{"id":4545,"date":"2025-10-31T11:12:00","date_gmt":"2025-10-31T11:12:00","guid":{"rendered":"https:\/\/lp.szlogic.cn\/knowledge-center\/25gbase-ieee-802-3by-single-lane-25gbe-standard\/"},"modified":"2026-06-18T08:24:18","modified_gmt":"2026-06-18T08:24:18","slug":"25gbase-ieee-802-3by-single-lane-25gbe-standard","status":"publish","type":"post","link":"https:\/\/lp.szlogic.cn\/ru\/knowledge-center\/25gbase-ieee-802-3by-single-lane-25gbe-standard","title":{"rendered":"25GBASE IEEE 802.3by: The Single-Lane 25 Gb Ethernet Standard"},"content":{"rendered":"<figure class=\"wp-block-image aligncenter size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1200\" height=\"712\" src=\"https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/ca1377e01de94208976debf546751df0.webp\" alt=\"What Is IEEE 802.3by?\" class=\"wp-image-4542\" srcset=\"https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/ca1377e01de94208976debf546751df0.webp 1200w, https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/ca1377e01de94208976debf546751df0-300x178.webp 300w, https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/ca1377e01de94208976debf546751df0-1024x608.webp 1024w, https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/ca1377e01de94208976debf546751df0-768x456.webp 768w, https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/ca1377e01de94208976debf546751df0-18x12.webp 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The explosion of cloud services, virtualization, AI workloads, and high-density server deployments has pushed data centers to pursue faster, more efficient Ethernet technologies. To bridge the gap between 10 GbE and cost-intensive 40\/100 GbE, the IEEE introduced <strong>IEEE 802.3by<\/strong>, defining a <strong>single-lane 25 Gb\/s Ethernet physical layer<\/strong>, commonly known as <strong>25GBASE<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This article explains what IEEE 802.3by is, why it matters, and how it enables scalable 25 GbE deployment \u2014 along with how <a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/store-26225-25g-sfp28.htm\">LINK-PP\u2019s SFP28 modules<\/a> support this ecosystem.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >&#x1f539; What Is IEEE 802.3by?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">IEEE 802.3by is an amendment to the IEEE 802.3 Ethernet standard that defines the specifications for <strong>25 Gigabit Ethernet over a single electrical lane<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It standardizes 25 Gb\/s transmission across:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Direct-attach copper (<a target=\"_blank\" rel=\"\" href=\"https:\/\/resources.l-p.com\/knowledge-center\/what-is-breakout-dac-and-why-breakout-dac-matters\">DAC<\/a>) cables<\/p><\/li><li><p>Backplane channels<\/p><\/li><li><p>Multimode fiber<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The goal: deliver a simple, cost-effective, high-density upgrade path from 10G to 25G, especially in data-center server-to-leaf switch connections.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >&#x1f539; Why 25GBASE Was Created<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" >1. Single-lane efficiency<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Earlier 40GbE links used <strong>4 \u00d7 10 Gb\/s lanes<\/strong>. In contrast, 25GBASE uses <strong>1 \u00d7 25 Gb\/s lane<\/strong>, offering:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Higher bandwidth per lane<\/p><\/li><li><p>Lower power consumption<\/p><\/li><li><p>Reduced cost per port<\/p><\/li><li><p>Simpler cabling and optics<\/p><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" >2. Perfect step-up from 10G<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">25 Gb\/s provides <strong>2.5\u00d7 the bandwidth of 10 Gb\/s<\/strong> with only a small increase in power and cost \u2014 ideal for high-density server I\/O.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >3. Scalable path to 50\/100 GbE<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">25G forms the building block for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>50G Ethernet (2 \u00d7 25G lanes)<\/p><\/li><li><p>100G Ethernet (<a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/products\/472118.htm\">4 \u00d7 25G lanes<\/a>)<\/p><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">It\u2019s a foundational speed in modern data-center fabrics.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >&#x1f539; Key Technical Features of 25GBASE (IEEE 802.3by)<\/h2>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"width: 303px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\" colwidth=\"303\"><p>Feature<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Description<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"303\"><p>Line speed<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>25 Gb\/s per lane<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"303\"><p>Coding<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>64b\/66b<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"303\"><p><a target=\"_blank\" rel=\"\" href=\"https:\/\/resources.l-p.com\/glossary\/fec-forward-error-correction-in-optical-communication\">FEC<\/a><\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Optional RS-FEC<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"303\"><p>Media<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Copper, backplane, multimode fiber<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"303\"><p>Module format<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>SFP28<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\" colwidth=\"303\"><p>Target use<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Server-to-switch interconnects<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" >&#x1f539; 25GBASE Interface Variants<\/h2>\n\n\n\n<figure class=\"wp-block-table\">\n<table class=\"has-fixed-layout\">\n<colgroup><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><col style=\"min-width: 25px;\"\/><\/colgroup><tbody><tr><th colspan=\"1\" rowspan=\"1\"><p>Standard<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Medium<\/p><\/th><th colspan=\"1\" rowspan=\"1\"><p>Use Case<\/p><\/th><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>25GBASE-CR \/ CR-S<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Twinax copper DAC<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Short-reach (1\u20135 m) rack interconnects<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p>25GBASE-KR \/ KR-S<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Backplane<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Server\/line-card backplane links<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/products\/476099.htm\">25GBASE-SR<\/a><\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Multimode fiber<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Up to ~100 m on OM4 fiber<\/p><\/td><\/tr><tr><td colspan=\"1\" rowspan=\"1\"><p><a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/products\/476046.htm\">25GBASE-LR<\/a>*<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>Single-mode fiber<\/p><\/td><td colspan=\"1\" rowspan=\"1\"><p>~10 km (*defined in later amendments)<\/p><\/td><\/tr><\/tbody>\n<\/table>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" >&#x1f539; Typical Deployment Scenarios<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" >Data-Center Leaf-Spine Networks<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">25GBASE helps operators scale east-west traffic while controlling infrastructure cost and footprint.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Server-to-Top-of-Rack (ToR) Links<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Servers with 25G NICs connect to ToR switches using SFP28 optics or DAC cables.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >Aggregation and <a target=\"_blank\" rel=\"\" href=\"https:\/\/resources.l-p.com\/knowledge-center\/what-you-need-to-know-about-edge-computing-key-benefits-uses\">Edge Computing<\/a><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">25G-capable uplinks provide the right balance between throughput and cost, especially in edge and AI-ready architectures.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >&#x1f539; Best Practices for Deploying 25GBASE<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" >1. Choose the right media<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p><strong>1\u20135 m:<\/strong> DAC copper (25GBASE-CR)<\/p><\/li><li><p><strong>Up to ~100 m:<\/strong> Multimode fiber (25GBASE-SR + OM4)<\/p><\/li><li><p><strong>Campus\/long-reach:<\/strong> Single-mode (25GBASE-LR or later specs)<\/p><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" >2. Validate hardware interoperability<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Ensure that switches, NICs, and <a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/store-26225-25g-sfp28.htm\">optical modules<\/a> all comply with IEEE 802.3by.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" >3. Consider FEC requirements<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Enable RS-FEC where link margin or EMC environments demand extra robustness.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" >&#x1f539; SFP28 Modules and LINK-PP Solutions<\/h2>\n\n\n\n<figure class=\"wp-block-image aligncenter size-large\"><img decoding=\"async\" width=\"1200\" height=\"712\" src=\"https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/dbd37648365f4364bc8c6a1ec2ef4a77.webp\" alt=\"LINK-PP SFP28 Modules\" class=\"wp-image-4543\" srcset=\"https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/dbd37648365f4364bc8c6a1ec2ef4a77.webp 1200w, https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/dbd37648365f4364bc8c6a1ec2ef4a77-300x178.webp 300w, https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/dbd37648365f4364bc8c6a1ec2ef4a77-1024x608.webp 1024w, https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/dbd37648365f4364bc8c6a1ec2ef4a77-768x456.webp 768w, https:\/\/lp.szlogic.cn\/wp-content\/uploads\/2026\/05\/dbd37648365f4364bc8c6a1ec2ef4a77-18x12.webp 18w\" sizes=\"(max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The primary form factor for 25GBASE is <strong>SFP28<\/strong> \u2014 mechanically similar to SFP+, but with enhanced electrical specifications for 25 Gb\/s signaling.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">LINK-PP offers <strong>IEEE 802.3by-aligned 25G SFP28 optical modules and DAC cables<\/strong> for high-density data-center deployments:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">&#x1f517;<a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/store-26225-25g-sfp28.htm\"><strong>LINK-PP 25G SFP28 Transceivers<\/strong><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Key benefits of LINK-PP 25G modules:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><p>Low-latency, high-stability link performance<\/p><\/li><li><p>OEM-grade compatibility for major switch brands<\/p><\/li><li><p>Proven reliability for hyperscale and enterprise data centers<\/p><\/li><li><p>Competitive pricing for volume deployments<\/p><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" >&#x1f539; Summary<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The IEEE 802.3by standard enables <strong>efficient, scalable, single-lane 25 GbE<\/strong> deployment \u2014 now a core technology in modern data centers. With straightforward cabling, strong backward-compatibility with 10G, and forward scalability to 50\/100G and 25GBASE, 25GBASE is an essential stepping stone in network evolution.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For engineers and planners moving to 25 GbE, <strong>LINK-PP <\/strong><a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/products\/476046.htm\"><strong>SFP28 modules<\/strong><\/a><strong> and <\/strong><a target=\"_blank\" rel=\"\" href=\"https:\/\/www.l-p.com\/store-26454-dac-aoc-aec-cables.htm\"><strong>DAC solutions<\/strong><\/a> provide reliable, cost-optimized connectivity aligned with IEEE 802.3by specifications.<\/p>","protected":false},"excerpt":{"rendered":"<p>Explore the IEEE 802.3by standard for 25GBASE Ethernet. Learn specs, media types, application scenarios, and how LINK-PP SFP28 modules support reliable 25GbE networks.<\/p>","protected":false},"author":1,"featured_media":4544,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[16,26],"class_list":["post-4545","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-knowledge-center","tag-link-pp-25g-sfp28-optical-modules","tag-optics-transceivers"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/posts\/4545","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/comments?post=4545"}],"version-history":[{"count":3,"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/posts\/4545\/revisions"}],"predecessor-version":[{"id":10185,"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/posts\/4545\/revisions\/10185"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/media\/4544"}],"wp:attachment":[{"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/media?parent=4545"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/categories?post=4545"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lp.szlogic.cn\/ru\/wp-json\/wp\/v2\/tags?post=4545"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}