From 2965519af66d7bc2aae181bf9def51faff839625 Mon Sep 17 00:00:00 2001 From: Robert Schmidt Date: Thu, 4 Jan 2024 09:30:33 +0100 Subject: [PATCH] Explain noS1 mode in documentation --- doc/RUNMODEM.md | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/doc/RUNMODEM.md b/doc/RUNMODEM.md index ae5781184c..85ed0d4e0c 100644 --- a/doc/RUNMODEM.md +++ b/doc/RUNMODEM.md @@ -145,9 +145,31 @@ In phy-test mode it is possible to mimic the reception of UE Capabilities at gNB ## noS1 setup with OAI UE -Instead of randomly generated payload, in the phy-test mode we can also inject/receive user-plane traffic over a TUN interface. This is the so-called noS1 mode. +Instead of randomly generated payload, in the phy-test mode we can also +inject/receive user-plane traffic over a TUN interface. This is the so-called +noS1 mode. -This setup is described in the [rfsimulator page](../radio/rfsimulator/README.md#5g-case). In theory this should also work with the real hardware target although this has yet to be tested. +The noS1 mode is applicable to both gNB/UE, and enabled by passing `--noS1` as +an option. The gNB/UE will open a TUN interface which the interface names and +IP addresses `oaitun_enb1`/10.0.1.1, and `oaitun_ue1`/10.0.1.2, respectively. +You can then use these interfaces to send traffic, e.g., +```bash +iperf -sui1 -B 10.0.1.2 +``` +to open an iperf server on the UE side, and +```bash +iperf -uc 10.0.1.2 -B 10.0.1.1 -i1 -t10 -b1M +``` +to send data from the gNB down to the UE. + +Note that this does not work if both interfaces are on the same host. We +recommend to use two different hosts, or at least network namespaces, to route +traffic through the gNB/UE tunnel. + +This option is only really helpful for phy-test/do-ra (see below) modes, in +which the UE does not connect to a core network. If the UE connects to a core +network, it receives an IP address for which it automatically opens a network +interface. ## do-ra setup with OAI