Amarisoft NR Core
Overview
Amarisoft runs on standard off-the-shelf x86/ARM hardware and standard Linux distributions. The source code is proprietary and protected by commercial software licenses. The Amarisoft NR core includes key 5G core elements such as AMF, SMF, UPF, NRF, AUSF, UDM, and an integrated IMS server for VoNR/VoLTE voice calls.
This guide describes how to connect OCUDU to an Amarisoft NR core when the gNB and core network run on separate Linux hosts. You can also co-host OCUDU with the Amarisoft NR core on a single machine.
Resources
Prerequisites
The deployment requires the following components:
- PC running Ubuntu 22.04 or later
- OCUDU CU/DU (commit
e5190292f6or later) - Amarisoft NR Core (version
2025-09-19or later) - USRP X310 connected over a 10GbE interface
- IP connectivity between the Amarisoft NR core host and the OCUDU host
1. Configure Amarisoft NR Core
This tutorial uses Amarisoft core version 2025-09-19. The Amarisoft release archive amarisoft.2025-09-19.tar.gz contains the archive ltemme-linux-2025-09-19.tar.gz. Extract this archive before proceeding. You can run the Amarisoft core directly from the unpacked directory without an explicit installation step. For more details, read the installation guide.
The ltemme binary inside the ltemme-linux-2025-09-19 directory initializes the core. The config folder contains example configuration files.
This tutorial uses the mme.cfg configuration file. Set the gtp_addr parameter to the IP address of the local network interface connected to the core network. The parameter defaults to localhost when co-hosting the gNB and core network on the same machine. Match the nssai slices between the core and the gNB. The mme.cfg configuration file defaults to plmn: "00101" and sst: 1. Configure the same values in OCUDU gNB.
gtp_addr: "10.254.250.47", // Local IP bound by the Amarisoft core for OCUDU gNB traffic.
Configure the subscriber details in the ue_dbsection. Use the count parameter to generate a batch of 128 subscribers by auto-incrementing the base imsi and K values. Alternatively, list each subscriber entry individually in the JSON configuration file.
ue_db: [
{
sim_algo: "milenage",
imsi: "001010000000001",
K: "fec86ba6eb707ed08905757b1bb44b8f",
opc: "C42449363BBAD02B66D16BC975D77CC1",
amf: 0x9001,
sqn: "000000000000",
count: 128,
},
],
Start the Amarisoft core:
./ltemme config/mme.ocudu.cfg
A successful startup displays the following terminal output:
Warning: GTP-U receive buffer set to 425984 instead of 5242880
Warning: GTP-U send buffer set to 425984 instead of 5242880
You may launch lte_init.sh script
(mme)
2. Configure OCUDU
Install OCUDU by following the OCUDU installation guide..
Use the following OCUDU parameters to connect to a remote Amarisoft core host:
cu_cp:
amf:
addrs: 10.254.250.47 # IP address of the remote Amarisoft core (AMF) machine
bind_addrs: 10.254.250.21 # Local IP address of gNB reachable by the Amarisoft core
supported_tracking_areas:
- tac: 1
plmn_list:
- plmn: "00101"
tai_slice_support_list:
- sst: 1
Start OCUDU gNB from the build directory using the updated configuration file:
sudo ./apps/gnb/gnb -c gnb_rf_x310_tdd_n78_40mhz.yml
The console output should be similar to the following:
--== OCUDU gNB (commit e5190292f6) ==--
Lower PHY in triple executor mode.
Available radio types: uhd, zmq and realtime_loopback.
[INFO] [UHD] linux; GNU C++ version 11.4.0; Boost_107400; DPDK_21.11; UHD_4.8.0.HEAD-0-g308126a4
[INFO] [LOGGING] Fastpath logging disabled at runtime.
Making USRP object with args 'type=x300,addr=192.168.40.2,send_frame_size=8000,recv_frame_size=8000,num_send_frames=512,num_recv_frames=512,master_clock_rate=184.32e6'
[INFO] [X300] X300 initialization sequence...
[INFO] [X300] Maximum frame size: 8000 bytes.
[INFO] [GPS] Found an internal GPSDO: LC_XO, Firmware Rev 0.929a
[INFO] [X300] Radio 1x clock: 184.32 MHz
Setting USRP time to 1788992613s
[INFO] [MULTI_USRP] 1) catch time transition at pps edge
[INFO] [MULTI_USRP] 2) set times next pps (synchronously)
[WARNING] [0/Radio#0] Attempting to set tick rate to 0. Skipping.
Cell pci=1, bw=40 MHz, 1T1R, dl_arfcn=632628 (n78), dl_freq=3489.42 MHz, dl_ssb_arfcn=631680, ul_freq=3489.42 MHz
N2: Connection to AMF on 10.254.250.47:38412 completed
Remote control server listening on 0.0.0.0:8001
==== gNB started ===
Type <h> to view help
The gNB detects the USRP X310 and establishes an N2 connection to the Amarisoft core. Execute the ng_ran command in the Amarisoft MME console to verify active NG-RAN nodes connected over N2/NGAP:
(mme) ng_ran
PLMN RAN_ID IP:Port #UEctx TACs
00101 0x19b 10.254.250.21:46242 0 0x1
This output verifies the OCUDU PLMN and IP connection. The UE context count remains zero until a UE connects to OCUDU.
3. Connect a 5G device
Program the SIM card with the subscriber credentials configured in the Amarisoft core ue_db.
This setup uses Amarisoft UE to verify RF and core connectivity. The following console output shows a successful connection to OCUDU and registration with the Amarisoft core:
RF0: sample_rate=61.440 MHz dl_freq=3489.420 MHz ul_freq=3489.420 MHz (band n78) dl_ant=1 ul_ant=1
/dev/sdr0 initialized (15s) (tries=0)
Waiting for GPS lock...
/dev/sdr0 Locked on GPS (1)
(ue) Cell 0: SIB found
(ue)
(ue) cells
Cell #0 / NR:
PCI: 1
TDD: config=0, ssf=0
EARFCN: DL=632628 UL=632628
RB: DL=106 UL=106
SFN: 1.732.13
(ue) power_on 1
(ue) ue 1
# UE_ID CL RNTI RRC_STATE EMM_STATE #ERAB IP_ADDR
NR 1 0 4601 running registered 1 192.168.4.2 CID 0
Execute ng_ran in the Amarisoft MME console to verify the active UE context on the OCUDU gNB:
(mme) ng_ran
PLMN RAN_ID IP:Port #UEctx TACs
00101 0x19b 10.254.250.21:46242 1 0x1
Execute uectx to inspect N2 control-plane bindings:
(mme) uectx
CN_UE_ID RAN_ID RAN_UE_ID M-TMSI/5G-TMSI
100 0x19b 0 0x5c51a253
Execute ue to inspect subscriber state and N3 user-plane bearer details:
(mme) ue
SUPI IMEISV CN M-TMSI/5G-TMSI REG TAC #BEARER IP_ADDR
001010000000001 0123456700000101 5GC 0x5c51a253 Y 00101. 0x1 1 internet/192.168.4.2
Conclusion
This tutorial validates cross-platform integration between the Amarisoft NR core and OCUDU gNB across separate hosts. The UE successfully completes 5GS registration, establishes a PDU session, and receives an IP address for user-plane traffic.