{"id":499,"date":"2026-05-04T04:08:54","date_gmt":"2026-05-04T04:08:54","guid":{"rendered":"https:\/\/kinghl.com\/?p=499"},"modified":"2026-05-04T04:12:19","modified_gmt":"2026-05-04T04:12:19","slug":"bai-1-mang-va-mo-hinh-tham-chieu","status":"publish","type":"post","link":"https:\/\/kinghl.com\/?p=499","title":{"rendered":"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu"},"content":{"rendered":"<h2>1. M\u1ea1ng l\u00e0 g\u00ec<\/h2>\n<p>M\u1ea1ng (network) l\u00e0 m\u1ed9t t\u1eadp h\u1ee3p c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng (router, switch,\u2026) v\u00e0 c\u00e1c h\u1ec7 th\u1ed1ng \u0111\u1ea7u cu\u1ed1i (nh\u01b0 c\u00e1c m\u00e1y t\u00ednh, c\u00e1c server,\u2026) \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u1edbi nhau b\u1edfi c\u00e1c \u0111\u01b0\u1eddng truy\u1ec1n (c\u00e1p quang, c\u00e1p \u0111\u1ed3ng, s\u00f3ng kh\u00f4ng d\u00e2y) \u0111\u1ec3 c\u00f3 th\u1ec3 trao \u0111\u1ed5i d\u1eef li\u1ec7u v\u1edbi nhau.<\/p>\n<p>M\u1ea1ng c\u00f3 quy m\u00f4 l\u1edbn nh\u1ea5t v\u00e0 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i nh\u1ea5t l\u00e0 m\u1ea1ng Internet to\u00e0n c\u1ea7u.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-537 \" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 1\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1.png\" sizes=\"auto, (max-width: 546px) 100vw, 546px\" srcset=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1.png 546w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-300x298.png 300w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-150x150.png 150w\" alt=\"Picture1\" width=\"546\" height=\"543\" \/><\/p>\n<p><em>H\u00ecnh 1.1. M\u1ea1ng l\u00e0 g\u00ec<\/em><\/p>\n<p><em>V\u00ed d\u1ee5:<\/em>\u00a0Tr\u00ean h\u00ecnh 1.1, nhi\u1ec1u \u0111\u1ed1i t\u01b0\u1ee3ng kh\u00e1c nhau k\u1ebft n\u1ed1i v\u00e0o Internet \u0111\u1ec3 c\u00f3 th\u1ec3 trao \u0111\u1ed5i d\u1eef li\u1ec7u v\u1edbi nhau. C\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng n\u00e0y c\u00f3 th\u1ec3 l\u00e0:<\/p>\n<ul>\n<li>M\u1ed9t ng\u01b0\u1eddi d\u00f9ng t\u1ea1i nh\u00e0 truy nh\u1eadp m\u1ea1ng th\u00f4ng qua m\u1ed9t k\u1ebft n\u1ed1i Internet b\u0103ng r\u1ed9ng nh\u01b0 ADSL, FTTH.<\/li>\n<li>M\u1ed9t ng\u01b0\u1eddi d\u00f9ng di \u0111\u1ed9ng \u0111ang s\u1eed d\u1ee5ng laptop, smartphone, m\u00e1y t\u00ednh b\u1ea3ng,\u2026 truy nh\u1eadp kh\u00f4ng d\u00e2y (b\u1eb1ng Wifi ho\u1eb7c 3G\/4G) v\u00e0o Internet.<\/li>\n<li>Tr\u1ee5 s\u1edf ch\u00ednh (Headquaters) v\u00e0 c\u00e1c v\u0103n ph\u00f2ng chi nh\u00e1nh (Branch Office) c\u1ee7a m\u1ed9t doanh nghi\u1ec7p k\u1ebft n\u1ed1i m\u1ea1ng \u0111\u1ec3 chia s\u1ebb th\u00f4ng tin v\u00e0 v\u1eadn h\u00e0nh c\u00e1c c\u00f4ng vi\u1ec7c c\u1ee7a m\u00ecnh.<\/li>\n<\/ul>\n<p>M\u1ed9t h\u1ec7 th\u1ed1ng m\u1ea1ng c\u00f3 th\u1ec3 bao g\u1ed3m r\u1ea5t nhi\u1ec1u thi\u1ebft b\u1ecb chuy\u00ean d\u1ee5ng ph\u1ee9c t\u1ea1p. Tuy nhi\u00ean, v\u1ec1 c\u01a1 b\u1ea3n nh\u1ea5t, m\u1ed9t m\u1ea1ng m\u00e1y t\u00ednh ng\u00e0y nay s\u1ebd c\u00f3 c\u00e1c th\u00e0nh ph\u1ea7n nh\u01b0 sau (h\u00ecnh 1.2):<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-538 aligncenter\" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 2\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Screenshot-2026-05-03-at-10.46.13.png\" sizes=\"auto, (max-width: 1428px) 100vw, 1428px\" srcset=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Screenshot-2026-05-03-at-10.46.13.png 1428w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Screenshot-2026-05-03-at-10.46.13-300x220.png 300w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Screenshot-2026-05-03-at-10.46.13-1024x752.png 1024w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Screenshot-2026-05-03-at-10.46.13-768x564.png 768w\" alt=\"Screenshot 2026 05 03 at 10.46.13\" width=\"1428\" height=\"1048\" \/><\/p>\n<p><em>H\u00ecnh 1.2. C\u00e1c th\u00e0nh ph\u1ea7n c\u01a1 b\u1ea3n c\u1ee7a m\u1ed9t m\u1ea1ng m\u00e1y t\u00ednh<\/em><\/p>\n<ul>\n<li><em>C\u00e1c thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i:<\/em>\u00a0L\u00e0 c\u00e1c thi\u1ebft b\u1ecb nh\u01b0 PC, laptop, smartphone, tablet, m\u00e1y in, server,\u2026 c\u1ea7n ph\u1ea3i k\u1ebft n\u1ed1i v\u00e0o m\u1ea1ng \u0111\u1ec3 truy nh\u1eadp v\u00e0 chia s\u1ebb d\u1eef li\u1ec7u c\u0169ng nh\u01b0 c\u00e1c t\u00e0i nguy\u00ean ph\u1ea7n c\u1ee9ng v\u00e0 ph\u1ea7n m\u1ec1m kh\u00e1c.<\/li>\n<li><em>C\u00e1c k\u1ebft n\u1ed1i:<\/em>\u00a0\u0110\u1ec3 c\u00f3 th\u1ec3 truy nh\u1eadp v\u00e0o m\u1ea1ng, c\u00e1c thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i ph\u1ea3i \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i \u0111\u1ebfn c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng. C\u00e1c k\u1ebft n\u1ed1i n\u00e0y c\u00f3 th\u1ec3 l\u00e0 k\u1ebft n\u1ed1i c\u00f3 d\u00e2y ho\u1eb7c k\u1ebft n\u1ed1i kh\u00f4ng d\u00e2y.<\/li>\n<li><em>Switch:<\/em>\u00a0C\u00e1c thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i s\u1eed d\u1ee5ng k\u1ebft n\u1ed1i c\u00f3 d\u00e2y nh\u01b0 PC, m\u00e1y in, server (h\u00ecnh 1.2) s\u1ebd \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u1ec1 m\u1ed9t thi\u1ebft b\u1ecb t\u1eadp trung c\u00f3 t\u00ean g\u1ecdi l\u00e0\u00a0<em>Switch<\/em>.<\/li>\n<li><em>Access point:<\/em>\u00a0C\u00e1c thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i s\u1eed d\u1ee5ng k\u1ebft n\u1ed1i kh\u00f4ng d\u00e2y nh\u01b0 laptop, smartphone, tablet (h\u00ecnh 1.2) s\u1ebd th\u1ef1c hi\u1ec7n truy nh\u1eadp kh\u00f4ng d\u00e2y v\u1ec1 m\u1ed9t thi\u1ebft b\u1ecb t\u1eadp trung c\u00f3 t\u00ean g\u1ecdi l\u00e0\u00a0<em>Access point<\/em>. Access point \u0111\u1ebfn l\u01b0\u1ee3t n\u00f3 l\u1ea1i \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i b\u1eb1ng d\u00e2y \u0111\u1ebfn switch \u0111\u1ec3 gi\u00fap cho c\u00e1c thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i kh\u00f4ng d\u00e2y v\u1eeba n\u00eau c\u00f3 th\u1ec3 truy nh\u1eadp m\u1ea1ng.<\/li>\n<li><em>LAN (Local Area Network) \u2013 M\u1ea1ng n\u1ed9i b\u1ed9<\/em>: \u0110\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a l\u00e0 m\u1ed9t lo\u1ea1i h\u00ecnh k\u1ebft n\u1ed1i m\u1ea1ng t\u1ed1c \u0111\u1ed9 cao, ph\u1ea1m vi h\u1eb9p, ch\u1ec9 s\u1eed d\u1ee5ng trong khu\u00f4n kh\u1ed5 m\u1ed9t v\u0103n ph\u00f2ng, m\u1ed9t tr\u01b0\u1eddng h\u1ecdc, m\u1ed9t b\u1ec7nh vi\u1ec7n,.v.v\u2026 Tr\u01b0\u1edbc \u0111\u00e2y c\u00f3 nhi\u1ec1u c\u00f4ng ngh\u1ec7 LAN, ng\u00e0y nay, g\u1ea7n nh\u01b0 ch\u1ec9 c\u00f2n m\u1ed9t c\u00f4ng ngh\u1ec7 LAN duy nh\u1ea5t \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng l\u00e0 Ethernet LAN. Switch l\u00e0 thi\u1ebft b\u1ecb chuy\u1ec3n m\u1ea1ch chuy\u00ean d\u1ee5ng trong Ethernet LAN (s\u1ebd \u0111\u01b0\u1ee3c \u0111\u1ec1 c\u1eadp chi ti\u1ebft \u1edf m\u1ed9t ch\u01b0\u01a1ng kh\u00e1c c\u1ee7a gi\u00e1o tr\u00ecnh).<\/li>\n<\/ul>\n<blockquote><p>B\u00ean c\u1ea1nh lo\u1ea1i h\u00ecnh m\u1ea1ng LAN ph\u1ea3i s\u1eed d\u1ee5ng k\u1ebft n\u1ed1i c\u00f3 d\u00e2y \u0111\u1ec3 \u0111\u1ea5u n\u1ed1i c\u00e1c thi\u1ebft b\u1ecb v\u1eeba n\u00eau, c\u00f2n c\u00f3 m\u1ed9t lo\u1ea1i LAN kh\u00e1c c\u0169ng r\u1ea5t ph\u1ed5 bi\u1ebfn l\u00e0 LAN kh\u00f4ng d\u00e2y (Wireless LAN). LAN kh\u00f4ng d\u00e2y ch\u1ec9 s\u1eed d\u1ee5ng s\u00f3ng \u0111i\u1ec7n t\u1eeb \u0111\u1ec3 k\u1ebft n\u1ed1i c\u00e1c thi\u1ebft b\u1ecb. Thi\u1ebft b\u1ecb chuy\u00ean d\u1ee5ng c\u1ee7a LAN kh\u00f4ng d\u00e2y ch\u00ednh l\u00e0 Access point. Ch\u1ee7 \u0111\u1ec1 Wireless LAN s\u1ebd \u0111\u01b0\u1ee3c \u0111\u1ec1 c\u1eadp chi ti\u1ebft trong m\u1ed9t ch\u01b0\u01a1ng kh\u00e1c c\u1ee7a gi\u00e1o tr\u00ecnh.<\/p><\/blockquote>\n<ul>\n<li>Switch v\u00e0 access point, c\u00f9ng v\u1edbi c\u00e1c thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i k\u1ebft n\u1ed1i \u0111\u1ebfn ch\u00fang t\u1ea1o th\u00e0nh m\u1ed9t m\u1ea1ng LAN chung c\u1ee7a m\u1ed9t khu v\u1ef1c.\u00a0<em>V\u00ed d\u1ee5:<\/em>\n<ul>\n<li>Trong h\u00ecnh 1.2 l\u00e0 s\u01a1 \u0111\u1ed3 c\u1ee7a m\u1ed9t m\u1ea1ng doanh nghi\u1ec7p c\u00f3 hai chi nh\u00e1nh g\u1ed3m m\u1ed9t tr\u1ee5 s\u1edf ch\u00ednh (Headquarters \u2013 HQ) v\u00e0 m\u1ed9t chi nh\u00e1nh (Branch \u2013 BR). Switch v\u00e0 access point b\u00ean khu v\u1ef1c m\u1ea1ng c\u1ee7a tr\u1ee5 s\u1edf ch\u00ednh th\u1ef1c hi\u1ec7n k\u1ebft n\u1ed1i c\u00e1c thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i t\u1ea1i \u0111\u00e2y t\u1ea1o th\u00e0nh m\u1ea1ng n\u1ed9i b\u1ed9 c\u1ee7a kh\u1ed1i tr\u1ee5 s\u1edf ch\u00ednh (HQ LAN); thi\u1ebft b\u1ecb switch b\u00ean khu v\u1ef1c m\u1ea1ng c\u1ee7a chi nh\u00e1nh th\u1ef1c hi\u1ec7n k\u1ebft n\u1ed1i c\u00e1c PC t\u1ea1i chi nh\u00e1nh t\u1ea1o th\u00e0nh m\u1ea1ng n\u1ed9i b\u1ed9 c\u1ee7a kh\u1ed1i chi nh\u00e1nh (BR LAN).<\/li>\n<\/ul>\n<\/li>\n<li><em>Router:<\/em>\u00a0C\u00e1c Switch \u0111\u1ebfn l\u01b0\u1ee3t ch\u00fang l\u1ea1i \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u1ec1 m\u1ed9t thi\u1ebft b\u1ecb t\u1eadp trung c\u00f3 t\u00ean g\u1ecdi l\u00e0 Router.\u00a0<em>Router \u2013 b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn,<\/em>\u00a0l\u00e0 thi\u1ebft b\u1ecb cho ph\u00e9p t\u00ecm \u0111\u01b0\u1eddng \u0111i t\u1ed1i \u01b0u tr\u00ean m\u1ea1ng, t\u1eeb \u0111\u00f3 cho ph\u00e9p c\u00e1c thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i c\u00f3 th\u1ec3 truy\u1ec1n th\u00f4ng v\u1edbi nhau v\u00e0 truy nh\u1eadp \u0111\u01b0\u1ee3c Internet. Ngo\u00e0i ra, router c\u0169ng c\u00f3 th\u1ec3 cung c\u1ea5p \u0111\u01b0\u1ee3c m\u1ed9t s\u1ed1 d\u1ecbch v\u1ee5 m\u1ea1ng nh\u1ea5t \u0111\u1ecbnh. Chi ti\u1ebft v\u1ec1 ho\u1ea1t \u0111\u1ed9ng \u0111\u1ecbnh tuy\u1ebfn v\u00e0 tri\u1ec3n khai d\u1ecbch v\u1ee5 m\u1ea1ng tr\u00ean router s\u1ebd \u0111\u01b0\u1ee3c tr\u00ecnh b\u00e0y trong c\u00e1c ch\u01b0\u01a1ng kh\u00e1c c\u1ee7a gi\u00e1o tr\u00ecnh.<\/li>\n<li><em>K\u1ebft n\u1ed1i WAN (Wide Area Network \u2013 M\u1ea1ng di\u1ec7n r\u1ed9ng):<\/em>\u00a0\u0110\u1ec3 c\u00e1c m\u1ea1ng LAN thu\u1ed9c c\u00e1c chi nh\u00e1nh kh\u00e1c nhau c\u00f3 th\u1ec3 trao \u0111\u1ed5i \u0111\u01b0\u1ee3c d\u1eef li\u1ec7u, doanh nghi\u1ec7p ph\u1ea3i thu\u00ea c\u00e1c \u0111\u01b0\u1eddng truy\u1ec1n\u00a0<em>WAN\u00a0<\/em>t\u1eeb c\u00e1c c\u00f4ng ty chuy\u00ean cung c\u1ea5p \u0111\u01b0\u1eddng truy\u1ec1n c\u1ef1 ly xa \u0111\u1ec3 k\u1ebft n\u1ed1i ch\u00fang l\u1ea1i. C\u00f3 nhi\u1ec1u lo\u1ea1i h\u00ecnh \u0111\u01b0\u1eddng truy\u1ec1n WAN \u0111\u01b0\u1ee3c cung c\u1ea5p b\u1edfi c\u00e1c c\u00f4ng ty n\u00e0y nh\u01b0: Leased \u2013 line k\u00eanh tr\u1eafng, Metro Ethernet, MPLS VPN,\u2026 C\u00e1c k\u1ef9 thu\u1eadt k\u1ebft n\u1ed1i WAN n\u00e0y s\u1ebd \u0111\u01b0\u1ee3c \u0111\u1ec1 c\u1eadp trong m\u1ed9t ch\u01b0\u01a1ng kh\u00e1c c\u1ee7a gi\u00e1o tr\u00ecnh.<\/li>\n<li><em>K\u1ebft n\u1ed1i Internet:<\/em>\u00a0B\u00ean c\u1ea1nh vi\u1ec7c k\u1ebft n\u1ed1i n\u1ed9i b\u1ed9, m\u1ea1ng m\u00e1y t\u00ednh doanh nghi\u1ec7p c\u00f2n ph\u1ea3i \u0111\u1ea3m b\u1ea3o ho\u1ea1t \u0111\u1ed9ng truy nh\u1eadp Internet cho ng\u01b0\u1eddi d\u00f9ng. Ho\u1ea1t \u0111\u1ed9ng truy nh\u1eadp Internet c\u1ee7a m\u1ed9t t\u1ed5 ch\u1ee9c, c\u00e1 nh\u00e2n s\u1ebd \u0111\u01b0\u1ee3c cung c\u1ea5p b\u1edfi c\u00e1c c\u00f4ng ty ISP (Internet Service Provider \u2013 Nh\u00e0 cung c\u1ea5p d\u1ecbch v\u1ee5 Internet) th\u00f4ng qua c\u00e1c lo\u1ea1i k\u1ebft n\u1ed1i Internet nh\u01b0: ADSL (Internet qua \u0111\u01b0\u1eddng c\u00e1p \u0111\u1ed3ng), FTTH (Internet qua \u0111\u01b0\u1eddng c\u00e1p quang), TV cable (Internet qua \u0111\u01b0\u1eddng c\u00e1p truy\u1ec1n h\u00ecnh), Leased \u2013 line Internet (Internet d\u00e0nh ri\u00eang cho doanh nghi\u1ec7p),\u2026<\/li>\n<\/ul>\n<h2>2. M\u00f4 h\u00ecnh tham chi\u1ebfu<\/h2>\n<h3>2.1. T\u1ea1i sao l\u1ea1i c\u1ea7n m\u00f4 h\u00ecnh tham chi\u1ebfu ?<\/h3>\n<p><em>Host<\/em>\u00a0l\u00e0 m\u1ed9t th\u1ef1c th\u1ec3 b\u1ea5t k\u1ef3 k\u1ebft n\u1ed1i v\u00e0o m\u1ea1ng m\u00e0 c\u00f3 mang tr\u00ean m\u00ecnh n\u00f3 m\u1ed9t\u00a0<em>\u0111\u1ecba ch\u1ec9 IP<\/em>. \u0110\u1ecba ch\u1ec9 IP l\u00e0 m\u1ed9t lo\u1ea1i \u0111\u1ecba ch\u1ec9 d\u00f9ng \u0111\u1ec3 \u0111\u1ecbnh v\u1ecb m\u1ecdi thi\u1ebft b\u1ecb k\u1ebft n\u1ed1i v\u00e0o m\u1ea1ng trong c\u00f4ng ngh\u1ec7 m\u1ea1ng ng\u00e0y nay. Ch\u00fang ta s\u1ebd kh\u1ea3o s\u00e1t v\u1ec1 lo\u1ea1i \u0111\u1ecba ch\u1ec9 \u0111\u1eb7c bi\u1ec7t n\u00e0y trong c\u00e1c ph\u1ea7n ti\u1ebfp theo c\u1ee7a ch\u01b0\u01a1ng n\u00e0y.<\/p>\n<p>Nh\u01b0 v\u1eady, kh\u00e1i ni\u1ec7m \u201chost\u201d l\u00e0 m\u1ed9t kh\u00e1i ni\u1ec7m r\u1ea5t r\u1ed9ng, b\u1edfi v\u00ec tr\u00ean m\u1ea1ng m\u00e1y t\u00ednh, c\u00f3 r\u1ea5t nhi\u1ec1u th\u1ef1c th\u1ec3 \u0111\u01b0\u1ee3c g\u00e1n \u0111\u1ecba ch\u1ec9 IP. Tuy v\u1eady, ng\u00e0y nay, \u201chost\u201d l\u1ea1i th\u01b0\u1eddng \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 ch\u1ec9 m\u1ed9t thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i nh\u01b0 PC, laptop, server,\u2026Do \u0111\u00f3, \u0111\u1ec3 \u0111\u01a1n gi\u1ea3n, ch\u00fang ta t\u1ea1m coi \u201chost\u201d l\u00e0 m\u1ed9t thi\u1ebft b\u1ecb \u0111\u1ea7u cu\u1ed1i.<\/p>\n<p><em>N\u1ed1i m\u1ea1ng \u2013 networking<\/em>, m\u1ee5c \u0111\u00edch cu\u1ed1i c\u00f9ng l\u00e0 \u0111\u1ea3m b\u1ea3o t\u1ed1i \u01b0u \u0111\u01b0\u1ee3c ho\u1ea1t \u0111\u1ed9ng truy\u1ec1n d\u1eef li\u1ec7u gi\u1eefa hai host b\u1ea5t k\u1ef3 tr\u00ean h\u1ec7 th\u1ed1ng m\u1ea1ng. \u0110\u1ec3 th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c \u0111i\u1ec1u n\u00e0y, ho\u1ea1t \u0111\u1ed9ng truy\u1ec1n d\u1eef li\u1ec7u gi\u1eefa hai host c\u1ea7n ph\u1ea3i \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n<em>\u00a0chuy\u00ean m\u00f4n h\u00f3a\u00a0<\/em>v\u00e0<em>\u00a0chu\u1ea9n h\u00f3a<\/em>, t\u1eeb \u0111\u00f3 d\u1eabn \u0111\u1ebfn s\u1ef1 ra \u0111\u1eddi c\u1ee7a c\u00e1c\u00a0<em>m\u00f4 h\u00ecnh ph\u00e2n l\u1edbp<\/em>.<\/p>\n<p><strong>Chuy\u00ean m\u00f4n h\u00f3a:<\/strong><\/p>\n<p>Vi\u1ec7c truy\u1ec1n d\u1eef li\u1ec7u t\u1eeb m\u1ed9t host \u0111\u1ebfn m\u1ed9t host kh\u00f4ng h\u1ec1 \u0111\u01a1n gi\u1ea3n, c\u00f3 r\u1ea5t nhi\u1ec1u c\u00e1c t\u00e1c v\u1ee5 c\u1ea7n ph\u1ea3i th\u1ef1c hi\u1ec7n \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o ho\u1ea1t \u0111\u1ed9ng truy\u1ec1n d\u1eef li\u1ec7u host \u2013 to \u2013 host di\u1ec5n ra th\u00e0nh c\u00f4ng, v\u00ed d\u1ee5:<\/p>\n<ul>\n<li>C\u00e1c \u1ee9ng d\u1ee5ng ng\u01b0\u1eddi d\u00f9ng c\u1ea7n ph\u1ea3i ch\u1ea1y th\u1ebf n\u00e0o? (Ch\u1eb3ng h\u1ea1n nh\u01b0 truy nh\u1eadp web \u0111\u01b0\u1ee3c ti\u1ebfn h\u00e0nh kh\u00e1c v\u1edbi truy nh\u1eadp mail nh\u01b0 th\u1ebf n\u00e0o.)<\/li>\n<li>L\u00e0m sao \u0111\u1ec3 d\u1eef li\u1ec7u hai host g\u1eedi cho nhau \u0111\u01b0\u1ee3c truy\u1ec1n theo m\u1ed9t l\u1ed9 tr\u00ecnh t\u1ed1i \u01b0u qua m\u1ed9t h\u1ec7 th\u1ed1ng m\u1ea1ng ph\u1ee9c t\u1ea1p?<\/li>\n<li>\u0110\u00f3ng g\u00f3i d\u1eef li\u1ec7u qua k\u1ebft n\u1ed1i LAN ph\u1ea3i \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n kh\u00e1c v\u1edbi \u0111\u00f3ng g\u00f3i d\u1eef li\u1ec7u g\u1eedi qua k\u1ebft n\u1ed1i WAN nh\u01b0 th\u1ebf n\u00e0o?<\/li>\n<li>S\u1eed d\u1ee5ng lo\u1ea1i c\u00e1p n\u00e0o v\u00e0 \u0111\u1ea7u n\u1ed1i lo\u1ea1i n\u00e0o \u0111\u1ec3 truy\u1ec1n d\u1eef li\u1ec7u? S\u1eed d\u1ee5ng ph\u01b0\u01a1ng th\u1ee9c truy\u1ec1n c\u00f3 d\u00e2y hay kh\u00f4ng d\u00e2y?<\/li>\n<li>\u2026<\/li>\n<\/ul>\n<p>C\u00e1c t\u00e1c v\u1ee5 v\u1eeba n\u00eau r\u1ea5t ph\u1ee9c t\u1ea1p v\u00e0 tr\u1ea3i r\u1ed9ng tr\u00ean r\u1ea5t nhi\u1ec1u l\u0129nh v\u1ef1c kh\u00e1c nhau c\u1ee7a ng\u00e0nh truy\u1ec1n s\u1ed1 li\u1ec7u. \u0110\u1ec3 gi\u1ea3m thi\u1ec3u t\u00ednh ph\u1ee9c t\u1ea1p c\u1ee7a vi\u1ec7c tri\u1ec3n khai m\u1ed9t h\u1ec7 th\u1ed1ng truy\u1ec1n s\u1ed1 li\u1ec7u nh\u01b0 tr\u00ean, c\u00e1c t\u00e1c v\u1ee5 ph\u1ea3i \u0111\u01b0\u1ee3c chia th\u00e0nh nhi\u1ec1u nh\u00f3m, m\u1ed7i nh\u00f3m g\u1ed3m c\u00e1c t\u00e1c v\u1ee5 c\u00f3 t\u00ednh ch\u1ea5t t\u01b0\u01a1ng t\u1ef1 nhau.\u00a0<em>V\u00ed d\u1ee5:<\/em>\u00a0c\u00e1c t\u00e1c v\u1ee5 v\u1ec1 \u1ee9ng d\u1ee5ng v\u00e0 giao ti\u1ebfp ng\u01b0\u1eddi d\u00f9ng \u0111\u01b0\u1ee3c x\u1ebfp v\u00e0o m\u1ed9t nh\u00f3m, c\u00e1c t\u00e1c v\u1ee5 v\u1ec1 t\u00ecm \u0111\u01b0\u1eddng \u0111i t\u1ed1i \u01b0u qua m\u1ea1ng \u0111\u01b0\u1ee3c x\u1ebfp v\u00e0o m\u1ed9t nh\u00f3m, c\u00e1c t\u00e1c v\u1ee5 v\u1ec1 c\u00e1p v\u00e0 \u0111\u1ea7u n\u1ed1i \u0111\u01b0\u1ee3c x\u1ebfp v\u00e0o m\u1ed9t nh\u00f3m,\u2026 C\u1ee9 m\u1ed7i nh\u00f3m t\u00e1c v\u1ee5 nh\u01b0 v\u1eady \u0111\u01b0\u1ee3c \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 m\u1ed9t\u00a0<em>l\u1edbp (layer)<\/em>\u00a0v\u00e0 m\u1ed9t m\u00f4 h\u00ecnh truy\u1ec1n s\u1ed1 li\u1ec7u g\u1ed3m nhi\u1ec1u l\u1edbp nh\u01b0 v\u1eady \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 m\u1ed9t\u00a0<em>m\u00f4 h\u00ecnh ph\u00e2n l\u1edbp<\/em>.<\/p>\n<p>V\u1edbi m\u00f4 h\u00ecnh ph\u00e2n l\u1edbp, c\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t m\u1ea1nh v\u1ec1 l\u1edbp n\u00e0o s\u1ebd ch\u1ec9 t\u1eadp trung s\u1ea3n xu\u1ea5t c\u00e1c thi\u1ebft b\u1ecb hay vi\u1ebft c\u00e1c ph\u1ea7n m\u1ec1m chuy\u00ean cho l\u1edbp \u0111\u00f3. Nh\u01b0 v\u1eady, vi\u1ec7c x\u00e2y d\u1ef1ng c\u00e1c h\u1ec7 th\u1ed1ng truy\u1ec1n s\u1ed1 li\u1ec7u \u0111\u00e3\u00a0<em>\u0111\u01b0\u1ee3c m\u00f4 \u0111un h\u00f3a, chuy\u00ean m\u00f4n h\u00f3a<\/em>, gi\u1ea3m b\u1edbt \u0111i s\u1ef1 ph\u1ee9c t\u1ea1p nh\u01b0ng v\u1eabn \u0111\u1ea3m b\u1ea3o t\u00ednh hi\u1ec7u qu\u1ea3, t\u1eeb \u0111\u00f3 th\u00fac \u0111\u1ea9y m\u1ea1nh m\u1ebd s\u1ef1 ph\u00e1t tri\u1ec3n c\u1ee7a l\u0129nh v\u1ef1c truy\u1ec1n s\u1ed1 li\u1ec7u v\u00e0 k\u1ebft n\u1ed1i m\u1ea1ng.<\/p>\n<p><strong>Chu\u1ea9n h\u00f3a:<\/strong><\/p>\n<p>B\u00ean c\u1ea1nh t\u00e1c d\u1ee5ng chuy\u00ean m\u00f4n h\u00f3a cao \u0111\u1ed9 c\u1ee7a c\u00e1c m\u00f4 h\u00ecnh ph\u00e2n l\u1edbp, vi\u1ec7c tham chi\u1ebfu \u0111\u1ebfn c\u00e1c m\u00f4 h\u00ecnh ph\u00e2n l\u1edbp c\u00f2n gi\u00fap cho ho\u1ea1t \u0111\u1ed9ng\u00a0<em>chu\u1ea9n h\u00f3a<\/em>\u00a0trong l\u0129nh v\u1ef1c m\u1ea1ng m\u00e1y t\u00ednh v\u00e0 truy\u1ec1n s\u1ed1 li\u1ec7u di\u1ec5n ra h\u1ebft s\u1ee9c thu\u1eadn l\u1ee3i. Ng\u00e0y nay, g\u1ea7n nh\u01b0 m\u1ecdi c\u00f4ng ngh\u1ec7, thi\u1ebft b\u1ecb, ph\u1ea7n m\u1ec1m,\u2026 trong l\u0129nh v\u1ef1c Internet v\u00e0 k\u1ebft n\u1ed1i m\u1ea1ng \u0111\u00e3 \u0111\u1ec1u \u0111\u01b0\u1ee3c chu\u1ea9n h\u00f3a theo c\u00e1c t\u00e0i li\u1ec7u chu\u1ea9n \u0111\u01b0\u1ee3c ph\u00e1t h\u00e0nh b\u1edfi c\u00e1c t\u1ed5 ch\u1ee9c chuy\u00ean m\u00f4n l\u1edbn c\u00f3 uy t\u00edn (v\u00ed d\u1ee5 nh\u01b0 c\u00e1c t\u00e0i li\u1ec7u RFC c\u1ee7a IETF) khi\u1ebfn cho vi\u1ec7c giao ti\u1ebfp gi\u1eefa c\u00e1c d\u00f2ng s\u1ea3n ph\u1ea9m, c\u00e1c lo\u1ea1i thi\u1ebft b\u1ecb v\u00e0 \u1ee9ng d\u1ee5ng di\u1ec5n ra r\u1ea5t d\u1ec5 d\u00e0ng v\u00e0 hi\u1ec7u qu\u1ea3. T\u1eeb \u0111\u00f3, l\u0129nh v\u1ef1c m\u1ea1ng m\u00e1y t\u00ednh v\u00e0 Internet ph\u00e1t tri\u1ec3n ng\u00e0y m\u1ed9t m\u1ea1nh m\u1ebd h\u01a1n.<\/p>\n<p>Hi\u1ec7n nay, c\u00f3 hai m\u00f4 h\u00ecnh ph\u00e2n l\u1edbp n\u1ed5i ti\u1ebfng \u0111ang \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng:\u00a0<strong>m\u00f4 h\u00ecnh OSI<\/strong>\u00a0v\u00e0\u00a0<strong>m\u00f4 h\u00ecnh TCP\/IP<\/strong>.<\/p>\n<blockquote><p>Giao th\u1ee9c (protocol) l\u00e0 m\u1ed9t t\u1eadp h\u1ee3p c\u00e1c quy t\u1eafc \u1ee9ng x\u1eed v\u00e0 \u0111\u00f3ng g\u00f3i d\u1eef li\u1ec7u m\u00e0 c\u00e1c b\u00ean tham gia truy\u1ec1n th\u00f4ng ph\u1ea3i tu\u00e2n theo \u0111\u1ec3 ho\u1ea1t \u0111\u1ed9ng truy\u1ec1n th\u00f4ng gi\u1eefa ch\u00fang c\u00f3 th\u1ec3 di\u1ec5n ra \u0111\u00fang \u0111\u1eafn. M\u1ed9t c\u00e1ch \u0111\u01a1n gi\u1ea3n, c\u00f3 th\u1ec3 coi giao th\u1ee9c l\u00e0 \u201cng\u00f4n ng\u1eef\u201d c\u1ee7a th\u1ebf gi\u1edbi m\u1ea1ng. C\u00e1c thi\u1ebft b\u1ecb mu\u1ed1n truy\u1ec1n d\u1eef li\u1ec7u v\u1edbi nhau th\u00ec ch\u00fang ph\u1ea3i s\u1eed d\u1ee5ng c\u00f9ng m\u1ed9t giao th\u1ee9c hay \u201cn\u00f3i c\u00f9ng m\u1ed9t ng\u00f4n ng\u1eef\u201d. V\u00ed d\u1ee5: c\u00e1c host k\u1ebft n\u1ed1i Internet ng\u00e0y nay \u0111\u1ec1u ph\u1ea3i s\u1eed d\u1ee5ng giao th\u1ee9c IP \u2013 \u201cng\u00f4n ng\u1eef chung\u201d c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng tr\u00ean Internet.<\/p><\/blockquote>\n<h3>2.2. M\u00f4 h\u00ecnh OSI<\/h3>\n<p>M\u00f4 h\u00ecnh\u00a0<em>OSI (Open System Interconnection)<\/em>\u00a0do t\u1ed5 ch\u1ee9c ISO \u0111\u01b0a ra v\u00e0o n\u0103m 1977 th\u1ef1c hi\u1ec7n chia c\u00e1c t\u00e1c v\u1ee5 truy\u1ec1n s\u1ed1 li\u1ec7u gi\u1eefa hai host th\u00e0nh 7 l\u1edbp c\u00f4ng vi\u1ec7c \u0111\u01b0\u1ee3c \u0111\u00e1nh s\u1ed1 th\u1ee9 t\u1ef1 t\u1eeb 1 \u0111\u1ebfn 7. C\u00e1c l\u1edbp c\u1ee7a m\u00f4 h\u00ecnh OSI \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n trong h\u00ecnh 1.3:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-539 aligncenter\" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 3\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-1.png\" sizes=\"auto, (max-width: 214px) 100vw, 214px\" srcset=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-1.png 214w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-1-193x300.png 193w\" alt=\"Picture1 1\" width=\"214\" height=\"333\" \/><\/p>\n<p><em>H\u00ecnh 1.3. C\u00e1c l\u1edbp c\u1ee7a m\u00f4 h\u00ecnh OSI<\/em><\/p>\n<p>Ch\u1ee9c n\u0103ng c\u1ee7a t\u1eebng l\u1edbp trong m\u00f4 h\u00ecnh OSI c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c t\u00f3m l\u01b0\u1ee3c nh\u01b0 sau:<\/p>\n<ol>\n<li><em>L\u1edbp Physical:\u00a0<\/em>L\u1edbp n\u00e0y \u0111\u1ecbnh ngh\u0129a c\u00e1c \u0111\u1eb7c t\u00ednh k\u1ef9 thu\u1eadt v\u1eadt l\u00fd c\u1ee5 th\u1ec3 c\u1ee7a m\u1ed9t \u0111\u01b0\u1eddng truy\u1ec1n. Ch\u1eb3ng h\u1ea1n nh\u01b0 \u0111\u01b0\u1eddng truy\u1ec1n n\u00e0y s\u1eed d\u1ee5ng lo\u1ea1i c\u00e1p n\u00e0o (c\u00e1p \u0111\u1ed3ng hay c\u00e1p quang, c\u00e1p \u0111\u1ed3ng tr\u1ee5c hay c\u00e1p xo\u1eafn \u0111\u00f4i,\u2026); k\u1ebft cu\u1ed1i b\u1eb1ng lo\u1ea1i \u0111\u1ea7u n\u1ed1i (connector) n\u00e0o (<em>v\u00ed d\u1ee5:\u00a0<\/em>c\u00e1p m\u1ea1ng LAN k\u1ebft cu\u1ed1i b\u1eb1ng \u0111\u1ea7u RJ45, c\u00e1p \u0111i\u1ec7n tho\u1ea1i k\u1ebft cu\u1ed1i b\u1eb1ng \u0111\u1ea7u RJ11); c\u00e1c ch\u00e2n (pin) trong card thu ph\u00e1t t\u00edn hi\u1ec7u \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng ra sao (<em>v\u00ed d\u1ee5:<\/em>\u00a0ch\u00e2n 1, 2 l\u00e0m nhi\u1ec7m v\u1ee5 ph\u00e1t t\u00edn hi\u1ec7u \u2013 Tx; ch\u00e2n 3, 6 l\u00e0m nhi\u1ec7m v\u1ee5 thu t\u00edn hi\u1ec7u \u2013 Rx); n\u1ebfu s\u1eed d\u1ee5ng \u0111\u01b0\u1eddng truy\u1ec1n kh\u00f4ng d\u00e2y th\u00ec d\u1ea3i t\u1ea7n thu ph\u00e1t l\u00e0 d\u1ea3i n\u00e0o, anten lo\u1ea1i g\u00ec,\u2026; vi\u1ec7c x\u1eed l\u00fd t\u00edn hi\u1ec7u \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n ra sao (s\u1eed d\u1ee5ng k\u1ef9 thu\u1eadt m\u00e3 h\u00f3a \u0111\u01b0\u1eddng d\u00e2y n\u00e0o, ph\u01b0\u01a1ng th\u1ee9c \u0111i\u1ec1u ch\u1ebf g\u00ec);.v.v\u2026 Nhi\u1ec7m v\u1ee5 c\u1ee7a l\u1edbp v\u1eadt l\u00fd l\u00e0 \u0111\u1ea3m b\u1ea3o truy\u1ec1n \u0111\u01b0\u1ee3c c\u00e1c bit nh\u1ecb ph\u00e2n qua m\u1ed9t m\u00f4i tr\u01b0\u1eddng v\u1eadt l\u00fd c\u1ee5 th\u1ec3 n\u00e0o \u0111\u00f3.<\/li>\n<li><em>L\u1edbp Data Link:<\/em>\u00a0\u0110\u1ecbnh ngh\u0129a c\u00e1ch th\u1ee9c \u0111\u00f3ng g\u00f3i d\u1eef li\u1ec7u cho ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c lo\u1ea1i \u0111\u01b0\u1eddng truy\u1ec1n. L\u1edbp data link quy \u0111\u1ecbnh c\u00e1ch th\u1ee9c m\u00e0 d\u1eef li\u1ec7u \u0111\u1ebfn t\u1eeb c\u00e1c l\u1edbp tr\u00ean truy nh\u1eadp v\u00e0o \u0111\u01b0\u1eddng truy\u1ec1n v\u1eadt l\u00fd v\u00e0 l\u1edbp n\u00e0y c\u0169ng th\u1ef1c hi\u1ec7n c\u00e1c t\u00e1c v\u1ee5 t\u01b0\u01a1ng t\u00e1c v\u1edbi c\u00e1c giao th\u1ee9c \u1edf l\u1edbp cao h\u01a1n.<\/li>\n<li><em>L\u1edbp Network:<\/em>\u00a0C\u00e1c th\u1ef1c th\u1ec3 c\u1ee7a l\u1edbp th\u1ee9 1 v\u00e0 l\u1edbp th\u1ee9 2 s\u1ebd gi\u00fap t\u1ea1o ra c\u00e1c\u00a0<em>\u0111\u01b0\u1eddng link\u00a0<\/em>k\u1ebft n\u1ed1i gi\u1eefa c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng. R\u1ea5t nhi\u1ec1u c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i b\u1edfi c\u00e1c \u0111\u01b0\u1eddng link s\u1ebd t\u1ea1o n\u00ean m\u1ed9t h\u1ec7 th\u1ed1ng m\u1ea1ng c\u00f3 topo ph\u1ee9c t\u1ea1p khi\u1ebfn cho d\u1eef li\u1ec7u c\u1ea7n di chuy\u1ec3n gi\u1eefa c\u00e1c host th\u00f4ng qua h\u1ec7 th\u1ed1ng m\u1ea1ng n\u00e0y s\u1ebd c\u00f3 r\u1ea5t nhi\u1ec1u\u00a0<em>tuy\u1ebfn \u0111\u01b0\u1eddng (path)<\/em>\u00a0kh\u00e1c nhau \u0111\u1ec3 l\u1ef1a ch\u1ecdn. Nhi\u1ec7m v\u1ee5 ch\u00ednh c\u1ee7a c\u00e1c th\u1ef1c th\u1ec3 l\u1edbp network l\u00e0 \u0111\u1ecbnh tuy\u1ebfn t\u00ecm tuy\u1ebfn \u0111\u01b0\u1eddng gi\u00fap d\u1eef li\u1ec7u di chuy\u1ec3n gi\u1eefa c\u00e1c host theo m\u1ed9t l\u1ed9 tr\u00ecnh t\u1ed1t nh\u1ea5t c\u00f3 th\u1ec3. Thi\u1ebft b\u1ecb chuy\u00ean d\u1ee5ng c\u1ee7a l\u1edbp network l\u00e0\u00a0<em>b\u1ed9 \u0111\u1ecbnh tuy\u1ebfn \u2013 Router<\/em>. C\u00e1c router, ho\u1eb7c theo s\u1ef1 thi\u1ebft l\u1eadp c\u1ee7a ng\u01b0\u1eddi qu\u1ea3n tr\u1ecb, ho\u1eb7c t\u1ef1 ch\u1ea1y v\u1edbi nhau c\u00e1c\u00a0<em>giao th\u1ee9c \u0111\u1ecbnh tuy\u1ebfn (routing protocol)<\/em>\u00a0s\u1ebd\u00a0 th\u1ef1c hi\u1ec7n c\u00f4ng vi\u1ec7c \u0111\u1ecbnh tuy\u1ebfn v\u1eeba n\u00eau \u1edf tr\u00ean.<\/li>\n<li><em>L\u1edbp Transport:<\/em>\u00a0Khi c\u00e1c th\u1ef1c th\u1ec3 c\u1ee7a c\u00e1c l\u1edbp 1, 2, 3 ho\u00e0n th\u00e0nh nhi\u1ec7m v\u1ee5 c\u1ee7a ch\u00fang, n\u1ebfu hai host b\u1ea5t k\u1ef3 mu\u1ed1n trao \u0111\u1ed5i d\u1eef li\u1ec7u v\u1edbi nhau, ch\u00fang s\u1ebd kh\u00f4ng c\u1ea7n ph\u1ea3i quan t\u00e2m d\u1eef li\u1ec7u ch\u00fang g\u1eedi \u0111i s\u1ebd ph\u1ea3i l\u00e0m c\u00e1ch n\u00e0o \u0111\u1ec3 \u0111i \u0111\u1ebfn \u0111\u01b0\u1ee3c host \u0111\u1ea7u xa b\u00ean kia, ch\u00fang ch\u1ec9 vi\u1ec7c g\u1eedi d\u1eef li\u1ec7u \u0111i v\u00e0 c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng \u1edf gi\u1eefa s\u1ebd t\u00ecm c\u00e1ch chuy\u1ec3n d\u1eef li\u1ec7u n\u00e0y \u0111\u1ebfn tay ng\u01b0\u1eddi nh\u1eadn. M\u1ed9t c\u00e1ch g\u1ea7n \u0111\u00fang, khi \u0111\u00f3, gi\u1eefa hai host nh\u01b0 th\u1ec3 \u0111\u00e3 h\u00ecnh th\u00e0nh m\u1ed9t \u201ck\u1ebft n\u1ed1i t\u01b0\u1edfng t\u01b0\u1ee3ng\u201d \u0111i xuy\u00ean qua c\u1ea3 h\u1ec7 th\u1ed1ng m\u1ea1ng \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng b\u1edfi c\u00e1c th\u1ef1c th\u1ec3 l\u1edbp 1, 2, 3 \u1edf d\u01b0\u1edbi. C\u00e1c giao th\u1ee9c l\u1edbp 4 \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng \u0111\u1ec3 t\u1ed1i \u01b0u vi\u1ec7c truy\u1ec1n t\u1ea3i d\u1eef li\u1ec7u ng\u01b0\u1eddi d\u00f9ng qua c\u00e1c \u201ck\u1ebft n\u1ed1i t\u01b0\u1edfng t\u01b0\u1ee3ng\u201d n\u00e0y. N\u00f3i c\u00e1ch kh\u00e1c, c\u00e1c th\u1ef1c th\u1ec3 l\u1edbp 4 ch\u1ec9 qu\u1ea3n l\u00fd v\u00e0 th\u1ef1c hi\u1ec7n c\u00e1c t\u00e1c v\u1ee5 truy\u1ec1n d\u1eef li\u1ec7u\u00a0<em>gi\u1eefa hai \u0111\u1ea7u cu\u1ed1i<\/em>\u00a0(<em>end \u2013 to \u2013 end<\/em>\u00a0hay\u00a0<em>host \u2013 to \u2013 host<\/em>), t\u1ed1i \u01b0u h\u00f3a ho\u1ea1t \u0111\u1ed9ng n\u00e0y; ch\u00fang kh\u00f4ng quan t\u00e2m l\u00e0m c\u00e1ch n\u00e0o d\u1eef li\u1ec7u c\u00f3 th\u1ec3 \u0111i \u0111\u01b0\u1ee3c t\u1eeb \u0111\u1ea7u cu\u1ed1i n\u00e0y \u0111\u1ebfn \u0111\u1ea7u cu\u1ed1i kia, \u0111\u00f3 l\u00e0 c\u00f4ng vi\u1ec7c c\u1ee7a c\u00e1c l\u1edbp d\u01b0\u1edbi 1, 2, 3.<\/li>\n<li><em>L\u1edbp Session:<\/em>\u00a0L\u1edbp n\u00e0y ch\u1ecbu tr\u00e1ch nhi\u1ec7m trong vi\u1ec7c thi\u1ebft l\u1eadp, duy tr\u00ec v\u00e0 gi\u1ea3i ph\u00f3ng c\u00e1c session trao \u0111\u1ed5i d\u1eef li\u1ec7u gi\u1eefa c\u00e1c th\u1ef1c th\u1ec3 \u1ee9ng d\u1ee5ng tr\u00ean hai host.<\/li>\n<li><em>L\u1edbp Presentation:<\/em>\u00a0Khi c\u00e1c \u1ee9ng d\u1ee5ng tr\u00ean hai host s\u1eed d\u1ee5ng c\u00e1c \u0111\u1ecbnh d\u1ea1ng d\u1eef li\u1ec7u kh\u00e1c nhau, l\u1edbp tr\u00ecnh b\u00e0y ph\u1ea3i ch\u1ecbu tr\u00e1ch nhi\u1ec7m \u201cth\u00f4ng d\u1ecbch\u201d v\u00e0 di\u1ec5n gi\u1ea3i \u0111\u1ec3 hai \u1ee9ng d\u1ee5ng \u1edf hai host \u0111ang truy\u1ec1n th\u00f4ng v\u1edbi nhau c\u00f3 th\u1ec3 hi\u1ec3u \u0111\u01b0\u01a1c nhau.<\/li>\n<li><em>L\u1edbp Application:<\/em>\u00a0Bao g\u1ed3m r\u1ea5t nhi\u1ec1u giao th\u1ee9c giao ti\u1ebfp tr\u1ef1c ti\u1ebfp v\u1edbi ng\u01b0\u1eddi d\u00f9ng \u0111\u1ea7u cu\u1ed1i, gi\u00fap g\u1eedi\/nh\u1eadn d\u1eef li\u1ec7u cho m\u1ed9t ho\u1ea1t \u0111\u1ed9ng n\u00e0o \u0111\u00f3 c\u1ee7a ng\u01b0\u1eddi d\u00f9ng nh\u01b0 truy nh\u1eadp web, g\u1eedi mail, truy\u1ec1n file,.v.v\u2026<\/li>\n<\/ol>\n<h3>2.3. Nguy\u00ean t\u1eafc ho\u1ea1t \u0111\u1ed9ng<\/h3>\n<p>V\u1edbi c\u00e1ch th\u1ee9c t\u1ed5 ch\u1ee9c nh\u01b0 \u0111\u00e3 tr\u00ecnh b\u00e0y, s\u1ef1 t\u01b0\u01a1ng t\u00e1c gi\u1eefa c\u00e1c l\u1edbp c\u1ee7a m\u00f4 h\u00ecnh OSI di\u1ec5n ra theo nguy\u00ean t\u1eafc nh\u01b0 sau:<\/p>\n<p><strong>C\u00e1c l\u1edbp d\u01b0\u1edbi cung c\u1ea5p d\u1ecbch v\u1ee5 tr\u1ef1c ti\u1ebfp cho c\u00e1c l\u1edbp ngay ph\u00eda tr\u00ean n\u00f3.<\/strong>\u00a0C\u00e1c l\u1edbp tr\u00ean s\u1ebd g\u1eedi y\u00eau c\u1ea7u xu\u1ed1ng l\u1edbp d\u01b0\u1edbi v\u00e0 nh\u1eadn l\u1ea1i k\u1ebft qu\u1ea3, c\u00e1c l\u1edbp tr\u00ean kh\u00f4ng c\u1ea7n bi\u1ebft ho\u1ea1t \u0111\u1ed9ng c\u1ee5 th\u1ec3 di\u1ec5n ra t\u1ea1i l\u1edbp d\u01b0\u1edbi, hay n\u00f3i c\u00e1ch kh\u00e1c ho\u1ea1t \u0111\u1ed9ng c\u1ee7a l\u1edbp d\u01b0\u1edbi ho\u00e0n to\u00e0n trong su\u1ed1t v\u00e0 l\u00e0 \u201ch\u1ed9p \u0111en\u201d v\u1edbi l\u1edbp tr\u00ean.<\/p>\n<p><strong>C\u00e1c l\u1edbp ngang h\u00e0ng tr\u00ean hai host t\u01b0\u01a1ng t\u00e1c tr\u1ef1c ti\u1ebfp v\u1edbi nhau.<\/strong>\u00a0Tuy nhi\u00ean, d\u1eef li\u1ec7u trao \u0111\u1ed5i gi\u1eefa hai th\u1ef1c th\u1ec3 ngang h\u00e0ng n\u00e0y \u0111\u1ec3 \u0111i \u0111\u1ebfn \u0111\u01b0\u1ee3c nhau ph\u1ea3i th\u00f4ng qua ho\u1ea1t \u0111\u1ed9ng c\u1ee7a c\u00e1c l\u1edbp b\u00ean d\u01b0\u1edbi n\u00f3. C\u1ee5 th\u1ec3, qu\u00e1 tr\u00ecnh truy\u1ec1n d\u1eef li\u1ec7u trong m\u00f4 h\u00ecnh OSI s\u1ebd \u0111i t\u1eeb c\u00e1c l\u1edbp tr\u00ean xu\u1ed1ng c\u00e1c l\u1edbp d\u01b0\u1edbi, qua c\u00e1c \u0111\u01b0\u1eddng truy\u1ec1n v\u1eadt l\u00fd \u0111\u1ec3 \u0111i t\u1edbi host \u0111\u1ea7u kia r\u1ed3i \u0111i ng\u01b0\u1ee3c l\u1ea1i t\u1eeb c\u00e1c l\u1edbp d\u01b0\u1edbi l\u00ean c\u00e1c l\u1edbp tr\u00ean.<\/p>\n<p><strong><em>\u0110\u00f3ng g\u00f3i v\u00e0 m\u1edf g\u00f3i (Encapsulation and De \u2013 encapsulation):<\/em><\/strong><\/p>\n<p>M\u1ea1ng m\u00e1y t\u00ednh ng\u00e0y nay s\u1eed d\u1ee5ng c\u00f4ng ngh\u1ec7\u00a0<em>chuy\u1ec3n m\u1ea1ch g\u00f3i \u2013 packet switching<\/em>\u00a0\u0111\u1ec3 truy\u1ec1n t\u1ea3i d\u1eef li\u1ec7u. M\u1ed7i giao th\u1ee9c truy\u1ec1n d\u1eef li\u1ec7u c\u1ee7a c\u00e1c l\u1edbp \u0111\u00e3 n\u00eau \u1edf tr\u00ean \u0111\u1ec1u chia d\u1eef li\u1ec7u c\u1ea7n truy\u1ec1n th\u00e0nh c\u00e1c ph\u1ea7n nh\u1ecf kh\u00e1c nhau v\u00e0 th\u1ef1c hi\u1ec7n \u0111\u00f3ng g\u00f3i m\u1ed7i ph\u1ea7n n\u00e0y th\u00e0nh c\u00e1c\u00a0<em>g\u00f3i tin<\/em>\u00a0\u0111\u1ec3 truy\u1ec1n \u0111i xa. C\u00e1c g\u00f3i tin n\u00e0y \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 c\u00e1c\u00a0<em>\u0110\u01a1n v\u1ecb d\u1eef li\u1ec7u c\u1ee7a giao th\u1ee9c (PDU \u2013 Protocol Data Unit)<\/em>. M\u1ed7i PDU \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng s\u1ebd g\u1ed3m hai th\u00e0nh ph\u1ea7n:\u00a0<em>Header<\/em>\u00a0v\u00e0\u00a0<em>Payload<\/em>. Header ch\u00ednh l\u00e0 ph\u1ea7n th\u00f4ng tin qu\u1ea3n l\u00fd c\u1ee7a g\u00f3i tin c\u00f2n payload ch\u00ednh l\u00e0 ph\u1ea7n d\u1eef li\u1ec7u th\u1ef1c s\u1ef1 c\u1ee7a g\u00f3i tin (h\u00ecnh 1.4).<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-540 aligncenter\" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 4\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1.jpg\" sizes=\"auto, (max-width: 340px) 100vw, 340px\" srcset=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1.jpg 340w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-300x46.jpg 300w\" alt=\"Picture1\" width=\"340\" height=\"52\" \/><\/p>\n<p><em>H\u00ecnh 1.4.\u00a0<\/em><em>C\u1ea5u tr\u00fac c\u1ee7a m\u1ed9t PDU.<\/em><\/p>\n<p>Khi c\u00e1c PDU c\u1ee7a c\u00e1c giao th\u1ee9c \u0111i t\u1eeb l\u1edbp tr\u00ean xu\u1ed1ng l\u1edbp d\u01b0\u1edbi, ch\u00fang \u0111\u01b0\u1ee3c \u0111\u00f3ng g\u00f3i tr\u1edf th\u00e0nh payload c\u1ee7a l\u1edbp b\u00ean d\u01b0\u1edbi v\u00e0 \u0111\u01b0\u1ee3c \u0111\u00f3ng th\u00eam header c\u1ee7a giao th\u1ee9c l\u1edbp d\u01b0\u1edbi. C\u1ee9 \u0111i xu\u1ed1ng m\u1ed9t l\u1edbp, m\u1ed9t header m\u1edbi l\u1ea1i \u0111\u01b0\u1ee3c th\u00eam v\u00e0o. Quy tr\u00ecnh \u0111\u00f3ng g\u00f3i n\u00e0y \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n trong h\u00ecnh 1.5:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-541 aligncenter\" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 5\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-2.png\" sizes=\"auto, (max-width: 870px) 100vw, 870px\" srcset=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-2.png 870w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-2-300x220.png 300w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-2-768x563.png 768w\" alt=\"Picture1 2\" width=\"870\" height=\"638\" \/><\/p>\n<p><em>H\u00ecnh 1.5. Qu\u00e1 tr\u00ecnh encapsulation khi \u0111i t\u1eeb l\u1edbp tr\u00ean xu\u1ed1ng l\u1edbp d\u01b0\u1edbi<\/em><\/p>\n<p>M\u1ed9t \u0111i\u1ec3m \u0111\u1eb7c bi\u1ec7t l\u00e0 ri\u00eang v\u1edbi l\u1edbp th\u1ee9 hai (data link), kh\u00f4ng ch\u1ec9 header \u0111\u01b0\u1ee3c th\u00eam v\u00e0o \u0111\u1ea7u c\u1ee7a n\u1ed9i dung payload m\u00e0 c\u00f2n c\u00f3 th\u00eam tr\u01b0\u1eddng ki\u1ec3m tra l\u1ed7i FCS \u0111\u01b0\u1ee3c th\u00eam v\u00e0o ph\u1ea7n \u0111u\u00f4i c\u1ee7a payload. Ph\u1ea7n n\u00e0y c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0\u00a0<em>Trailer<\/em>. Trailer s\u1eed d\u1ee5ng k\u1ef9 thu\u1eadt ki\u1ec3m tra l\u1ed7i\u00a0<em>FCS (Frame Check Sequence)<\/em>\u00a0\u0111\u1ec3 \u0111\u1ea3m b\u1ea3o nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c l\u1ed7i x\u1ea3y ra khi truy\u1ec1n d\u1eef li\u1ec7u qua m\u1ed9t \u0111\u01b0\u1eddng truy\u1ec1n n\u00e0o \u0111\u00f3. \u0110\u00e2y l\u00e0 tr\u01b0\u1eddng \u0111\u1eb7c th\u00f9 c\u1ee7a \u0111\u00f3ng g\u00f3i d\u1eef li\u1ec7u l\u1edbp 2.<\/p>\n<p>T\u1ea1i \u0111\u1ea7u nh\u1eadn, ti\u1ebfn tr\u00ecnh l\u1ea1i di\u1ec5n ra theo chi\u1ec1u ng\u01b0\u1ee3c l\u1ea1i: d\u1eef li\u1ec7u s\u1ebd \u0111\u01b0\u1ee3c di chuy\u1ec3n t\u1eeb l\u1edbp d\u01b0\u1edbi l\u00ean l\u1edbp tr\u00ean. C\u1ee9 m\u1ed7i l\u1ea7n \u0111i l\u00ean m\u1ed9t l\u1edbp, header c\u1ee7a l\u1edbp d\u01b0\u1edbi l\u1ea1i \u0111\u01b0\u1ee3c g\u1ee1 b\u1ecf \u0111\u1ec3 tr\u1ea3 l\u1ea1i PDU cho l\u1edbp tr\u00ean. Cu\u1ed1i c\u00f9ng, khi \u0111i l\u00ean \u0111\u1ebfn l\u1edbp Application, d\u1eef li\u1ec7u s\u1ebd \u0111\u01b0\u1ee3c m\u1edf g\u00f3i ho\u00e0n to\u00e0n v\u00e0 g\u1eedi \u0111\u1ebfn giao di\u1ec7n t\u01b0\u01a1ng t\u00e1c v\u1edbi ng\u01b0\u1eddi d\u00f9ng. Qu\u00e1 tr\u00ecnh de \u2013 encapsulation \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 trong h\u00ecnh 1.6:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-542 aligncenter\" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 6\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-3.png\" sizes=\"auto, (max-width: 895px) 100vw, 895px\" srcset=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-3.png 895w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-3-300x220.png 300w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-3-768x563.png 768w\" alt=\"Picture1 3\" width=\"895\" height=\"656\" \/><\/p>\n<p><em>H\u00ecnh 1.6. Qu\u00e1 tr\u00ecnh de \u2013 encapsulation khi \u0111i t\u1eeb l\u1edbp d\u01b0\u1edbi l\u00ean l\u1edbp tr\u00ean<\/em><\/p>\n<p>C\u00e1c PDU c\u1ee7a c\u00e1c giao th\u1ee9c thu\u1ed9c c\u00e1c l\u1edbp \u0111\u01b0\u1ee3c g\u1ecdi t\u00ean theo quy \u01b0\u1edbc nh\u01b0 sau (h\u00ecnh 1.7):<\/p>\n<ul>\n<li>C\u00e1c l\u1edbp Application, Presentation, Session:\u00a0<em>Data<\/em>.<\/li>\n<li>L\u1edbp Transport:\u00a0<em>Segment<\/em>.<\/li>\n<li>L\u1edbp Network:\u00a0<em>Packet<\/em>.<\/li>\n<li>L\u1edbp Data Link:\u00a0<em>Frame<\/em>.<\/li>\n<li>L\u1edbp Physical:\u00a0<em>Bit<\/em>.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-543 aligncenter\" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 7\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-4.png\" sizes=\"auto, (max-width: 935px) 100vw, 935px\" srcset=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-4.png 935w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-4-300x179.png 300w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-4-768x459.png 768w\" alt=\"Picture1 4\" width=\"935\" height=\"559\" \/><\/p>\n<p><em>H\u00ecnh 1.7. \u0110\u01a1n v\u1ecb d\u1eef li\u1ec7u c\u1ee7a c\u00e1c l\u1edbp<\/em><\/p>\n<h3>2.4. M\u00f4 h\u00ecnh TCP\/IP<\/h3>\n<p>B\u00ean c\u1ea1nh m\u00f4 h\u00ecnh OSI, m\u1ed9t m\u00f4 h\u00ecnh ph\u00e2n l\u1edbp kh\u00e1c c\u0169ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ea5t r\u1ed9ng r\u00e3i l\u00e0 m\u00f4 h\u00ecnh TCP\/IP. Kh\u00e1c v\u1edbi OSI, m\u00f4 h\u00ecnh TCP\/IP t\u1ed5 ch\u1ee9c c\u00e1c t\u00e1c v\u1ee5 c\u1ee7a vi\u1ec7c truy\u1ec1n d\u1eef li\u1ec7u th\u00e0nh 4 l\u1edbp thay v\u00ec 7 l\u1edbp. C\u00e1c l\u1edbp t\u1eeb tr\u00ean xu\u1ed1ng d\u01b0\u1edbi l\u1ea7n l\u01b0\u1ee3t l\u00e0: Application, Transport, Internet v\u00e0 Network Access (h\u00ecnh 1.8).<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-544 aligncenter\" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 8\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-5.png\" alt=\"Picture1 5\" width=\"147\" height=\"275\" \/><\/p>\n<p><em>H\u00ecnh 1.8. M\u00f4 h\u00ecnh TCP\/IP<\/em><\/p>\n<p>Trong \u0111\u00f3:<\/p>\n<ul>\n<li><em>L\u1edbp Application<\/em>\u00a0ki\u00eam nhi\u1ec7m vai tr\u00f2 c\u1ee7a ba l\u1edbp 5, 6, 7 c\u1ee7a m\u00f4 h\u00ecnh OSI. C\u00e1c th\u1ef1c th\u1ec3 c\u1ee7a l\u1edbp Application c\u0169ng cung c\u1ea5p giao ti\u1ebfp \u0111\u1ebfn ng\u01b0\u1eddi d\u00f9ng, cung c\u1ea5p c\u00e1c giao th\u1ee9c cho ph\u00e9p ng\u01b0\u1eddi d\u00f9ng trao \u0111\u1ed5i d\u1eef li\u1ec7u c\u1ee7a nhi\u1ec1u lo\u1ea1i \u1ee9ng d\u1ee5ng qua m\u1ea1ng. V\u00ec \u0111\u1ea3m nh\u1eadn lu\u00f4n vai tr\u00f2 c\u1ee7a l\u1edbp 5 v\u00e0 l\u1edbp 6 c\u1ee7a OSI, c\u00e1c th\u1ef1c th\u1ec3 c\u1ee7a l\u1edbp Application trong m\u00f4 h\u00ecnh TCP\/IP c\u1ee7a c\u00f9ng m\u1ed9t giao th\u1ee9c \u0111\u1ec1u th\u1ed1ng nh\u1ea5t nhau v\u1ec1 \u0111\u1ecbnh d\u1ea1ng d\u1eef li\u1ec7u c\u0169ng nh\u01b0 c\u00e1ch thi\u1ebft l\u1eadp v\u00e0 qu\u1ea3n l\u00fd c\u00e1c session t\u1eeb \u0111\u00f3 kh\u00f4ng c\u1ea7n ph\u1ea3i c\u00f3 c\u00e1c ph\u00e2n l\u1edbp ri\u00eang cho c\u00e1c t\u00e1c v\u1ee5 n\u00e0y n\u1eefa.<\/li>\n<li><em>L\u1edbp Transport<\/em>\u00a0\u0111\u1ea3m nh\u1eadn nhi\u1ec7m v\u1ee5 gi\u1ed1ng nh\u01b0 l\u1edbp Transport b\u00ean m\u00f4 h\u00ecnh OSI. Hai giao th\u1ee9c n\u1ed5i ti\u1ebfng c\u1ee7a t\u1ea7ng Transport thu\u1ed9c m\u00f4 h\u00ecnh TCP\/IP l\u00e0 TCP v\u00e0 UDP.<\/li>\n<li><em>L\u1edbp Internet<\/em>\u00a0c\u00f3 nhi\u1ec7m v\u1ee5 gi\u1ed1ng v\u1edbi l\u1edbp Network c\u1ee7a m\u00f4 h\u00ecnh OSI. M\u1ed9t giao th\u1ee9c r\u1ea5t n\u1ed5i ti\u1ebfng v\u00e0 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i c\u1ee7a l\u1edbp Internet l\u00e0 giao th\u1ee9c IP.<\/li>\n<li><em>L\u1edbp Network Access<\/em>\u00a0\u0111\u1ea3m nh\u1eadn nhi\u1ec7m v\u1ee5 c\u1ee7a hai l\u1edbp Data Link v\u00e0 Physical c\u1ee7a m\u00f4 h\u00ecnh OSI.<\/li>\n<\/ul>\n<p>Nh\u01b0 v\u1eady, v\u1ec1 m\u1eb7t so s\u00e1nh, c\u00f3 th\u1ec3 n\u00f3i, ba l\u1edbp 5, 6, 7 c\u1ee7a m\u00f4 h\u00ecnh OSI \u0111\u00e3 \u0111\u01b0\u1ee3c t\u00edch h\u1ee3p th\u00e0nh l\u1edbp Application; l\u1edbp Network c\u1ee7a m\u00f4 h\u00ecnh OSI \u0111\u01b0\u1ee3c chuy\u1ec3n th\u00e0nh l\u1edbp Internet v\u00e0 hai l\u1edbp Data Link, Physical c\u1ee7a m\u00f4 h\u00ecnh OSI \u0111\u00e3 \u0111\u01b0\u1ee3c t\u00edch h\u1ee3p th\u00e0nh l\u1edbp Network Access c\u1ee7a m\u00f4 h\u00ecnh TCP\/IP. \u0110i\u1ec1u n\u00e0y \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n tr\u00ean h\u00ecnh 1.9:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-545 aligncenter\" title=\"B\u00e0i 1 : M\u1ea1ng v\u00e0 M\u00f4 h\u00ecnh tham chi\u1ebfu 9\" src=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-6.png\" sizes=\"auto, (max-width: 485px) 100vw, 485px\" srcset=\"https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-6.png 485w, https:\/\/kainetworks.vn\/wp-content\/uploads\/2026\/05\/Picture1-6-300x191.png 300w\" alt=\"Picture1 6\" width=\"485\" height=\"308\" \/><\/p>\n<p><em>H\u00ecnh 1.9. So s\u00e1nh TCP\/IP v\u00e0 OSI<\/em><\/p>\n<p>B\u00ean c\u1ea1nh vi\u1ec7c \u0111\u01b0a ra m\u1ed9t ki\u1ebfn tr\u00fac ph\u00e2n l\u1edbp m\u00e0 ta g\u1ecdi l\u00e0 m\u00f4 h\u00ecnh tham chi\u1ebfu nh\u01b0 \u0111\u00e3 tr\u00ecnh b\u00e0y \u1edf tr\u00ean, m\u1ed7i m\u00f4 h\u00ecnh ph\u00e2n l\u1edbp c\u00f2n \u0111\u1ecbnh ngh\u0129a ra m\u1ed9t h\u1ec7 th\u1ed1ng c\u00e1c giao th\u1ee9c c\u1ee5 th\u1ec3 cho t\u1eebng l\u1edbp c\u1ee7a m\u00f4 h\u00ecnh. H\u1ec7 th\u1ed1ng c\u00e1c giao th\u1ee9c \u0111i k\u00e8m n\u00e0y \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 ch\u1ed3ng giao th\u1ee9c (protocol stack).<\/p>\n<p>C\u1ea3 hai m\u00f4 h\u00ecnh OSI v\u00e0 TCP\/IP \u0111\u1ec1u c\u00f3 ch\u1ed3ng giao th\u1ee9c ri\u00eang c\u1ee7a m\u00ecnh nh\u01b0ng trong c\u00e1c m\u1ea1ng ng\u00e0y nay, g\u1ea7n nh\u01b0 ch\u1ec9 c\u00f2n ch\u1ed3ng giao th\u1ee9c TCP\/IP \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng. C\u00e1c giao th\u1ee9c c\u1ee7a ch\u1ed3ng giao th\u1ee9c OSI ch\u1ec9 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ea5t \u00edt \u1ecfi trong m\u1ed9t s\u1ed1 tr\u01b0\u1eddng h\u1ee3p \u0111\u1eb7c th\u00f9. Tuy nhi\u00ean, khi tham chi\u1ebfu m\u1ed9t c\u00f4ng ngh\u1ec7, ng\u01b0\u1eddi ta v\u1eabn c\u00f3 th\u00f3i quen tham chi\u1ebfu \u0111\u1ebfn m\u00f4 h\u00ecnh 7 l\u1edbp OSI.<\/p>\n<p><em>V\u00ed d\u1ee5:<\/em>\u00a0khi n\u00f3i \u0111\u1ebfn c\u00e1c giao th\u1ee9c TCP, UDP, ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c n\u00f3i l\u00e0 giao th\u1ee9c l\u1edbp 4; giao th\u1ee9c IP l\u00e0 giao th\u1ee9c l\u1edbp 3; ARP l\u00e0 giao th\u1ee9c l\u1edbp 2,\u2026 Trong khi \u0111\u00f3 c\u00e1c l\u1edbp 2, 3, 4 l\u00e0 c\u00e1c kh\u00e1i ni\u1ec7m c\u1ee7a m\u00f4 h\u00ecnh OSI c\u00f2n c\u00e1c giao th\u1ee9c v\u1eeba n\u00eau \u0111\u1ec1u thu\u1ed9c v\u1ec1 ch\u1ed3ng giao th\u1ee9c TCP\/IP.<\/p>\n<p>Do t\u1eadp qu\u00e1n c\u1ee7a l\u0129nh v\u1ef1c networking l\u00e0 s\u1eed d\u1ee5ng TCP\/IP nh\u01b0ng l\u1ea1i tham chi\u1ebfu \u0111\u1ebfn OSI, n\u00ean trong c\u00e1c ph\u1ea7n ti\u1ebfp theo, ch\u00fang ta s\u1ebd c\u00f9ng kh\u1ea3o s\u00e1t m\u1ed9t v\u00e0i \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a c\u00e1c l\u1edbp Application, Transport, Network, Data Link v\u00e0 Physical, b\u1ecf qua hai l\u1edbp Presentation v\u00e0 Session. C\u00e1c giao th\u1ee9c \u0111\u01b0\u1ee3c nh\u1eafc t\u1edbi trong qu\u00e1 tr\u00ecnh kh\u1ea3o s\u00e1t n\u00e0y ho\u00e0n to\u00e0n l\u00e0 c\u00e1c giao th\u1ee9c c\u1ee7a ch\u1ed3ng giao th\u1ee9c TCP\/IP nh\u01b0ng ta v\u1eabn gi\u1eef c\u00e1c t\u00ean tham chi\u1ebfu c\u1ee7a c\u00e1c l\u1edbp t\u01b0\u01a1ng \u1ee9ng b\u00ean m\u00f4 h\u00ecnh OSI.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>1. M\u1ea1ng l\u00e0 g\u00ec M\u1ea1ng (network) l\u00e0 m\u1ed9t t\u1eadp h\u1ee3p c\u00e1c thi\u1ebft b\u1ecb m\u1ea1ng (router, switch,\u2026) v\u00e0 c\u00e1c h\u1ec7 th\u1ed1ng \u0111\u1ea7u cu\u1ed1i (nh\u01b0 c\u00e1c m\u00e1y t\u00ednh, c\u00e1c server,\u2026) \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i v\u1edbi nhau b\u1edfi c\u00e1c \u0111\u01b0\u1eddng truy\u1ec1n (c\u00e1p quang, c\u00e1p \u0111\u1ed3ng, s\u00f3ng kh\u00f4ng d\u00e2y) \u0111\u1ec3 c\u00f3 th\u1ec3 trao \u0111\u1ed5i d\u1eef li\u1ec7u v\u1edbi nhau. M\u1ea1ng c\u00f3 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":500,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[32],"tags":[],"class_list":["post-499","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ccna"],"acf":[],"_links":{"self":[{"href":"https:\/\/kinghl.com\/index.php?rest_route=\/wp\/v2\/posts\/499","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kinghl.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kinghl.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kinghl.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kinghl.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=499"}],"version-history":[{"count":1,"href":"https:\/\/kinghl.com\/index.php?rest_route=\/wp\/v2\/posts\/499\/revisions"}],"predecessor-version":[{"id":501,"href":"https:\/\/kinghl.com\/index.php?rest_route=\/wp\/v2\/posts\/499\/revisions\/501"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kinghl.com\/index.php?rest_route=\/wp\/v2\/media\/500"}],"wp:attachment":[{"href":"https:\/\/kinghl.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=499"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kinghl.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=499"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kinghl.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=499"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}