After enabling lossless queues for RoCE, a microburst still drops U…

Question

After enabling lossless queues for RoCE, a microburst still drops UDP telemetry on county leaves. What CoS tradeoff should the team recognize?

Accepted Answer

Protecting RDMA with prioritized or lossless CoS can starve or drop traffic in other classes during congestion — Giving the glass elevator reserved brakes means somebody else’s cart may hit the floor first. When you shield RoCE, scavenger or telemetry queues can still drop in a microburst—that is the tradeoff, not a bug in VXLAN.

Answer

Lossless configuration guarantees every other class receives unlimited buffer under microbursts

Answer

UDP telemetry always preempts RoCE once PFC is enabled anywhere in the pod

Answer

Microbursts cannot affect non-RDMA classes if VXLAN is enabled on the VTEPs

After enabling lossless queues for RoCE, a microburst still drops UDP telemetry on county leaves. What CoS tradeoff should the team recognize?

Short Explanation

Full Explanation