{"id":19468,"date":"2026-06-01T06:00:23","date_gmt":"2026-06-01T06:00:23","guid":{"rendered":"https:\/\/www.fibermall.com\/blog\/?p=19468"},"modified":"2026-06-01T06:00:27","modified_gmt":"2026-06-01T06:00:27","slug":"what-is-qsfp28-complete-guide-for-network-engineers-2026","status":"publish","type":"post","link":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm","title":{"rendered":"What Is QSFP28? Complete Guide for Network Engineers (2026)"},"content":{"rendered":"\n<p>QSFP28 (Quad Small Form-factor Pluggable 28) is an industry-standard transceiver form factor that delivers 100 Gigabit Ethernet over four 25 Gbps lanes. It uses the same physical size as QSFP+ but supports 2.5\u00d7 the bandwidth, making it the dominant 100G standard in modern data centers.<\/p>\n\n\n\n<p>Pretty much every switch shipped today with 100G ports uses QSFP28. We&#8217;ve installed thousands of them.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img fetchpriority=\"high\" decoding=\"async\" width=\"800\" height=\"473\" src=\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/100g-qsfp28-sr4.png\" alt=\"100g qsfp28 sr4\" class=\"wp-image-19470\" style=\"width:800px\" srcset=\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/100g-qsfp28-sr4.png 800w, https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/100g-qsfp28-sr4-300x177.png 300w, https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/100g-qsfp28-sr4-768x454.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>The ports are everywhere \u2014 leaf switches, spine switches, border routers, DCI platforms. But the questions we hear most aren&#8217;t about speed. They&#8217;re about compatibility, module selection, and whether that QSFP+ inventory will still work.<\/p>\n\n\n\n<p>what is qsfp28 exactly? How does it differ from QSFP+? Which module type do you actually need? And will your existing optics work in that new switch?<\/p>\n\n\n\n<p>This guide answers all of it. By the end, you&#8217;ll know the specs, the module types, the compatibility rules, and how to pick the right one for your link.<\/p>\n\n\n\n<p>For a comprehensive technical deep dive, see our <a href=\"https:\/\/www.fibermall.com\/blog\/qsfp28-transceiver-guide.htm \" target=\"_blank\"><u>QSFP28 Transceiver Complete Guide<\/u><u>.<\/u><\/a><\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_76 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/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 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#What_Does_QSFP28_Stand_For\" >What Does QSFP28 Stand For?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#QSFP28_Specifications_at_a_Glance\" >QSFP28 Specifications at a Glance<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#QSFP28_vs_QSFP_Whats_the_Difference\" >QSFP28 vs QSFP+: What&#8217;s the Difference?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#Common_QSFP28_Module_Types\" >Common QSFP28 Module Types<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#When_to_Use_Breakout_Cables\" >When to Use Breakout Cables<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#QSFP28_Compatibility_What_Works_in_What_Port\" >QSFP28 Compatibility: What Works in What Port?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#Is_QSFP28_Still_the_Right_Choice_in_2026\" >Is QSFP28 Still the Right Choice in 2026?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#Frequently_Asked_Questions\" >Frequently Asked Questions<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\/#What_Is_QSFP28_The_Bottom_Line\" >What Is QSFP28? The Bottom Line<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Does_QSFP28_Stand_For\"><\/span><strong>What Does QSFP28 Stand For?<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>The acronym breaks down pretty simply.<\/p>\n\n\n\n<p><strong>Q<\/strong>&nbsp;= Quad. Four transmission lanes.<\/p>\n\n\n\n<p><strong>SFP<\/strong>&nbsp;= Small Form-factor Pluggable. The same family as SFP and SFP+ modules.<\/p>\n\n\n\n<p><strong>28<\/strong>&nbsp;= 28 Gbps signaling rate per lane. That&#8217;s the maximum electrical signaling speed the interface supports.<\/p>\n\n\n\n<p>Here&#8217;s the part that trips people up.<\/p>\n\n\n\n<p>The &#8220;28&#8221; refers to signaling capability, not data rate. QSFP28 actually carries four lanes of 25 Gbps NRZ data. That&#8217;s 100 Gbps aggregate.<\/p>\n\n\n\n<p>The extra 3 Gbps per lane is overhead for encoding and protocol. So yes, the name says 28. The payload is 25.<\/p>\n\n\n\n<p>That&#8217;s just how the spec works.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img decoding=\"async\" width=\"800\" height=\"412\" src=\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/What-Does-QSFP28-Stand-For.png\" alt=\"What Does QSFP28 Stand For\" class=\"wp-image-19471\" style=\"width:800px\" srcset=\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/What-Does-QSFP28-Stand-For.png 800w, https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/What-Does-QSFP28-Stand-For-300x155.png 300w, https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/What-Does-QSFP28-Stand-For-768x396.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>The electrical interface is CAUI-4 (100 Gigabit Attachment Unit Interface, 4 lanes). It&#8217;s a completely different electrical standard than QSFP+&#8217;s XLPPI. That&#8217;s why QSFP28 modules won&#8217;t work in QSFP+ ports \u2014 even though the modules look identical.<\/p>\n\n\n\n<p>Physically, QSFP28 measures 18.35 mm wide, 8.5 mm tall, and 72.4 mm deep. Same dimensions as QSFP+. Same cage. Same bezel cutout. The difference is entirely in the electrical signaling and the optics inside.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"QSFP28_Specifications_at_a_Glance\"><\/span><strong>QSFP28 Specifications at a Glance<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Specification<\/strong><\/td><td><strong>Value<\/strong><\/td><\/tr><tr><td>Form Factor<\/td><td>QSFP28 (SFF-8665)<\/td><\/tr><tr><td>Total Bandwidth<\/td><td>100 Gbps<\/td><\/tr><tr><td>Lanes<\/td><td>4 \u00d7 25 Gbps NRZ<\/td><\/tr><tr><td>Electrical Interface<\/td><td>CAUI-4<\/td><\/tr><tr><td>Typical Power<\/td><td>3.5\u20134.5W<\/td><\/tr><tr><td>Max Power (MSA)<\/td><td>4.5W<\/td><\/tr><tr><td>Dimensions<\/td><td>18.35 \u00d7 8.5 \u00d7 72.4 mm<\/td><\/tr><tr><td>Connector<\/td><td>MPO-12 (SR4) or Duplex LC (SMF)<\/td><\/tr><tr><td>Temperature<\/td><td>0\u00b0C to 70\u00b0C (commercial)<\/td><\/tr><tr><td>Hot-Pluggable<\/td><td>Yes<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>Those specs matter when you&#8217;re loading a switch. A fully populated 32-port QSFP28 switch draws roughly 112\u2013144W from optics alone. That&#8217;s before the switch ASIC, fans, and power supply losses. Not huge, but not negligible either.<\/p>\n\n\n\n<p>QSFP28 is MSA-compliant and hot-pluggable. You can swap modules without powering down the switch. In practice, most network engineers do exactly that during maintenance windows.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"QSFP28_vs_QSFP_Whats_the_Difference\"><\/span><strong>QSFP28 vs QSFP+: What&#8217;s the Difference?<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Feature<\/strong><\/td><td><strong>QSFP+<\/strong><\/td><td><strong>QSFP28<\/strong><\/td><\/tr><tr><td>Speed<\/td><td>40 Gbps<\/td><td>100 Gbps<\/td><\/tr><tr><td>Per-lane Rate<\/td><td>10 Gbps<\/td><td>25 Gbps<\/td><\/tr><tr><td>Electrical Interface<\/td><td>XLPPI<\/td><td>CAUI-4<\/td><\/tr><tr><td>Typical Power<\/td><td>1.5\u20133.5W<\/td><td>3.5\u20134.5W<\/td><\/tr><tr><td>Breakout<\/td><td>4 \u00d7 SFP+ (10G)<\/td><td>4 \u00d7 SFP28 (25G)<\/td><\/tr><tr><td>Year Introduced<\/td><td>~2013<\/td><td>~2016<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>QSFP28 is 2.5\u00d7 faster than QSFP+. Same size. More power. Different electrical standard.<\/p>\n\n\n\n<p>The backward compatibility works in one direction only.<\/p>\n\n\n\n<p>A QSFP+ module will work in a QSFP28 port. The switch detects the slower module and runs the port at 40G.<\/p>\n\n\n\n<p>But a <a href=\"https:\/\/www.fibermall.com\/store-16528-100g-qsfp28.htm\" target=\"_blank\" rel=\"noreferrer noopener\">QSFP28 module<\/a> will not work in a QSFP+ port. The host ASIC in QSFP+ switches can&#8217;t handle 25 Gbps lanes.<\/p>\n\n\n\n<p>We had a customer last year who bought 120 QSFP28 LR4 modules for their &#8220;QSFP switches.&#8221; They didn&#8217;t check the plus sign. The modules wouldn&#8217;t even link up. They had to return the entire batch and reorder QSFP+ optics. The ports look identical. The electrical signaling doesn&#8217;t.<\/p>\n\n\n\n<p>Breakout follows the same logic. QSFP+ breaks out to four SFP+ ports at 10G each. QSFP28 breaks out to four SFP28 ports at 25G each. The cables are physically different \u2014 you can&#8217;t use a QSFP+ breakout DAC on a QSFP28 port and expect 100G.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img decoding=\"async\" width=\"800\" height=\"876\" src=\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/QSFP28-vs-QSFP-Whats-the-Difference.png\" alt=\"QSFP28 vs QSFP+ What's the Difference\" class=\"wp-image-19472\" style=\"width:800px\" srcset=\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/QSFP28-vs-QSFP-Whats-the-Difference.png 800w, https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/QSFP28-vs-QSFP-Whats-the-Difference-274x300.png 274w, https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/QSFP28-vs-QSFP-Whats-the-Difference-768x841.png 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Common_QSFP28_Module_Types\"><\/span><strong>Common QSFP28 Module Types<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Module<\/strong><\/td><td><strong>Distance<\/strong><\/td><td><strong>Fiber Type<\/strong><\/td><td><strong>Connector<\/strong><\/td><td><strong>Best Use Case<\/strong><\/td><\/tr><tr><td>SR4<\/td><td>70m (OM3) \/ 100m (OM4)<\/td><td>MMF OM3\/OM4<\/td><td>MPO-12<\/td><td>Intra-DC, adjacent racks<\/td><\/tr><tr><td>PSM4<\/td><td>500m<\/td><td>SMF<\/td><td>MPO-12<\/td><td>Short SMF runs<\/td><\/tr><tr><td>CWDM4<\/td><td>2km<\/td><td>SMF<\/td><td>Duplex LC<\/td><td>Cost-optimized DCI<\/td><\/tr><tr><td><a href=\"https:\/\/www.fibermall.com\/sale-419868-qsfp28-100g-lr4-1310nm-10km.htm\" target=\"_blank\" rel=\"noreferrer noopener\">LR4<\/a><\/td><td>10km<\/td><td>SMF<\/td><td>Duplex LC<\/td><td>Campus, metro links<\/td><\/tr><tr><td>ER4<\/td><td>30\u201340km<\/td><td>SMF<\/td><td>Duplex LC<\/td><td>Extended metro<\/td><\/tr><tr><td>ZR4<\/td><td>80km<\/td><td>SMF<\/td><td>Duplex LC<\/td><td>Long-haul DCI<\/td><\/tr><tr><td>BiDi<\/td><td>70\u2013100m<\/td><td>MMF<\/td><td>LC<\/td><td>Duplex MMF with LC<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>Most data center deployments use SR4 for in-rack and row-to-row links. It&#8217;s the cheapest option and works fine over multimode fiber up to 100 meters.<\/p>\n\n\n\n<p>CWDM4 is the sweet spot for data center interconnect. Two kilometers over single-mode fiber, duplex LC connector, no MPO cable needed. We&#8217;ve seen CWDM4 replace PSM4 in a lot of deployments because the fiber plant is simpler.<\/p>\n\n\n\n<p>LR4 handles campus and metro links at 10km. ER4 and ZR4 push into telecom territory at 30\u201380km. For anything beyond 80km, you&#8217;re usually looking at coherent optics in a CFP2-DCO form factor \u2014 not QSFP28.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"When_to_Use_Breakout_Cables\"><\/span><strong>When to Use Breakout Cables<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Breakout cables split one QSFP28 into four SFP28 connections. One hundred gigabits in. Twenty-five gigabits out of each of four ports.<\/p>\n\n\n\n<p>Here&#8217;s when breakout makes sense.<\/p>\n\n\n\n<p>You&#8217;re upgrading your leaf switches to 100G but your servers still have 25G NICs. Instead of buying separate 25G leaf switches, you use breakout DACs or AOCs. One QSFP28 port feeds four servers. Clean, simple, cost-effective.<\/p>\n\n\n\n<p>Breakout also helps during migration. You can run a mix of 100G uplinks and 25G server access from the same switch. No need for separate switching tiers.<\/p>\n\n\n\n<p>DAC breakout cables work for in-rack connections up to about 3\u20135 meters. AOC breakout cables reach 7\u201330 meters if you need to cross rows. Both are plug-and-play \u2014 no configuration needed beyond switch port breakout mode.<\/p>\n\n\n\n<p>Not all switches support breakout, though. Check your datasheet. Some platforms require specific ports for breakout. Others support it on any QSFP28 port.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"QSFP28_Compatibility_What_Works_in_What_Port\"><\/span><strong>QSFP28 Compatibility: What Works in What Port?<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><strong>Module<\/strong><\/td><td><strong>QSFP+ Port<\/strong><\/td><td><strong>QSFP28 Port<\/strong><\/td><td><strong>QSFP56 Port<\/strong><\/td><\/tr><tr><td>QSFP+ (40G)<\/td><td>\u2705 Yes<\/td><td>\u2705 Yes (at 40G)<\/td><td>\u26a0\ufe0f Check switch<\/td><\/tr><tr><td>QSFP28 (100G)<\/td><td>\u274c No<\/td><td>\u2705 Yes<\/td><td>\u2705 Yes (at 100G)<\/td><\/tr><tr><td>QSFP56 (200G)<\/td><td>\u274c No<\/td><td>\u274c No<\/td><td>\u2705 Yes<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>The compatibility matrix is pretty simple once you know the rule. Newer ports accept older modules. Older ports reject newer modules.<\/p>\n\n\n\n<p><a href=\"https:\/\/www.fibermall.com\/blog\/qsfp-vs-qsfp28-vs-qsfp56.htm\" target=\"_blank\"><u>QSFP+ in a QSFP28 port works.<\/u><\/a>&nbsp;The switch auto-negotiates down to 40G. QSFP28 in a QSFP+ port does not work. The electrical interface is incompatible.<\/p>\n\n\n\n<p>QSFP56 ports usually accept QSFP28 modules at 100G. That&#8217;s because QSFP56 is designed for backward compatibility. But always check your switch datasheet \u2014 some early QSFP56 platforms had spotty support.<\/p>\n\n\n\n<p>Don&#8217;t assume DAC cables are interchangeable either. A QSFP+ DAC uses 10G\/lane signaling. A QSFP28 DAC uses 25G\/lane signaling. They&#8217;re physically keyed the same, but electrically different. We&#8217;ve seen engineers try to reuse old QSFP+ DACs in new QSFP28 ports. The link won&#8217;t come up.<\/p>\n\n\n\n<p>Here&#8217;s the practical checklist we give customers:<\/p>\n\n\n\n<p>1. Check your switch port type (QSFP+, QSFP28, or QSFP56)<\/p>\n\n\n\n<p>2. Match the module to the port speed<\/p>\n\n\n\n<p>3. Verify your fiber type (MMF or SMF)<\/p>\n\n\n\n<p>4. Confirm connector type (MPO-12 or LC)<\/p>\n\n\n\n<p>5. Check DAC\/AOC compatibility if using direct-attach cables<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<div class=\"ast-oembed-container \" style=\"height: 100%;\"><iframe title=\"100G QSFP28 CWDM4 Optical Transceiver: 2km Data Center Solution | FiberMall\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/bQpTw9omaqc?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/div>\n<\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Is_QSFP28_Still_the_Right_Choice_in_2026\"><\/span><strong>Is QSFP28 Still the Right Choice in 2026?<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>QSFP28 is the mature 100G standard. It&#8217;s been around since 2016. The ecosystem is proven. The pricing is competitive.<\/p>\n\n\n\n<p>And frankly, most data centers are still deploying it in 2026.<\/p>\n\n\n\n<p>So when does QSFP28 still make sense?<\/p>\n\n\n\n<p>You&#8217;re building or maintaining a 100G network<\/p>\n\n\n\n<p>You need proven interoperability across vendors<\/p>\n\n\n\n<p>Your budget doesn&#8217;t stretch to 200G or 400G<\/p>\n\n\n\n<p>You&#8217;re upgrading from 40G and want a well-understood platform<\/p>\n\n\n\n<p>When should you look at newer form factors?<\/p>\n\n\n\n<p>QSFP56 for 200G spine-leaf upgrades<\/p>\n\n\n\n<p>QSFP-DD for 400G greenfield data centers<\/p>\n\n\n\n<p>OSFP for 400G+ AI training clusters<\/p>\n\n\n\n<p>The reality is that 100G isn&#8217;t going anywhere. Most enterprise data centers, telecom edge nodes, and campus cores run QSFP28. The hyperscalers might be at 400G, but the rest of the industry is still solidly at 100G.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Frequently_Asked_Questions\"><\/span><strong>Frequently Asked Questions<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>What speed does QSFP28 support?<\/strong><br>QSFP28 supports 100 Gigabit Ethernet. That&#8217;s four lanes of 25 Gbps NRZ signaling, for an aggregate 100 Gbps data rate. Some switches also support QSFP28 ports at 40G when using QSFP+ modules.<\/p>\n\n\n\n<p><strong>Can I use a QSFP+ module in a QSFP28 port?<\/strong><br>Yes. QSFP28 ports are backward compatible with QSFP+ modules. The switch detects the 40G module and runs the port at 40 Gbps. You cannot use a QSFP28 module in a QSFP+ port, though \u2014 the electrical interface is incompatible.<\/p>\n\n\n\n<p><strong>What is the difference between QSFP28 SR4 and CWDM4?<\/strong><br>SR4 uses multimode fiber and an MPO-12 connector for distances up to 100 meters. CWDM4 uses single-mode fiber and a duplex LC connector for distances up to 2 kilometers. SR4 is cheaper and better for intra-data center links. CWDM4 is the cost-optimized choice for DCI.<\/p>\n\n\n\n<p><strong>Do QSFP28 modules work in QSFP56 ports?<\/strong><br>Usually yes. Most QSFP56 ports accept QSFP28 modules and run them at 100G. QSFP56 is designed with backward compatibility in mind. Always verify with your switch datasheet, though \u2014 some early QSFP56 platforms had limited support.<\/p>\n\n\n\n<p><strong>How much power does a QSFP28 module use?<\/strong><br>Typical power consumption is 3.5\u20134.5W per module. The MSA spec limits maximum power to 4.5W. A fully loaded 32-port switch draws roughly 112\u2013144W from optics alone.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Is_QSFP28_The_Bottom_Line\"><\/span><strong>What Is QSFP28? The Bottom Line<\/strong><strong><\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>QSFP28 is the industry-standard 100G transceiver form factor. Four lanes of 25 Gbps. Same physical size as QSFP+. Backward compatible one direction only. Dominant in data centers, enterprise cores, and telecom networks worldwide.<\/p>\n\n\n\n<p>Here&#8217;s the selection framework in plain terms:<\/p>\n\n\n\n<p>1. Check your switch port type \u2014 QSFP28 ports accept QSFP+ at 40G, but not vice versa<\/p>\n\n\n\n<p>2. Measure your fiber distance \u2014 under 100m with MMF means SR4; over 100m means SMF<\/p>\n\n\n\n<p>3. Match your fiber type \u2014 MMF for SR4\/BiDi, SMF for everything else<\/p>\n\n\n\n<p>4. Consider breakout if you need 25G server access from 100G ports<\/p>\n\n\n\n<p>5. Buy MSA-compliant modules from a vendor who tests compatibility<\/p>\n\n\n\n<p>QSFP28 has been the workhorse of 100G networking for nearly a decade. It&#8217;s proven, widely supported, and cost-effective.<\/p>\n\n\n\n<p>Whether you&#8217;re building a new leaf-spine fabric or upgrading from 40G, QSFP28 is still the right call for most networks in 2026.<\/p>\n\n\n\n<p>Need help selecting the right QSFP28 modules for your deployment? FiberMall offers MSA-compatible QSFP28 SR4, CWDM4, LR4, ER4, and BiDi modules tested for compatibility with Cisco, Arista, Juniper, and major switch platforms. Contact our team for a free compatibility check and volume quote.<\/p>\n\n\n\n<p><\/p>\n<style>\r\n\r\n        .lwrp.link-whisper-related-posts{\r\n            \r\n            margin-top: 40px;\nmargin-bottom: 30px;\r\n        }\r\n        .lwrp .lwrp-title{\r\n            \r\n            \r\n        }\r\n        .lwrp .lwrp-description{\r\n            \r\n            \r\n\r\n        }\r\n        .lwrp .lwrp-list-container{\r\n        }\r\n        .lwrp .lwrp-list-multi-container{\r\n            display: flex;\r\n        }\r\n        .lwrp .lwrp-list-double{\r\n            width: 48%;\r\n        }\r\n        .lwrp .lwrp-list-triple{\r\n            width: 32%;\r\n        }\r\n        .lwrp .lwrp-list-row-container{\r\n            display: flex;\r\n            justify-content: space-between;\r\n        }\r\n        .lwrp .lwrp-list-row-container .lwrp-list-item{\r\n            width: calc(100% - 20px);\r\n        }\r\n        .lwrp .lwrp-list-item:not(.lwrp-no-posts-message-item){\r\n            \r\n            list-style: decimal;\r\n        }\r\n        .lwrp .lwrp-list-item img{\r\n            max-width: 100%;\r\n            height: auto;\r\n        }\r\n        .lwrp .lwrp-list-item.lwrp-empty-list-item{\r\n            background: initial !important;\r\n        }\r\n        .lwrp .lwrp-list-item .lwrp-list-link .lwrp-list-link-title-text,\r\n        .lwrp .lwrp-list-item .lwrp-list-no-posts-message{\r\n            \r\n                \r\n        }\r\n        @media screen and (max-width: 480px) {\r\n            .lwrp.link-whisper-related-posts{\r\n                \r\n                \r\n            }\r\n            .lwrp .lwrp-title{\r\n                \r\n                \r\n            }\r\n            .lwrp .lwrp-description{\r\n                \r\n                \r\n            }\r\n            .lwrp .lwrp-list-multi-container{\r\n                flex-direction: column;\r\n            }\r\n            .lwrp .lwrp-list-multi-container ul.lwrp-list{\r\n                margin-top: 0px;\r\n                margin-bottom: 0px;\r\n                padding-top: 0px;\r\n                padding-bottom: 0px;\r\n            }\r\n            .lwrp .lwrp-list-double,\r\n            .lwrp .lwrp-list-triple{\r\n                width: 100%;\r\n            }\r\n            .lwrp .lwrp-list-row-container{\r\n                justify-content: initial;\r\n                flex-direction: column;\r\n            }\r\n            .lwrp .lwrp-list-row-container .lwrp-list-item{\r\n                width: 100%;\r\n            }\r\n            .lwrp .lwrp-list-item:not(.lwrp-no-posts-message-item){\r\n                \r\n                \r\n            }\r\n            .lwrp .lwrp-list-item .lwrp-list-link .lwrp-list-link-title-text,\r\n            .lwrp .lwrp-list-item .lwrp-list-no-posts-message{\r\n                \r\n                    \r\n            }\r\n        }<\/style>\r\n<div id=\"link-whisper-related-posts-widget\" class=\"link-whisper-related-posts lwrp\">\r\n            <h3 class=\"lwrp-title\">Related Posts<\/h3>    \r\n        <div class=\"lwrp-list-container\">\r\n                                            <ul class=\"lwrp-list lwrp-list-single\">\r\n                    <li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/difference-between-50g-sfp56-and-qsfp28.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">What is the Difference Between 50G SFP56 and QSFP28?<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/server-network-cards.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">The Introduction of Server Network Cards<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/questions\/what-are-100g-lambda-optics.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">What are \u201c100G Lambda\u201d\u00a0Optics?<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/multimode-fiber.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">The Ultimate Guide to Multimode Fiber Optic Cable<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/400g-qsfp-dd-module-types-guide.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">400G QSFP-DD Module Types: SR8 vs DR4 vs FR4 vs LR4 Guide<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/cwdm-transceiver.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">Everything You Need to Know About CWDM Transceivers: From SFP Modules to 80km Optical Fiber Connectivity<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/best-network-switch.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">How to Choose the Best Network Switch for Your Needs<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/what-are-optical-transceiver-modules-aoc-dac-acc.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">Optical Interconnection Technology: What are Optical Transceiver Modules, AOC, DAC, and ACC?<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/combo-pon.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">Combo PON: Efficient Integration of GPON and XG(S)-PON<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/what-is-pam4-signal-and-its-challenges.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">What is PAM4 Signal and its Characterization Test Challenges<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/what-is-fiber-bend.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">What\u00a0is Fiber\u00a0Bend?<\/span><\/a><\/li><li class=\"lwrp-list-item\"><a href=\"https:\/\/www.fibermall.com\/blog\/48-port-network-switch.htm\" class=\"lwrp-list-link\"><span class=\"lwrp-list-link-title-text\">The Ultimate Guide to Choosing a 48-Port Gigabit Ethernet Switch<\/span><\/a><\/li>                <\/ul>\r\n                        <\/div>\r\n<\/div>","protected":false},"excerpt":{"rendered":"<p>QSFP28 (Quad Small Form-factor Pluggable 28) is an industry-standard transceiver form factor that delivers 100 Gigabit Ethernet over four 25 Gbps lanes. It uses the same physical size as QSFP+ but supports 2.5\u00d7 the bandwidth, making it the dominant 100G standard in modern data centers. Pretty much every switch shipped today with 100G ports uses [&hellip;]<\/p>\n","protected":false},"author":227,"featured_media":19475,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":"","_wpscppro_dont_share_socialmedia":false,"_wpscppro_custom_social_share_image":0,"_facebook_share_type":"default","_twitter_share_type":"default","_linkedin_share_type":"default","_pinterest_share_type":"default","_linkedin_share_type_page":"default","_instagram_share_type":"default","_medium_share_type":"default","_threads_share_type":"default","_google_business_share_type":"default","_selected_social_profile":[{"id":"skM9ewvR8O","platform":"linkedin","platformKey":0,"name":"Jason Xue","type":"person","thumbnail_url":"https:\/\/media.licdn.com\/dms\/image\/C5603AQErPqKD0j6qBg\/profile-displayphoto-shrink_100_100\/0\/1599138392315?e=1723075200&v=beta&t=joEkh1OeKQ0F-QpAPv4xxQyBdGlHyccIQZauRSs6RvU","share_type":"default"}],"_wpsp_enable_custom_social_template":false,"_wpsp_social_scheduling":{"enabled":false,"datetime":null,"platforms":[],"status":"template_only","dateOption":"today","timeOption":"now","customDays":"","customHours":"","customDate":"","customTime":"","schedulingType":"absolute"},"_wpsp_active_default_template":true},"categories":[2,30],"tags":[],"class_list":["post-19468","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","category-fiber-optic-transceivers"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v20.13 (Yoast SEO v25.8) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>What Is QSFP28? Complete Guide for Network Engineers (2026)<\/title>\n<meta name=\"description\" content=\"What is QSFP28? Learn the 100G transceiver specs, module types, QSFP+ compatibility, and how to choose the right QSFP28 for your network.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"What Is QSFP28? Complete Guide for Network Engineers (2026)\" \/>\n<meta property=\"og:description\" content=\"QSFP28 (Quad Small Form-factor Pluggable 28) is an industry-standard transceiver form factor that delivers 100 Gigabit Ethernet over four 25 Gbps lanes.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\" \/>\n<meta property=\"og:site_name\" content=\"fibermall.com\" \/>\n<meta property=\"article:published_time\" content=\"2026-06-01T06:00:23+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-06-01T06:00:27+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"900\" \/>\n\t<meta property=\"og:image:height\" content=\"600\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Catherine\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Catherine\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"9 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\"},\"author\":{\"name\":\"Catherine\",\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/person\/bd2cf8d53f883c88f6ebaa5c3ed1258d\"},\"headline\":\"What Is QSFP28? Complete Guide for Network Engineers (2026)\",\"datePublished\":\"2026-06-01T06:00:23+00:00\",\"dateModified\":\"2026-06-01T06:00:27+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\"},\"wordCount\":1671,\"publisher\":{\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#organization\"},\"image\":{\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg\",\"articleSection\":[\"Blog\",\"Fiber Optic Transceivers\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\",\"url\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\",\"name\":\"What Is QSFP28? Complete Guide for Network Engineers (2026)\",\"isPartOf\":{\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg\",\"datePublished\":\"2026-06-01T06:00:23+00:00\",\"dateModified\":\"2026-06-01T06:00:27+00:00\",\"description\":\"What is QSFP28? Learn the 100G transceiver specs, module types, QSFP+ compatibility, and how to choose the right QSFP28 for your network.\",\"breadcrumb\":{\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#primaryimage\",\"url\":\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg\",\"contentUrl\":\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg\",\"width\":900,\"height\":600,\"caption\":\"what is qsfp28\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.fibermall.com\/blog.htm\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"What Is QSFP28? Complete Guide for Network Engineers (2026)\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#website\",\"url\":\"https:\/\/www.fibermall.com\/blog.htm\/\",\"name\":\"fibermall.com\",\"description\":\"Optical Communication Expert\",\"publisher\":{\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.fibermall.com\/blog.htm\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#organization\",\"name\":\"fibermall.com\",\"url\":\"https:\/\/www.fibermall.com\/blog.htm\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2024\/12\/cropped-Fiber-Mall-Logo.jpg\",\"contentUrl\":\"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2024\/12\/cropped-Fiber-Mall-Logo.jpg\",\"width\":200,\"height\":67,\"caption\":\"fibermall.com\"},\"image\":{\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/person\/bd2cf8d53f883c88f6ebaa5c3ed1258d\",\"name\":\"Catherine\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/3a11235a453567962b9c9bb843b31bb4396259dd8abad3f3c3758babd287d778?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/3a11235a453567962b9c9bb843b31bb4396259dd8abad3f3c3758babd287d778?s=96&d=mm&r=g\",\"caption\":\"Catherine\"},\"description\":\"Optical Communications Engineer\",\"sameAs\":[\"https:\/\/www.fibermall.com\/\"],\"url\":\"https:\/\/www.fibermall.com\/blog.htm?author=227\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"What Is QSFP28? Complete Guide for Network Engineers (2026)","description":"What is QSFP28? Learn the 100G transceiver specs, module types, QSFP+ compatibility, and how to choose the right QSFP28 for your network.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm","og_locale":"en_US","og_type":"article","og_title":"What Is QSFP28? Complete Guide for Network Engineers (2026)","og_description":"QSFP28 (Quad Small Form-factor Pluggable 28) is an industry-standard transceiver form factor that delivers 100 Gigabit Ethernet over four 25 Gbps lanes.","og_url":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm","og_site_name":"fibermall.com","article_published_time":"2026-06-01T06:00:23+00:00","article_modified_time":"2026-06-01T06:00:27+00:00","og_image":[{"width":900,"height":600,"url":"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg","type":"image\/jpeg"}],"author":"Catherine","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Catherine","Est. reading time":"9 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#article","isPartOf":{"@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm"},"author":{"name":"Catherine","@id":"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/person\/bd2cf8d53f883c88f6ebaa5c3ed1258d"},"headline":"What Is QSFP28? Complete Guide for Network Engineers (2026)","datePublished":"2026-06-01T06:00:23+00:00","dateModified":"2026-06-01T06:00:27+00:00","mainEntityOfPage":{"@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm"},"wordCount":1671,"publisher":{"@id":"https:\/\/www.fibermall.com\/blog.htm\/#organization"},"image":{"@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#primaryimage"},"thumbnailUrl":"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg","articleSection":["Blog","Fiber Optic Transceivers"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm","url":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm","name":"What Is QSFP28? Complete Guide for Network Engineers (2026)","isPartOf":{"@id":"https:\/\/www.fibermall.com\/blog.htm\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#primaryimage"},"image":{"@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#primaryimage"},"thumbnailUrl":"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg","datePublished":"2026-06-01T06:00:23+00:00","dateModified":"2026-06-01T06:00:27+00:00","description":"What is QSFP28? Learn the 100G transceiver specs, module types, QSFP+ compatibility, and how to choose the right QSFP28 for your network.","breadcrumb":{"@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#primaryimage","url":"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg","contentUrl":"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2026\/06\/what-is-qsfp28.jpg","width":900,"height":600,"caption":"what is qsfp28"},{"@type":"BreadcrumbList","@id":"https:\/\/www.fibermall.com\/blog\/what-is-qsfp28.htm#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.fibermall.com\/blog.htm"},{"@type":"ListItem","position":2,"name":"What Is QSFP28? Complete Guide for Network Engineers (2026)"}]},{"@type":"WebSite","@id":"https:\/\/www.fibermall.com\/blog.htm\/#website","url":"https:\/\/www.fibermall.com\/blog.htm\/","name":"fibermall.com","description":"Optical Communication Expert","publisher":{"@id":"https:\/\/www.fibermall.com\/blog.htm\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.fibermall.com\/blog.htm\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.fibermall.com\/blog.htm\/#organization","name":"fibermall.com","url":"https:\/\/www.fibermall.com\/blog.htm\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/logo\/image\/","url":"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2024\/12\/cropped-Fiber-Mall-Logo.jpg","contentUrl":"https:\/\/www.fibermall.com\/blog\/wp-content\/uploads\/2024\/12\/cropped-Fiber-Mall-Logo.jpg","width":200,"height":67,"caption":"fibermall.com"},"image":{"@id":"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/person\/bd2cf8d53f883c88f6ebaa5c3ed1258d","name":"Catherine","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.fibermall.com\/blog.htm\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/3a11235a453567962b9c9bb843b31bb4396259dd8abad3f3c3758babd287d778?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/3a11235a453567962b9c9bb843b31bb4396259dd8abad3f3c3758babd287d778?s=96&d=mm&r=g","caption":"Catherine"},"description":"Optical Communications Engineer","sameAs":["https:\/\/www.fibermall.com\/"],"url":"https:\/\/www.fibermall.com\/blog.htm?author=227"}]}},"_links":{"self":[{"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=\/wp\/v2\/posts\/19468","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=\/wp\/v2\/users\/227"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=19468"}],"version-history":[{"count":3,"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=\/wp\/v2\/posts\/19468\/revisions"}],"predecessor-version":[{"id":19474,"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=\/wp\/v2\/posts\/19468\/revisions\/19474"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=\/wp\/v2\/media\/19475"}],"wp:attachment":[{"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19468"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19468"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fibermall.com\/blog.htm\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}