{"product_id":"the-glass-thread-single-mode-sfp-transceiver","title":"The Glass Thread | 1.25G Single-Mode SFP Transceiver with LC Duplex, 20km and 40km","description":"\u003cdiv class=\"product-narrative\"\u003e\n\u003cp\u003e\u003cstrong\u003eDistance Is a Cable Problem Until It Becomes a Light Problem.\u003c\/strong\u003e Copper works beautifully for thirty metres and then stops being an engineering choice. Beyond that the signal needs repeaters, the cable gets thick and stiff, and every run becomes a lightning path between two buildings that happen to share an electrical ground. Single-mode fibre replaces all of that with a strand of glass and a laser, and the interface between the fibre and the switch is a small, hot-swappable module that costs less than the labour of pulling the cable. Choose the optic correctly and the run just works for a decade.\u003c\/p\u003e\n\u003cp\u003eThis is that module. The ONT-C311GD-L2S transmits at 1.25Gbps over single-mode duplex fibre through duplex LC\/UPC connectors, reaching 20km on the 1310nm wavelength variant with a 40km option in the same family. DDM and DOM digital diagnostics are supported, so the switch can report optical transmit power, receive power and temperature, which turns a suspected cable fault into a number you can read from the management interface. The module is CE certified and compatibility is stated for Cisco and Mikrotik equipment, which covers the majority of small and mid-sized network cabinets. Options list the single module at 20km, a ten-pack at 20km, and a ten-pack at 40km, so a project can buy one spare or kit out an entire rack in a single order.\u003c\/p\u003e\n\u003cp\u003eThe uses are mundane and constant: linking two buildings on a campus without trusting the mains earth between them, running a warehouse office to a production floor switch across a long hall, connecting a gatehouse or a camera mast, joining a Mikrotik router to a Cisco distribution switch, or upgrading an ISP handoff where the carrier delivers single-mode glass. Wherever two pieces of equipment are further apart than copper wants to go, this is the part that closes the distance.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eCopper degrades with length. Glass degrades with neglect, and you can measure both.\u003c\/em\u003e\u003c\/p\u003e\n\u003c\/div\u003e\u003chr style=\"margin: 20px 0; border: 0; border-top: 1px solid #eee;\"\u003e\u003cdiv class=\"product-features\"\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul style=\"list-style: none; padding: 0;\"\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e✦ 1.25Gbps transmission over single-mode duplex fibre\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e✦ Duplex LC\/UPC connectors, the standard interface in enterprise and carrier cabinets\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e✦ Reach options at 20km on 1310nm and 40km in the same module family\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e✦ DDM and DOM digital diagnostics support for live optical power and temperature readings\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e✦ Compatibility stated for Cisco and Mikrotik switches\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e✦ Hot-swappable SFP form factor, so a link can be changed without touching the switch\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e✦ Sold as a single module or as sealed ten-packs for rack-scale deployment\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e✦ CE certified for the intended network installation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\u003chr style=\"margin: 20px 0; border: 0; border-top: 1px solid #eee;\"\u003e\u003cdiv class=\"product-specs\"\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cul style=\"list-style: none; padding: 0;\"\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eModel Number:\u003c\/strong\u003e ONT-C311GD-L2S\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eForm Factor:\u003c\/strong\u003e SFP, hot-swappable\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eData Rate:\u003c\/strong\u003e 1.25Gbps\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eFiber Type:\u003c\/strong\u003e Single-mode duplex\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eWavelength:\u003c\/strong\u003e 1310nm on the 20km and 40km options listed\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eReach Options:\u003c\/strong\u003e 20km and 40km\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eConnector:\u003c\/strong\u003e Duplex LC\/UPC\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eDiagnostics:\u003c\/strong\u003e DDM and DOM supported\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eStated Compatibility:\u003c\/strong\u003e Cisco and Mikrotik switches\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eOrder Options:\u003c\/strong\u003e Single 20km module, 10-pack 20km, 10-pack 40km\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eCertification:\u003c\/strong\u003e CE\u003c\/li\u003e\n\u003cli style=\"padding: 8px 0; border-bottom: 1px solid #f0f0f0;\"\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e ONTi\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\u003chr style=\"margin: 20px 0; border: 0; border-top: 1px solid #eee;\"\u003e\u003cdiv class=\"product-applications\"\u003e\n\u003ch3\u003eWhere It Belongs\u003c\/h3\u003e\n\u003cp\u003eThis module belongs wherever network runs outgrow copper. Campus links between buildings that have separate electrical supplies. Warehouse switches at opposite ends of a long production hall. Gatehouse, workshop and camera-mast connections back to a main cabinet. ISP handoffs and last-mile links where the carrier terminates in single-mode glass. Small data centres and comms rooms that need a spare optic on the shelf rather than a next-day order. Also useful for any network engineer standardising on a single module to reduce the number of part numbers in the spares kit.\u003c\/p\u003e\n\u003c\/div\u003e\u003chr style=\"margin: 20px 0; border: 0; border-top: 1px solid #eee;\"\u003e\u003cdiv class=\"product-faq\"\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cdiv style=\"margin-bottom: 15px;\"\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Will it work in my Cisco or Mikrotik switch?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eCompatibility is stated for Cisco and Mikrotik equipment. Confirm that your switch accepts third-party SFP modules, since some vendors restrict optics in firmware.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 15px;\"\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What is the difference between DDM and DOM?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBoth describe digital diagnostics on the module: the switch can read optical transmit power, receive power and temperature. That reporting is what turns a suspected fibre fault into a measurable value.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 15px;\"\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Which variant do I need for a short building-to-building link?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe 20km 1310nm option covers far more than a typical campus run, and it is the lower-cost of the two reach options listed. Choose the 40km variant only for genuinely long spans.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 15px;\"\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Can I buy a single module?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. The listing offers one 20km module as well as ten-packs at 20km and 40km, so a single spare or a full rack can be ordered in one go.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 15px;\"\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Is it plug and play?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt is a hot-swappable SFP module. Insert it into an SFP port, connect duplex LC single-mode fibre, and the link negotiates at 1.25Gbps.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"margin-bottom: 15px;\"\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What connector does the fibre side use?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eDuplex LC\/UPC, which is the standard patch-lead connector in enterprise and carrier installations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003chr style=\"margin: 20px 0; border: 0; border-top: 1px solid #eee;\"\u003e\u003cdiv class=\"product-promise\" style=\"background: #fafafa; padding: 18px 20px; border-left: 3px solid #1a1a2e;\"\u003e\n\u003ch3 style=\"margin-top: 0;\"\u003eThe EastSupplier Promise\u003c\/h3\u003e\n\u003cp\u003eEvery unit is inspected before it leaves the warehouse. If a specification on this page does not match what arrives, we cover the return shipping and replace it. English-language support answers within one business day, and replacement parts for this category are stocked so that a working unit stays working.\u003c\/p\u003e\n\u003c\/div\u003e\u003cdiv class=\"product-gallery\" style=\"margin-top: 30px; text-align: center;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H7d2c1e44fb4240ca90288270891ac7abH.webp?v=1698882268\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H5d7c89daa65b49bba04051ac91bcbe7cF.webp?v=1698882270\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H40c4a531235f4abfa58f277c17b10aebq.webp?v=1698882269\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H3cf927a0353442eca301f8442e558f4cn.webp?v=1698882268\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/Hd9cd5afa0bf248d891dce7bbd584a102i.webp?v=1698882268\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H6ccb89fd0e9649d89812ba6eedd1dc7bq.webp?v=1698882269\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/He7ab445579664f02be5e1c30c114b660y.webp?v=1698882269\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H37133842c80a4ac88695aaa0b6874e372.webp?v=1698882270\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H0131980b611247648ea07a39731cf84dk.webp?v=1698882270\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H03296309bbac44e18c59209c726eec82B.webp?v=1698882269\" alt=\"The Glass Thread\" style=\"max-width: 100%; height: auto; margin: 8px 0; border-radius: 6px;\"\u003e\n\u003c\/div\u003e\u003cscript type=\"application\/ld+json\"\u003e\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"Product\",\"name\":\"The Glass Thread | 1.25G Single-Mode SFP Transceiver with LC Duplex, 20km and 40km\",\"brand\":{\"@type\":\"Brand\",\"name\":\"EastSupplier\"},\"description\":\"A 1.25Gbps single-mode SFP optic with duplex LC\/UPC connectors, DDM support and 20km or 40km reach, compatible with Cisco and Mikrotik switches and sold singly or in tens.\",\"image\":[\"https:\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H7d2c1e44fb4240ca90288270891ac7abH.webp?v=1698882268\"],\"sku\":\"Network Hardware\",\"offers\":{\"@type\":\"AggregateOffer\",\"priceCurrency\":\"USD\",\"lowPrice\":\"28.13\",\"highPrice\":\"199.8\",\"offerCount\":3,\"availability\":\"https:\/\/schema.org\/InStock\",\"url\":\"https:\/\/eastsupplier.com\/products\/the-glass-thread-single-mode-sfp-transceiver\"},\"aggregateRating\":{\"@type\":\"AggregateRating\",\"ratingValue\":\"4.75\",\"reviewCount\":\"4\"}}\n\u003c\/script\u003e","brand":"East Supplier Platform","offers":[{"title":"20km 1310nm","offer_id":44477601022175,"sku":"4000265957277-20km 1310nm","price":28.13,"currency_code":"USD","in_stock":true},{"title":"10pcs 20km 1310nm","offer_id":44477601186015,"sku":"4000265957277-10pcs 20km 1310nm","price":199.8,"currency_code":"USD","in_stock":true},{"title":"10pcs 40km 1310nm","offer_id":44477601218783,"sku":"4000265957277-10pcs 40km 1310nm","price":348.57,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0503\/6412\/1244\/files\/H7d2c1e44fb4240ca90288270891ac7abH.webp?v=1698882268","url":"https:\/\/eastsupplier.com\/pt-jp\/products\/the-glass-thread-single-mode-sfp-transceiver","provider":"EastSupplier Platform","version":"1.0","type":"link"}