raww
INCAST Spectrum-X switches Bluefield DPUs Flow level loadbalancing vs packet level loadbalancing (spraying) Leads to out-of-order NVIDIA's RoCE (RDMA over Converged Ethernet) RDMA HPC - high performance computing Need for - high speed low latency connections Eveyday internet use TCP/IP not good for this Application > OS > TCP/IP stack > NIC card (CPU intence) - adds latency RDMA Approach -rNIC offlocading (OS,stack) 1.Infiniband (dedicated nw switch & nic) 2.iWARP - internet wide area RDMS protocol (need iWARP capablie NICs) 3a.RoCE 3b.RoCEv2 (UDP+IP packets) for RDMA lossless is must *traditional ethernet is lossy when there is a congestion 1.MTU 2.QoS - prioritse roce packet dscp 3.PFC - priority flow control Network switch (receving switch send a pause frame to sending switch , this will make sending switch to stop sending for some time) this will help in lossless transaction but intraduce Head-of-line-blocaking 4.DCQCN -...