{"id":20359,"date":"2026-09-22T06:29:49","date_gmt":"2026-09-22T06:29:49","guid":{"rendered":"https:\/\/www.fibermall.com\/blog\/?p=20359"},"modified":"2026-09-22T06:29:54","modified_gmt":"2026-09-22T06:29:54","slug":"qsfp112-module-types-vr4-sr4-dr4-fr4-and-lr4-compared","status":"publish","type":"post","link":"https:\/\/www.fibermall.com\/blog\/qsfp112-module-types.htm","title":{"rendered":"QSFP112 Module Types: VR4, SR4, DR4, FR4 and LR4 Compared"},"content":{"rendered":"\n

Send a request for \u201ca 400G QSFP112 module\u201d<\/strong> to three different vendors and you may receive three different recommendations. One vendor may quote a DR4. Another may suggest a DR4+. A third may ask about your installed fiber infrastructure and explain that neither option matches your deployment requirements.<\/p>\n\n\n\n

That is not simply vendor confusion. QSFP112 modules use several overlapping naming systems, and some commonly used names are industry terms rather than IEEE-defined interface names. When a link fails to establish, a mismatch between the requested module type and the actual optical specification is one of the first things to verify.<\/p>\n\n\n\n

QSFP112 is a form factor<\/strong>, not an optical specification. It defines the mechanical package and electrical interface requirements, but it does not determine whether the module uses multimode or single-mode fiber, which connector is required, or what transmission distance it supports. Those decisions are determined by the optical variant, and QSFP112 module types differ mainly in these areas.<\/p>\n\n\n\n

This guide covers the five common optical variants, the LPO implementation approach that can be combined with different optical designs, common naming differences that lead to ordering mistakes, breakout capability as a key deployment consideration, and current 2026 pricing. For more background, see our complete QSFP112 400G guide.<\/strong><\/u><\/strong><\/a><\/p>\n\n\n\n

\"400G<\/figure>\n\n\n\n
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