Update doc as per Sagar's comments

doc/ORAN_FHI7.2_Tutorial.md

@@ -229,7 +229,8 @@ You can see these steps in case your ptp logs have erorrs or `rms` reported in `
 
 1. Make sure that you have `skew_tick=1` in `/proc/cmdline`
 2. For Intel E-810 cards set `tx_timestamp_timeout` to 50 or 100 if there are errors in ptp4l logs
-3. Other time sources than PTP are not configured NTP or chrony timesource. If yes then you need to disable them
+3. Other time sources than PTP, such as NTP or chrony timesources, should be disabled. Make sure they are enabled as further below.
+4. If `rms` or `delay` remain high, you can try pinning the PTP process to an isolated CPU.
 
 ```bash
 #to check there is NTP enabled or not
@@ -251,8 +252,6 @@ cd
 wget http://fast.dpdk.org/rel/dpdk-20.11.7.tar.xz
 ```
 
-Note that you can also use a recent version of DPDK: `wget http://fast.dpdk.org/rel/dpdk-20.11.8.tar.xz`.
-
 ### DPDK Compilation and Installation
 
 ```bash
@@ -390,11 +389,10 @@ sudo apt install -y libnuma-dev
 # on RHEL
 sudo dnf install -y numactl-devel
 export PKG_CONFIG_PATH=/opt/dpdk/lib64/pkgconfig/
+./build_oai -I  # if you never installed OAI, use this command once before the next line
 ./build_oai --gNB --ninja -t oran_fhlib_5g --cmake-opt -Dxran_LOCATION=$HOME/phy/fhi_lib/lib
 ```
 
-(if you never installed OAI before, run `./build_oai -I` beforehand).
-
 You can optionally check that everything has been linked properly with
 ```bash
 ldd ran_build/build/liboran_fhlib_5g.so
@@ -433,12 +431,20 @@ cmake .. -GNinja -DOAI_FHI72=ON -Dxran_LOCATION=$HOME/phy/fhi_lib/lib
 ninja nr-softmodem oran_fhlib_5g params_libconfig
 ```
 
+# Configure the RU
+
+Contact the RU vendor to get the configuration manual, and configure the RU
+appropriately. You can orient on the OAI configuration files mentioned further
+below.
+
+We are evaluating if we can share RU configuration steps.
+
 # Configure OAI gNB
 
 Sample configuration files for OAI gNB, specific to the manufacturer of the radio unit, are available at:
-1. LITE-ON RU: [`gnb.sa.band78.273prb.fhi72.4x4-liteon.conf`](../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-liteon.conf)
-2. Benetel 650 RU: [`gnb.sa.band78.273prb.fhi72.4x2-benetel650.conf`](../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x2-benetel650.conf)
-3. VVDN RU: [`gnb.sa.band77.273prb.fhi72.4x4-vvdn.conf`](../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band77.273prb.fhi72.4x4-vvdn.conf)
+1. LITE-ON RU: [`gnb.sa.band78.273prb.fhi72.4x4-liteon.conf`](../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-liteon.conf) (band n78, 273 PRBs, 3.5GHz center freq, 4x4 antenna configuration with 9 bit I/Q samples (compressed) for PUSCH/PDSCH/PRACH, 2x2 DL MIMO, UL SISO)
+2. Benetel 650 RU: [`gnb.sa.band78.273prb.fhi72.4x2-benetel650.conf`](../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x2-benetel650.conf) (band n78, 273 PRBs, 3.5GHz center freq, 4x2 antenna configuration with 9 bit I/Q samples (compressed) for PUSCH/PDSCH/PRACH, 2x2 DL MIMO, UL SISO)
+3. VVDN RU: [`gnb.sa.band77.273prb.fhi72.4x4-vvdn.conf`](../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band77.273prb.fhi72.4x4-vvdn.conf) (band n77, 273 PRBs, 4.0GHz center freq, 4x4 antenna configuration with 9 bit I/Q samples (compressed) for PUSCH/PDSCH/PRACH, 2x2 DL MIMO, UL SISO)
 
 ## Adapt the OAI-gNB configuration file to your system/workspace