Step 4: Set ToS in the Application (or for All RoCEv2 Traffic)

Notices and Disclaimers
Revision History
Introduction
- QoS/Flow Control Limitations on the 800 Series
Background
Link-Level Flow Control
- LFC Setup Instructions
- Symmetric vs. Asymmetric LFC
Priority Flow Control - Fundamentals
Congestion Management – Tuning Parameters
Priority Flow Control - Planning and Guidelines
- Steps
- Example Configurations
Priority Flow Control - Verification
Troubleshooting

ToS is an 8-bit field in the IP header used to prioritize network traffic. On Intel 800 Series NICs, you can set ToS in two ways:

For an application: Use the application command line.
For example:
- LAN applications (Set ToS directly in the command line of your application): ping -Q 16 <destination_ip> iperf3 -c <server-ip> -S 16 netperf -H <server_ip> -- -Y 16
- RDMA applications: ucmatose -s <server_ip> -t 16 ib_write_bw <server_ip> -R -T 16

For all RoCEv2 traffic on an interface: Use default_roce_tos in configfs.
For example, set ToS 16 on device irdma0, port 1:
# mkdir /sys/kernel/config/rdma_cm/irdma0 # echo 16 > /sys/kernel/config/rdma_cm/irdma0/ports/1/default_roce_tos

Note:LAN tools are included to help test and verify ToS settings before applying them to RDMA traffic.

Step 3: UP to TC Overview