{"id":776,"date":"2008-05-05T11:41:00","date_gmt":"2008-05-05T03:41:00","guid":{"rendered":"http:\/\/note.systw.net\/note\/?p=776"},"modified":"2023-11-05T11:54:54","modified_gmt":"2023-11-05T03:54:54","slug":"tcpudp","status":"publish","type":"post","link":"https:\/\/systw.net\/note\/archives\/776","title":{"rendered":"TCP&UDP"},"content":{"rendered":"\n

TCP and UDP\u3000<\/strong>
\u63d0\u4f9b\u8a31\u591a\u4e00\u822cApplication Protocol Standards(\u61c9\u7528\u6a19\u6e96)
\u4f7f\u7528\u57e0\u865f\u6982\u5ff5\u4f86\u6a19\u8b58\u767c\u9001\u65b9\u548c\u63a5\u6536\u65b9\u7684\u61c9\u7528\u5c64,well-know port:0-1023
\u5c07\u5c01\u5305\u4ea4\u7d66\u6b63\u78ba\u7684\u884c\u7a0b\u8655\u7406\u7528\u901a\u8a0a\u57e0\u53e3port(\u5b9a\u7fa9\u5728http:\/\/www.iana.org\/<\/a>)
\u652f\u63f4\u7684\u61c9\u7528\u5982\u4e0b
\u3000tcp\u652f\u63f4:ftp,telnet,http,smtp,dns,…\u7b49
\u3000udp\u652f\u63f4:tftp,bootp,nfs,rpc,xdr,dns,dhcp,snmp,..\u7b49

tcp\u8207udp\u652f\u63f4\u7684\u670d\u52d9\u6bd4\u8f03<\/p>\n\n\n\n

\u670d\u52d9:<\/td>tcp<\/td>udp<\/td><\/tr>
reassembly(\u5c07\u4e0b\u5c64\u5c01\u5305\u91cd\u7d44\u6210\u8cc7\u6599)\u548cfragmentation(\u5c07\u4e0a\u5c64\u8cc7\u6599\u62c6\u6210\u5c01\u5305)<\/td>*<\/td>*<\/td><\/tr>
\u5c07\u7247\u6bb5\u8cc7\u6599\u5f9e\u4e00\u88dd\u7f6e\u50b3\u9001\u81f3\u53e6\u4e00\u88dd\u7f6e<\/td>*<\/td>*<\/td><\/tr>
connection(\u9023\u7dda\u5c0e\u5411),\u5efa\u7acb\u9ede\u5c0d\u9ede\u4e4b\u9023\u7dda<\/td>*<\/td> <\/td><\/tr>
\u7531\u6ed1\u52d5\u8996\u7a97\u6240\u63d0\u4f9b\u7684flow control(\u6d41\u91cf\u63a7\u5236)<\/td>*<\/td> <\/td><\/tr>
\u7531\u5e8f\u865f\u8207\u78ba\u8a8d\u63d0\u4f9b\u4e4breliable(\u53ef\u9760\u6027)<\/td>*<\/td> <\/td><\/tr>
\u5c01\u5305\u6536\u9001\u6709\u9806\u5e8f <\/td>* <\/td> <\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

 <\/p>\n\n\n\n

………………………………………….<\/p>\n\n\n\n

TCP(transmission control protocol,\u50b3\u8f38\u63a7\u5236\u5354\u5b9a)<\/strong><\/h2>\n\n\n\n

ps:tcp\u662f\u8907\u96dc\u7684,\u800c\u4e14\u6703\u589e\u52a0\u4e0d\u5c0f\u7684\u7db2\u8def\u8ca0\u64d4<\/p>\n\n\n\n

TCP<\/strong>\u7279\u8272<\/strong>
Reliable Stream Transport Service<\/strong>
\u3000\u8cc7\u6599\u6d41\u5207\u5272\u4e26sequencing number(\u9806\u5e8f\u7de8\u865f)\u50b3\u9001,\u8207\u63a5\u6536\u65b9acknowledgement\u4fdd\u8b49\u8cc7\u6599\u5b8c\u6574\u6027
\u3000\u5229\u7528forward reference acknowledgment(\u5411\u524d\u53c3\u7167\u78ba\u8a8d)\u7684\u65b9\u5f0f\u63d0\u4f9b\u8cc7\u6599\u7247\u6bb5\u4e4b\u9806\u5e8f
\u3000\u9808\u5c07\u8cc7\u6599\u7247\u6bb5\u91cd\u65b0\u6392\u5217\u6210\u5b8c\u6574\u7684\u8a0a\u606f
\u3000\u9808\u5c07\u7db2\u8def\u4e2d\u6bc0\u640d,\u907a\u5931,\u91cd\u8907\u6216\u50b3\u9001\u9806\u5e8f\u4e0d\u5c0d\u7684\u8cc7\u6599\u5fa9\u539f
\u3000\u6d41\u7a0b\u63a7\u5236\u548c\u932f\u8aa4\u8655\u7406,\u7528Sliding Window(\u6ed1\u52d5\u8996\u7a97)\u63a7\u5236\u901a\u8a0a\u9023\u7dda\u4e0a\u7684\u8cc7\u6599\u6d41\u91cf
End-to-End Acknowledgements
\u3000\u78ba\u8a8d\u6a21\u5f0f\u4ee5\u7aef\u5230\u7aef\u9032\u884c,\u7121\u9700\u7406\u6703\u5c01\u5305\u4ea4\u63db\u904e\u7a0b\u6240\u53c3\u8207\u7684\u5176\u5b83\u8a2d\u5099
\u3000\u70ba\u4f7f\u7528\u8005\u5728\u61c9\u7528\u7a0b\u5f0f\u9593\u63d0\u4f9b\u7684\u662fvirtual circuit
\u3000\u5168\u96d9\u5de5end-to-end(\u7aef\u5c0d\u7aef)\u901a\u8a0a\u5354\u5b9a
<\/strong><\/p>\n\n\n\n

TCP\u7248\u672c<\/strong>
TCP Tahoe:<\/strong>\u5177\u5099TCP\u7684\u57fa\u672c\u67b6\u69cb
TCP<\/strong> Reno<\/strong>\uff1a\u76ee\u524d\u6700\u5e38\u898b\u7684\u7248\u672c\uff0c\u5177Slow Start\u3001AIMD\u7b49\u6a5f\u5236\uff0c\u4f46\u56e0\u70baCongestion Window\u6703Oscillation(\u6ce2\u52d5)\u4e14Overreact(\u904e\u5ea6\u53cd\u61c9) to Packet Loss\uff0c\u800c\u5c0e\u81f4\u5176Jitter\u8f03\u5927\uff0c\u4e26\u4e14\u5728\u4f30\u8a08\u983b\u5bec\u4e0a\u4e5f\u8f03\u6c92\u6548\u7387
TCP<\/strong> Vegas\uff1aTCP Reno\u6539\u9032\u7248\uff0c\u9069\u7576\u50b3\u8f38\u91cf\u4e0a\u8f03\u6709\u6548\u7387\uff0c\u5176Oscillation\u4e5f\u8f03\u5c0f
TCP<\/strong> Westwood\uff1a\u7531UCLA\u4e3b\u5c0e\uff0c\u767c\u5c55\u4e2d\u7684Protocol\uff0c\u5177\u6709\u4f30\u8a08\u6700\u9069\u50b3\u8f38\u91cf\u7684\u529f\u80fd\uff0c\u5c0dPacket Loss\u8f03\u4e0d\u654f\u611f\uff0c\u9069\u7528Wireless\u74b0\u5883\u4e0b<\/p>\n\n\n\n

……..<\/p>\n\n\n\n

TCP\u8cc7\u6599\u7d50\u69cb<\/strong>
\u53ef\u53c3\u8003RFC-793\ufe51RFC-1122\ufe51RFC-813\ufe51RFC-879\ufe51RFC-896
\u5c01\u5305\u6700\u5927\u70ba65535byte
\u5c01\u5305\u7531\u4ee5\u4e0b\u5169\u90e8\u4efd\u7d44\u6210
\u3000header\uff1a\u57fa\u672c\u9577\u5ea6\u70ba20byte ,\u82e5\u542boption\u6b04\u4f4d\u5247\u4e0d\u5b9a,\u4f46\u4e00\u5b9a\u662f4byte\u7684\u500d\u6578
\u3000data:\u5132\u5b58\u8cc7\u6599\u7684\u5340\u6bb5,\u8cc7\u6599\u9577\u5ea6\u53d6\u6c7a\u65bcMSS(maximum segment size,\u6700\u5927\u5340\u6bb5\u5927\u5c0f) 
ps:
MSS\u662f\u6839\u64dalayer2\u7684frame\u53ef\u63a5\u53d7\u7684MTU(maximum transmission unit,\u6700\u5927\u50b3\u8f38\u55ae\u5143)\u6240\u6c7a\u5b9a<\/p>\n\n\n\n

header\u5167\u542b\u4ee5\u4e0b:
1-32bit:
\u3000Source Port 16bit& Destination Port 16bit
33-64bit:
\u3000Sequence Number(\u5e8f\u865f)<\/strong> 32bit:\u7528\u65bc\u78ba\u4fdd\u627a\u9054\u8cc7\u6599\u70ba\u6b63\u78ba\u9806\u5e8f\u7684\u7de8\u865f,\u5171\u67092^32(4billion\/40\u5104)\u7d44\u5408 
65-96bit:
\u3000Acknowledge Number(\u78ba\u8a8d\u7de8\u865f)<\/strong> 32bit:\u5167\u542b\u767c\u9001\u5e8f\u865f+\u8cc7\u6599\u9577\u5ea6,TCP\u78ba\u8a8d\u6703\u6307\u51fa\u63a5\u6536\u7aef\u4e0b\u4e00\u500b\u671f\u671b\u6536\u5230\u7684\u5e8f\u865f
97-128bit:
\u3000HLEN(\u8868\u982d\u9577\u5ea6)<\/strong>4bit:\u4ee5\u5b57\u7d4432bit(4byte)\u70ba\u55ae\u4f4d,\u82e5options\u6b04\u4f4d\u70ba\u7a7a\u5247\u9577\u5ea6\u662f20bytes(0x14),double word\u9577\u5ea6\u8868 5
\u3000Reserved(\u4fdd\u7559<\/strong>)6bit:\u4fdd\u7559\u5340\u9593,\u7b2c5\u500bbit\u53ef\u80fd\u70bacwr,\u7b2c6\u500bbit\u53ef\u80fd\u70baecn-echo,\u9019\u5169\u500b\u662f\u7528\u505aqos\u7684\u529f\u80fd  
\u3000Contral Flag(\u63a7\u5236\u65d7\u6a19)<\/strong> 6bit:\u7528\u4f86\u63a7\u5236\u6703\u8ac7\u7684\u5efa\u7acb\u8207\u7d42\u7d50,\u5b50\u6b04\u4f4d\u5982\u4e0b:
\u3000\u3000URG(Urgent data)\u7dca\u6025\u8cc7\u6599\u9700\u512a\u5148\u8655\u7406,\u7528\u65bc\u4e2d\u65b7\u8a0a\u606f
\u3000\u3000ACK(Acknowledge field significant)\u70ba1\u8868\u6b64\u5c01\u5305Acknowledge Number\u6709\u6548,\u70ba0\u8868\u793a\u53ef\u52ff\u7565ack
\u3000\u3000PSH(Push function)\u63a5\u6536\u7aef\u9808\u99ac\u4e0a\u5c07\u6536\u5230\u8cc7\u6599\u7d66\u7a0b\u5f0f\u8655\u7406,\u4e0d\u53ef\u8b93\u7de9\u885d\u5340\u6eff\u4e86\u624d\u7d66\u7a0b\u5f0f
\u3000\u3000RST(Reset)\u9023\u7dda\u99ac\u4e0a\u7d50\u675f
\u3000\u3000SYN(Synchronize sequence number)\u8981\u6c42\u5efa\u7acb\u9023\u7dda
\u3000\u3000FIN(No more data fro sender)\u50b3\u9001\u7d50\u675f
\u3000Window(\u8996\u7a97)<\/strong> 16bit:\u63a5\u6536\u7aef\u56de\u61c9\u975e0\u8868\u53ef\u7e7c\u7e8c\u50b3\u9001,0\u8868\u793a\u63a5\u6536\u7aef\u66ab\u505c\u6536\u8cc7\u6599(\u4f46\u53ef\u50b3\u7dca\u6025\u8cc7\u6599,1byte\u5340\u6bb5)
129-160bit:
\u3000Checksum(\u7e3d\u5408\u6aa2\u67e5)<\/strong>16bit:\u586b\u5165\u9001\u51fa\u8cc7\u6599\u7684\u6821\u9a57\u503c,\u4f7f\u7528crc,\u6703\u6aa2\u67e5header\u548cdata
\u3000Urgent Pointer(\u7dca\u6025\u6307\u6a19)<\/strong>16bit:\u6307\u793a\u51fa\u7dca\u6025\u8cc7\u6599\u6240\u5728\u4f4d\u7f6e,\u53ea\u6709\u7576contral flag\u7684URG\u6709\u8a2d\u5b9a\u6642\u6b64\u6b04\u4f4d\u624d\u6709\u6548
161-192bit:
\u3000Option(\u9078\u9805) 0-32bit\u500d\u6578:\u9078\u64c7\u6027,\u9577\u5ea6\u4e00\u5b9a\u662f4byte\u7684\u500d\u6578,\u82e5\u4e0d\u662f\u5247\u6703\u81ea\u52d5\u88dc0\u76f4\u5230\u7b26\u54084byte\u7684\u500d\u6578
\u3000\u589e\u52a0\u8868\u982d\u6c92\u6709\u7684\u5176\u4ed6\u529f\u80fd,\u540c\u6b65\u52d5\u4f5c\u7684\u7a0b\u5f0f\u7528\u4f86\u6307\u5b9a\u8cc7\u6599\u5c01\u5305\u5927\u5c0f
\u3000window scale\u8996\u7a97\u898f\u6a21RFC1323:\u5141\u8a31\u50b3\u9001\u7aef\u53ca\u63a5\u6536\u7aef\u5f7c\u6b64\u5354\u5546\u51fa\u8996\u7a97\u7684\u898f\u6a21\u4fc2\u6578,window\u53ef\u905430byte
\u3000NAK,RFC1106:\u5141\u8a31\u63a5\u6536\u7aef\u8981\u6c42\u67d0\u500b\u7279\u5b9a\u5340\u7aef,\u53ef\u6e1b\u5c11\u8cc7\u6599\u91cd\u50b3\u6578\u91cf<\/p>\n\n\n\n

refer
windows scale,http:\/\/m.oschina.net\/blog\/297925<\/p>\n\n\n\n

 <\/p>\n\n\n\n

TCP\u904b\u4f5c\u6a5f\u5236
https:\/\/systw.net\/note\/af\/sblog\/more.php?id=322 <\/a><\/p>\n\n\n\n

…………………………………………………………………………………………………………………….<\/p>\n\n\n\n

UDP(user datagram protocol,\u4f7f\u7528\u8005\u8cc7\u6599\u5143\u5354\u5b9a)<\/strong><\/h2>\n\n\n\n

\u8a0a\u606f\u70ba\u4e3b,\u6700\u7701\u529b\u50b3\u9001
header\u6bd4\u8f03\u5c0f
\u53ef\u4efb\u610f\u50b3\u9001(1to1,1to\u591a,\u591ato1,\u591ato\u591a),\u652f\u63f4\u55ae\u64ad,\u7fa4\u64ad,\u5ee3\u64ad
\u5373\u6642\u6027\u8f03tcp\u597d
\u5c01\u5305\u6536\u9001\u9806\u5e8f\u4e0d\u56fa\u5b9a

udp\u5c01\u5305<\/strong>
\u53ef\u53c3\u8003RFC-768
\u5927\u5c0f\u70ba6-8byte
\u6b04\u4f4d\u5982\u4e0b:
Source Port<\/strong>\u00a016bit &\u00a0Destination Port<\/strong>\u00a016bit
Message Length(\u9577\u5ea6)<\/strong>16bit:\u5c01\u5305\u9577\u5ea6\uff0c\u6700\u5c0f\u70ba8bit
Checksum(\u7e3d\u5408\u6aa2\u67e5)<\/strong>\u00a016bit\u9078\u64c7\u6027\u6b04\u4f4d,\u7528\u4f86\u6aa2\u67e5\u5c01\u5305\u53ca\u8cc7\u6599\u7684\u6821\u9a57\u503c,\u5176\u503c\u8207UDP Pseudo Header(\u865b\u64ec\u8868\u982d)<\/strong>\u4e00\u8d77\u8a08\u7b97
data(\u8cc7\u6599):<\/strong>\u8f03\u4e0a\u5c64\u5354\u5b9a\u4e4b\u8cc7\u6599<\/p>\n","protected":false},"excerpt":{"rendered":"

TCP and UDP\u3000\u63d0\u4f9b\u8a31\u591a\u4e00\u822cApplication …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[25],"tags":[],"class_list":["post-776","post","type-post","status-publish","format-standard","hentry","category-osi-layer3"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/776","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=776"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/776\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=776"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}