{"id":1349,"date":"2021-09-29T10:00:00","date_gmt":"2021-09-29T10:00:00","guid":{"rendered":"http:\/\/124.223.68.123\/?p=1349"},"modified":"2024-06-19T12:12:00","modified_gmt":"2024-06-19T12:12:00","slug":"1349-2","status":"publish","type":"post","link":"https:\/\/www.zenosic.com\/en\/1349-2\/","title":{"rendered":"RDMA\u53ca\u5176\u76f8\u5173\u7f51\u7edc\u6280\u672f"},"content":{"rendered":"

\u6982\u8ff0<\/p>\n\n\n\n

\u672c\u6587\u4ecb\u7ecd\u4e86RDMA\u6280\u672f\u7684\u53d1\u5c55\u6cbf\u9769\uff0c\u5206\u6790\u4e86RDMA\u6240\u9700\u7684\u65e0\u635f\u7f51\u7edc\u7684\u6280\u672f\u8981\u6c42\uff0c\u8ba8\u8bba\u4e86PFC\u6280\u672f\u5b9e\u73b0\u65f6\u7684\u4ea4\u6362\u673a\u5185\u90e8\u7f13\u5b58\u6280\u672f\uff0c\u6b7b\u9501\u95ee\u9898\u7b49\u5e38\u89c1\u95ee\u9898\uff0c\u5e76\u4ecb\u7ecd\u4e86ECN\u8fd0\u4f5c\u673a\u5236\u3002
 <\/p>\n\n\n\n

1.\u5f15\u8a00<\/strong><\/p>\n\n\n\n

\u4ee5\u592a\u7f51\u4e00\u76f4\u662f\u7f51\u7edc\u6280\u672f\u7684\u4e3b\u6d41\uff0c\u5728\u4e0d\u540c\u7684\u5386\u53f2\u65f6\u671f\uff0c\u5b83\u603b\u662f\u9047\u5230\u4e00\u4e9b\u7ade\u4e89\u5bf9\u624b\uff0c\u5982ATM\uff0c\u4f46\u4eba\u4eec\u8fd8\u662f\u5728\u4e0d\u65ad\u5438\u53d6\u5176\u4ed6\u6280\u672f\u7684\u4f18\u70b9\u6765\u5b8c\u5584\u5b83\uff0c\u7ee7\u7eed\u4f7f\u7528\u5b83\u3002\u5728\u5f53\u524d\u5927\u89c4\u6a21\u4e92\u8054\u7f51\uff0c\u4eba\u5de5\u667a\u80fd\u7b49\u9700\u8981\u9ad8\u5e26\u5bbd\uff0c\u4f4e\u5ef6\u8fdf\u7684\u5e94\u7528\u73af\u5883\u4e0b\uff0c\u4ee5\u592a\u7f51\u5229\u7528RoCEv2\u7b49RDMA\u65b0\u6280\u672f\uff0c\u518d\u6b21\u8868\u73b0\u51fa\u65b0\u7684\u6d3b\u529b\uff0c\u4e3a\u884c\u4e1a\u6240\u63a5\u6536\u3002\u672c\u6587\u5c06\u4ecb\u7ecdDRMA\u6280\u672f\u548c\u5176\u76f8\u5173\u7f51\u7edc\u6280\u672f\u548c\u5e94\u7528\u3002
<\/p>\n\n\n\n

\uff12.RDMA\u53d1\u5c55\u6cbf\u9769<\/strong><\/p>\n\n\n\n

\u4f20\u7edf\u7684TCP\/IP\u67b6\u6784\u8bbe\u8ba1\u56e0\u4e3a\u5176\u8bde\u751f\u7684\u65f6\u4ee3\u9650\u5236\uff0c\u5b58\u5728\u7740\u7f51\u7edc\u4f20\u8f93\u5ef6\u8fdf\u8f83\u5927\u3001\u591a\u6b21\u6570\u636e\u62f7\u8d1d\u548c\u4e2d\u65ad\u5904\u7406\u7b49\u95ee\u9898\u3002RDMA\uff08RemoteDirect MemoryAccess\uff09\uff0c\u8fdc\u7a0b\u76f4\u63a5\u5185\u5b58\u8bbf\u95ee\u6280\u672f\uff0c\u5c31\u662f\u4e3a\u4e86\u89e3\u51b3\u7f51\u7edc\u4f20\u8f93\u4e2d\u670d\u52a1\u5668\u7aef\u6570\u636e\u5904\u7406\u7684\u5ef6\u8fdf\u800c\u4ea7\u751f\u7684\u6280\u672f\u3002RDMA\u5c06\u6570\u636e\u76f4\u63a5\u4ece\u4e00\u53f0\u8ba1\u7b97\u673a\u7684\u5185\u5b58\u4f20\u8f93\u5230\u53e6\u4e00\u53f0\u8ba1\u7b97\u673a\uff0c\u65e0\u9700\u53cc\u65b9\u64cd\u4f5c\u7cfb\u7edf\u7684\u4ecb\u5165\u3002\u8fd9\u5141\u8bb8\u9ad8\u541e\u5410\u3001\u4f4e\u5ef6\u8fdf\u7684\u7f51\u7edc\u901a\u4fe1\uff0c\u5c24\u5176\u9002\u5408\u5728\u5927\u89c4\u6a21\u5e76\u884c\u8ba1\u7b97\u673a\u96c6\u7fa4\u4e2d\u4f7f\u7528\u3002\u901a\u8fc7\u7f51\u7edc\u5c06\u6570\u636e\u76f4\u63a5\u4f20\u5165\u8ba1\u7b97\u673a\u7684\u5b58\u50a8\u533a\u95f4\uff0c\u5c06\u6570\u636e\u4ece\u4e00\u4e2a\u7cfb\u7edf\u5feb\u901f\u4f20\u8f93\u670d\u52a1\u5668\u7684\u5b58\u50a8\u7a7a\u95f4\uff0c\u6d88\u9664\u4e86\u4f20\u8f93\u8fc7\u7a0b\u4e2d\u9700\u8981\u591a\u6b21\u6570\u636e\u590d\u5236\u7684\u64cd\u4f5c\uff0c\u56e0\u800c\u80fd\u89e3\u653e\u5185\u5b58\u5e26\u5bbd\u548cCPU\u5468\u671f\u7528\u4e8e\u6539\u8fdb\u5e94\u7528\u7cfb\u7edf\u6027\u80fd\u3002<\/p>\n\n\n\n

RDMA\u53d1\u5c55\u7ecf\u5386\u4e863\u79cd\u6280\u672f\uff0cInfiniband\uff0ciWarp\uff0cRoCEv1\u548cRoCEv2\u3002<\/p>\n\n\n\n

Infiniband<\/strong><\/p>\n\n\n\n

2000\u5e74IBTA\uff08InfiniBandTradeAssociation\uff09\u53d1\u5e03\u4e86\u6700\u65e9\u7684RDMA\u6280\u672f\uff0cInfiniband\u3002\u5b83\u662f\u4e13\u4e3aRDMA\u8bbe\u8ba1\u7684\u7f51\u7edc\uff0c\u4ece\u786c\u4ef6\u7ea7\u522b\u4fdd\u8bc1\u53ef\u9760\u4f20\u8f93\u3002\u63d0\u4f9b\u4e86\u57fa\u4e8e\u901a\u9053\u7684\u70b9\u5bf9\u70b9\u6d88\u606f\u961f\u5217\u8f6c\u53d1\uff0c\u6bcf\u4e2a\u5e94\u7528\u81ea\u5df1\u90fd\u53ef\u901a\u8fc7\u521b\u5efa\u7684\u865a\u62df\u901a\u9053\u76f4\u63a5\u83b7\u53d6\u672c\u5e94\u7528\u7684\u6570\u636e\u6d88\u606f\u3002InfiniBan\u6280\u672f\u91c7\u7528\u4e86RDMA\u6280\u672f\uff0c\u53ef\u4ee5\u8fdb\u884c\u8fdc\u7a0b\u8282\u70b9\u76f4\u63a5\u8bfb\u5199\u8bbf\u95ee\u3002InfiniBand\u5c5e\u4e8e\u539f\u751f\u7684RDMA\uff0c\u5fc5\u987b\u4f7f\u7528InfiniBan\u4ea4\u6362\u673a\u548cInfiniBan\u7f51\u5361\u624d\u53ef\u5b9e\u73b0\u3002<\/p>\n\n\n\n

iWarp\uff08internetWide Area RDMA Protocol\uff09<\/strong><\/p>\n\n\n\n

\u4e92\u8054\u7f51\u5e7f\u57dfRDMA\u534f\u8bae\uff0c\u5373RDMAover TCP,\u662fIEEE\/IETF\u6807\u51c6\u5316\u7684\u6280\u672f\u3002\u5141\u8bb8\u901a\u8fc7TCP\u6267\u884cRDMA\u7684\u7f51\u7edc\u534f\u8bae\u3002\u8fd9\u5141\u8bb8\u5728\u6807\u51c6\u4ee5\u592a\u7f51\u57fa\u7840\u67b6\u6784(\u4ea4\u6362\u673a)\u4e0a\u4f7f\u7528RDMA\uff0c\u53ea\u4e0d\u8fc7\u7f51\u5361\u8981\u6c42\u662f\u652f\u6301iWARP(\u5982\u679c\u4f7f\u7528CPUoffload\u7684\u8bdd)\u7684NIC\u3002\u5426\u5219\uff0c\u6240\u6709iWARP\u6808\u90fd\u53ef\u4ee5\u5728\u8f6f\u4ef6\u4e2d\u5b9e\u73b0\uff0c\u4f46\u662f\u5931\u53bb\u4e86\u5927\u90e8\u5206\u7684RDMA\u6027\u80fd\u4f18\u52bf\u3002<\/p>\n\n\n\n

RoCE\uff08RDMAover Converged Ethernet\uff09<\/strong><\/p>\n\n\n\n

2010\u5e744\u6708\uff0cIBTA\u53d1\u5e03\u4e86RoCEv1\uff0c\u6b64\u6807\u51c6\u662f\u4f5c\u4e3aInfinibandArchitecture Specification\u7684\u9644\u52a0\u4ef6\u53d1\u5e03\u7684\uff0c\u6240\u4ee5\u53c8\u88ab\u79f0\u4e3aIBoE\uff08InfiniBandoverEthernet\uff09\u3002RoCE\u6807\u51c6\u662f\u5728\u4ee5\u592a\u94fe\u8def\u5c42\u4e4b\u4e0a\u7528IB\u7f51\u7edc\u5c42\u4ee3\u66ff\u4e86TCP\/IP\u7f51\u7edc\u5c42\uff0c\u4e0d\u652f\u6301IP\u8def\u7531\u529f\u80fd\u3002\u4ee5\u592a\u7c7b\u578b\u4e3a0x8915\u3002\u5728RoCE\u4e2d\uff0cinfiniband\u7684\u94fe\u8def\u5c42\u534f\u8bae\u5934\u88ab\u53bb\u6389\uff0c\u7528\u6765\u8868\u793a\u5730\u5740\u7684GUID\u88ab\u8f6c\u6362\u6210\u4ee5\u592a\u7f51\u7684MAC\u3002Infiniband\u4f9d\u8d56\u4e8e\u65e0\u635f\u7684\u7269\u7406\u4f20\u8f93\uff0cRoCE\u4e5f\u540c\u6837\u4f9d\u8d56\u4e8e\u65e0\u635f\u7684\u4ee5\u592a\u4f20\u8f93\uff0c<\/p>\n\n\n\n

RoCEv2<\/strong><\/p>\n\n\n\n

\u7531\u4e8eRoCEv1\u7684\u6570\u636e\u5e27\u4e0d\u5e26IP\u5934\u90e8\uff0c\u53ea\u80fd\u57282\u5c42\u7f51\u7edc\u5185\u901a\u4fe1\u3002\u4e3a\u4e86\u89e3\u51b3\u6b64\u95ee\u9898\uff0c2014\u5e74IBTA\u63d0\u51fa\u4e86RoCEV2\uff0cRoCEv2\u6269\u5c55\u4e86RoCEv1\uff0c\u5c06GRH(GlobalRoutingHeader)\u6362\u6210UDPheader +\u3000IPheader\u3002\u91c7\u7528UDPPort4791\u8fdb\u884c\u4f20\u8f93\u3002\u7531\u4e8eRoCEv2\u62a5\u6587\u57283\u5c42\u7684\u53ef\u8fdb\u884c\u8def\u7531\uff0c\u6240\u4ee5\u6709\u65f6\u53c8\u4f1a\u79f0\u4e3a\u201cRoutableRoCE\u201d\u6216\u7b80\u79f0\u201cRRoCE\u201d\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

RoCE\u6280\u672f\u53ef\u901a\u8fc7\u666e\u901a\u4ee5\u592a\u7f51\u4ea4\u6362\u673a\u5b9e\u73b0\uff0c\u4f46\u670d\u52a1\u5668\u9700\u8981\u652f\u6301RoCE\u7f51\u5361\u3002\u7531\u4e8eRoCE\u662fUDP\u534f\u8bae\uff0c\u867d\u7136UDP\u534f\u8bae\u6548\u7387\u6bd4\u8f83\u9ad8\uff0c\u4f46\u4e0d\u50cfTCP\u534f\u8bae\u90a3\u6837\u6709\u91cd\u4f20\u673a\u5236\u7b49\u6765\u4fdd\u969c\u53ef\u9760\u7684\u4f20\u8f93\uff0c\u4e00\u65e6\u51fa\u73b0\u4e22\u5305\uff0c\u5fc5\u987b\u4f9d\u9760\u4e0a\u5c42\u5e94\u7528\u53d1\u73b0\u4e86\u518d\u505a\u91cd\u4f20\uff0c\u8fd9\u5c31\u4f1a\u5927\u5927\u964d\u4f4eRDMA\u7684\u4f20\u8f93\u6548\u7387\u3002\u6240\u4ee5\u8981\u60f3\u53d1\u6325\u51faRoCE\u7684\u771f\u6b63\u7684\u6548\u679c\uff0c\u5fc5\u987b\u8981\u4e3aRDMA\u642d\u5efa\u4e00\u5957\u4e0d\u4e22\u5305\u7684\u65e0\u635f\u7f51\u7edc\u73af\u5883\u3002<\/p>\n\n\n\n

RoCE\u53ef\u4ee5\u8fd0\u884c\u5728\u65e0\u635f\u7f51\u7edc\u73af\u5883\u548c\u6709\u635f\u7f51\u7edc\u73af\u5883\u4e2d\uff0c\u5982\u679c\u8fd0\u884c\u5728\u6709\u635f\u7f51\u7edc\u73af\u5883\u4e2d\uff0c\u79f0\u4e3a\u5f39\u6027RoCE(ResilientRoCE)\uff1b\u5982\u679c\u8fd0\u884c\u5728\u65e0\u635f\u7f51\u7edc\u73af\u5883\u4e2d\uff0c\u79f0\u4e3a\u65e0\u635fRoCE(LosslessRoCE)<\/p>\n\n\n\n

3.PFC\u529f\u80fd<\/strong><\/p>\n\n\n\n

\u65e0\u635f\u4ee5\u592a\u7f51\uff0c\u5728\u7f51\u7edc\u8bbe\u5907\u4e0a\u81f3\u5c11\u9700\u8981\u652f\u63012\u5927\u5173\u952e\u529f\u80fd\uff0cPFC\u548cECN\u3002<\/p>\n\n\n\n

3.1PFC\uff08Priority-basedFlowControl\uff0c\u57fa\u4e8e\u4f18\u5148\u7ea7\u7684\u6d41\u91cf\u63a7\u5236\uff09<\/strong>\uff1a\u5f53\u4ea4\u6362\u673a\u7aef\u53e3\u7684\u63a5\u6536\u961f\u5217\u8d85\u8fc7\u4e00\u5b9a\u9600\u503c(shreshold)\u65f6\uff0c\u5c31\u4f1a\u5411\u5bf9\u7aef\u53d1\u9001PFC\u6682\u505c\u62a5\u6587(pauseframe)\uff0c\u901a\u77e5\u53d1\u9001\u7aef\u505c\u6b62\u53d1\u5305\u6216\u8005\u964d\u4f4e\u901f\u7387\u3002\u5f53\u63a5\u6536\u961f\u5217\u4f4e\u4e8e\u53e6\u4e00\u4e2a\u9600\u503c\u65f6\uff0c\u5c31\u4f1a\u53d1\u9001\u4e00\u4e2apausewith zeroduration\uff0c\u901a\u77e5\u53d1\u9001\u7aef\u6062\u590d\u53d1\u5305\u3002PFC\u662f\u94fe\u8def\u5c42\u534f\u8bae\uff0c\u53ea\u80fd\u9488\u5bf9\u7aef\u53e3\u8fdb\u884c\u6d41\u63a7\uff0c\u9897\u7c92\u5ea6\u8f83\u7c97\u3002\u4e00\u65e6\u53d1\u751f\u62e5\u585e\uff0c\u4f1a\u5bfc\u81f4\u6574\u4e2a\u7aef\u53e3\u505c\u6b62(\u540e\u6587\u6709\u6781\u7aef\u6848\u4f8b\u4ecb\u7ecd)\u3002\u8fd9\u5c31\u4e0d\u592a\u5408\u7406\u3002<\/p>\n\n\n\n

\u6b63\u5e38\u60c5\u51b5\u4e0b\uff0c\u5f53\u4e00\u53f0\u4ea4\u6362\u673a\u7684\u7aef\u53e3\u51fa\u73b0\u62e5\u585e\u5e76\u89e6\u53d1XOFF\u6c34\u7ebf\u65f6\uff0c\u6570\u636e\u8fdb\u5165\u7684\u65b9\u5411\uff08\u5373\u4e0b\u6e38\u8bbe\u5907\uff09\u5c06\u53d1\u9001PAUSE\u5e27\u53cd\u538b\uff0c\u4e0a\u6e38\u8bbe\u5907\u63a5\u6536\u5230PAUSE\u5e27\u540e\u505c\u6b62\u53d1\u9001\u6570\u636e\u3002\u5982\u679c\u5176\u672c\u5730\u7aef\u53e3\u7f13\u5b58\u6d88\u8017\u8d85\u8fc7\u9608\u503c\uff0c\u5219\u7ee7\u7eed\u5411\u4e0a\u6e38\u53cd\u538b\u3002\u5982\u6b64\u4e00\u7ea7\u7ea7\u53cd\u538b\uff0c\u76f4\u5230\u7f51\u7edc\u7ec8\u7aef\u670d\u52a1\u5668\u5728PAUSE\u5e27\u4e2d\u6307\u5b9aPauseTime\u5185\u6682\u505c\u53d1\u9001\u6570\u636e\uff0c\u4ece\u800c\u6d88\u9664\u7f51\u7edc\u8282\u70b9\u56e0\u62e5\u585e\u9020\u6210\u7684\u4e22\u5305\u3002<\/p>\n\n\n\n

PFC\u5728IEEE802.3X\u6d41\u63a7\u7684\u57fa\u7840\u4e0a\u8fdb\u884c\u6269\u5c55\uff0c\u5141\u8bb8\u5728\u4e00\u6761\u4ee5\u592a\u7f51\u94fe\u8def\u4e0a\u521b\u5efa8\u4e2a\u865a\u62df\u901a\u9053\uff0c\u5e76\u4e3a\u6bcf\u6761\u865a\u62df\u901a\u9053\u6307\u5b9a\u76f8\u5e94\u4f18\u5148\u7ea7\uff0c\u5141\u8bb8\u5355\u72ec\u6682\u505c\u548c\u91cd\u542f\u5176\u4e2d\u4efb\u610f\u4e00\u6761\u865a\u62df\u901a\u9053\uff0c\u540c\u65f6\u5141\u8bb8\u5176\u5b83\u865a\u62df\u901a\u9053\u7684\u6d41\u91cf\u65e0\u4e2d\u65ad\u901a\u8fc7\u3002\u4e00\u822c\u5c06RoCE\u7684\u6570\u636e\u6d41\u548cTCP\/IP\u7b49\u5176\u5b83\u6570\u636e\u6d41\u8bbe\u7f6e\u4e0d\u540c\u7684\u4f18\u5148\u7ea7\u3002\u5982\u53ef\u4ee5\u6309\u7167Vlan\u6216\u8005DSCP\u6765\u5206\u7c7b\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

3.2 \u5e38\u89c1\u82af\u7247\u5185\u90e8\u7f13\u5b58\u673a\u5236<\/strong><\/p>\n\n\n\n

\u9274\u4e8e\u76ee\u524d\u5e02\u573a\u4e0a\u7edd\u5927\u591a\u6570\u7684\u4ea4\u6362\u673a\u5382\u5bb6\u90fd\u4f7f\u7528\u535a\u901a(Broadcom)\u7684\u4ea4\u6362\u82af\u7247\uff0c\u7279\u522b\u662f\u6570\u636e\u4e2d\u5fc3\u7684ToR\u4ea4\u6362\u673a\u591a\u91c7\u7528\u535a\u901aXGS\u7cfb\u5217\u82af\u7247\uff0c\u6240\u4ee5\u5e02\u573a\u4e0a\u7edd\u5927\u90e8\u5206\u4ea4\u6362\u673a\u90fd\u6709\u76f8\u540c\u7c7b\u4f3c\u7684PFC\u529f\u80fd\u3002\u6545\u4e0b\u6587\u5c06\u4ee5\u535a\u901aXGS\u5bf9PFC\u7684\u5904\u7406\u4e3a\u4f8b\uff0c\u5c55\u5f00\u4ecb\u7ecd\u3002\u535a\u901aXGS\u7cfb\u5217\u82af\u7247\u90fd\u6709\u4e00\u4e2a\u7f13\u5b58\u7ba1\u7406\u5355\u5143MMU(memorymanagementunit)\uff0c\u5b83\u8bbe\u8ba1\u4e86PG-Guaranteed\u3001PG-Share\u3001Headroom\u4e09\u79cd\u7c7b\u578b\u7684\u5165\u7aef\u53e3\u7f13\u5b58\u3002\u6839\u636e\u82af\u7247\u578b\u53f7\u7684\u4e0d\u540c\uff0c\u7f13\u5b58\u5927\u5c0f\u4f1a\u6709\u6240\u4e0d\u540c\u3002<\/p>\n\n\n\n

Guaranteed:\u56fa\u5b9a\u7f13\u5b58\u533a\uff0c\u4e3a\u7aef\u53e3\u63d0\u4f9b\u6700\u5c0f\u4fdd\u8bc1\u53ef\u7528\u7684\u7f13\u5b58\u7a7a\u95f4\u3002<\/p>\n\n\n\n

Share\uff1a\u5171\u4eab\u7f13\u5b58\u533a\uff0c\u5f53\u6700\u5c0f\u4fdd\u8bc1\u7a7a\u95f4\u4e0d\u8db3\u65f6\uff0c\u4e3a\u7aef\u53e3\u63d0\u4f9b\u7684\u5171\u4eab\u7f13\u5b58\u7a7a\u95f4\u3002<\/p>\n\n\n\n

PG_Headroom\uff1a\u5f53\u6700\u5c0f\u4fdd\u8bc1\u7a7a\u95f4\u4e0e\u5171\u4eab\u7f13\u5b58\u7a7a\u95f4\u90fd\u4e0d\u8db3\u65f6\uff0c\u518d\u63d0\u4f9b\u4e00\u4e9b\u989d\u5916\u7684\u7f13\u5b58\u7a7a\u95f4\u3002\u8be5\u7f13\u5b58\u7a7a\u95f4\u4e3b\u8981\u662f\u7528\u6765\u5b58\u50a8\uff0c\u5f53\u6d41\u63a7\u5e27\u53d1\u9001\u51fa\u53bb\u5230\u5bf9\u7aef\u505c\u6b62\u53d1\u9001\u62a5\u6587\u7684\u8fd9\u6bb5\u65f6\u95f4\uff0c\u53ef\u80fd\u4f1a\u6536\u5230\u5bf9\u7aef\u53d1\u9001\u8fc7\u6765\u7684\u90e8\u5206\u62a5\u6587\u3002<\/p>\n\n\n\n

GlobalHeadroom\uff1a\u5982\u679c\u6ca1\u6709\u4e3a\u6bcf\u4e2a\u7aef\u53e3\u5355\u72ec\u5206\u914dPGheadroom\uff0c\u5219\u7528\u8fd9\u90e8\u5206\u7f13\u5b58\u7a7a\u95f4\u4f5c\u4e3a\u6240\u6709\u7aef\u53e3\u7684PGheadroom\u5171\u4eab\u7a7a\u95f4\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u7f13\u5b58\u89c4\u5219\u662f\u5728\u62a5\u6587\u63a5\u6536\u65f6\uff0c\u4f18\u5148\u4f7f\u7528guaranteed\u56fa\u5b9a\u7f13\u5b58\u533a\uff0c\u7136\u540e\u4f7f\u7528\u5171\u4eab\u7f13\u5b58\u533a\uff0c\u6700\u540e\u4f7f\u7528headroom\u7f13\u5b58\u533a\uff1b\u5f53\u62a5\u6587\u53d1\u9001\u540e\uff0c\u5219\u4f18\u5148\u91ca\u653eheadroom\u7f13\u5b58\u533a\uff0c\u7136\u540e\u662f\u5171\u4eab\u7f13\u5b58\u533a\uff0c\u6700\u540e\u662f\u56fa\u5b9a\u7f13\u5b58\u533a\u3002<\/p>\n\n\n\n

\u7f13\u5b58\u5927\u5c0f\u88ab\u79f0\u4e3a\u9608\u503c(threshold)\uff0c\u4e5f\u7ecf\u5e38\u88ab\u79f0\u4f5c\u6c34\u7ebf\uff08watermark\uff09\uff0c\u5f53\u7f13\u5b58\u533a\u88ab\u4f7f\u7528\u5b8c\u6bd5\uff0c\u5c31\u79f0\u4e4b\u4e3a\u201c\u7f13\u5b58\u6c34\u4f4d\u201d\u5230\u8fbe\u4e86\u201c\u67d0\u6c34\u7ebf\u201d\u3002<\/p>\n\n\n\n

\u4e0a\u8ff0\u7f13\u5b58\u7684\u4f7f\u7528\uff0c\u6709\u4e00\u4e9b\u6700\u4f73\u5b9e\u8df5\uff1a<\/p>\n\n\n\n

\u56e0\u4e3aPG-Guaranteed\u662f\u56fa\u5b9a\u5927\u5c0f\uff0c\u6240\u4ee5\u662f\u65e0\u6cd5\u8c03\u8282\u7684\u3002<\/p>\n\n\n\n

PG-share\uff0c\u5171\u4eab\u7f13\u5b58\uff0c\u6709\u4e00\u4e2a\u52a8\u6001\u7f13\u5b58\u6c34\u7ebf\u7684\u6280\u672f(DynamicMemoryThresholds)\u3002\u8be5\u673a\u5236\u57fa\u4e8e\u53ef\u7528\u7684\u5171\u4eab\u5185\u5b58\u6765\u8c03\u6574\u4e22\u5f03\u9608\u503c\uff0c\u4ece\u800c\u4fdd\u6301\u516c\u5e73\u6027\uff0c\u5e76\u5bf9\u5728\u5171\u4eab\u7f13\u51b2\u533a\u7684\u9ad8\u7a81\u53d1\u6570\u636e\u8fdb\u884c\u5438\u6536\u3002\u52a8\u6001\u9608\u503c\u662f\u53ef\u7528\u7f13\u51b2\u5b58\u50a8\u5668\u7684\u7ebf\u6027\u51fd\u6570\uff0c\u4e58\u4ee5\u6bd4\u4f8b\u56e0\u5b50\uff08\u03b1\uff09\u3002\u5176\u4f7f\u7528\u7684\u6761\u4ef6\u662f\uff0c\u5982\u679c\u5f53\u524d\u7f13\u5b58\u4f7f\u7528>\u03b1*\u53ef\u7528\u7f13\u5b58\uff0c\u5219\u4e22\u5305\u3002\u4f8b\u5982\uff1a\u03b1= 4, A = 100, Q1 = 420, \u56e0\u4e3a420> 4*100\uff0c\u6240\u4ee5\u4e22\u5305\u3002<\/p>\n\n\n\n

Headroom\uff0c\u662f\u5728PFC\u542f\u52a8\u540e\uff0c\u5230PFC\u771f\u6b63\u5de5\u4f5c\u7684\u65f6\u95f4\u95f4\u9694\u4e4b\u95f4\u7684\u62a5\u6587\uff0c\u7528\u6765\u7f13\u5b58\u62a5\u6587\u7684\u3002Headroom\u7a7a\u95f4\u5927\u5c0f\u548c\u4ee5\u4e0b4\u4e2a\u56e0\u7d20\u76f8\u5173\uff1a<\/p>\n\n\n\n

    \n
  • <\/li>\n\n\n\n
  • PG\u68c0\u6d4b\u5230XOFF\u7528\u5b8c\uff0c\u89e6\u53d1\u5230\u4e86XOFF\u6c34\u7ebf\uff0c\u5230\u6784\u9020PFC\u5e27\u53d1\u51fa\u7684\u65f6\u95f4\uff08\u56fa\u5b9a\u503c\uff09<\/li>\n\n\n\n
  • \u4e0a\u6e38\u6536\u5230\u4e0b\u6e38\u4f20\u4e0a\u6765\u7684PFC \u00a0 \u00a0 \u6682\u505c\u5e27\uff0c\u5230\u505c\u6b62\u961f\u5217\u8f6c\u53d1\u7684\u65f6\u95f4\uff08\u56fa\u5b9a\u503c\uff09<\/li>\n\n\n\n
  • PFC\u6682\u505c\u5e27\u5728\u94fe\u8def\u4e0a\u7684\u4f20\u8f93\u65f6\u95f4\uff08\u548c\u7ebf\u7f06\/\u5149\u7ea4\u8ddd\u79bb\u6210\u6b63\u6bd4\uff09<\/li>\n\n\n\n
  • \u961f\u5217\u6682\u505c\u53d1\u9001\u540e\u94fe\u8def\u4e2d\u62a5\u6587\u7684\u4f20\u8f93\u65f6\u95f4\uff08\u548c\u7ebf\u7f06\/\u5149\u7ea4\u8ddd\u79bb\u6210\u6b63\u6bd4\uff09<\/li>\n<\/ul>\n\n\n\n

    \u4e00\u4e2a\u53c2\u8003\u7684\u6700\u4f73\u5b9e\u8df5\u662f100G\u7aef\u53e3\uff0c\u8fde\u63a5100M\u5149\u7ea4\uff0cheadroom\u4e3a408cell\u3002<\/p>\n\n\n\n

    \u5728\u73b0\u5b9e\u64cd\u4f5c\u4e0a\uff0c\u5728\u601d\u79d1\u4f7f\u7528\u535a\u901a\u82af\u7247\u7684nexus3k\u6570\u636e\u4e2d\u5fc3\u4ea4\u6362\u673a\u4e0a\u6709\u4e0b\u5217\u914d\u7f6e\u547d\u4ee4\u53ef\u4ee5\u6fc0\u6d3bPFC\uff1a<\/p>\n\n\n\n

    interface{{type slot\/port}|{port-channel number}}<\/p>\n\n\n\n

    (config-if)#priority-flow-controlmode <on\/off\/auto><\/p>\n\n\n\n

    \u4e0b\u5217\u914d\u7f6e\u547d\u4ee4\u53ef\u4ee5\u8c03\u8282pause\u5e27\u7f13\u5b58\u548c\u52a8\u6001\u7f13\u5b58\u7a7a\u95f4\uff1a<\/p>\n\n\n\n

    hardwareqosinternal-interface pause buffer-sizebuffer-sizepause-thresholdxoff-sizeresume-thresholdxon-size<\/p>\n\n\n\n

    \u4e0b\u5217\u914d\u7f6e\u547d\u4ee4\u53ef\u4ee5\u8c03\u6574headroom\u5b58\u50a8\u7a7a\u95f4\u6bd4\u4f8b\uff1a<\/p>\n\n\n\n

    platform|hardware } qos { ing-pg-hdrm-reserve percent <percent-val> [module<module><\/p>\n\n\n\n

    3.3PFC\u80cc\u538b\u5e26\u6765\u7684\u7f51\u7edc\u62e5\u585e\u95ee\u9898<\/strong><\/p>\n\n\n\n

    \u5f53\u4ea4\u6362\u673a\u7684\u5165\u7aef\u53e3\u6d41\u91cf\u5927\u4e8e\u51fa\u7aef\u53e3\u7684\u5e26\u5bbd\u65f6\uff0c\u4f1a\u53d1\u751f\u7f51\u7edc\u62e5\u585e\u3002\u5178\u578b\u7684\u4f8b\u5b50\u662f\u591a\u6253\u4e00\uff0c\u5373\u591a\u4e2a\u53d1\u9001\u65b9\u540c\u65f6\u5411\u540c\u4e00\u4e2a\u76ee\u7684\u5730\u53d1\u9001\u7f51\u7edc\u6570\u636e\u3002\u4ea4\u6362\u673a\u7684\u7f13\u5b58\u53ef\u4ee5\u5904\u7406\u6682\u65f6\u7684\u62e5\u585e\uff0c\u4f46\u662f\u5f53\u62e5\u585e\u592a\u4e45\u65f6\uff0c\u5c31\u4f1a\u8d85\u8fc7\u4ea4\u6362\u673a\u7684\u7f13\u5b58\u6c34\u7ebf\uff0c\u800c\u5931\u53bb\u4e86\u7f13\u5b58\u529f\u80fd\uff0c\u6536\u5230\u7684\u65b0\u7684\u62a5\u6587\u5c31\u4f1a\u88ab\u4e22\u5f03\u3002\u4e22\u5305\u4f1a\u56e0\u4e3a\u91cd\u4f20\u800c\u964d\u4f4e\u4e86\u5e94\u7528\u6027\u80fd\u3002\u65e0\u635f\u7f51\u7edc\u91c7\u7528PFC\u7b49\u6d41\u63a7\u673a\u5236\uff0c\u5728\u5230\u8fbe\u7f13\u5b58\u6c34\u7ebf\u65f6\u6682\u505c\u8f93\u5165\u7aef\u53e3\u53d1\u9001\u6d41\u91cf\uff0c\u963b\u6b62\u4e86\u4e22\u5305\u73b0\u8c61\u3002\u7136\u800c\uff0c\u6d41\u63a7\u672c\u8eab\u4e5f\u4f1a\u9020\u6210\u62e5\u585e\u4f20\u64ad\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n

    \u6709\u4e2a\u7ecf\u5178\u573a\u666f\u5982\u4e0b\u56fe\u6240\u793a\uff1a\u5047\u8bbe\u4ea4\u6362\u673a1\u4e0a\u7684\u7aef\u53e3A\u5230E\u90fd\u5728\u5411\u7aef\u53e3G\u4f20\u8f93\u62a5\u6587\uff0c\u7aef\u53e3G\u4ee5100%\u7684\u6027\u80fd\u6765\u63a5\u6536\u5e76\u8f6c\u53d1\u62a5\u6587\u3002\u5982\u679c\u6b64\u65f6\u7ea7\u8054\u4ea4\u6362\u673a2\u7684\u7aef\u53e3F\u4e5f\u5728\u5411\u4ea4\u6362\u673a1\u7684\u7aef\u53e3G\u53d1\u9001\u62a5\u6587\uff0c\u901f\u7387\u662f\u94fe\u8def\u5e26\u5bbd\u768420%\u3002\u7531\u4e8e\u7aef\u53e3G\u7684\u51fa\u53e3\u8d1f\u8f7d\u5df2\u7ecf\u5230\u8fbe100%\u4e86\uff0c\u7aef\u53e3F\u5c06\u4f1a\u88ab\u6d41\u63a7\u5236\u673a\u5236\u6682\u505c\u53d1\u9001\u62a5\u6587\u3002\u6b64\u65f6\uff0c\u7aef\u53e3G\u5c06\u4f1a\u51fa\u73b0\u62e5\u585e\u3002\u5982\u679c\u6b64\u65f6\uff0c\u4ea4\u6362\u673a2\u4e0a\u7684\u7aef\u53e3X\uff0c\u4ee520%\u7684\u901f\u5ea6\u5411\u4ea4\u6362\u673a1\u4e0a\u7684\u7aef\u53e3Y\u53d1\u9001\u62a5\u6587\u3002\u7aef\u53e3G\uff0c\u8fd9\u4e2a\u62e5\u585e\u6e90\u5e76\u4e0d\u5904\u4e8e\u7aef\u53e3X\u5230\u7aef\u53e3Y\u7684\u4f20\u8f93\u8def\u5f84\u4e0a\u3002\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u4e5f\u8bb8\u4f1a\u8ba4\u4e3a\u7aef\u53e3F\u53ea\u4f7f\u7528\u4e86\u4ea4\u6362\u673a\u95f4\u94fe\u8def\u768420%\u5e26\u5bbd\uff0c\u5269\u4f59\u768480%\u5e26\u5bbd\u5bf9\u4e8e\u7aef\u53e3X\u662f\u53ef\u7528\u7684\u3002\u7136\u800c\u5e76\u975e\u5982\u6b64\uff0c\u56e0\u4e3a\u6765\u81ea\u7aef\u53e3F\u7684\u6d41\u91cf\u6700\u7ec8\u89e6\u53d1\u6d41\u63a7\u673a\u5236\u4f7f\u5f97\u4ea4\u6362\u673a\u95f4\u7684\u94fe\u8def\u5904\u4e8e\u6682\u505c\u53d1\u9001\u3002<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    3.4PFC\u6b7b\u9501\u95ee\u9898<\/strong><\/p>\n\n\n\n

    \u6307\u5f53\u591a\u53f0\u4ea4\u6362\u673a\u4e4b\u95f4\u56e0\u5fae\u73af\u8def\u7b49\u539f\u56e0\u540c\u65f6\u51fa\u73b0\u62e5\u585e,\u5404\u81ea\u7aef\u53e3\u7684\u7f13\u5b58\u6d88\u8017\u8d85\u8fc7\u6c34\u7ebf\uff0c\u800c\u53c8\u76f8\u4e92\u7b49\u5f85\u5bf9\u65b9\u91ca\u653e\u7f13\u5b58\u8d44\u6e90\uff0c\u4ece\u800c\u5bfc\u81f4\u6240\u6709\u4ea4\u6362\u673a\u90fd\u5904\u4e8e\u963b\u585e\u72b6\u6001\u3002<\/p>\n\n\n\n

    \u6b63\u5e38\u60c5\u51b5\u4e0b\uff0c\u5f53\u4ea4\u6362\u673a\u7684\u7aef\u53e3\u51fa\u73b0\u62e5\u585e\u5e76\u89e6\u53d1XOFF\u6c34\u7ebf\u65f6\uff0c\u4e0b\u6e38\u8bbe\u5907\u5c06\u53d1\u9001PAUSE\u5e27\u53cd\u538b\uff0c\u4e0a\u6e38\u8bbe\u5907\u63a5\u6536\u5230PAUSE\u5e27\u540e\u505c\u6b62\u53d1\u9001\u6570\u636e\uff0c\u5982\u679c\u7aef\u53e3\u7f13\u5b58\u8d85\u8fc7\u6c34\u7ebf\uff0c\u5219\u8fdb\u5165\u7b49\u5f85\u72b6\u6001\uff0c\u76f4\u5230\u7f13\u5b58\u4e2d\u7684\u62a5\u6587\u88ab\u8f6c\u53d1\u4e3a\u6b62\u3002<\/p>\n\n\n\n

    \u5728\u5f02\u5e38\u60c5\u51b5\u4e0b\uff0c\u5982\u53d1\u751f\u94fe\u8def\u6216\u8bbe\u5907\u6545\u969c\u65f6\uff0c\u8def\u7531\u6536\u655b\u65f6\uff0c\u53ef\u80fd\u4f1a\u51fa\u73b0\u77ed\u6682\u73af\u8def\uff0c\u9020\u6210\u8fde\u63a5\u7684\u4ea4\u6362\u673a\u7684\u7f13\u5b58\u90fd\u8fbe\u5230\u6c34\u7ebf\uff0c\u90fd\u540c\u65f6\u5411\u5bf9\u7aef\u53d1\u9001PAUSE\u5e27\uff0c\u6b64\u65f6\u6240\u6709\u76f8\u5173\u4ea4\u6362\u673a\u90fd\u5904\u4e8e\u975e\u8f6c\u53d1\u72b6\u6001\uff0c\u6574\u4e2a\u533a\u57df\u7684\u7f51\u7edc\u541e\u5410\u91cf\u5c06\u53d8\u4e3a\u96f6\u3002\u5373\u4f7f\u5728\u65e0\u73af\u7f51\u7edc\u4e2d\u5f62\u6210\u77ed\u6682\u73af\u8def\u65f6\uff0c\u4e5f\u53ef\u80fd\u53d1\u751f\u6b7b\u9501\u3002\u867d\u7136\u7ecf\u8fc7\u4fee\u590d\uff0c\u77ed\u6682\u73af\u8def\u4f1a\u5f88\u5feb\u6d88\u5931\uff0c\u4f46\u5b83\u4eec\u9020\u6210\u7684\u6b7b\u9501\u4e0d\u662f\u6682\u65f6\u7684\uff0c\u5373\u4fbf\u91cd\u542f\u670d\u52a1\u5668\u4e2d\u65ad\u6d41\u91cf\uff0c\u6b7b\u9501\u4e5f\u4e0d\u80fd\u81ea\u52a8\u6062\u590d\u3002<\/p>\n\n\n\n

    \u4e3a\u4e86\u89e3\u9664\u6b7b\u9501\u72b6\u6001\uff0c\u4e00\u65b9\u9762\u662f\u8981\u675c\u7edd\u6570\u636e\u4e2d\u5fc3\u91cc\u7684\u73af\u8def\u4ea7\u751f\uff0c\u53e6\u4e00\u65b9\u9762\u5219\u53ef\u4ee5\u901a\u8fc7\u7f51\u7edc\u8bbe\u5907\u7684\u6b7b\u9501\u68c0\u6d4b\u529f\u80fd\u6765\u5b9e\u73b0\u3002<\/p>\n\n\n\n

    \u53ef\u4ee5\u68c0\u6d4b\u5230\u51fa\u73b0X-OFF(PFCPause)\u62a5\u6587\u72b6\u6001\u540e\u7684\u4e00\u6bb5\u65f6\u95f4\u5185\uff0c\u662f\u5426\u6301\u7eed\u6536\u5230X-Off(\u6216\u8005\u672a\u6536\u5230X-On),\u5982\u679c\u6301\u7eed\u5230\u8fbe\u9608\u503c\uff0c\u5219\u5ffd\u7565\u6536\u5230\u7684PFC\u5e27\uff0c\u540c\u65f6\u5bf9\u7f13\u5b58\u4e2d\u7684\u62a5\u6587\u6267\u884c\u8f6c\u53d1\u6216\u4e22\u5f03\u7684\u64cd\u4f5c\u3002\u6240\u4ee5\u5728\u4ea4\u6362\u673a\u4e2d\uff0c\u63d0\u4f9b\u76d1\u63a7PFC\u72b6\u6001\u7684\u529f\u80fd\uff0c\u9632\u6b62\u8fd9\u79cdPFC\u98ce\u66b4\u5bfc\u81f4\u7684\u6b7b\u9501\u60c5\u51b5\u3002\u5982\u601d\u79d1\u4ea4\u6362\u673a\u4e0a\u5c31\u6709pfcwatchdog\u7684\u529f\u80fd\uff0c<\/p>\n\n\n\n

    priority-flow-controlwatch-dog-interval on<\/p>\n\n\n\n

    priority-flow-controlwatch-dog interval<\/p>\n\n\n\n

    \u53d1\u73b0PFC\u6b7b\u9501\uff0c<\/p>\n\n\n\n

    priority-flow-controlwatch-dog shutdown-multiplier<\/p>\n\n\n\n

    \u4f7f\u4ea4\u6362\u673a\u81ea\u52a8\u4ecePFC\u6b7b\u9501\u4e2d\u6062\u590d\u8fc7\u6765\uff1a<\/p>\n\n\n\n

    priority-flow-controlauto-restoremultiplier<\/p>\n\n\n\n

    \u624b\u5de5\u63a7\u5236\uff0c\u4f7f\u4ea4\u6362\u673a\u4ece\u67d0\u4e2a\u7aef\u53e3\u5728PFC\u6b7b\u9501\u4e2d\u6062\u590d\u8fc7\u6765\uff1a<\/p>\n\n\n\n

    priority-flow-controlrecoverinterface ethernet <\/><\/p>\n\n\n\n

    3.5RDMA\u4f20\u8f93livelock<\/strong><\/p>\n\n\n\n

    \u5c3d\u7ba1PFC\u53ef\u4ee5\u907f\u514d\u7f13\u5b58\u6ea2\u51fa\u5bfc\u81f4\u7684\u4e22\u5305\uff0c\u4f46\u5176\u5b83\u4e00\u4e9b\u539f\u56e0\uff0c\u5982FCS\u9519\u8bef\/\u94fe\u8def\u6545\u969c\uff0c\u4e5f\u53ef\u80fd\u5bfc\u81f4\u7f51\u7edc\u4e22\u5305\u3002RDMA\u7684go-back-0\u7b97\u6cd5\uff0c\u5728\u6bcf\u6b21\u51fa\u73b0\u4e22\u5305\u65f6\uff0c\u90fd\u4f1a\u5bfc\u81f4\u5305\u542b\u6574\u4e2a\u6d88\u606f\u7684\u6240\u6709\u62a5\u6587\u90fd\u4f1a\u91cd\u4f20\uff0c\u4ece\u800c\u5bfc\u81f4livelock\u3002TCP\u6709SACK\u7b97\u6cd5\uff0c\u7531\u4e8eRDMA\u4f20\u8f93\u5c42\u5728\u7f51\u5361\u5b9e\u73b0\uff0c\u53d7\u9650\u4e8e\u786c\u4ef6\u8d44\u6e90\uff0c\u7f51\u5361\u5f88\u96be\u5b9e\u73b0SACK\u7b97\u6cd5\u3002\u53ef\u4ee5\u4f7f\u7528go-back-N\u7b97\u6cd5\u6765\u907f\u514d\u8fd9\u4e2a\u95ee\u9898\u3002<\/p>\n\n\n\n

    3.6\u7f51\u5361PFC\u6682\u505c\u5e27\u98ce\u66b4<\/strong><\/p>\n\n\n\n

    \u7531\u4e8ePFC\u6682\u505c\u5e27\u662f\u4f20\u9012\u7684\uff0c\u6240\u4ee5\u5f88\u5bb9\u6613\u5f15\u8d77\u6682\u505c\u5e27\u98ce\u66b4\u3002\u4f8b\u5982\uff0c\u7f51\u5361\u56e0\u4e3abug\u5bfc\u81f4\u63a5\u6536\u7f13\u51b2\u533a\u5230\u8fbe\u6c34\u7ebf\uff0c\u7f51\u5361\u4f1a\u4e00\u76f4\u5bf9\u5916\u53d1\u9001\u6682\u505c\u5e27\u3002\u9700\u8981\u5728\u7f51\u5361\u548c\u4ea4\u6362\u673a\u7aef\u4f7f\u7528watchdog\u673a\u5236\u6765\u9632\u6b62\u6682\u505c\u5e27\u98ce\u66b4(\u9700\u8981\u7f51\u7edc\/\u670d\u52a1\u5668\u914d\u5408)\u3002\u4e3a\u4e86\u9632\u6b62\u5355\u4e00\u670d\u52a1\u5668\u7f51\u5361\u56e0\u4e3abug\u5f71\u54cd\u6574\u4f53\u7f51\u7edc\uff0c\u7f51\u7edc\u8bbe\u5907\u4e5f\u5728\u63a2\u8ba8watchdog\u4fdd\u62a4\u673a\u5236\uff0c\u5bf9\u5355\u4e00\u7f51\u5361\u77ed\u65f6\u95f4\u5185\u591a\u6b21\u89e6\u53d1watchdog\u7684\u7aef\u53e3\uff0c\u5217\u4e3a\u4e0d\u4fe1\u4efb\u7aef\u53e3\uff0c\u5ffd\u7565\u5bf9\u65b9PFC\u6682\u505c\u5e27\uff0c\u5f3a\u5236\u53d1\u9001\u6570\u636e\u9632\u6b62\u9020\u6210\u5168\u7f51\u62e5\u585e\u3002<\/p>\n\n\n\n

    4.ECN:Explicit Congestion Notification<\/p>\n\n\n\n

    \u6700\u65e9\u5728RFC3168\u4e2d\u5b9a\u4e49\uff0c\u5728IP\u5305\u5934\u5b9a\u4e49\u62e5\u585e\u6307\u793a\u4f4d\uff0c\u5e76\u5728TCP\u5305\u5934\u5b9a\u4e49\u4e00\u4e2a\u5bf9\u5e94\u8be5\u6307\u793a\u4f4d\u7684ACK\u3002\u8fd9\u4e2a\u62e5\u585e\u63a7\u5236\u673a\u5236\u4e5f\u88ab\u7528\u5728RoCEv2\u3002ECN\u662f\u4e00\u4e2a\u7aef\u5230\u7aef\u7684\u62e5\u585e\u901a\u77e5\u673a\u5236\uff0c\u800c\u4e0d\u9700\u8981\u4e22\u5305\u3002ECN\u662f\u53ef\u9009\u7684\u7279\u6027\uff0c\u5b83\u9700\u8981\u7aef\u70b9\u5f00\u542fECN\u652f\u6301\uff0c\u540c\u65f6\u5e95\u5c42\u7684\u7f51\u7edc\u4e5f\u9700\u8981\u652f\u6301\u3002<\/p>\n\n\n\n

    \u4f20\u7edf\u7684TCP\/IP\u7f51\u7edc\uff0c\u901a\u8fc7\u4e22\u5305\u6765\u8868\u660e\u7f51\u7edc\u62e5\u585e\uff0c\u4ea4\u6362\u673a\u8def\u7531\u5668\u7b49\u7f51\u7edc\u8bbe\u5907\u90fd\u4f1a\u8fd9\u4e48\u505a\u3002\u800c\u5bf9\u4e8e\u652f\u6301ECN\u7684\u8bbe\u5907\uff0c\u5f53\u53d1\u751f\u7f51\u7edc\u62e5\u585e\u65f6\uff0c\u4f1a\u8bbe\u7f6eIP\u5934\u90e8\u7684ECN(2bits)\u6807\u5fd7\u4f4d\uff0c\u800c\u63a5\u6536\u7aef\u4f1a\u7ed9\u53d1\u9001\u7aef\u8fd4\u56de\u62e5\u585e\u7684\u901a\u77e5(echoof thecongestionindication)\uff0c\u7136\u540e\u53d1\u9001\u7aef\u964d\u4f4e\u53d1\u9001\u901f\u7387\u3002\u4f20\u7edf\u7f51\u7edc\u4e2d\u7531\u4e8e\u53d1\u9001\u901f\u7387\u7531\u4f20\u8f93\u5c42(TCP)\u63a7\u5236\uff0cECN\u9700\u8981TCP\u548cIP\u5c42\u540c\u65f6\u914d\u5408\u3002\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    RoCEv2\u6807\u51c6\u5b9a\u4e49\u4e86RoCEv2\u62e5\u585e\u7ba1\u7406(RCM\uff0cCongestionManagement)\u3002\u5f53\u4ea4\u6362\u673a\u7684\u51fa\u7aef\u53e3\u7f13\u5b58\u5230\u8fbe\u6c34\u7ebf\uff08\u9608\u503c\uff09\u65f6\uff0c\u4ea4\u6362\u673a\u4fee\u6539\u62a5\u6587\u5305\u5934\u4e2d\u7684ECN\u4f4d\uff0c\u7ed9\u62a5\u6587\u6253\u4e0aECN\u6807\u7b7e\uff0c\u5f53\u5e26\u6709ECN\u6807\u7b7e\u7684\u62a5\u6587\u5230\u8fbe\u63a5\u6536\u7aef\u4ee5\u540e\uff0c\u63a5\u6536\u7aef\u4f1a\u751f\u6210CNP\u62a5\u6587(CongestionNotification Packet)\u5e76\u5c06\u5b83\u53d1\u9001\u7ed9\u53d1\u9001\u7aef\uff0c\u5f53\u63a5\u6536\u7aef\u6536\u5230CNP\u540e\uff0c\u5c31\u4f1a\u964d\u4f4e\u53d1\u9001\u901f\u7387\u3002<\/p>\n\n\n\n

    ECN\u5de5\u4f5c\u673a\u5236\u5982\u4e0b\u56fe\u6d41\u7a0b\u6240\u793a\uff1a<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    1.\u53d1\u9001\u7aef\u5728IP\u5305\u5934\u8bbe\u7f6eECN\u503c\uff0cECN\u503c\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n\n\n\n

    \"\"<\/figure>\n\n\n\n

    2.RoCEv2\u6570\u636e\u62a5\u6587\u8fdb\u5165\u7f51\u7edc\u3002<\/p>\n\n\n\n

    3.\u4ea4\u6362\u673a\u5728\u53d1\u751f\u62e5\u585e\u7684\u961f\u5217\u4e0a\u63a5\u6536\u5230\u62a5\u6587\u65f6\uff0c\u68c0\u67e5\u662f\u5426\u5f00\u542f\u4e86ECN\u529f\u80fd\uff0c\u5982\u679c\u5f00\u542f\uff0c\u5c31\u5728IP\u5305\u5934\u8bbe\u7f6eCE\u4f4d\u3002<\/p>\n\n\n\n

    4.\u62a5\u6587\u5230\u8fbe\u63a5\u6536\u7aef\u3002<\/p>\n\n\n\n

    5.\u63a5\u6536\u7aef\u5bf9\u8bbe\u7f6eCE\u4f4d\u7684RoCE\u62a5\u6587\u8fdb\u884c\u5904\u7406\uff0c\u7136\u540e\u518d\u5c06\u62a5\u6587\u653e\u5165\u4e0b\u4e00\u6b65\u5904\u7406\u6d41\u7a0b\u3002<\/p>\n\n\n\n

    6-7.\u63a5\u6536\u7aef\u5c06CNP\u62a5\u6587\u6570\u636e\u5305\u53d1\u9001\u56de\u8f93\u5165\u7aef\u3002\u62a5\u6587\u4e2d\u7684ECN\u4f4d\u8bbe\u7f6e\u4e3a’01’\u6765\u9a8c\u8bc1\u8be5\u62a5\u6587\u6ca1\u6709\u88ab\u7f51\u7edc\u8bbe\u5907\u4e22\u5f03\u3002<\/p>\n\n\n\n

    8.CNP\u5305\u4ece\u63a5\u6536\u7aef\u8fd4\u56de\u5230\u7f51\u7edc\u4e2d\u3002<\/p>\n\n\n\n

    9.\u4ea4\u6362\u673a\u5c06CNP\u62a5\u6587\u4f5c\u4e3a\u666e\u901a\u7684IP\u62a5\u6587\u8f6c\u53d1\u3002<\/p>\n\n\n\n

    10.CNP\u62a5\u6587\u5230\u8fbe\u53d1\u9001\u65b9\u3002\u53d1\u9001\u65b9\u5bf9ECN\u8bbe\u7f6e\u4f4d\u4e3a’01’\u7684RoCE\u7684\u62a5\u6587\u4f7f\u7528QoS\u673a\u5236\u8fdb\u884c\u5904\u7406\u3002<\/p>\n\n\n\n

    \u5728\u4ea4\u6362\u673a\u4e2d\uff0c\u53ef\u63d0\u4f9bECN\u529f\u80fd\uff0c\u5982\u601d\u79d1\u4ea4\u6362\u673a\u4e0a\u7684ECN\u914d\u7f6e\u5982\u4e0b\uff1a<\/p>\n\n\n\n

    hardwarerandom-detect min-thresh10g 10g-min-threshold 40g 40g-min-<\/p>\n\n\n\n

    thresholdmax-thresh 10g10g-max-threshold 40g 40g-max-threshold ecn qos-groupqos-group-number<\/p>\n\n\n\n

    5.\u7ed3\u675f\u8bed<\/strong><\/p>\n\n\n\n

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