HCCL_RDMA_TC

Description

Sets the traffic class (TC) of the RDMA NIC.

The value of this environment variable corresponds to the DSCP of RoCE packets. Since the DSCP field in the IP packet header has its six most significant bits with bits 0 and 1 fixed at zero in the DS domain, the value should be configured as the DSCP value multiplied by 4.

The default value is 132, which corresponds to DSCP 33 (132 = 33 x 4).

Example

# If the DSCP is 25, the environment variable should be set to 100 (25 x 4 = 100).
export HCCL_RDMA_TC=100

Restrictions

None

Applicability

Atlas Training Series Product