--- title: Is X.25 Still Alive? « ipSpace.net blog | daily.dev description: X.25, the packet-switching protocol from the pre-internet era, is not entirely dead. It persisted in airline check-in terminals for decades, often tunneled... canonical: https://daily.dev/posts/is-x-25-still-alive-ipspace-net-blog-iisl8vl9z twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Is X.25 Still Alive? « ipSpace.net blog | daily.dev og:description: X.25, the packet-switching protocol from the pre-internet era, is not entirely dead. It persisted in airline check-in terminals for decades, often tunneled... og:url: https://daily.dev/posts/is-x-25-still-alive-ipspace-net-blog-iisl8vl9z og:image: https://api.daily.dev/og/posts/Iisl8vL9Z.png og:image:alt: Is X.25 Still Alive? « ipSpace.net blog og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Is X.25 Still Alive? « ipSpace.net blog **[ipSpace.net Blog](https://daily.dev/sources/ipspace)** · 3 min read · 0 upvotes · 0 comments ## Summary X.25, the packet-switching protocol from the pre-internet era, is not entirely dead. It persisted in airline check-in terminals for decades, often tunneled over TCP via XOT (X.25 over TCP). France Telecom's Minitel network, which ran on X.25, wasn't shut down until 2012 with 800,000 terminals still active. X.25 also lives on in aviation: it is part of the VHF Data Link (VDLm2) protocol stack for air-to-ground communications and is expected to remain in use until at least 2030. AX.25, a derivative, is still used by amateur radio operators for packet radio. Cisco even added X.25/XOT support to its ISR 4000 series in IOS XE 16.10.1a as late as 2018, likely driven by aviation industry customers. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Is X.25 still used anywhere in the world? X.25 is still in active use in several niches. Airline check-in terminals have used it for decades, often tunneled via XOT (X.25 over TCP). It is part of the VDLm2 (VHF Data Link mode 2) protocol stack for aircraft-to-ground communications and is expected to remain there until at least 2030. AX.25, a derivative, is used by amateur radio operators for packet radio networks. Cisco added X.25/XOT support to ISR 4000 routers in IOS XE 16.10.1a in 2018. _Network engineers maintaining legacy infrastructure track protocol end-of-life timelines on daily.dev._ ### Why was X.25 so popular for airline check-in terminals? X.25 suited airline check-in terminals for three reasons: billing was usage-based with no fixed recurring fee for remote airfield circuits, bandwidth requirements were minimal since terminals used short CLI commands, and X.25 was resilient enough to operate over high-error-rate links that would stall TCP connections. These properties made it cost-effective and reliable for geographically dispersed, low-throughput terminal deployments. _Engineers modernizing aviation ground infrastructure share migration experiences on daily.dev._ ## Similar posts on daily.dev - [IEEE Spectrum's Top Telecom Stories of 2025](https://daily.dev/posts/ieee-spectrum-s-top-telecom-stories-of-2025-o8meodh4g) · IEEE Spectrum · 0 upvotes · 0 comments - [IPv6 in 2025 – Transitioning to IPv6](https://daily.dev/posts/ipv6-in-2025-transitioning-to-ipv6-x1lwgorkb) · Cisco · 0 upvotes · 0 comments - [The IPV4 We Didn’t Get](https://daily.dev/posts/the-ipv4-we-didn-t-get-mgaj9qpb2) · Hackaday · 0 upvotes · 0 comments - [2026-01-14: The Day the telnet Died – GreyNoise Labs](https://daily.dev/posts/2026-01-14-the-day-the-telnet-died-greynoise-labs-h8gd1lqll) · Hacker News · 0 upvotes · 0 comments --- Tags: [#networking](https://daily.dev/tags/networking) [View this post on daily.dev](https://daily.dev/posts/is-x-25-still-alive-ipspace-net-blog-iisl8vl9z) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Is X.25 Still Alive? « ipSpace.net blog","url":"https://daily.dev/posts/is-x-25-still-alive-ipspace-net-blog-iisl8vl9z","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/is-x-25-still-alive-ipspace-net-blog-iisl8vl9z"},"datePublished":"2026-08-11T08:52:54.978Z","dateModified":"2026-08-11T09:03:33.342Z","description":"X.25, the packet-switching protocol from the pre-internet era, is not entirely dead. 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Airline check-in terminals have used it for decades, often tunneled via XOT (X.25 over TCP). It is part of the VDLm2 (VHF Data Link mode 2) protocol stack for aircraft-to-ground communications and is expected to remain there until at least 2030. AX.25, a derivative, is used by amateur radio operators for packet radio networks. Cisco added X.25/XOT support to ISR 4000 routers in IOS XE 16.10.1a in 2018. Network engineers maintaining legacy infrastructure track protocol end-of-life timelines on daily.dev."}},{"@type":"Question","name":"Why was X.25 so popular for airline check-in terminals?","acceptedAnswer":{"@type":"Answer","text":"X.25 suited airline check-in terminals for three reasons: billing was usage-based with no fixed recurring fee for remote airfield circuits, bandwidth requirements were minimal since terminals used short CLI commands, and X.25 was resilient enough to operate over high-error-rate links that would stall TCP connections. These properties made it cost-effective and reliable for geographically dispersed, low-throughput terminal deployments. Engineers modernizing aviation ground infrastructure share migration experiences on daily.dev."}}]} ```