{"id":32977,"date":"2025-09-19T11:41:19","date_gmt":"2025-09-19T04:41:19","guid":{"rendered":"https:\/\/interdata.vn\/blog\/?p=32977"},"modified":"2025-09-24T09:55:09","modified_gmt":"2025-09-24T02:55:09","slug":"physical-layer-la-gi","status":"publish","type":"post","link":"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/","title":{"rendered":"Physical Layer l\u00e0 g\u00ec? Ch\u1ee9c n\u0103ng &#038; Vai tr\u00f2 c\u1ee7a T\u1ea7ng V\u1eadt l\u00fd (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\/physical-layer-la-gi\/#Physical-Layer-la-gi\" >Physical 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\/physical-layer-la-gi\/#Tang-vat-ly-physical-layer-lam-nhiem-vu-gi\" >T\u1ea7ng v\u1eadt l\u00fd (physical layer) l\u00e0m nhi\u1ec7m v\u1ee5 g\u00ec?<\/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\/physical-layer-la-gi\/#Thuc-hien-giao-tiep-vat-ly\" >Th\u1ef1c hi\u1ec7n giao ti\u1ebfp v\u1eadt l\u00fd<\/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\/physical-layer-la-gi\/#Ma-hoa-tin-hieu\" >M\u00e3 h\u00f3a t\u00edn hi\u1ec7u<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Dong-bo-hoa\" >\u0110\u1ed3ng b\u1ed9 h\u00f3a<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Chuc-nang-chinh-cua-lop-Physical-Layer\" >Ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a l\u1edbp Physical Layer<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Cau-hinh-vat-ly-Topology\" >C\u1ea5u h\u00ecnh v\u1eadt l\u00fd (Topology)<\/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\/physical-layer-la-gi\/#Dinh-nghia-tin-hieu-dientin-hieu-quang\" >\u0110\u1ecbnh ngh\u0129a t\u00edn hi\u1ec7u \u0111i\u1ec7n\/t\u00edn hi\u1ec7u quang<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Quy-dinh-chuan-cap-toc-do-truyen\" >Quy \u0111\u1ecbnh chu\u1ea9n c\u00e1p, t\u1ed1c \u0111\u1ed9 truy\u1ec1n<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Cac-phuong-tien-truyen-dan-o-Physical-Layer\" >C\u00e1c ph\u01b0\u01a1ng ti\u1ec7n truy\u1ec1n d\u1eabn \u1edf Physical Layer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Cac-ky-thuat-dieu-che-va-truyen-tin-hieu-o-tang-Physical-Layer\" >C\u00e1c k\u1ef9 thu\u1eadt \u0111i\u1ec1u ch\u1ebf v\u00e0 truy\u1ec1n t\u00edn hi\u1ec7u \u1edf t\u1ea7ng Physical Layer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Phan-biet-Physical-Layer-voi-cac-tang-khac\" >Ph\u00e2n bi\u1ec7t Physical Layer v\u1edbi c\u00e1c t\u1ea7ng kh\u00e1c<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Cau-truc-vat-ly-Physical-topology\" >C\u1ea5u tr\u00fac v\u1eadt l\u00fd (Physical topology)<\/a><\/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\/physical-layer-la-gi\/#Cac-che-do-truyen-du-lieu-o-tang-Physical-Layer\" >C\u00e1c ch\u1ebf \u0111\u1ed9 truy\u1ec1n d\u1eef li\u1ec7u \u1edf t\u1ea7ng Physical Layer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/#Vi-du-ve-cac-giao-thuc-o-lop-Physical-Layer\" >V\u00ed d\u1ee5 v\u1ec1 c\u00e1c giao th\u1ee9c \u1edf l\u1edbp Physical Layer<\/a><\/li><\/ul><\/nav><\/div>\n<p>B\u1ea1n c\u00f3 bao gi\u1edd t\u1ef1 h\u1ecfi l\u00e0m th\u1ebf n\u00e0o d\u1eef li\u1ec7u t\u1eeb m\u00e1y t\u00ednh c\u1ee7a b\u1ea1n l\u1ea1i c\u00f3 th\u1ec3 truy\u1ec1n \u0111i tr\u00ean m\u1ed9t s\u1ee3i c\u00e1p m\u1ea1ng hay qua s\u00f3ng Wi-Fi? C\u00e2u tr\u1ea3 l\u1eddi n\u1eb1m \u1edf t\u1ea7ng th\u1ea5p nh\u1ea5t l\u00e0 <strong>t\u1ea7ng v\u1eadt k\u00fd &#8211; Physical Layer<\/strong>, hay c\u00f2n g\u1ecdi l\u00e0 T\u1ea7ng v\u1eadt l\u00fd. B\u00e0i vi\u1ebft n\u00e0y s\u1ebd gi\u00fap b\u1ea1n gi\u1ea3i m\u00e3 m\u1ecdi kh\u00e1i ni\u1ec7m v\u1ec1 t\u1ea7ng <strong>Physical Layer l\u00e0 g\u00ec<\/strong>, t\u1eeb nhi\u1ec7m v\u1ee5, ch\u1ee9c n\u0103ng, ph\u00e2n bi\u1ec7t Physical Layer v\u1edbi c\u00e1c t\u1ea7ng kh\u00e1c\u00a0cho \u0111\u1ebfn c\u00e1c thi\u1ebft b\u1ecb ho\u1ea1t \u0111\u1ed9ng \u1edf t\u1ea7ng n\u00e0y.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Physical-Layer-la-gi\"><\/span>Physical Layer l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong><a href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/\">Physical Layer<\/a> <\/strong>l\u00e0 t\u1ea7ng \u0111\u1ea7u ti\u00ean v\u00e0 th\u1ea5p nh\u1ea5t trong m\u00f4 h\u00ecnh 7 t\u1ea7ng OSI (Open Systems Interconnection), nhi\u1ec7m v\u1ee5 ch\u00ednh c\u1ee7a n\u00f3 l\u00e0 truy\u1ec1n t\u1ea3i d\u00f2ng bit (chu\u1ed7i c\u00e1c s\u1ed1 0 v\u00e0 1) t\u1eeb thi\u1ebft b\u1ecb g\u1eedi \u0111\u1ebfn thi\u1ebft b\u1ecb nh\u1eadn qua m\u1ed9t k\u00eanh truy\u1ec1n v\u1eadt l\u00fd.<\/p>\n<figure id=\"attachment_32981\" aria-describedby=\"caption-attachment-32981\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-32981\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Tang-Physical-Layer-la-gi.jpg\" alt=\"T\u1ea7ng Physical Layer l\u00e0 g\u00ec\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Tang-Physical-Layer-la-gi.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Tang-Physical-Layer-la-gi-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Tang-Physical-Layer-la-gi-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-32981\" class=\"wp-caption-text\">T\u1ea7ng Physical Layer l\u00e0 g\u00ec?<\/figcaption><\/figure>\n<p>Hay n\u00f3i m\u1ed9t c\u00e1ch \u0111\u01a1n gi\u1ea3n h\u01a1n, t\u1ea7ng v\u1eadt l\u00fd trong <a href=\"https:\/\/interdata.vn\/blog\/mo-hinh-osi-la-gi\/\">m\u00f4 h\u00ecnh OSI<\/a> l\u00e0 n\u01a1i c\u00e1c t\u00edn hi\u1ec7u \u0111i\u1ec7n, quang ho\u1eb7c s\u00f3ng v\u00f4 tuy\u1ebfn \u0111\u01b0\u1ee3c t\u1ea1o ra \u0111\u1ec3 truy\u1ec1n d\u1eef li\u1ec7u. T\u1ea7ng n\u00e0y kh\u00f4ng quan t\u00e2m \u0111\u1ebfn n\u1ed9i dung c\u1ee7a d\u1eef li\u1ec7u, m\u00e0 ch\u1ec9 t\u1eadp trung v\u00e0o vi\u1ec7c bi\u1ebfn \u0111\u1ed5i c\u00e1c bit th\u00e0nh t\u00edn hi\u1ec7u v\u00e0 \u0111\u1ea3m b\u1ea3o vi\u1ec7c truy\u1ec1n t\u1ea3i ch\u00fang m\u1ed9t c\u00e1ch v\u1eadt l\u00fd.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Tang-vat-ly-physical-layer-lam-nhiem-vu-gi\"><\/span>T\u1ea7ng v\u1eadt l\u00fd (physical layer) l\u00e0m nhi\u1ec7m v\u1ee5 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Vai tr\u00f2 ch\u00ednh c\u1ee7a physical layer l\u00e0 g\u00ec?<\/strong> T\u1ea7ng Physical Layer \u0111\u00f3ng vai tr\u00f2 n\u1ec1n t\u1ea3ng cho m\u1ecdi ho\u1ea1t \u0111\u1ed9ng truy\u1ec1n th\u00f4ng trong m\u1ea1ng m\u00e1y t\u00ednh. Kh\u00f4ng c\u00f3 t\u1ea7ng n\u00e0y, c\u00e1c thi\u1ebft b\u1ecb kh\u00f4ng th\u1ec3 k\u1ebft n\u1ed1i v\u00e0 trao \u0111\u1ed5i d\u1eef li\u1ec7u v\u1edbi nhau. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 ba vai tr\u00f2 ch\u00ednh c\u1ee7a n\u00f3.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Thuc-hien-giao-tiep-vat-ly\"><\/span>Th\u1ef1c hi\u1ec7n giao ti\u1ebfp v\u1eadt l\u00fd<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Vai tr\u00f2 \u0111\u1ea7u ti\u00ean v\u00e0 quan tr\u1ecdng nh\u1ea5t c\u1ee7a t\u1ea7ng v\u1eadt l\u00fd l\u00e0 thi\u1ebft l\u1eadp v\u00e0 duy tr\u00ec k\u1ebft n\u1ed1i v\u1eadt l\u00fd gi\u1eefa c\u00e1c thi\u1ebft b\u1ecb. C\u00e1c k\u1ebft n\u1ed1i n\u00e0y c\u00f3 th\u1ec3 l\u00e0 c\u00f3 d\u00e2y (nh\u01b0 c\u00e1p Ethernet, c\u00e1p quang) ho\u1eb7c kh\u00f4ng d\u00e2y (nh\u01b0 s\u00f3ng Wi-Fi, Bluetooth). T\u1ea7ng v\u1eadt l\u00fd quy \u0111\u1ecbnh c\u00e1c ti\u00eau chu\u1ea9n v\u1ec1 lo\u1ea1i c\u00e1p, ch\u00e2n c\u1eafm, v\u00e0 c\u00e1ch c\u00e1c thi\u1ebft b\u1ecb k\u1ebft n\u1ed1i v\u1edbi nhau \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o t\u00edn hi\u1ec7u \u0111\u01b0\u1ee3c truy\u1ec1n \u0111i \u0111\u00fang c\u00e1ch.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Ma-hoa-tin-hieu\"><\/span>M\u00e3 h\u00f3a t\u00edn hi\u1ec7u<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>D\u1eef li\u1ec7u tr\u00ean m\u00e1y t\u00ednh l\u00e0 c\u00e1c bit (0 v\u00e0 1), nh\u01b0ng ch\u00fang kh\u00f4ng th\u1ec3 truy\u1ec1n tr\u1ef1c ti\u1ebfp qua c\u00e1p, t\u1ea7ng v\u1eadt l\u00fd c\u00f3 ch\u1ee9c n\u0103ng bi\u1ebfn \u0111\u1ed5i c\u00e1c bit nh\u1ecb ph\u00e2n n\u00e0y th\u00e0nh c\u00e1c t\u00edn hi\u1ec7u v\u1eadt l\u00fd.<\/p>\n<p>V\u00ed d\u1ee5, n\u00f3 c\u00f3 th\u1ec3 bi\u1ebfn \u0111\u1ed5i bit 1 th\u00e0nh m\u1ed9t xung \u0111i\u1ec7n d\u01b0\u01a1ng v\u00e0 bit 0 th\u00e0nh m\u1ed9t xung \u0111i\u1ec7n \u00e2m. \u0110\u1ed1i v\u1edbi c\u00e1p quang, bit 1 c\u00f3 th\u1ec3 l\u00e0 \u00e1nh s\u00e1ng, c\u00f2n bit 0 l\u00e0 kh\u00f4ng c\u00f3 \u00e1nh s\u00e1ng. Qu\u00e1 tr\u00ecnh n\u00e0y \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 m\u00e3 h\u00f3a \u0111\u01b0\u1eddng truy\u1ec1n (line encoding).<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Dong-bo-hoa\"><\/span>\u0110\u1ed3ng b\u1ed9 h\u00f3a<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u1ec3 qu\u00e1 tr\u00ecnh truy\u1ec1n v\u00e0 nh\u1eadn d\u1eef li\u1ec7u di\u1ec5n ra ch\u00ednh x\u00e1c, thi\u1ebft b\u1ecb g\u1eedi v\u00e0 thi\u1ebft b\u1ecb nh\u1eadn c\u1ea7n ph\u1ea3i \u0111\u1ed3ng b\u1ed9 v\u1ec1 th\u1eddi gian. T\u1ea7ng Physical Layer \u0111\u1ea3m b\u1ea3o hai b\u00ean ho\u1ea1t \u0111\u1ed9ng \u1edf c\u00f9ng m\u1ed9t t\u1ed1c \u0111\u1ed9 v\u00e0 bi\u1ebft ch\u00ednh x\u00e1c khi n\u00e0o m\u1ed9t bit b\u1eaft \u0111\u1ea7u v\u00e0 k\u1ebft th\u00fac. \u0110i\u1ec1u n\u00e0y ng\u0103n ng\u1eeba t\u00ecnh tr\u1ea1ng m\u1ea5t bit ho\u1eb7c nh\u1eadn sai th\u1ee9 t\u1ef1, \u0111\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n c\u1ee7a d\u1eef li\u1ec7u trong qu\u00e1 tr\u00ecnh truy\u1ec1n t\u1ea3i.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Chuc-nang-chinh-cua-lop-Physical-Layer\"><\/span>Ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a l\u1edbp Physical Layer<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Sau khi hi\u1ec3u v\u1ec1 vai tr\u00f2 t\u1ed5ng quan c\u1ee7a Physical Layer l\u00e0 g\u00ec, ch\u00fang ta c\u00f9ng \u0111i s\u00e2u v\u00e0o c\u00e1c ch\u1ee9c n\u0103ng c\u1ee5 th\u1ec3 c\u1ee7a t\u1ea7ng V\u1eadt l\u00fd trong m\u00f4 h\u00ecnh OSI.<\/p>\n<p>L\u1edbp v\u1eadt l\u00fd ch\u1ecbu tr\u00e1ch nhi\u1ec7m truy\u1ec1n c\u00e1c bit t\u1eeb m\u00e1y t\u00ednh n\u00e0y sang m\u00e1y t\u00ednh kh\u00e1c th\u00f4ng qua m\u1ea1ng. Vai tr\u00f2 c\u1ee7a n\u00f3 l\u00e0 x\u00e1c \u0111\u1ecbnh c\u00e1ch thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i v\u1eadt l\u00fd v\u1edbi m\u1ea1ng, c\u0169ng nh\u01b0 c\u00e1ch bi\u1ec3u di\u1ec5n c\u00e1c bit th\u00e0nh t\u00edn hi\u1ec7u c\u00f3 th\u1ec3 d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c \u2014 d\u01b0\u1edbi d\u1ea1ng t\u00edn hi\u1ec7u \u0111i\u1ec7n, t\u00edn hi\u1ec7u quang ho\u1eb7c s\u00f3ng v\u00f4 tuy\u1ebfn.<\/p>\n<p>\u0110\u1ec3 th\u1ef1c hi\u1ec7n \u0111i\u1ec1u \u0111\u00f3, t\u1ea7ng v\u1eadt l\u00fd \u0111\u1ea3m nh\u1eadn nhi\u1ec1u ch\u1ee9c n\u0103ng kh\u00e1c nhau, bao g\u1ed3m:<\/p>\n<ul>\n<li><strong>\u0110\u1ecbnh ngh\u0129a bit<\/strong>: X\u00e1c \u0111\u1ecbnh c\u00e1ch c\u00e1c bit (0 v\u00e0 1) \u0111\u01b0\u1ee3c chuy\u1ec3n \u0111\u1ed5i th\u00e0nh t\u00edn hi\u1ec7u.<\/li>\n<li><strong>T\u1ed1c \u0111\u1ed9 d\u1eef li\u1ec7u<\/strong>: X\u00e1c \u0111\u1ecbnh t\u1ed1c \u0111\u1ed9 truy\u1ec1n d\u1eef li\u1ec7u, t\u00ednh b\u1eb1ng s\u1ed1 bit tr\u00ean gi\u00e2y.<\/li>\n<li><strong>\u0110\u1ed3ng b\u1ed9 h\u00f3a<\/strong>: \u0110\u1ea3m b\u1ea3o thi\u1ebft b\u1ecb g\u1eedi v\u00e0 thi\u1ebft b\u1ecb nh\u1eadn ho\u1ea1t \u0111\u1ed9ng \u0111\u1ed3ng b\u1ed9.<\/li>\n<li><strong>Ch\u1ebf \u0111\u1ed9 truy\u1ec1n<\/strong>: X\u00e1c \u0111\u1ecbnh h\u01b0\u1edbng truy\u1ec1n d\u1eef li\u1ec7u, g\u1ed3m: simplex (ch\u1ec9 truy\u1ec1n m\u1ed9t chi\u1ec1u), half-duplex (truy\u1ec1n hai chi\u1ec1u nh\u01b0ng kh\u00f4ng \u0111\u1ed3ng th\u1eddi) v\u00e0 full-duplex (truy\u1ec1n hai chi\u1ec1u c\u00f9ng l\u00fac).<\/li>\n<li><strong>Giao di\u1ec7n k\u1ebft n\u1ed1i<\/strong>: X\u00e1c \u0111\u1ecbnh c\u00e1ch c\u00e1c thi\u1ebft b\u1ecb k\u1ebft n\u1ed1i v\u1edbi m\u00f4i tr\u01b0\u1eddng truy\u1ec1n d\u1eabn, ch\u1eb3ng h\u1ea1n nh\u01b0 Ethernet ho\u1eb7c s\u00f3ng v\u00f4 tuy\u1ebfn.<\/li>\n<li><strong>C\u1ea5u h\u00ecnh k\u1ebft n\u1ed1i<\/strong>: H\u1ed7 tr\u1ee3 c\u1ea5u h\u00ecnh \u0111i\u1ec3m\u2013\u0111i\u1ec3m v\u00e0 c\u1ea5u h\u00ecnh \u0111a \u0111i\u1ec3m.<\/li>\n<li><strong>\u0110i\u1ec1u ch\u1ebf (Modulation)<\/strong>: Bi\u1ebfn \u0111\u1ed5i d\u1eef li\u1ec7u th\u00e0nh s\u00f3ng v\u00f4 tuy\u1ebfn.<\/li>\n<li><strong>C\u01a1 ch\u1ebf chuy\u1ec3n m\u1ea1ch<\/strong>: G\u1eedi c\u00e1c g\u00f3i d\u1eef li\u1ec7u t\u1eeb c\u1ed5ng n\u00e0y sang c\u1ed5ng kh\u00e1c.<\/li>\n<li><strong>C\u00e2n b\u1eb1ng t\u00edn hi\u1ec7u (Signal equalization)<\/strong>: Gi\u00fap k\u1ebft n\u1ed1i \u1ed5n \u0111\u1ecbnh h\u01a1n v\u00e0 h\u1ed7 tr\u1ee3 qu\u00e1 tr\u00ecnh gh\u00e9p k\u00eanh d\u1ec5 d\u00e0ng h\u01a1n.<\/li>\n<\/ul>\n<figure id=\"attachment_32982\" aria-describedby=\"caption-attachment-32982\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-32982\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Chuc-nang-chinh-cua-Physical-Layer.jpg\" alt=\"Ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a Physical Layer\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Chuc-nang-chinh-cua-Physical-Layer.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Chuc-nang-chinh-cua-Physical-Layer-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Chuc-nang-chinh-cua-Physical-Layer-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-32982\" class=\"wp-caption-text\">Ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a Physical Layer<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Cau-hinh-vat-ly-Topology\"><\/span>C\u1ea5u h\u00ecnh v\u1eadt l\u00fd (Topology)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Ch\u1ee9c n\u0103ng n\u00e0y x\u00e1c \u0111\u1ecbnh c\u00e1ch c\u00e1c thi\u1ebft b\u1ecb trong m\u1ea1ng \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp v\u00e0 k\u1ebft n\u1ed1i v\u1edbi nhau. C\u00e1c c\u1ea5u h\u00ecnh ph\u1ed5 bi\u1ebfn bao g\u1ed3m:<\/p>\n<ul>\n<li><strong>Bus Topology:<\/strong> T\u1ea5t c\u1ea3 c\u00e1c thi\u1ebft b\u1ecb \u0111\u1ec1u \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u00e0o m\u1ed9t \u0111\u01b0\u1eddng c\u00e1p ch\u00ednh.<\/li>\n<li><strong>Ring Topology:<\/strong> C\u00e1c thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i th\u00e0nh m\u1ed9t v\u00f2ng tr\u00f2n.<\/li>\n<li><strong>Star Topology:<\/strong> T\u1ea5t c\u1ea3 c\u00e1c thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u1edbi m\u1ed9t thi\u1ebft b\u1ecb trung t\u00e2m (nh\u01b0 hub ho\u1eb7c <a href=\"https:\/\/interdata.vn\/blog\/switch-la-gi\/\">switch<\/a>).<\/li>\n<li><strong>Mesh Topology:<\/strong> M\u1ed7i thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u1edbi m\u1ecdi thi\u1ebft b\u1ecb kh\u00e1c, t\u1ea1o ra nhi\u1ec1u \u0111\u01b0\u1eddng d\u1eabn d\u1ef1 ph\u00f2ng.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Dinh-nghia-tin-hieu-dientin-hieu-quang\"><\/span>\u0110\u1ecbnh ngh\u0129a t\u00edn hi\u1ec7u \u0111i\u1ec7n\/t\u00edn hi\u1ec7u quang<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>T\u1ea7ng v\u1eadt l\u00fd \u0111\u1ecbnh ngh\u0129a c\u00e1c \u0111\u1eb7c t\u00ednh c\u1ee7a t\u00edn hi\u1ec7u \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 truy\u1ec1n d\u1eef li\u1ec7u. V\u00ed d\u1ee5:<\/p>\n<ul>\n<li><strong>T\u00edn hi\u1ec7u \u0111i\u1ec7n:<\/strong> T\u1ea7ng n\u00e0y x\u00e1c \u0111\u1ecbnh m\u1ee9c \u0111i\u1ec7n \u00e1p, c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n, v\u00e0 d\u1ea1ng s\u00f3ng \u0111\u1ec3 bi\u1ec3u di\u1ec5n bit 0 v\u00e0 1.<\/li>\n<li><strong>T\u00edn hi\u1ec7u quang:<\/strong> T\u1ea7ng n\u00e0y quy \u0111\u1ecbnh b\u01b0\u1edbc s\u00f3ng \u00e1nh s\u00e1ng, c\u01b0\u1eddng \u0111\u1ed9 \u00e1nh s\u00e1ng \u0111\u1ec3 bi\u1ec3u di\u1ec5n c\u00e1c bit.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Quy-dinh-chuan-cap-toc-do-truyen\"><\/span>Quy \u0111\u1ecbnh chu\u1ea9n c\u00e1p, t\u1ed1c \u0111\u1ed9 truy\u1ec1n<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>C\u00e1c chu\u1ea9n c\u00f4ng nghi\u1ec7p nh\u01b0 IEEE 802.3 (Ethernet) ho\u1eb7c ANSI\/TIA-568 quy \u0111\u1ecbnh chi ti\u1ebft v\u1ec1 c\u00e1c lo\u1ea1i c\u00e1p (UTP, STP, c\u00e1p quang), \u0111\u1ea7u n\u1ed1i (RJ45), v\u00e0 t\u1ed1c \u0111\u1ed9 truy\u1ec1n. S\u1ef1 tu\u00e2n th\u1ee7 c\u00e1c chu\u1ea9n n\u00e0y \u0111\u1ea3m b\u1ea3o c\u00e1c thi\u1ebft b\u1ecb t\u1eeb c\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t kh\u00e1c nhau c\u00f3 th\u1ec3 ho\u1ea1t \u0111\u1ed9ng c\u00f9ng nhau.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-phuong-tien-truyen-dan-o-Physical-Layer\"><\/span>C\u00e1c ph\u01b0\u01a1ng ti\u1ec7n truy\u1ec1n d\u1eabn \u1edf Physical Layer<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u1ede t\u1ea7ng v\u1eadt l\u00fd, d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c truy\u1ec1n \u0111i nh\u1edd nhi\u1ec1u lo\u1ea1i ph\u01b0\u01a1ng ti\u1ec7n kh\u00e1c nhau. M\u1ed9t s\u1ed1 ph\u01b0\u01a1ng ti\u1ec7n th\u01b0\u1eddng g\u1eb7p g\u1ed3m:<\/p>\n<ul>\n<li><strong>C\u00e1p xo\u1eafn \u0111\u00f4i<\/strong>: l\u1ef1a ch\u1ecdn ph\u1ed5 bi\u1ebfn trong c\u00e1c h\u1ec7 th\u1ed1ng m\u1ea1ng LAN.<\/li>\n<li><strong>C\u00e1p \u0111\u1ed3ng tr\u1ee5c<\/strong>: th\u01b0\u1eddng d\u00f9ng cho truy\u1ec1n h\u00ecnh c\u00e1p v\u00e0 m\u1ed9t s\u1ed1 li\u00ean k\u1ebft Internet <a href=\"https:\/\/interdata.vn\/blog\/bang-thong-la-gi\/\">b\u0103ng th\u00f4ng<\/a> r\u1ed9ng (trong l\u1ecbch s\u1eed). Hi\u1ec7n t\u1ea1i \u1edf m\u00f4i tr\u01b0\u1eddng LAN n\u1ed9i b\u1ed9, coax \u00edt ph\u1ed5 bi\u1ebfn h\u01a1n.<\/li>\n<li><strong>S\u00f3ng v\u00f4 tuy\u1ebfn<\/strong>: \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong m\u1ea1ng di \u0111\u1ed9ng v\u00e0 k\u1ebft n\u1ed1i WiFi.<\/li>\n<li><strong>Tia h\u1ed3ng ngo\u1ea1i<\/strong>: th\u00edch h\u1ee3p cho truy\u1ec1n th\u00f4ng kh\u00f4ng d\u00e2y trong ph\u1ea1m vi ng\u1eafn.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Cac-ky-thuat-dieu-che-va-truyen-tin-hieu-o-tang-Physical-Layer\"><\/span>C\u00e1c k\u1ef9 thu\u1eadt \u0111i\u1ec1u ch\u1ebf v\u00e0 truy\u1ec1n t\u00edn hi\u1ec7u \u1edf t\u1ea7ng Physical Layer<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>T\u1ea7ng V\u1eadt l\u00fd trong m\u00f4 h\u00ecnh OSI c\u00f2n s\u1eed d\u1ee5ng nhi\u1ec1u k\u1ef9 thu\u1eadt kh\u00e1c nhau \u0111\u1ec3 m\u00e3 h\u00f3a v\u00e0 truy\u1ec1n t\u1ea3i th\u00f4ng tin. C\u00e1c k\u1ef9 thu\u1eadt th\u01b0\u1eddng g\u1eb7p bao g\u1ed3m:<\/p>\n<ul>\n<li><strong>AM (Amplitude Modulation \u2013 \u0110i\u1ec1u ch\u1ebf bi\u00ean \u0111\u1ed9)<\/strong>: thay \u0111\u1ed5i bi\u00ean \u0111\u1ed9 s\u00f3ng mang d\u1ef1a tr\u00ean t\u00edn hi\u1ec7u.<\/li>\n<li><strong>FM (Frequency Modulation \u2013 \u0110i\u1ec1u ch\u1ebf t\u1ea7n s\u1ed1)<\/strong>: thay \u0111\u1ed5i t\u1ea7n s\u1ed1 s\u00f3ng mang \u0111\u1ec3 mang theo th\u00f4ng tin.<\/li>\n<li><strong>ASK (Amplitude Shift Keying \u2013 Chuy\u1ec3n d\u1ecbch bi\u00ean \u0111\u1ed9)<\/strong>: thay \u0111\u1ed5i bi\u00ean \u0111\u1ed9 s\u00f3ng mang gi\u1eefa hai gi\u00e1 tr\u1ecb kh\u00e1c nhau.<\/li>\n<li><strong>FSK (Frequency Shift Keying \u2013 Chuy\u1ec3n d\u1ecbch t\u1ea7n s\u1ed1)<\/strong>: thay \u0111\u1ed5i t\u1ea7n s\u1ed1 s\u00f3ng mang gi\u1eefa hai gi\u00e1 tr\u1ecb nh\u1ea5t \u0111\u1ecbnh.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Phan-biet-Physical-Layer-voi-cac-tang-khac\"><\/span>Ph\u00e2n bi\u1ec7t Physical Layer v\u1edbi c\u00e1c t\u1ea7ng kh\u00e1c<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Nhi\u1ec1u ng\u01b0\u1eddi th\u01b0\u1eddng nh\u1ea7m l\u1eabn gi\u1eefa ch\u1ee9c n\u0103ng c\u1ee7a c\u00e1c t\u1ea7ng trong m\u00f4 h\u00ecnh OSI. H\u00e3y c\u00f9ng so s\u00e1nh Physical Layer so v\u1edbi c\u00e1c t\u1ea7ng <a href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/\">Data Link Layer<\/a> (T\u1ea7ng 2), t\u1ea7ng <a href=\"https:\/\/interdata.vn\/blog\/network-layer-la-gi\/\">Network Layer<\/a> (T\u1ea7ng 3) \u0111\u1ec3 c\u00f3 c\u00e1i nh\u00ecn r\u00f5 r\u00e0ng h\u01a1n.<br \/>\n<!-- B\u1ea3ng so s\u00e1nh 3 t\u1ea7ng OSI (CSS inline) --><\/p>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 b\u1ea3ng so s\u00e1nh Physical Layer so v\u1edbi c\u00e1c t\u1ea7ng Data Link Layer (T\u1ea7ng 2), t\u1ea7ng Network Layer (T\u1ea7ng 3):<\/p>\n<div style=\"overflow-x: auto; width: 100%; box-sizing: border-box; padding: 8px; background: #f8f9ff; border-radius: 8px;\">\n<table style=\"width: 100%; min-width: 900px; border-collapse: collapse; font-family: Arial, sans-serif; font-size: 14px; color: #212529;\">\n<thead>\n<tr>\n<th style=\"padding: 12px 16px; background: #0d6efd; color: #ffffff; border: 1px solid rgba(13, 110, 253, 0.15); text-align: center;\">Ti\u00eau ch\u00ed<\/th>\n<th style=\"padding: 12px 16px; background: #0d6efd; color: #ffffff; border: 1px solid rgba(13, 110, 253, 0.15); text-align: center;\">L\u1edbp v\u1eadt l\u00fd (T\u1ea7ng 1)<\/th>\n<th style=\"padding: 12px 16px; background: #0d6efd; color: #ffffff; border: 1px solid rgba(13, 110, 253, 0.15); text-align: center;\">T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u (T\u1ea7ng 2)<\/th>\n<th style=\"padding: 12px 16px; background: #0d6efd; color: #ffffff; border: 1px solid rgba(13, 110, 253, 0.15); text-align: center;\">T\u1ea7ng m\u1ea1ng (T\u1ea7ng 3)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th style=\"text-align: left; padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\" scope=\"row\"><span style=\"color: #000000;\">Vai tr\u00f2 ch\u00ednh<\/span><\/th>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">Truy\u1ec1n d\u1eef li\u1ec7u d\u01b0\u1edbi d\u1ea1ng t\u00edn hi\u1ec7u<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">\u0110\u00f3ng g\u00f3i d\u1eef li\u1ec7u (khung), ki\u1ec3m so\u00e1t l\u1ed7i, \u0111i\u1ec1u khi\u1ec3n truy c\u1eadp m\u00f4i tr\u01b0\u1eddng truy\u1ec1n d\u1eabn<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">\u0110\u1ecbnh tuy\u1ebfn v\u00e0 chuy\u1ec3n g\u00f3i d\u1eef li\u1ec7u gi\u1eefa c\u00e1c m\u1ea1ng kh\u00e1c nhau<\/span><\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 12px 16px; background: #f7fbff; border: 1px solid #e9eefb; vertical-align: top;\" scope=\"row\"><span style=\"color: #000000;\">Lo\u1ea1i d\u1eef li\u1ec7u x\u1eed l\u00fd<\/span><\/th>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">Bit (chu\u1ed7i t\u00edn hi\u1ec7u v\u1eadt l\u00fd)<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">Khung d\u1eef li\u1ec7u (Frame)<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">G\u00f3i d\u1eef li\u1ec7u (Packet)<\/span><\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\" scope=\"row\"><span style=\"color: #000000;\">Ch\u1ee9c n\u0103ng ch\u00ednh<\/span><\/th>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">&#8211; Bi\u1ec3u di\u1ec5n bit th\u00e0nh t\u00edn hi\u1ec7u (\u0111i\u1ec7n, quang, s\u00f3ng)<\/span><br \/>\n<span style=\"color: #000000;\">&#8211; \u0110\u1ed3ng b\u1ed9 t\u00edn hi\u1ec7u gi\u1eefa thi\u1ebft b\u1ecb g\u1eedi v\u00e0 nh\u1eadn<\/span><br \/>\n<span style=\"color: #000000;\">&#8211; Ki\u1ec3m so\u00e1t t\u1ed1c \u0111\u1ed9 truy\u1ec1n v\u00e0 \u0111\u1eb7c t\u00ednh t\u00edn hi\u1ec7u<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">&#8211; \u0110\u00f3ng khung d\u1eef li\u1ec7u th\u00e0nh frame<\/span><br \/>\n<span style=\"color: #000000;\">&#8211; Ki\u1ec3m tra v\u00e0 s\u1eeda l\u1ed7i truy\u1ec1n t\u1ea3i (v\u00ed d\u1ee5 CRC)<\/span><br \/>\n<span style=\"color: #000000;\">&#8211; Qu\u1ea3n l\u00fd truy c\u1eadp ph\u01b0\u01a1ng ti\u1ec7n (MAC control)<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">&#8211; \u0110\u1ecbnh tuy\u1ebfn g\u00f3i d\u1eef li\u1ec7u gi\u1eefa c\u00e1c m\u1ea1ng<\/span><br \/>\n<span style=\"color: #000000;\">&#8211; Qu\u1ea3n l\u00fd \u0111\u1ecba ch\u1ec9 logic (v\u00ed d\u1ee5: <a href=\"https:\/\/interdata.vn\/blog\/dia-chi-ip-la-gi\/\">\u0111\u1ecba ch\u1ec9 IP<\/a>)<\/span><br \/>\n<span style=\"color: #000000;\">&#8211; T\u00ecm \u0111\u01b0\u1eddng \u0111i t\u1ed1i \u01b0u cho d\u1eef li\u1ec7u<\/span><\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 12px 16px; background: #f7fbff; border: 1px solid #e9eefb; vertical-align: top;\" scope=\"row\"><span style=\"color: #000000;\">V\u1ecb tr\u00ed trong m\u00f4 h\u00ecnh<\/span><\/th>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">T\u1ea7ng th\u1ea5p nh\u1ea5t c\u1ee7a m\u00f4 h\u00ecnh OSI<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">Ngay tr\u00ean L\u1edbp V\u1eadt l\u00fd, d\u01b0\u1edbi L\u1edbp M\u1ea1ng<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">Ngay tr\u00ean L\u1edbp Li\u00ean k\u1ebft d\u1eef li\u1ec7u<\/span><\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\" scope=\"row\"><span style=\"color: #000000;\">M\u00f4i tr\u01b0\u1eddng truy\u1ec1n d\u1eabn<\/span><\/th>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">C\u00e1p \u0111\u1ed3ng, c\u00e1p quang, s\u00f3ng v\u00f4 tuy\u1ebfn, t\u00edn hi\u1ec7u \u00e1nh s\u00e1ng (LED\/laser)<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">L\u00e0m vi\u1ec7c tr\u00ean c\u00f9ng m\u00f4i tr\u01b0\u1eddng v\u1eadt l\u00fd; qu\u1ea3n l\u00fd c\u00e1ch thi\u1ebft b\u1ecb truy c\u1eadp t\u00e0i nguy\u00ean truy\u1ec1n d\u1eabn<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">K\u1ebft n\u1ed1i c\u00e1c m\u1ea1ng kh\u00e1c nhau, truy\u1ec1n g\u00f3i qua nhi\u1ec1u li\u00ean k\u1ebft m\u1ea1ng<\/span><\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 12px 16px; background: #f7fbff; border: 1px solid #e9eefb; vertical-align: top;\" scope=\"row\"><span style=\"color: #000000;\">Li\u00ean k\u1ebft c\u1ea5u h\u00ecnh thi\u1ebft b\u1ecb<\/span><\/th>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">Hub, Repeater (b\u1ed9 l\u1eb7p)<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\">Switch (c\u00f4ng t\u1eafc), Bridge (c\u1ea7u n\u1ed1i)<\/span><\/td>\n<td style=\"padding: 12px 16px; background: #ffffff; border: 1px solid #e9eefb; vertical-align: top;\"><span style=\"color: #000000;\"><a href=\"https:\/\/interdata.vn\/blog\/router-la-gi\/\">Router<\/a> (b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn)<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p><strong>T\u00f3m t\u1eaft l\u1ea1i:<\/strong><\/p>\n<ul>\n<li>L\u1edbp v\u1eadt l\u00fd ch\u1ee7 y\u1ebfu quan t\u00e2m \u0111\u1ebfn vi\u1ec7c chuy\u1ec3n c\u00e1c bit d\u01b0\u1edbi d\u1ea1ng t\u00edn hi\u1ec7u v\u1eadt l\u00fd qua m\u00f4i tr\u01b0\u1eddng truy\u1ec1n d\u1eabn m\u00e0 kh\u00f4ng x\u1eed l\u00fd th\u00f4ng tin ho\u1eb7c ki\u1ec3m tra l\u1ed7i.<\/li>\n<li>L\u1edbp li\u00ean k\u1ebft d\u1eef li\u1ec7u \u0111\u00f3ng vai tr\u00f2 \u0111\u1ea3m b\u1ea3o truy\u1ec1n d\u1eef li\u1ec7u gi\u1eefa c\u00e1c thi\u1ebft b\u1ecb trong c\u00f9ng m\u1ed9t v\u1eadt l\u00fd m\u1ea1ng, x\u1eed l\u00fd \u0111\u00f3ng g\u00f3i, ph\u00e1t hi\u1ec7n l\u1ed7i s\u1eeda l\u1ed7i v\u00e0 ki\u1ec3m so\u00e1t quy\u1ec1n truy c\u1eadp m\u1ea1ng.<\/li>\n<li>L\u1edbp m\u1ea1ng qu\u1ea3n l\u00fd c\u00f4ng vi\u1ec7c \u0111\u1ecbnh tuy\u1ebfn, chuy\u1ec3n ti\u1ebfp g\u00f3i d\u1eef li\u1ec7u gi\u1eefa c\u00e1c m\u1ea1ng kh\u00e1c nhau, x\u1eed l\u00fd logic \u0111\u1ecba ch\u1ec9 v\u00e0 l\u1ef1a ch\u1ecdn \u0111\u01b0\u1eddng truy\u1ec1n t\u1ed1t nh\u1ea5t cho \u0111\u00edch \u0111\u1ebfn d\u1eef li\u1ec7u.<\/li>\n<\/ul>\n<p>S\u1ef1 r\u00f5 r\u00e0ng c\u1ee7a t\u1ea7ng n\u00e0y gi\u00fap m\u00f4 h\u00ecnh h\u00f3a OSI t\u1ed5 ch\u1ee9c qu\u00e1 tr\u00ecnh hi\u1ec7u qu\u1ea3 truy\u1ec1n th\u00f4ng tin t\u1eeb v\u1eadt ch\u1ea5t t\u00edn hi\u1ec7u \u0111\u1ebfn qu\u00e1 tr\u00ecnh x\u1eed l\u00fd v\u00e0 n\u00e2ng c\u1ea5p d\u1eef li\u1ec7u ti\u1ebfp theo gi\u1eefa c\u00e1c m\u1ea1ng l\u1edbn h\u01a1n.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cau-truc-vat-ly-Physical-topology\"><\/span>C\u1ea5u tr\u00fac v\u1eadt l\u00fd (Physical topology)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>C\u1ea5u tr\u00fac v\u1eadt l\u00fd m\u00f4 t\u1ea3 c\u00e1ch c\u00e1c thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u1edbi nhau. M\u1ed9t s\u1ed1 d\u1ea1ng c\u1ea5u tr\u00fac v\u1eadt l\u00fd ph\u1ed5 bi\u1ebfn g\u1ed3m:<\/p>\n<ul>\n<li><strong>C\u1ea5u tr\u00fac d\u1ea1ng l\u01b0\u1edbi (Mesh topology)<\/strong>: C\u00e1c thi\u1ebft b\u1ecb, hay c\u00f2n g\u1ecdi l\u00e0 n\u00fat (node), \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u1edbi t\u1ea5t c\u1ea3 c\u00e1c n\u00fat kh\u00e1c trong m\u1ea1ng. C\u00e1ch thi\u1ebft l\u1eadp n\u00e0y gi\u00fap vi\u1ec7c \u0111\u1ecbnh tuy\u1ebfn d\u1eef li\u1ec7u gi\u1eefa c\u00e1c thi\u1ebft b\u1ecb v\u00e0 ng\u01b0\u1eddi d\u00f9ng tr\u1edf n\u00ean hi\u1ec7u qu\u1ea3.<\/li>\n<li><strong>C\u1ea5u tr\u00fac h\u00ecnh sao (Star topology)<\/strong>: T\u1ea5t c\u1ea3 c\u00e1c n\u00fat trong m\u1ea1ng LAN \u0111\u1ec1u k\u1ebft n\u1ed1i tr\u1ef1c ti\u1ebfp v\u1edbi m\u1ed9t m\u00e1y t\u00ednh trung t\u00e2m chung.<\/li>\n<li><strong>C\u1ea5u tr\u00fac tuy\u1ebfn bus (Bus topology)<\/strong>: Nhi\u1ec1u thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i chung qua m\u1ed9t s\u1ee3i c\u00e1p g\u1ecdi l\u00e0 backbone (c\u00e1p tr\u1ee5c ch\u00ednh). C\u00e1c thi\u1ebft b\u1ecb trong c\u00f9ng m\u1ea1ng bus c\u00f3 th\u1ec3 truy\u1ec1n d\u1eef li\u1ec7u tr\u1ef1c ti\u1ebfp cho nhau.<\/li>\n<li><strong>C\u1ea5u tr\u00fac v\u00f2ng (Ring topology)<\/strong>: M\u1ed7i n\u00fat k\u1ebft n\u1ed1i tr\u1ef1c ti\u1ebfp v\u1edbi hai n\u00fat kh\u00e1c, t\u1ea1o th\u00e0nh m\u1ed9t v\u00f2ng kh\u00e9p k\u00edn. Khi d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c g\u1eedi \u0111i, n\u00f3 s\u1ebd l\u1ea7n l\u01b0\u1ee3t \u0111i qua t\u1eebng n\u00fat trong v\u00f2ng cho \u0111\u1ebfn khi \u0111\u1ebfn \u0111\u00fang \u0111\u1ecba ch\u1ec9 \u0111\u00edch.<\/li>\n<li><strong>C\u1ea5u tr\u00fac c\u00e2y (<a href=\"https:\/\/interdata.vn\/blog\/cau-truc-du-lieu-tree-cay\/\">Tree<\/a> topology)<\/strong>: C\u1ea5u tr\u00fac ph\u00e2n c\u1ea5p gi\u1ed1ng nh\u01b0 m\u1ed9t c\u00e1i c\u00e2y, c\u00e1c n\u00fat \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u1edbi nhau theo t\u1ea7ng b\u1eadc. Khi v\u1ebd s\u01a1 \u0111\u1ed3 m\u1ea1ng, c\u00e1c n\u00fat hi\u1ec3n th\u1ecb th\u00e0nh d\u1ea1ng c\u00e2y ph\u00e2n nh\u00e1nh.<\/li>\n<li><strong>C\u1ea5u tr\u00fac lai (Hybrid topology)<\/strong>: L\u00e0 s\u1ef1 k\u1ebft h\u1ee3p c\u1ee7a hai ho\u1eb7c nhi\u1ec1u lo\u1ea1i t\u00f4-p\u00f4 kh\u00e1c, \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng t\u00f9y theo nhu c\u1ea7u v\u1ec1 hi\u1ec7u n\u0103ng, \u0111\u1ed9 tin c\u1eady ho\u1eb7c chi ph\u00ed.<\/li>\n<\/ul>\n<figure id=\"attachment_32983\" aria-describedby=\"caption-attachment-32983\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-32983\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Cau-truc-vat-ly-.jpg\" alt=\"C\u1ea5u tr\u00fac v\u1eadt l\u00fd \" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Cau-truc-vat-ly-.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Cau-truc-vat-ly--300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Cau-truc-vat-ly--768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-32983\" class=\"wp-caption-text\">C\u1ea5u tr\u00fac v\u1eadt l\u00fd<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Cac-che-do-truyen-du-lieu-o-tang-Physical-Layer\"><\/span>C\u00e1c ch\u1ebf \u0111\u1ed9 truy\u1ec1n d\u1eef li\u1ec7u \u1edf t\u1ea7ng Physical Layer<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>T\u1ea7ng v\u1eadt l\u00fd c\u00f2n h\u1ed7 tr\u1ee3 c\u00e1c ch\u1ebf \u0111\u1ed9 truy\u1ec1n d\u1eef li\u1ec7u sau:<\/p>\n<ul>\n<li><strong>Simplex<\/strong>: Ch\u1ec9 m\u1ed9t n\u00fat c\u00f3 th\u1ec3 g\u1eedi d\u1eef li\u1ec7u, n\u00fat c\u00f2n l\u1ea1i ch\u1ec9 c\u00f3 th\u1ec3 nh\u1eadn.<\/li>\n<li><strong>Half-duplex<\/strong>: Hai n\u00fat c\u00f3 th\u1ec3 g\u1eedi v\u00e0 nh\u1eadn d\u1eef li\u1ec7u, nh\u01b0ng kh\u00f4ng \u0111\u1ed3ng th\u1eddi.<\/li>\n<li><strong>Full-duplex<\/strong>: Hai n\u00fat c\u00f3 th\u1ec3 v\u1eeba g\u1eedi v\u1eeba nh\u1eadn d\u1eef li\u1ec7u c\u00f9ng m\u1ed9t l\u00fac.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Vi-du-ve-cac-giao-thuc-o-lop-Physical-Layer\"><\/span>V\u00ed d\u1ee5 v\u1ec1 c\u00e1c giao th\u1ee9c \u1edf l\u1edbp Physical Layer<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>T\u1ea7ng v\u1eadt l\u00fd th\u01b0\u1eddng bao g\u1ed3m c\u1ea3 ph\u1ea7n m\u1ec1m v\u00e0 ph\u1ea7n c\u1ee9ng, n\u00f3 c\u00f3 nhi\u1ec1u giao th\u1ee9c quy \u0111\u1ecbnh c\u00e1ch truy\u1ec1n d\u1eef li\u1ec7u trong m\u1ea1ng. M\u1ed9t s\u1ed1 giao th\u1ee9c \u1edf t\u1ea7ng 1 g\u1ed3m:<\/p>\n<ul>\n<li>Ethernet 1000BASE-T.<\/li>\n<li>Ethernet 1000BASE-SX.<\/li>\n<li>Ethernet 100BaseTX.<\/li>\n<li>SONET\/SDH (Synchronous Optical Networking\/Synchronous Digital Hierarchy).<\/li>\n<li>C\u00e1c bi\u1ebfn th\u1ec3 v\u1eadt l\u00fd c\u1ee7a 802.11 (Wi-Fi).<\/li>\n<li>Bluetooth.<\/li>\n<li>Controller Area Network (CAN).<\/li>\n<li>Universal Serial Bus (USB).<\/li>\n<\/ul>\n<p>Sau khi t\u00ecm hi\u1ec3u chi ti\u1ebft v\u1ec1 t\u1ea7ng Physical Layer l\u00e0 g\u00ec, b\u1ea1n \u0111\u00e3 c\u00f3 th\u1ec3 th\u1ea5y \u0111\u01b0\u1ee3c t\u1ea7m quan tr\u1ecdng c\u1ee7a n\u00f3. T\u1ea7ng v\u1eadt l\u00fd ch\u00ednh l\u00e0 n\u1ec1n m\u00f3ng, l\u00e0 \u201cs\u1ee3i d\u00e2y\u201d k\u1ebft n\u1ed1i m\u1ecdi thi\u1ebft b\u1ecb trong m\u1ed9t h\u1ec7 th\u1ed1ng m\u1ea1ng.<\/p>\n<p>Hi\u1ec3u r\u00f5 v\u1ec1 t\u1ea7ng n\u00e0y kh\u00f4ng ch\u1ec9 gi\u00fap b\u1ea1n c\u1ee7ng c\u1ed1 ki\u1ebfn th\u1ee9c n\u1ec1n t\u1ea3ng v\u1ec1 m\u1ea1ng m\u00e1y t\u00ednh m\u00e0 c\u00f2n gi\u00fap b\u1ea1n d\u1ec5 d\u00e0ng h\u01a1n trong vi\u1ec7c ch\u1ea9n \u0111o\u00e1n v\u00e0 kh\u1eafc ph\u1ee5c c\u00e1c s\u1ef1 c\u1ed1 li\u00ean quan \u0111\u1ebfn k\u1ebft n\u1ed1i v\u1eadt l\u00fd, t\u1eeb m\u1ed9t s\u1ee3i c\u00e1p b\u1ecb l\u1ed7i cho \u0111\u1ebfn m\u1ed9t c\u1ed5ng m\u1ea1ng kh\u00f4ng ho\u1ea1t \u0111\u1ed9ng.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>B\u1ea1n c\u00f3 bao gi\u1edd t\u1ef1 h\u1ecfi l\u00e0m th\u1ebf n\u00e0o d\u1eef li\u1ec7u t\u1eeb m\u00e1y t\u00ednh c\u1ee7a b\u1ea1n l\u1ea1i c\u00f3 th\u1ec3 truy\u1ec1n \u0111i tr\u00ean m\u1ed9t s\u1ee3i c\u00e1p m\u1ea1ng hay qua s\u00f3ng Wi-Fi? C\u00e2u tr\u1ea3 l\u1eddi n\u1eb1m \u1edf t\u1ea7ng th\u1ea5p nh\u1ea5t l\u00e0 t\u1ea7ng v\u1eadt k\u00fd &#8211; Physical Layer, hay c\u00f2n g\u1ecdi l\u00e0 T\u1ea7ng v\u1eadt l\u00fd. B\u00e0i vi\u1ebft n\u00e0y<\/p>\n","protected":false},"author":11,"featured_media":32984,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[83],"tags":[],"class_list":["post-32977","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bao-mat-an-ninh-mang"],"_links":{"self":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/32977","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\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/comments?post=32977"}],"version-history":[{"count":6,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/32977\/revisions"}],"predecessor-version":[{"id":33396,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/32977\/revisions\/33396"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media\/32984"}],"wp:attachment":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media?parent=32977"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/categories?post=32977"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/tags?post=32977"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}