{"id":33352,"date":"2025-09-24T16:04:04","date_gmt":"2025-09-24T09:04:04","guid":{"rendered":"https:\/\/interdata.vn\/blog\/?p=33352"},"modified":"2025-09-24T16:07:03","modified_gmt":"2025-09-24T09:07:03","slug":"application-layer-la-gi","status":"publish","type":"post","link":"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/","title":{"rendered":"Application Layer l\u00e0 g\u00ec? Ch\u1ee9c n\u0103ng, Vai tr\u00f2 t\u1ea7ng \u1ee9ng d\u1ee5ng OSI"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-white ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">N\u1ed8I DUNG<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-toggle-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Application-Layer-la-gi\" >Application Layer l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Vi-tri-cua-Application-Layer-trong-cac-Mo-hinh-Mang\" >V\u1ecb tr\u00ed c\u1ee7a Application Layer trong c\u00e1c M\u00f4 h\u00ecnh M\u1ea1ng<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Mo-hinh-OSI-Open-Systems-Interconnection\" >M\u00f4 h\u00ecnh OSI (Open Systems Interconnection)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Mo-hinh-TCPIP\" >M\u00f4 h\u00ecnh TCP\/IP<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#3-Chuc-nang-chinh-cua-Application-Layer\" >3 Ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a Application Layer<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Cung-cap-dich-vu-mang-cho-nguoi-dung\" >Cung c\u1ea5p d\u1ecbch v\u1ee5 m\u1ea1ng cho ng\u01b0\u1eddi d\u00f9ng<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Xac-dinh-giao-thuc-va-dong-bo-hoa-ung-dung\" >X\u00e1c \u0111\u1ecbnh giao th\u1ee9c v\u00e0 \u0111\u1ed3ng b\u1ed9 h\u00f3a \u1ee9ng d\u1ee5ng<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Tuong-tac-voi-nguoi-dung-va-xu-ly-du-lieu\" >T\u01b0\u01a1ng t\u00e1c v\u1edbi ng\u01b0\u1eddi d\u00f9ng v\u00e0 x\u1eed l\u00fd d\u1eef li\u1ec7u<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Cac-Giao-thuc-quan-trong-cua-Presentation-Layer-va-Vi-du-thuc-te\" >C\u00e1c Giao th\u1ee9c quan tr\u1ecdng c\u1ee7a Presentation Layer v\u00e0 V\u00ed d\u1ee5 th\u1ef1c t\u1ebf<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Giao-thuc-HTTP-Hypertext-Transfer-Protocol\" >Giao th\u1ee9c HTTP (Hypertext Transfer Protocol)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Giao-thuc-FTP-File-Transfer-Protocol\" >Giao th\u1ee9c FTP (File Transfer Protocol)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Giao-thuc-SMTP-Simple-Mail-Transfer-Protocol\" >Giao th\u1ee9c SMTP (Simple Mail Transfer Protocol)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Giao-thuc-DNS-Domain-Name-System\" >Giao th\u1ee9c DNS (Domain Name System)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Phan-biet-Application-Layer-voi-cac-Tang-khac-trong-mo-hinh-OSI\" >Ph\u00e2n bi\u1ec7t Application Layer v\u1edbi c\u00e1c T\u1ea7ng kh\u00e1c trong m\u00f4 h\u00ecnh OSI<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#So-sanh-voi-Presentation-Layer-Tang-Trinh-bay\" >So s\u00e1nh v\u1edbi Presentation Layer (T\u1ea7ng Tr\u00ecnh b\u00e0y)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#So-sanh-voi-Transport-Layer-Tang-Giao-van\" >So s\u00e1nh v\u1edbi Transport Layer (T\u1ea7ng Giao v\u1eadn)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Loi-ich-cua-viec-hieu-ve-Application-Layer\" >L\u1ee3i \u00edch c\u1ee7a vi\u1ec7c hi\u1ec3u v\u1ec1 Application Layer<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Doi-voi-sinh-vien-IT\" >\u0110\u1ed1i v\u1edbi sinh vi\u00ean IT<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Doi-voi-lap-trinh-vien\" >\u0110\u1ed1i v\u1edbi l\u1eadp tr\u00ecnh vi\u00ean<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Doi-voi-Quan-tri-vien-he-thong\" >\u0110\u1ed1i v\u1edbi Qu\u1ea3n tr\u1ecb vi\u00ean h\u1ec7 th\u1ed1ng<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Doi-voi-nguoi-dung-thong-thuong\" >\u0110\u1ed1i v\u1edbi ng\u01b0\u1eddi d\u00f9ng th\u00f4ng th\u01b0\u1eddng<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/#Cau-hoi-thuong-gap-ve-Application-Layer\" >C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 Application Layer<\/a><\/li><\/ul><\/nav><\/div>\n<p>B\u1ea1n c\u00f3 bao gi\u1edd th\u1eafc m\u1eafc v\u00ec sao c\u00e1c \u1ee9ng d\u1ee5ng nh\u01b0 tr\u00ecnh duy\u1ec7t, email hay chat c\u00f3 th\u1ec3 k\u1ebft n\u1ed1i m\u01b0\u1ee3t m\u00e0 v\u1edbi internet? C\u00e2u tr\u1ea3 l\u1eddi n\u1eb1m \u1edf Application Layer \u2013 t\u1ea7ng \u1ee9ng d\u1ee5ng c\u1ee7a m\u00f4 h\u00ecnh m\u1ea1ng. B\u00e0i vi\u1ebft s\u1ebd gi\u00fap b\u1ea1n hi\u1ec3u r\u00f5 Application Layer l\u00e0 g\u00ec, v\u1ecb tr\u00ed c\u1ee7a n\u00f3 trong c\u00e1c m\u00f4 h\u00ecnh ph\u1ed5 bi\u1ebfn, c\u00e1c ch\u1ee9c n\u0103ng c\u1ed1t l\u00f5i, nh\u1eefng giao th\u1ee9c quan tr\u1ecdng nh\u01b0 HTTP, <a href=\"https:\/\/interdata.vn\/blog\/ftp-la-gi\/\">FTP<\/a>, <a href=\"https:\/\/interdata.vn\/blog\/dns-la-gi\/\">DNS<\/a>, k\u00e8m v\u00ed d\u1ee5 th\u1ef1c t\u1ebf v\u00e0 l\u1ee3i \u00edch khi n\u1eafm v\u1eefng ki\u1ebfn th\u1ee9c n\u00e0y.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Application-Layer-la-gi\"><\/span><strong>Application Layer l\u00e0 g\u00ec?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/\"><strong>Application Layer<\/strong><\/a> (hay c\u00f2n g\u1ecdi l\u00e0 <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong>) l\u00e0 t\u1ea7ng cao nh\u1ea5t trong m\u00f4 h\u00ecnh m\u1ea1ng m\u00e1y t\u00ednh, c\u00f3 tr\u00e1ch nhi\u1ec7m cung c\u1ea5p giao di\u1ec7n tr\u1ef1c ti\u1ebfp gi\u1eefa c\u00e1c \u1ee9ng d\u1ee5ng ph\u1ea7n m\u1ec1m m\u00e0 ng\u01b0\u1eddi d\u00f9ng s\u1eed d\u1ee5ng v\u00e0 m\u1ea1ng l\u01b0\u1edbi.<\/p>\n<p>C\u00f3 th\u1ec3 h\u00ecnh dung <strong>Application Layer<\/strong> gi\u1ed1ng nh\u01b0 m\u1ed9t &#8220;ng\u01b0\u1eddi phi\u00ean d\u1ecbch&#8221; ho\u1eb7c &#8220;ng\u01b0\u1eddi ph\u1ee5c v\u1ee5&#8221; trong m\u1ed9t nh\u00e0 h\u00e0ng. B\u1ea1n, v\u1edbi t\u01b0 c\u00e1ch l\u00e0 ng\u01b0\u1eddi d\u00f9ng, mu\u1ed1n g\u1ecdi m\u00f3n \u0103n (t\u01b0\u01a1ng t\u00e1c v\u1edbi d\u1ecbch v\u1ee5 m\u1ea1ng). B\u1ea1n kh\u00f4ng c\u1ea7n ph\u1ea3i bi\u1ebft nh\u00e0 b\u1ebfp ho\u1ea1t \u0111\u1ed9ng th\u1ebf n\u00e0o, quy tr\u00ecnh chu\u1ea9n b\u1ecb m\u00f3n \u0103n ra sao. B\u1ea1n ch\u1ec9 c\u1ea7n n\u00f3i v\u1edbi ng\u01b0\u1eddi ph\u1ee5c v\u1ee5 (Application Layer) m\u00f3n b\u1ea1n mu\u1ed1n, v\u00e0 ng\u01b0\u1eddi \u0111\u00f3 s\u1ebd lo ph\u1ea7n c\u00f2n l\u1ea1i, t\u1eeb vi\u1ec7c ghi l\u1ea1i y\u00eau c\u1ea7u \u0111\u1ebfn vi\u1ec7c \u0111\u01b0a y\u00eau c\u1ea7u \u0111\u00f3 \u0111\u1ebfn \u0111\u00fang n\u01a1i.<\/p>\n<p>Khi b\u1ea1n m\u1edf tr\u00ecnh duy\u1ec7t web \u0111\u1ec3 v\u00e0o m\u1ed9t trang tin t\u1ee9c, khi b\u1ea1n g\u1eedi m\u1ed9t email cho \u0111\u1ed3ng nghi\u1ec7p, hay khi b\u1ea1n xem m\u1ed9t video tr\u1ef1c tuy\u1ebfn, ch\u00ednh <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong> \u0111ang ho\u1ea1t \u0111\u1ed9ng \u00e2m th\u1ea7m \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o y\u00eau c\u1ea7u c\u1ee7a b\u1ea1n \u0111\u01b0\u1ee3c x\u1eed l\u00fd v\u00e0 truy\u1ec1n \u0111i m\u1ed9t c\u00e1ch ch\u00ednh x\u00e1c.<\/p>\n<figure id=\"attachment_33353\" aria-describedby=\"caption-attachment-33353\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33353\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Application-Layer-la-gi.jpg\" alt=\"Application Layer l\u00e0 g\u00ec\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Application-Layer-la-gi.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Application-Layer-la-gi-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Application-Layer-la-gi-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33353\" class=\"wp-caption-text\">Application Layer l\u00e0 g\u00ec<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Vi-tri-cua-Application-Layer-trong-cac-Mo-hinh-Mang\"><\/span><strong>V\u1ecb tr\u00ed c\u1ee7a Application Layer trong c\u00e1c M\u00f4 h\u00ecnh M\u1ea1ng<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 <strong>Application Layer<\/strong>, ch\u00fang ta c\u1ea7n \u0111\u1eb7t n\u00f3 v\u00e0o b\u1ed1i c\u1ea3nh c\u1ee7a hai m\u00f4 h\u00ecnh m\u1ea1ng ph\u1ed5 bi\u1ebfn nh\u1ea5t: M\u00f4 h\u00ecnh OSI v\u00e0 M\u00f4 h\u00ecnh TCP\/IP.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Mo-hinh-OSI-Open-Systems-Interconnection\"><\/span>M\u00f4 h\u00ecnh OSI (Open Systems Interconnection)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u00f4 h\u00ecnh OSI l\u00e0 m\u1ed9t m\u00f4 h\u00ecnh tham chi\u1ebfu l\u00fd thuy\u1ebft g\u1ed3m 7 t\u1ea7ng. M\u1ee5c ti\u00eau c\u1ee7a n\u00f3 l\u00e0 chu\u1ea9n h\u00f3a c\u00e1ch th\u1ee9c giao ti\u1ebfp gi\u1eefa c\u00e1c h\u1ec7 th\u1ed1ng m\u00e1y t\u00ednh kh\u00e1c nhau. Trong m\u00f4 h\u00ecnh n\u00e0y, <strong>Application Layer<\/strong> n\u1eb1m \u1edf v\u1ecb tr\u00ed cao nh\u1ea5t, t\u1ee9c l\u00e0 <strong>T\u1ea7ng 7<\/strong>.<\/p>\n<ul>\n<li><strong>T\u1ea7ng 7 &#8211; Application Layer (T\u1ea7ng \u1ee8ng d\u1ee5ng):<\/strong> T\u1ea7ng n\u00e0y tr\u1ef1c ti\u1ebfp h\u1ed7 tr\u1ee3 c\u00e1c \u1ee9ng d\u1ee5ng ng\u01b0\u1eddi d\u00f9ng, cho ph\u00e9p ch\u00fang truy c\u1eadp v\u00e0 t\u01b0\u01a1ng t\u00e1c v\u1edbi m\u1ea1ng. C\u00e1c \u1ee9ng d\u1ee5ng nh\u01b0 tr\u00ecnh duy\u1ec7t web, email client hay ph\u1ea7n m\u1ec1m chat \u0111\u1ec1u ho\u1ea1t \u0111\u1ed9ng tr\u00ean t\u1ea7ng n\u00e0y.<\/li>\n<li><strong>T\u1ea7ng 6 &#8211; <a href=\"https:\/\/interdata.vn\/blog\/presentation-layer-la-gi\/\">Presentation Layer<\/a> (T\u1ea7ng Tr\u00ecnh b\u00e0y):<\/strong> T\u1ea7ng n\u00e0y ch\u1ecbu tr\u00e1ch nhi\u1ec7m \u0111\u1ecbnh d\u1ea1ng d\u1eef li\u1ec7u \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o c\u00e1c \u1ee9ng d\u1ee5ng c\u00f3 th\u1ec3 hi\u1ec3u \u0111\u01b0\u1ee3c.<\/li>\n<li><strong>T\u1ea7ng 5 &#8211; <a href=\"https:\/\/interdata.vn\/blog\/session-layer-la-gi\/\">Session Layer<\/a> (T\u1ea7ng Phi\u00ean):<\/strong> T\u1ea7ng n\u00e0y thi\u1ebft l\u1eadp, qu\u1ea3n l\u00fd v\u00e0 k\u1ebft th\u00fac c\u00e1c phi\u00ean giao ti\u1ebfp gi\u1eefa hai h\u1ec7 th\u1ed1ng.<\/li>\n<li><strong>T\u1ea7ng 4 &#8211; <a href=\"https:\/\/interdata.vn\/blog\/transport-layer-lop-van-chuyen-trong-ois-la-gi\/\">Transport Layer<\/a> (T\u1ea7ng Giao v\u1eadn):<\/strong> T\u1ea7ng n\u00e0y chia nh\u1ecf d\u1eef li\u1ec7u th\u00e0nh c\u00e1c g\u00f3i tin (packet) v\u00e0 \u0111\u1ea3m b\u1ea3o ch\u00fang \u0111\u01b0\u1ee3c g\u1eedi \u0111\u1ebfn \u0111\u00fang n\u01a1i.<\/li>\n<li><strong>T\u1ea7ng 3 &#8211; <a href=\"https:\/\/interdata.vn\/blog\/network-layer-la-gi\/\">Network Layer<\/a> (T\u1ea7ng M\u1ea1ng):<\/strong> T\u1ea7ng n\u00e0y c\u00f3 nhi\u1ec7m v\u1ee5 t\u00ecm \u0111\u01b0\u1eddng \u0111i t\u1ed1i \u01b0u cho c\u00e1c g\u00f3i tin tr\u00ean m\u1ea1ng.<\/li>\n<li><strong>T\u1ea7ng 2 &#8211; <a href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/\">Data Link Layer<\/a> (T\u1ea7ng Li\u00ean k\u1ebft D\u1eef li\u1ec7u):<\/strong> T\u1ea7ng n\u00e0y qu\u1ea3n l\u00fd vi\u1ec7c truy\u1ec1n d\u1eef li\u1ec7u gi\u1eefa hai thi\u1ebft b\u1ecb tr\u1ef1c ti\u1ebfp k\u1ebft n\u1ed1i.<\/li>\n<li><strong>T\u1ea7ng 1 &#8211; <a href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/\">Physical Layer<\/a> (T\u1ea7ng V\u1eadt l\u00fd):<\/strong> T\u1ea7ng th\u1ea5p nh\u1ea5t, li\u00ean quan \u0111\u1ebfn c\u00e1c ph\u01b0\u01a1ng ti\u1ec7n v\u1eadt l\u00fd nh\u01b0 c\u00e1p m\u1ea1ng, s\u00f3ng radio.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Mo-hinh-TCPIP\"><\/span>M\u00f4 h\u00ecnh TCP\/IP<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u00f4 h\u00ecnh TCP\/IP l\u00e0 m\u1ed9t m\u00f4 h\u00ecnh th\u1ef1c t\u1ebf h\u01a1n, \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i tr\u00ean Internet hi\u1ec7n nay. M\u00f4 h\u00ecnh n\u00e0y c\u00f3 4 t\u1ea7ng, v\u00e0 <strong>Application Layer<\/strong> c\u0169ng l\u00e0 t\u1ea7ng cao nh\u1ea5t.<\/p>\n<ul>\n<li><strong>T\u1ea7ng 4 &#8211; Application Layer (T\u1ea7ng \u1ee8ng d\u1ee5ng):<\/strong> T\u1ea7ng n\u00e0y c\u1ee7a m\u00f4 h\u00ecnh TCP\/IP k\u1ebft h\u1ee3p ch\u1ee9c n\u0103ng c\u1ee7a ba t\u1ea7ng tr\u00ean c\u00f9ng c\u1ee7a m\u00f4 h\u00ecnh OSI (Application, Presentation, v\u00e0 Session). T\u1ea7ng n\u00e0y x\u1eed l\u00fd t\u1ea5t c\u1ea3 c\u00e1c v\u1ea5n \u0111\u1ec1 li\u00ean quan \u0111\u1ebfn vi\u1ec7c cung c\u1ea5p d\u1ecbch v\u1ee5 m\u1ea1ng cho c\u00e1c \u1ee9ng d\u1ee5ng.<\/li>\n<li><strong>T\u1ea7ng 3 &#8211; Transport Layer (T\u1ea7ng Giao v\u1eadn):<\/strong> T\u01b0\u01a1ng t\u1ef1 nh\u01b0 trong OSI, t\u1ea7ng n\u00e0y ch\u1ecbu tr\u00e1ch nhi\u1ec7m truy\u1ec1n d\u1eef li\u1ec7u t\u1eeb \u1ee9ng d\u1ee5ng n\u00e0y \u0111\u1ebfn \u1ee9ng d\u1ee5ng kh\u00e1c.<\/li>\n<li><strong>T\u1ea7ng 2 &#8211; Internet Layer (T\u1ea7ng M\u1ea1ng):<\/strong> T\u01b0\u01a1ng \u1ee9ng v\u1edbi Network Layer trong OSI, t\u1ea7ng n\u00e0y ch\u1ecbu tr\u00e1ch nhi\u1ec7m \u0111\u1ecbnh tuy\u1ebfn c\u00e1c g\u00f3i tin.<\/li>\n<li><strong>T\u1ea7ng 1 &#8211; Network Access Layer (T\u1ea7ng Truy c\u1eadp M\u1ea1ng):<\/strong> T\u1ea7ng n\u00e0y k\u1ebft h\u1ee3p hai t\u1ea7ng d\u01b0\u1edbi c\u00f9ng c\u1ee7a OSI, ch\u1ecbu tr\u00e1ch nhi\u1ec7m x\u1eed l\u00fd c\u00e1c chi ti\u1ebft v\u1eadt l\u00fd c\u1ee7a vi\u1ec7c g\u1eedi v\u00e0 nh\u1eadn d\u1eef li\u1ec7u tr\u00ean m\u1ea1ng.<\/li>\n<\/ul>\n<p>V\u1ecb tr\u00ed c\u1ee7a <strong>Application Layer<\/strong> trong c\u1ea3 hai m\u00f4 h\u00ecnh \u0111\u1ec1u cho th\u1ea5y t\u1ea7m quan tr\u1ecdng c\u1ee7a n\u00f3. \u0110\u00e2y l\u00e0 n\u01a1i m\u1ecdi t\u01b0\u01a1ng t\u00e1c c\u1ee7a ng\u01b0\u1eddi d\u00f9ng \u0111\u01b0\u1ee3c kh\u1edfi \u0111\u1ea7u v\u00e0 k\u1ebft th\u00fac, l\u00e0 \u0111i\u1ec3m giao thoa gi\u1eefa con ng\u01b0\u1eddi v\u00e0 h\u1ec7 th\u1ed1ng m\u1ea1ng ph\u1ee9c t\u1ea1p.<\/p>\n<figure id=\"attachment_33354\" aria-describedby=\"caption-attachment-33354\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33354\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Vi-tri-cua-Application-Layer.jpg\" alt=\"V\u1ecb tr\u00ed c\u1ee7a Application Layer\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Vi-tri-cua-Application-Layer.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Vi-tri-cua-Application-Layer-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Vi-tri-cua-Application-Layer-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33354\" class=\"wp-caption-text\">V\u1ecb tr\u00ed c\u1ee7a Application Layer<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"3-Chuc-nang-chinh-cua-Application-Layer\"><\/span><strong>3 Ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a Application Layer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Application Layer<\/strong> kh\u00f4ng ch\u1ec9 \u0111\u01a1n gi\u1ea3n l\u00e0 m\u1ed9t giao di\u1ec7n. N\u00f3 th\u1ef1c hi\u1ec7n nhi\u1ec1u ch\u1ee9c n\u0103ng c\u1ed1t l\u00f5i \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o c\u00e1c \u1ee9ng d\u1ee5ng c\u00f3 th\u1ec3 giao ti\u1ebfp v\u1edbi nhau qua m\u1ea1ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Cung-cap-dich-vu-mang-cho-nguoi-dung\"><\/span>Cung c\u1ea5p d\u1ecbch v\u1ee5 m\u1ea1ng cho ng\u01b0\u1eddi d\u00f9ng<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Ch\u1ee9c n\u0103ng \u0111\u1ea7u ti\u00ean v\u00e0 quan tr\u1ecdng nh\u1ea5t c\u1ee7a <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong> l\u00e0 cung c\u1ea5p c\u00e1c d\u1ecbch v\u1ee5 m\u1ea1ng m\u00e0 ch\u00fang ta s\u1eed d\u1ee5ng h\u00e0ng ng\u00e0y. H\u00e3y ngh\u0129 v\u1ec1 c\u00e1c \u1ee9ng d\u1ee5ng m\u00e0 b\u1ea1n m\u1edf tr\u00ean m\u00e1y t\u00ednh ho\u1eb7c \u0111i\u1ec7n tho\u1ea1i. M\u1ed7i \u1ee9ng d\u1ee5ng \u0111\u1ec1u c\u00f3 m\u1ed9t m\u1ee5c \u0111\u00edch c\u1ee5 th\u1ec3: duy\u1ec7t web, g\u1eedi email, chia s\u1ebb file.<\/p>\n<p><strong>Application Layer<\/strong> ch\u00ednh l\u00e0 n\u01a1i c\u00e1c d\u1ecbch v\u1ee5 n\u00e0y \u0111\u01b0\u1ee3c cung c\u1ea5p. Ch\u1eb3ng h\u1ea1n, khi b\u1ea1n m\u1edf tr\u00ecnh duy\u1ec7t web, t\u1ea7ng \u1ee9ng d\u1ee5ng s\u1ebd k\u00edch ho\u1ea1t giao th\u1ee9c HTTP \u0111\u1ec3 g\u1eedi y\u00eau c\u1ea7u \u0111\u1ebfn m\u00e1y ch\u1ee7. Khi b\u1ea1n so\u1ea1n m\u1ed9t email, t\u1ea7ng \u1ee9ng d\u1ee5ng s\u1ebd s\u1eed d\u1ee5ng giao th\u1ee9c <a href=\"https:\/\/interdata.vn\/blog\/smtp-la-gi\/\">SMTP<\/a> \u0111\u1ec3 g\u1eedi th\u01b0. Kh\u00f4ng c\u00f3 <strong>Application Layer<\/strong>, c\u00e1c \u1ee9ng d\u1ee5ng c\u1ee7a b\u1ea1n s\u1ebd kh\u00f4ng th\u1ec3 &#8220;n\u00f3i chuy\u1ec7n&#8221; v\u1edbi m\u1ea1ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Xac-dinh-giao-thuc-va-dong-bo-hoa-ung-dung\"><\/span>X\u00e1c \u0111\u1ecbnh giao th\u1ee9c v\u00e0 \u0111\u1ed3ng b\u1ed9 h\u00f3a \u1ee9ng d\u1ee5ng<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1ed7i d\u1ecbch v\u1ee5 m\u1ea1ng \u0111\u1ec1u c\u1ea7n m\u1ed9t ng\u00f4n ng\u1eef ri\u00eang \u0111\u1ec3 giao ti\u1ebfp, v\u00e0 <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong> ch\u1ecbu tr\u00e1ch nhi\u1ec7m x\u00e1c \u0111\u1ecbnh ng\u00f4n ng\u1eef \u0111\u00f3. &#8220;Ng\u00f4n ng\u1eef&#8221; \u1edf \u0111\u00e2y ch\u00ednh l\u00e0 c\u00e1c giao th\u1ee9c (protocols). C\u00e1c giao th\u1ee9c n\u00e0y gi\u1ed1ng nh\u01b0 m\u1ed9t b\u1ed9 quy t\u1eafc \u0111\u01b0\u1ee3c chu\u1ea9n h\u00f3a, gi\u00fap hai \u1ee9ng d\u1ee5ng \u1edf hai \u0111\u1ea7u k\u1ebft n\u1ed1i c\u00f3 th\u1ec3 hi\u1ec3u nhau.<\/p>\n<p>V\u00ed d\u1ee5, \u0111\u1ec3 m\u1ed9t \u1ee9ng d\u1ee5ng email bi\u1ebft c\u00e1ch g\u1eedi th\u01b0, <strong>Application Layer<\/strong> s\u1ebd quy \u0111\u1ecbnh vi\u1ec7c s\u1eed d\u1ee5ng giao th\u1ee9c SMTP. \u0110\u1ec3 t\u1ea3i m\u1ed9t trang web, n\u00f3 s\u1ebd s\u1eed d\u1ee5ng HTTP. S\u1ef1 \u0111\u1ed3ng b\u1ed9 h\u00f3a n\u00e0y l\u00e0 c\u1ea7n thi\u1ebft \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c \u0111\u1ecbnh d\u1ea1ng v\u00e0 truy\u1ec1n \u0111i m\u1ed9t c\u00e1ch nh\u1ea5t qu\u00e1n, tr\u00e1nh nh\u1eefng l\u1ed7i kh\u00f4ng \u0111\u00e1ng c\u00f3.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Tuong-tac-voi-nguoi-dung-va-xu-ly-du-lieu\"><\/span>T\u01b0\u01a1ng t\u00e1c v\u1edbi ng\u01b0\u1eddi d\u00f9ng v\u00e0 x\u1eed l\u00fd d\u1eef li\u1ec7u<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Application Layer<\/strong> l\u00e0 c\u1ea7u n\u1ed1i gi\u1eefa ng\u01b0\u1eddi d\u00f9ng v\u00e0 m\u1ea1ng. D\u1eef li\u1ec7u m\u00e0 b\u1ea1n nh\u1eadp v\u00e0o (v\u00ed d\u1ee5: m\u1ed9t tin nh\u1eafn, m\u1ed9t \u0111\u1ecba ch\u1ec9 URL) s\u1ebd \u0111\u01b0\u1ee3c <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong> ti\u1ebfp nh\u1eadn. Sau \u0111\u00f3, n\u00f3 s\u1ebd <a href=\"https:\/\/interdata.vn\/blog\/data-preprocessing-la-gi\/\">x\u1eed l\u00fd d\u1eef li\u1ec7u<\/a> n\u00e0y \u0111\u1ec3 chuy\u1ec3n xu\u1ed1ng c\u00e1c t\u1ea7ng d\u01b0\u1edbi. Qu\u00e1 tr\u00ecnh n\u00e0y bao g\u1ed3m vi\u1ec7c th\u00eam c\u00e1c th\u00f4ng tin c\u1ea7n thi\u1ebft, ch\u1eb3ng h\u1ea1n nh\u01b0 \u0111\u1ecba ch\u1ec9 c\u1ee7a \u1ee9ng d\u1ee5ng \u0111\u00edch (v\u00ed d\u1ee5, s\u1ed1 c\u1ed5ng) \u0111\u1ec3 c\u00e1c t\u1ea7ng d\u01b0\u1edbi bi\u1ebft c\u00e1ch \u0111\u1ecbnh tuy\u1ebfn d\u1eef li\u1ec7u.<\/p>\n<p>Ng\u01b0\u1ee3c l\u1ea1i, khi d\u1eef li\u1ec7u t\u1eeb m\u1ea1ng \u0111\u01b0\u1ee3c g\u1eedi v\u1ec1, <strong>Application Layer<\/strong> s\u1ebd nh\u1eadn d\u1eef li\u1ec7u t\u1eeb c\u00e1c t\u1ea7ng d\u01b0\u1edbi v\u00e0 chuy\u1ec3n \u0111\u1ed5i n\u00f3 th\u00e0nh \u0111\u1ecbnh d\u1ea1ng m\u00e0 \u1ee9ng d\u1ee5ng c\u00f3 th\u1ec3 hi\u1ec3n th\u1ecb cho b\u1ea1n.<\/p>\n<figure id=\"attachment_33355\" aria-describedby=\"caption-attachment-33355\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33355\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Chuc-nang-cua-Application-Layer.jpg\" alt=\"Ch\u1ee9c n\u0103ng c\u1ee7a Application Layer\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Chuc-nang-cua-Application-Layer.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Chuc-nang-cua-Application-Layer-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Chuc-nang-cua-Application-Layer-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33355\" class=\"wp-caption-text\">Ch\u1ee9c n\u0103ng c\u1ee7a Application Layer<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Cac-Giao-thuc-quan-trong-cua-Presentation-Layer-va-Vi-du-thuc-te\"><\/span><strong>C\u00e1c Giao th\u1ee9c quan tr\u1ecdng c\u1ee7a Presentation Layer v\u00e0 V\u00ed d\u1ee5 th\u1ef1c t\u1ebf<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng trong m\u00f4 h\u00ecnh OSI<\/strong>, ch\u00fang ta c\u1ea7n t\u00ecm hi\u1ec3u c\u00e1c &#8220;ng\u00f4n ng\u1eef&#8221; m\u00e0 n\u00f3 s\u1eed d\u1ee5ng. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng giao th\u1ee9c ph\u1ed5 bi\u1ebfn nh\u1ea5t ho\u1ea1t \u0111\u1ed9ng t\u1ea1i <strong>Application Layer<\/strong>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Giao-thuc-HTTP-Hypertext-Transfer-Protocol\"><\/span>Giao th\u1ee9c HTTP (Hypertext Transfer Protocol)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>HTTP l\u00e0 m\u1ed9t trong nh\u1eefng giao th\u1ee9c quan tr\u1ecdng nh\u1ea5t. N\u00f3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 truy\u1ec1n t\u1ea3i d\u1eef li\u1ec7u tr\u00ean <a href=\"https:\/\/interdata.vn\/blog\/world-wide-web\/\">World Wide Web<\/a>. Khi b\u1ea1n g\u00f5 m\u1ed9t \u0111\u1ecba ch\u1ec9 <a href=\"https:\/\/interdata.vn\/blog\/website-la-gi\/\">website<\/a> v\u00e0o tr\u00ecnh duy\u1ec7t, b\u1ea1n \u0111ang s\u1eed d\u1ee5ng giao th\u1ee9c HTTP.<\/p>\n<p><strong>HTTP ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o?<\/strong><\/p>\n<ul>\n<li><strong>G\u1eedi y\u00eau c\u1ea7u:<\/strong> Tr\u00ecnh duy\u1ec7t web c\u1ee7a b\u1ea1n, ho\u1ea1t \u0111\u1ed9ng \u1edf <strong>Application Layer<\/strong>, g\u1eedi m\u1ed9t y\u00eau c\u1ea7u HTTP \u0111\u1ebfn <a href=\"https:\/\/interdata.vn\/blog\/web-server\/\">m\u00e1y ch\u1ee7 web<\/a>. Y\u00eau c\u1ea7u n\u00e0y bao g\u1ed3m th\u00f4ng tin v\u1ec1 trang b\u1ea1n mu\u1ed1n truy c\u1eadp.<\/li>\n<li><strong>M\u00e1y ch\u1ee7 x\u1eed l\u00fd:<\/strong> M\u00e1y ch\u1ee7 nh\u1eadn y\u00eau c\u1ea7u HTTP. N\u00f3 x\u1eed l\u00fd v\u00e0 t\u00ecm ki\u1ebfm trang web t\u01b0\u01a1ng \u1ee9ng.<\/li>\n<li><strong>G\u1eedi ph\u1ea3n h\u1ed3i:<\/strong> M\u00e1y ch\u1ee7 g\u1eedi l\u1ea1i m\u1ed9t ph\u1ea3n h\u1ed3i HTTP, bao g\u1ed3m m\u00e3 tr\u1ea1ng th\u00e1i (v\u00ed d\u1ee5: 200 OK n\u1ebfu th\u00e0nh c\u00f4ng) v\u00e0 d\u1eef li\u1ec7u c\u1ee7a trang web \u0111\u00f3 (<a href=\"https:\/\/interdata.vn\/blog\/html-la-gi\/\">HTML<\/a>, <a href=\"https:\/\/interdata.vn\/blog\/css-la-gi\/\">CSS<\/a>, <a href=\"https:\/\/interdata.vn\/blog\/javascript-la-gi\/\">JavaScript<\/a>, h\u00ecnh \u1ea3nh, v.v.).<\/li>\n<li><strong>Tr\u00ecnh duy\u1ec7t hi\u1ec3n th\u1ecb:<\/strong> Tr\u00ecnh duy\u1ec7t c\u1ee7a b\u1ea1n, ho\u1ea1t \u0111\u1ed9ng \u1edf <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong>, nh\u1eadn ph\u1ea3n h\u1ed3i n\u00e0y v\u00e0 hi\u1ec3n th\u1ecb trang web tr\u00ean m\u00e0n h\u00ecnh.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Giao-thuc-FTP-File-Transfer-Protocol\"><\/span>Giao th\u1ee9c FTP (File Transfer Protocol)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>FTP l\u00e0 giao th\u1ee9c ti\u00eau chu\u1ea9n \u0111\u1ec3 truy\u1ec1n file gi\u1eefa m\u00e1y kh\u00e1ch v\u00e0 m\u00e1y ch\u1ee7. Giao th\u1ee9c n\u00e0y cho ph\u00e9p ng\u01b0\u1eddi d\u00f9ng t\u1ea3i l\u00ean (upload) v\u00e0 t\u1ea3i xu\u1ed1ng (download) c\u00e1c t\u1eadp tin.<\/p>\n<p><strong>V\u00ed d\u1ee5 th\u1ef1c t\u1ebf:<\/strong> M\u1ed9t nh\u00e0 ph\u00e1t tri\u1ec3n web mu\u1ed1n t\u1ea3i l\u00ean c\u00e1c file <a href=\"https:\/\/interdata.vn\/blog\/source-code-la-gi\/\">m\u00e3 ngu\u1ed3n<\/a> c\u1ee7a m\u1ed9t website l\u00ean m\u00e1y ch\u1ee7. Anh \u1ea5y s\u1ebd s\u1eed d\u1ee5ng m\u1ed9t ph\u1ea7n m\u1ec1m FTP Client. Ph\u1ea7n m\u1ec1m n\u00e0y, th\u00f4ng qua <strong>Application Layer<\/strong>, s\u1ebd s\u1eed d\u1ee5ng giao th\u1ee9c FTP \u0111\u1ec3 thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i v\u1edbi m\u00e1y ch\u1ee7 web. Sau khi x\u00e1c th\u1ef1c, c\u00e1c file s\u1ebd \u0111\u01b0\u1ee3c truy\u1ec1n t\u1eeb m\u00e1y t\u00ednh c\u1ee7a anh \u1ea5y \u0111\u1ebfn m\u00e1y ch\u1ee7, s\u1eed d\u1ee5ng c\u00e1c quy t\u1eafc c\u1ee7a giao th\u1ee9c FTP.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Giao-thuc-SMTP-Simple-Mail-Transfer-Protocol\"><\/span>Giao th\u1ee9c SMTP (Simple Mail Transfer Protocol)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SMTP l\u00e0 giao th\u1ee9c \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 g\u1eedi v\u00e0 nh\u1eadn email. Khi b\u1ea1n nh\u1ea5n n\u00fat &#8220;G\u1eedi&#8221; trong \u1ee9ng d\u1ee5ng email, SMTP ch\u00ednh l\u00e0 giao th\u1ee9c ch\u1ecbu tr\u00e1ch nhi\u1ec7m chuy\u1ec3n email c\u1ee7a b\u1ea1n \u0111\u1ebfn m\u00e1y ch\u1ee7 th\u01b0.<\/p>\n<p><strong>V\u00ed d\u1ee5 th\u1ef1c t\u1ebf:<\/strong> B\u1ea1n so\u1ea1n m\u1ed9t email v\u00e0 g\u1eedi cho m\u1ed9t ng\u01b0\u1eddi b\u1ea1n.<\/p>\n<ul>\n<li><strong>G\u1eedi email:<\/strong> \u1ee8ng d\u1ee5ng email c\u1ee7a b\u1ea1n (ch\u1eb3ng h\u1ea1n nh\u01b0 Outlook) s\u1eed d\u1ee5ng giao th\u1ee9c SMTP \u0111\u1ec3 g\u1eedi email \u0111\u1ebfn m\u00e1y ch\u1ee7 SMTP c\u1ee7a nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 email c\u1ee7a b\u1ea1n.<\/li>\n<li><strong>M\u00e1y ch\u1ee7 x\u1eed l\u00fd:<\/strong> M\u00e1y ch\u1ee7 SMTP n\u00e0y s\u1ebd x\u1eed l\u00fd email v\u00e0 g\u1eedi n\u00f3 \u0111\u1ebfn m\u00e1y ch\u1ee7 SMTP c\u1ee7a ng\u01b0\u1eddi nh\u1eadn.<\/li>\n<li><strong>Nh\u1eadn email:<\/strong> M\u00e1y ch\u1ee7 c\u1ee7a ng\u01b0\u1eddi nh\u1eadn s\u1ebd l\u01b0u tr\u1eef email cho \u0111\u1ebfn khi ng\u01b0\u1eddi b\u1ea1n c\u1ee7a b\u1ea1n m\u1edf \u1ee9ng d\u1ee5ng email v\u00e0 t\u1ea3i v\u1ec1. L\u00fac n\u00e0y, m\u1ed9t giao th\u1ee9c kh\u00e1c nh\u01b0 POP3 ho\u1eb7c <a href=\"https:\/\/interdata.vn\/blog\/imap-la-gi\/\">IMAP<\/a> s\u1ebd \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 l\u1ea5y email. \u0110i\u1ec1u n\u00e0y cho th\u1ea5y s\u1ef1 ph\u1ed1i h\u1ee3p ph\u1ee9c t\u1ea1p gi\u1eefa c\u00e1c giao th\u1ee9c \u1edf <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong>.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Giao-thuc-DNS-Domain-Name-System\"><\/span>Giao th\u1ee9c DNS (Domain Name System)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>DNS c\u00f3 vai tr\u00f2 v\u00f4 c\u00f9ng quan tr\u1ecdng. N\u00f3 gi\u00fap chuy\u1ec3n \u0111\u1ed5i c\u00e1c <a href=\"https:\/\/interdata.vn\/blog\/domain-la-gi\/\">t\u00ean mi\u1ec1n<\/a> d\u1ec5 nh\u1edb (v\u00ed d\u1ee5: <a href=\"https:\/\/interdata.vn\/blog\/giao-thuc-https-la-gi\/\">https<\/a>:\/\/www.google.com\/search?q=google.com) th\u00e0nh <a href=\"https:\/\/interdata.vn\/blog\/dia-chi-ip-la-gi\/\">\u0111\u1ecba ch\u1ec9 IP<\/a> kh\u00f3 nh\u1edb (v\u00ed d\u1ee5: 142.250.191.142) \u0111\u1ec3 m\u00e1y t\u00ednh c\u00f3 th\u1ec3 t\u00ecm th\u1ea5y m\u00e1y ch\u1ee7 web t\u01b0\u01a1ng \u1ee9ng.<\/p>\n<p><strong>V\u00ed d\u1ee5 th\u1ef1c t\u1ebf:<\/strong> Khi b\u1ea1n g\u00f5 <code>interdata.com<\/code> v\u00e0o tr\u00ecnh duy\u1ec7t, tr\u01b0\u1edbc khi tr\u00ecnh duy\u1ec7t c\u00f3 th\u1ec3 g\u1eedi y\u00eau c\u1ea7u HTTP, n\u00f3 c\u1ea7n bi\u1ebft \u0111\u1ecba ch\u1ec9 IP c\u1ee7a m\u00e1y ch\u1ee7.<\/p>\n<ul>\n<li><strong>Y\u00eau c\u1ea7u DNS:<\/strong> <strong>Application Layer<\/strong> c\u1ee7a tr\u00ecnh duy\u1ec7t s\u1ebd g\u1eedi m\u1ed9t y\u00eau c\u1ea7u DNS \u0111\u1ebfn m\u00e1y ch\u1ee7 DNS.<\/li>\n<li><strong>M\u00e1y ch\u1ee7 DNS ph\u1ea3n h\u1ed3i:<\/strong> M\u00e1y ch\u1ee7 DNS t\u00ecm ki\u1ebfm trong c\u01a1 s\u1edf d\u1eef li\u1ec7u c\u1ee7a n\u00f3 v\u00e0 g\u1eedi l\u1ea1i \u0111\u1ecba ch\u1ec9 IP c\u1ee7a <code>interdata.com<\/code>.<\/li>\n<li><strong>K\u1ebft n\u1ed1i HTTP:<\/strong> L\u00fac n\u00e0y, tr\u00ecnh duy\u1ec7t \u0111\u00e3 c\u00f3 \u0111\u1ecba ch\u1ec9 IP v\u00e0 c\u00f3 th\u1ec3 g\u1eedi y\u00eau c\u1ea7u HTTP \u0111\u1ebfn \u0111\u00fang m\u00e1y ch\u1ee7 \u0111\u1ec3 t\u1ea3i trang web.<\/li>\n<\/ul>\n<div class=\"mceTemp\"><\/div>\n<figure id=\"attachment_33357\" aria-describedby=\"caption-attachment-33357\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33357\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Giao-thuc-quan-trong-cua-Tang-Ung-dung.jpg\" alt=\"Giao th\u1ee9c quan tr\u1ecdng c\u1ee7a T\u1ea7ng \u1ee8ng d\u1ee5ng\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Giao-thuc-quan-trong-cua-Tang-Ung-dung.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Giao-thuc-quan-trong-cua-Tang-Ung-dung-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Giao-thuc-quan-trong-cua-Tang-Ung-dung-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33357\" class=\"wp-caption-text\">Giao th\u1ee9c quan tr\u1ecdng c\u1ee7a T\u1ea7ng \u1ee8ng d\u1ee5ng<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Phan-biet-Application-Layer-voi-cac-Tang-khac-trong-mo-hinh-OSI\"><\/span><strong>Ph\u00e2n bi\u1ec7t Application Layer v\u1edbi c\u00e1c T\u1ea7ng kh\u00e1c trong m\u00f4 h\u00ecnh OSI<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>M\u1ed9t trong nh\u1eefng th\u1eafc m\u1eafc ph\u1ed5 bi\u1ebfn nh\u1ea5t l\u00e0 s\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa <strong>Application Layer<\/strong> v\u00e0 c\u00e1c t\u1ea7ng l\u00e2n c\u1eadn nh\u01b0 Presentation Layer hay Transport Layer.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"So-sanh-voi-Presentation-Layer-Tang-Trinh-bay\"><\/span>So s\u00e1nh v\u1edbi Presentation Layer (T\u1ea7ng Tr\u00ecnh b\u00e0y)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>Application Layer:<\/strong> T\u1eadp trung v\u00e0o vi\u1ec7c cung c\u1ea5p d\u1ecbch v\u1ee5 cho ng\u01b0\u1eddi d\u00f9ng cu\u1ed1i. N\u00f3 l\u00e0 giao di\u1ec7n m\u00e0 b\u1ea1n t\u01b0\u01a1ng t\u00e1c tr\u1ef1c ti\u1ebfp. V\u00ed d\u1ee5: b\u1ea1n mu\u1ed1n g\u1eedi m\u1ed9t email, \u0111\u00f3 l\u00e0 nhi\u1ec7m v\u1ee5 c\u1ee7a <strong>Application Layer<\/strong>.<\/li>\n<li><strong>Presentation Layer:<\/strong> T\u1eadp trung v\u00e0o \u0111\u1ecbnh d\u1ea1ng d\u1eef li\u1ec7u. T\u1ea7ng n\u00e0y \u0111\u1ea3m b\u1ea3o d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c m\u00e3 h\u00f3a, n\u00e9n v\u00e0 \u0111\u1ecbnh d\u1ea1ng \u0111\u00fang c\u00e1ch \u0111\u1ec3 t\u1ea7ng \u1ee9ng d\u1ee5ng c\u00f3 th\u1ec3 \u0111\u1ecdc \u0111\u01b0\u1ee3c. V\u00ed d\u1ee5: khi b\u1ea1n xem m\u1ed9t file h\u00ecnh \u1ea3nh JPEG, Presentation Layer s\u1ebd ch\u1ecbu tr\u00e1ch nhi\u1ec7m gi\u1ea3i n\u00e9n v\u00e0 chuy\u1ec3n \u0111\u1ed5i d\u1eef li\u1ec7u \u0111\u00f3 th\u00e0nh \u0111\u1ecbnh d\u1ea1ng m\u00e0 \u1ee9ng d\u1ee5ng xem \u1ea3nh (Application Layer) c\u00f3 th\u1ec3 hi\u1ec3n th\u1ecb.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"So-sanh-voi-Transport-Layer-Tang-Giao-van\"><\/span>So s\u00e1nh v\u1edbi Transport Layer (T\u1ea7ng Giao v\u1eadn)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>Application Layer:<\/strong> Quan t\u00e2m \u0111\u1ebfn vi\u1ec7c &#8220;t\u1ea1i sao&#8221; m\u1ed9t d\u1ecbch v\u1ee5 \u0111\u01b0\u1ee3c y\u00eau c\u1ea7u (v\u00ed d\u1ee5: &#8220;t\u00f4i mu\u1ed1n g\u1eedi email&#8221;).<\/li>\n<li><strong>Transport Layer:<\/strong> Quan t\u00e2m \u0111\u1ebfn vi\u1ec7c &#8220;l\u00e0m th\u1ebf n\u00e0o&#8221; \u0111\u1ec3 d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c truy\u1ec1n \u0111i m\u1ed9t c\u00e1ch \u0111\u00e1ng tin c\u1eady. T\u1ea7ng n\u00e0y ch\u1ecbu tr\u00e1ch nhi\u1ec7m chia d\u1eef li\u1ec7u t\u1eeb <strong>Application Layer<\/strong> th\u00e0nh c\u00e1c ph\u00e2n \u0111o\u1ea1n (segment) nh\u1ecf h\u01a1n v\u00e0 g\u1eedi ch\u00fang \u0111i. T\u1ea7ng n\u00e0y c\u0169ng \u0111\u1ea3m b\u1ea3o c\u00e1c ph\u00e2n \u0111o\u1ea1n n\u00e0y \u0111\u01b0\u1ee3c t\u1eadp h\u1ee3p l\u1ea1i \u0111\u00fang th\u1ee9 t\u1ef1 \u1edf \u0111\u1ea7u nh\u1eadn. Hai giao th\u1ee9c ch\u00ednh c\u1ee7a Transport Layer l\u00e0 TCP v\u00e0 UDP.<\/li>\n<\/ul>\n<p>S\u1ef1 ph\u00e2n bi\u1ec7t r\u00f5 r\u00e0ng gi\u1eefa c\u00e1c t\u1ea7ng cho th\u1ea5y m\u00f4 h\u00ecnh OSI \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1ec3 m\u1ed7i t\u1ea7ng ch\u1ec9 th\u1ef1c hi\u1ec7n m\u1ed9t ch\u1ee9c n\u0103ng ri\u00eang bi\u1ec7t, gi\u00fap qu\u00e1 tr\u00ecnh truy\u1ec1n d\u1eef li\u1ec7u tr\u1edf n\u00ean c\u00f3 t\u1ed5 ch\u1ee9c v\u00e0 hi\u1ec7u qu\u1ea3 h\u01a1n.<\/p>\n<figure id=\"attachment_33356\" aria-describedby=\"caption-attachment-33356\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33356\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Application-Layer-voi-cac-Tang-khac.jpg\" alt=\"Application Layer v\u1edbi c\u00e1c T\u1ea7ng kh\u00e1c\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Application-Layer-voi-cac-Tang-khac.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Application-Layer-voi-cac-Tang-khac-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Application-Layer-voi-cac-Tang-khac-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33356\" class=\"wp-caption-text\">Application Layer v\u1edbi c\u00e1c T\u1ea7ng kh\u00e1c<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Loi-ich-cua-viec-hieu-ve-Application-Layer\"><\/span><strong>L\u1ee3i \u00edch c\u1ee7a vi\u1ec7c hi\u1ec3u v\u1ec1 Application Layer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Hi\u1ec3u v\u1ec1 <strong>Application Layer<\/strong> kh\u00f4ng ch\u1ec9 d\u1eebng l\u1ea1i \u1edf l\u00fd thuy\u1ebft. N\u00f3 mang l\u1ea1i nhi\u1ec1u l\u1ee3i \u00edch thi\u1ebft th\u1ef1c cho c\u00f4ng vi\u1ec7c v\u00e0 h\u1ecdc t\u1eadp.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Doi-voi-sinh-vien-IT\"><\/span><strong>\u0110\u1ed1i v\u1edbi sinh vi\u00ean IT<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Vi\u1ec7c n\u1eafm v\u1eefng <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong>\u00a0l\u00e0 n\u1ec1n t\u1ea3ng v\u1eefng ch\u1eafc \u0111\u1ec3 h\u1ecdc c\u00e1c m\u00f4n chuy\u00ean ng\u00e0nh s\u00e2u h\u01a1n nh\u01b0 <a href=\"https:\/\/interdata.vn\/blog\/lap-trinh-la-gi\/\">L\u1eadp tr\u00ecnh<\/a> m\u1ea1ng, Qu\u1ea3n tr\u1ecb h\u1ec7 th\u1ed1ng, v\u00e0 B\u1ea3o m\u1eadt m\u1ea1ng. N\u00f3 gi\u00fap b\u1ea1n hi\u1ec3u \u0111\u01b0\u1ee3c v\u00ec sao m\u1ed9t ph\u1ea7n m\u1ec1m client l\u1ea1i c\u00f3 th\u1ec3 &#8220;k\u1ebft n\u1ed1i&#8221; \u0111\u01b0\u1ee3c v\u1edbi m\u1ed9t m\u00e1y ch\u1ee7 \u1edf xa.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Doi-voi-lap-trinh-vien\"><\/span><strong>\u0110\u1ed1i v\u1edbi l\u1eadp tr\u00ecnh vi\u00ean<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Khi ph\u00e1t tri\u1ec3n m\u1ed9t <a href=\"https:\/\/interdata.vn\/blog\/web-application-la-gi\/\">\u1ee9ng d\u1ee5ng web<\/a>, b\u1ea1n c\u1ea7n bi\u1ebft c\u00e1ch th\u1ee9c giao ti\u1ebfp gi\u1eefa client (tr\u00ecnh duy\u1ec7t) v\u00e0 server. Hi\u1ec3u v\u1ec1 c\u00e1c giao th\u1ee9c nh\u01b0 HTTP s\u1ebd gi\u00fap b\u1ea1n vi\u1ebft code hi\u1ec7u qu\u1ea3 h\u01a1n, x\u1eed l\u00fd l\u1ed7i nhanh ch\u00f3ng h\u01a1n. B\u1ea1n s\u1ebd bi\u1ebft c\u00e1ch t\u1ed1i \u01b0u h\u00f3a c\u00e1c y\u00eau c\u1ea7u HTTP \u0111\u1ec3 gi\u1ea3m \u0111\u1ed9 tr\u1ec5, ho\u1eb7c bi\u1ebft c\u00e1ch x\u1eed l\u00fd c\u00e1c m\u00e3 tr\u1ea1ng th\u00e1i ph\u1ea3n h\u1ed3i t\u1eeb m\u00e1y ch\u1ee7.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Doi-voi-Quan-tri-vien-he-thong\"><\/span><strong>\u0110\u1ed1i v\u1edbi Qu\u1ea3n tr\u1ecb vi\u00ean h\u1ec7 th\u1ed1ng<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>B\u1ea1n c\u00f3 th\u1ec3 d\u1ec5 d\u00e0ng ch\u1ea9n \u0111o\u00e1n v\u00e0 x\u1eed l\u00fd c\u00e1c s\u1ef1 c\u1ed1 m\u1ea1ng. V\u00ed d\u1ee5, n\u1ebfu ng\u01b0\u1eddi d\u00f9ng kh\u00f4ng truy c\u1eadp \u0111\u01b0\u1ee3c website, b\u1ea1n c\u00f3 th\u1ec3 ki\u1ec3m tra xem giao th\u1ee9c HTTP c\u00f3 ho\u1ea1t \u0111\u1ed9ng kh\u00f4ng, hay c\u00f3 ph\u1ea3i c\u00f3 v\u1ea5n \u0111\u1ec1 v\u1edbi giao th\u1ee9c DNS kh\u00f4ng.<\/p>\n<p>M\u1ed9t v\u00ed d\u1ee5 c\u1ee5 th\u1ec3, n\u1ebfu m\u1ed9t d\u1ecbch v\u1ee5 web b\u00e1o l\u1ed7i 404 Not Found, ng\u01b0\u1eddi qu\u1ea3n tr\u1ecb bi\u1ebft ngay r\u1eb1ng \u0111\u00f3 l\u00e0 m\u1ed9t l\u1ed7i \u1edf <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong> v\u00e0 nguy\u00ean nh\u00e2n l\u00e0 do kh\u00f4ng t\u00ecm th\u1ea5y t\u00e0i nguy\u00ean tr\u00ean m\u00e1y ch\u1ee7.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Doi-voi-nguoi-dung-thong-thuong\"><\/span><strong>\u0110\u1ed1i v\u1edbi ng\u01b0\u1eddi d\u00f9ng th\u00f4ng th\u01b0\u1eddng<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Hi\u1ec3u bi\u1ebft c\u01a1 b\u1ea3n v\u1ec1 <strong>Application Layer<\/strong> gi\u00fap b\u1ea1n nh\u1eadn th\u1ee9c \u0111\u01b0\u1ee3c c\u00e1c nguy c\u01a1 v\u1ec1 b\u1ea3o m\u1eadt. V\u00ed d\u1ee5, b\u1ea1n c\u00f3 th\u1ec3 ph\u00e2n bi\u1ec7t gi\u1eefa HTTP v\u00e0 HTTPS \u0111\u1ec3 bi\u1ebft trang web n\u00e0o an to\u00e0n h\u01a1n khi nh\u1eadp th\u00f4ng tin c\u00e1 nh\u00e2n. HTTPS, v\u1edbi ch\u1eef &#8220;S&#8221; \u1edf cu\u1ed1i, cho bi\u1ebft giao th\u1ee9c n\u00e0y c\u00f3 th\u00eam m\u1ed9t l\u1edbp b\u1ea3o m\u1eadt.<\/p>\n<figure id=\"attachment_33358\" aria-describedby=\"caption-attachment-33358\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33358\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Hieu-ve-Application-Layer.jpg\" alt=\"Hi\u1ec3u v\u1ec1 Application Layer\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Hieu-ve-Application-Layer.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Hieu-ve-Application-Layer-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Hieu-ve-Application-Layer-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33358\" class=\"wp-caption-text\">Hi\u1ec3u v\u1ec1 Application Layer<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Cau-hoi-thuong-gap-ve-Application-Layer\"><\/span><strong>C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 Application Layer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 gi\u00fap b\u1ea1n c\u1ee7ng c\u1ed1 ki\u1ebfn th\u1ee9c, t\u00f4i s\u1ebd tr\u1ea3 l\u1eddi m\u1ed9t s\u1ed1 c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 <strong>Application Layer<\/strong>.<\/p>\n<p><strong>T\u1ea7ng \u1ee9ng d\u1ee5ng c\u00f3 ph\u1ea3i l\u00e0 t\u1ea7ng cao nh\u1ea5t kh\u00f4ng?<\/strong><\/p>\n<p>\u0110\u00fang v\u1eady. Trong c\u1ea3 hai m\u00f4 h\u00ecnh OSI v\u00e0 TCP\/IP, <strong>Application Layer<\/strong> l\u00e0 t\u1ea7ng cao nh\u1ea5t. \u0110\u00e2y l\u00e0 t\u1ea7ng duy nh\u1ea5t t\u01b0\u01a1ng t\u00e1c tr\u1ef1c ti\u1ebfp v\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng ph\u1ea7n m\u1ec1m c\u1ee7a ng\u01b0\u1eddi d\u00f9ng.<\/p>\n<p><strong>Application Layer g\u1ed3m nh\u1eefng g\u00ec?<\/strong><\/p>\n<p><strong>Application Layer<\/strong> kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t t\u1ea7ng v\u1eadt l\u00fd m\u00e0 l\u00e0 m\u1ed9t t\u1ea7ng ch\u1ee9c n\u0103ng. N\u00f3 bao g\u1ed3m c\u00e1c giao th\u1ee9c v\u00e0 d\u1ecbch v\u1ee5 m\u1ea1ng nh\u01b0 HTTP, FTP, SMTP, DNS, Telnet, POP3, IMAP, v\u00e0 nhi\u1ec1u giao th\u1ee9c kh\u00e1c. T\u1ea5t c\u1ea3 c\u00e1c giao th\u1ee9c n\u00e0y \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1ec3 \u0111\u00e1p \u1ee9ng c\u00e1c nhu c\u1ea7u c\u1ee5 th\u1ec3 c\u1ee7a c\u00e1c \u1ee9ng d\u1ee5ng ph\u1ea7n m\u1ec1m.<\/p>\n<p><strong>T\u1ea1i sao c\u1ea7n c\u00f3 Application Layer?<\/strong><\/p>\n<p><strong>Application Layer<\/strong> t\u1ed3n t\u1ea1i \u0111\u1ec3 tr\u1eebu t\u01b0\u1ee3ng h\u00f3a s\u1ef1 ph\u1ee9c t\u1ea1p c\u1ee7a m\u1ea1ng l\u01b0\u1edbi. N\u00f3 gi\u00fap ng\u01b0\u1eddi ph\u00e1t tri\u1ec3n \u1ee9ng d\u1ee5ng kh\u00f4ng c\u1ea7n ph\u1ea3i b\u1eadn t\u00e2m v\u1ec1 c\u00e1ch d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c truy\u1ec1n \u0111i \u1edf c\u00e1c t\u1ea7ng d\u01b0\u1edbi. Thay v\u00e0o \u0111\u00f3, h\u1ecd ch\u1ec9 c\u1ea7n t\u1eadp trung v\u00e0o vi\u1ec7c t\u1ea1o ra c\u00e1c giao di\u1ec7n v\u00e0 ch\u1ee9c n\u0103ng ph\u1ee5c v\u1ee5 ng\u01b0\u1eddi d\u00f9ng, v\u00e0 giao ph\u00f3 vi\u1ec7c truy\u1ec1n t\u1ea3i d\u1eef li\u1ec7u cho c\u00e1c giao th\u1ee9c c\u1ee7a <strong>t\u1ea7ng \u1ee9ng d\u1ee5ng<\/strong>.<\/p>\n<p>B\u00e0i vi\u1ebft n\u00e0y \u0111\u00e3 cung c\u1ea5p m\u1ed9t c\u00e1i nh\u00ecn t\u1ed5ng quan nh\u01b0ng chi ti\u1ebft v\u1ec1 Application Layer trong m\u1ea1ng m\u00e1y t\u00ednh. Ch\u00fang ta \u0111\u00e3 c\u00f9ng nhau t\u00ecm hi\u1ec3u Application Layer l\u00e0 g\u00ec, v\u1ecb tr\u00ed c\u1ee7a n\u00f3 trong c\u00e1c m\u00f4 h\u00ecnh m\u1ea1ng, v\u00e0 c\u00e1c ch\u1ee9c n\u0103ng c\u1ed1t l\u00f5i. Hi\u1ec3u r\u00f5 v\u1ec1 Application Layer kh\u00f4ng ch\u1ec9 l\u00e0 n\u1eafm v\u1eefng l\u00fd thuy\u1ebft m\u00e0 c\u00f2n l\u00e0 l\u00e0m ch\u1ee7 c\u00e1ch c\u00e1c \u1ee9ng d\u1ee5ng v\u00e0 d\u1ecbch v\u1ee5 m\u1ea1ng ho\u1ea1t \u0111\u1ed9ng.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>B\u1ea1n c\u00f3 bao gi\u1edd th\u1eafc m\u1eafc v\u00ec sao c\u00e1c \u1ee9ng d\u1ee5ng nh\u01b0 tr\u00ecnh duy\u1ec7t, email hay chat c\u00f3 th\u1ec3 k\u1ebft n\u1ed1i m\u01b0\u1ee3t m\u00e0 v\u1edbi internet? C\u00e2u tr\u1ea3 l\u1eddi n\u1eb1m \u1edf Application Layer \u2013 t\u1ea7ng \u1ee9ng d\u1ee5ng c\u1ee7a m\u00f4 h\u00ecnh m\u1ea1ng. B\u00e0i vi\u1ebft s\u1ebd gi\u00fap b\u1ea1n hi\u1ec3u r\u00f5 Application Layer l\u00e0 g\u00ec, v\u1ecb tr\u00ed c\u1ee7a n\u00f3<\/p>\n","protected":false},"author":27,"featured_media":33360,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[151],"tags":[],"class_list":["post-33352","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mang"],"_links":{"self":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/33352","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/users\/27"}],"replies":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/comments?post=33352"}],"version-history":[{"count":6,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/33352\/revisions"}],"predecessor-version":[{"id":33429,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/33352\/revisions\/33429"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media\/33360"}],"wp:attachment":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media?parent=33352"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/categories?post=33352"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/tags?post=33352"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}