Robert Schmidt
07629e29d6
This is a simple CU-UP load tester. It sets up a configurable number of UEs in the
CU-UP, then sends GTP traffic in downlink/uplink in the N3-F1/F1-N3
direction at the CU-UP. It then compares the sent and received data.
Additional parameters, such as amount of traffic, test length, packet
size, and IP addresses/ports are configurable.
To run:
mkdir build && cd build && cmake .. -GNinja && ninja nr-cuup nr-cuup-load-test params_libconfig
./tests/nr-cuup/nr-cuup-load-test
./nr-cuup -O ../tests/nr-cuup/load-test.conf
The tester should be able to detect lost and reordered packets.
Example lost: Receive order 2,3,5,6 (lost packet 4)
=> on packet 2, expected 2, next=expected+1=3
=> on packet 3, expected 3, next=expected+1=4
=> on packet 5, expected 4, diff=5-4=1 (lost 1), next=payload+1=6
=> on packet 6, expected 6
=> 1 lost
Example reordered: Receiver order 2,5,3,6 (lost packet 4)
=> on packet 2, expected 2, next=expected+1=3
=> on packet 5, expected 3, diff=5-3=2 (lost 2), next=payload+1=6
=> on packet 3, expected 6, (reduce lost by 1 to 1), next=expected=6
=> on packet 6, expected 6
=> 1 lost
Example reordered: Receiver order 2,5,3,4,6 (no losses)
2.8 KiB
This is a simple tester for the CU-UP. It configures the CU-UP via E1, and can stream data via GTP in uplink and downlink directions.
[[TOC]]
Overview
From a schematic point of view, the tester/CU-UP interaction looks like this:
+-------+
+------>| CU-UP |<------+
| +-------+ |
| | |
| F1-U | E1 | NG-U
| (data) | (control) | (data)
| | |
| +-------+ |
+------>|tester |<------+
+-------+
The tester is for performance testing of a CU-UP, and behaves like an integrated DU/CU-CP/UPF from the CU-UP's point of view.
The tester and CU-UP have an E1 connection through which control information is exchanged, e.g., configuration of UEs/bearers and associated information. In other words, towards the CU-UP, the tester appears like a CU-CP.
Further, for each UE/bearer, CU-UP is configured with GTP IP information and the corresponding TEID. The CU-UP will forward downlink data arriving on NG-U on the F1-U interface, and uplink data arriving on F1-U on the NG-U interface. In other words, on the F1-U interface, the tester appears like a DU to the CU-UP, and on the NG-U interface, the tester appears like a UPF to the CU-UP.
A test scenario is fixed to these steps:
- The tester sets up a number of UEs via the E1 interface (it is possible to see the message exchange in Wireshark).
- The tester streams data in downlink/uplink (from the CU-UP's point of view) and measures how much data is lost.
- The tester releases all the UEs via the E1 interface, and disconnects from the CU-UP.
Note: The tester uses the same GTP module as the CU-UP. Thus, data might not only be lost at the GTP interface of the CU-UP, but also at the tester.
Usage
You can build the CU-UP and the tester like so:
cd ~/openairinterface5g
mkdir build && cd build && cmake .. -GNinja && ninja nr-cuup nr-cuup-load-test params_libconfig
./tests/nr-cuup/nr-cuup-load-test
./nr-cuup -O ../tests/nr-cuup/load-test.conf
This builds both tester and CU-UP in the directory build/, then starts the
load tester with default values
- 1 UE
- 10s of Test
- 60 Mbps of traffic in both downlik/uplink with a packet size of 1400 bytes
To see the available options, run
./tests/nr-cuup/nr-cuup-load-test -h
The configuration file load-test.conf matches the default
tester configuration (F1-U GTP traffic over non-standard port 2153, NG-U GTP
over 2152, tests on localhost). The configuration file includes this
non-standard port 2153 as the GTP module, as of now, cannot bind on the same
interface and port for both F1-U and NG-U due to internal limitations.
Limitations
- The tester does not yet create/remove UEs during a traffic test.
- It might be possible to integrate with an external GTP traffic generator, but we did not test this.