人工智能 - 数据包修剪.pdf

1、Prince Sunny MicrosoftKumaresh Perumal-MicrosoftPacket Trimming in AI NetworksPacket Trimming for AI NetworkPrince Sunny and Kumaresh Perumal-MicrosoftOCP SPECIAL FOCUS:ARTIFICIAL INTELLIGENCE(AI)In the world of AI,each packet loss counts and in the existing deployments,when the lossy queue exceeds

2、a buffer threshold,it drops packets without any notification to the destination host.Most of the packet loss recovery is slow.Either timeouts or NACK+Go-Back-N for retransmission.Packet Trimming is introduced to help in faster loss notification and retransmission or other actions.Trimmed packet trav

3、erses the same path as the original packet as it retains the original forwarding header.AI-Packet Trimming IntroductionWhen a trim-eligible queue is congested,dropped packets are trimmed and enqueued to a different queue.Trim queues are configured with higher DWRR weights or strict-priority.Trim pac

4、kets are remarked with different DSCP for End-Host to identify and take immediate actions.Trim packets are remarked with different DSCP using TC and TC_TO_DSCP profile attached to Egress Ports.No other additional overhead added to the trim packet.Trim action can be disabled through ACL for certain f

5、lows.Packet Trimming OverviewPacket TrimmingCongested packets from Q1 are trimmed and sent out on Q3.Trimmed packets are marked with DSCP=3Trim Size=256Trim DSCP=3Trim Queue=3Trim packets map to a TC.Trim packets final DSCP based on TC_TO_DSCP attached to the portTRIM_TC=8TRIM_Queue=3Packet Trimming

6、 Asymmetric DSCPSwitchTC(8)DSCP(30)TC(8)DSCP(40)IPortEPort1EPort2When EndHost receives trim packet,it transmits NACK to Source with forwarding path details.If SRv6 is used for the forwarding,EndHost can change the SID list for the future packets.Retransmission packets may take di