40G-QSFP-1.4 is Multi-Vendor MSA Compatible QSFP (Quad Small Form-factor Pluggable) Transceiver, operating over four parallel pairs of singlemode optical fiber providing four independent optical communication lanes. It has minimum guaranteed optical budget of 6.3 dB, which in most cases is enough to reach 1.4km distance using single-mode cable. However, distance is just indicative parameter calculated for comfort of identification. Eventually we calculate distance taking in account minimal optical budget and average attenuation of optical cabling in industry. For each lane 40G-QSFP-1.4 uses 4 x FP transmitting lasers and 4 x PIN receivers, operating each lane with speeds of 11.2 Gbps, giving an aggregated maximum bandwidth of 44.8 Gbps. Module supports DDM/DOM optical diagnostics, which provide diagnostic information about the present operating conditions. 40G-QSFP-1.4 operates in Standard 0°-70°C temperature range and has MPO 12 connector. 40G-QSFP-1.4 support 39.81 – 44.8 Gbps data rate and such applications as 40G Ethernet (41.25 Gbps), STM256 (39.81 Gbps), OTU3 (43.108 Gbps) and OTU3e2 (44.58 Gbps). 40G-QSFP-1.4 optical transceiver is multi-purpose module used in number of different places of today’s networking. Consequently, most popular applications are Internet Service Provider (ISP) Fiber To The Home aggregation and backbone, Mobile operator core and back-haul 40G applications, Data Center networking site interconnections and other optical links.