: seq=29, tti=2481, ra-rnti=0x2
Reestablishment Reject. Going to RRC IDLE
Random Access Complete. c-rnti=0x70, ta=1
RRC IDLE
Service Request with cause mo-Data.
Random Access Transmission: seq=38, tti=2521, ra-rnti=0x2
RRC Connected
Random Access Complete. c-rnti=0x71, ta=1
Service Request successful.
RF status: O=0, U=1, L=0
Warning: Detected Radio-Link Failure
RRC Connection Reestablishment to PCI=1, EARFCN=3150 (Cause: "otherFailure")
Random Access Transmission: seq=6, tti=8681, ra-rnti=0x2
Reestablishment OK
RRC Connected
Random Access Complete. c-rnti=0x72, ta=1
RF status: O=0, U=1, L=0
RF status: O=0, U=1, L=0
RF status: O=0, U=1, L=0
RF status: O=0, U=1, L=0
RF status: O=0, U=1, L=0
Scheduling request failed: releasing RRC connection...
Random Access Transmission: seq=6, tti=341, ra-rnti=0x2
Random Access Transmission: seq=35, tti=421, ra-rnti=0x2
Random Access Transmission: seq=3, tti=501, ra-rnti=0x2
Random Access Transmission: seq=3, tti=581, ra-rnti=0x2
Random Access Transmission: seq=20, tti=661, ra-rnti=0x2
Random Access Transmission: seq=16, tti=741, ra-rnti=0x2
Random Access Transmission: seq=45, tti=821, ra-rnti=0x2
Random Access Transmission: seq=14, tti=901, ra-rnti=0x2
Random Access Transmission: seq=24, tti=981, ra-rnti=0x2
Random Access Transmission: seq=36, tti=1061, ra-rnti=0x2
Warning: Detected Radio-Link Failure
RRC Connection Reestablishment to PCI=1, EARFCN=3150 (Cause: "otherFailure")
Random Access Transmission: seq=30, tti=1141, ra-rnti=0x2
Reestablishment Reject. Going to RRC IDLE
Random Access Complete. c-rnti=0x7d, ta=1
RRC IDLE
Service Request with cause mo-Data.
Random Access Transmission: seq=31, tti=2951, ra-rnti=0x2
RRC Connected
Random Access Complete. c-rnti=0x7e, ta=1
Service Request successful.
Received service reject with EMM cause=0x9.
Received RRC Connection Release (releaseCause: other)
RRC IDLE
[ERROR] [UHD RF] std::bad_alloc
.
Found Cell: Mode=FDD, PCI=1, PRB=50, Ports=1, CP=Normal, CFO=3.3 KHz
[ERROR] [UHD RF] std::bad_alloc
Found PLMN: Id=00101, TAC=1
Could not find Home PLMN Id=99970, trying to connect to PLMN Id=00101
Random Access Transmission: seq=9, tti=7541, ra-rnti=0x2
RRC Connected
Random Access Complete. c-rnti=0x7f, ta=1
Network attach successful. IP: 192.168.100.4
nTp) 22/8/2025 11:59:55 TZ:128
t
Enter t to stop trace.
---------Signal-----------|-----------------DL-----------------|-----------UL-----------
cc pci rsrp pl cfo | mcs snr iter brate bler ta_us | mcs buff brate bler
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 0 31 0.0 0.0 0% 0.5 | 0 0.0 0.0 0%
0 1 -66 66 3.1k | 24 30 1.0 5.7M 0% 0.5 | 21 889 266k 0%
---------Signal-----------|-----------------DL-----------------|-----------UL-----------
cc pci rsrp pl cfo | mcs snr iter brate bler ta_us | mcs buff brate bler
0 1 -66 66 3.1k | 24 28 1.0 27M 0% 1.6 | 21 334 784k 0%
enb
lte 1 72 14 0 24 27M 1000 0 0% | 38.1 35.3 31 22 688k 179 0 0% 0.0
lte 1 72 13 0 24 27M 1000 0 0% | 38.2 35.4 31 21 712k 195 0 0% 0.0
lte 1 72 13 0 24 27M 1000 0 0% | 38.1 35.4 31 21 733k 192 0 0% 0.0
lte 1 72 14 0 24 27M 1000 0 0% | 37.9 35.2 31 21 722k 190 0 0% 0.0
lte 1 72 13 0 24 27M 1000 0 0% | 38.0 35.4 31 21 701k 203 0 0% 0.0
lte 1 72 15 0 24 514k 19 128 87% | 9.0 35.3 31 21 23k 7 16 69% 0.0
-----------------DL----------------|-------------------------UL-------------------------
rat pci rnti cqi ri mcs brate ok nok (%) | pusch pucch phr mcs brate ok nok (%) bsr
lte 1 72 15 0 0 0 0 0 0% | n/a 99.9 0 0 0 0 0 0% 0.0
lte 1 72 15 0 0 0 0 0 0% | n/a 99.9 0 0 0 0 0 0% 0.0
lte 1 72 15 0 0 0 0 0 0% | n/a 99.9 0 0 0 0 0 0% 0.0
Disconnecting rnti=0x72.
RACH: tti=341, cc=0, pci=1, preamble=6, offset=1, temp_crnti=0x73
Disconnecting rnti=0x73.
RACH: tti=421, cc=0, pci=1, preamble=35, offset=1, temp_crnti=0x74
Disconnecting rnti=0x74.
RACH: tti=501, cc=0, pci=1, preamble=3, offset=1, temp_crnti=0x75
Disconnecting rnti=0x75.
RACH: tti=581, cc=0, pci=1, preamble=3, offset=1, temp_crnti=0x76
Disconnecting rnti=0x76.
RACH: tti=661, cc=0, pci=1, preamble=20, offset=1, temp_crnti=0x77
Disconnecting rnti=0x77.
RACH: tti=741, cc=0, pci=1, preamble=16, offset=1, temp_crnti=0x78
Disconnecting rnti=0x78.
RACH: tti=821, cc=0, pci=1, preamble=45, offset=1, temp_crnti=0x79
Disconnecting rnti=0x79.
RACH: tti=901, cc=0, pci=1, preamble=14, offset=1, temp_crnti=0x7a
Disconnecting rnti=0x7a.
RACH: tti=981, cc=0, pci=1, preamble=24, offset=1, temp_crnti=0x7b
RACH: tti=1061, cc=0, pci=1, preamble=36, offset=1, temp_crnti=0x7c
Disconnecting rnti=0x7b.
Disconnecting rnti=0x7c.
RACH: tti=1141, cc=0, pci=1, preamble=30, offset=1, temp_crnti=0x7d
RRCReestablishmentReject for rnti=0x7d. Cause: no context available
Disconnecting rnti=0x7d.
RACH: tti=2951, cc=0, pci=1, preamble=31, offset=1, temp_crnti=0x7e
Disconnecting rnti=0x7e.
RACH: tti=7541, cc=0, pci=1, preamble=9, offset=1, temp_crnti=0x7f
User 0x7f connected
lte 1 7f 15 0 20 30k 16 0 0% | 35.4 29.7 31 17 48k 10 0 0% 0.0
tlte 1 7f 15 0 0 0 0 0 0% | n/a 99.9 0 0 0 0 0 0% 0.0
Enter t to restart trace.