Regarding Ethernet or 10GBASE-T, since 2017 [10GBASE-T, finally popular?], we delivered all 11 episodes and 2 extra episodes.However, twisted pair copper wiring Ethernet is up to 10GBASE-T, and 25/40GBASE-T has not yet been put into practical use.The base is "200GBASE-FR4" defined by "IEEE 802.3bs", as mentioned in "Each standard of 'IEEE 802.3bs' that achieves 400 Gbps at 50/25 Gbps per lane"."As a base" means that it is naturally different or customized, and the differences are as follows.The last story is also interesting.Probably, the reach of the "CWDM4-OCP-100G" introduced last time is only 500m, but there are about 20% of cases that exceed this.Even if you close your eyes to the 3km range, it seems that the CWDM4-100G introduced in this article was used to connect in the 2km range.And perhaps as a result of sequential upgrades in the form of replacing this CWDM4-100G module with 200G-FR4-OCP, CWDM4-100G and CWDM4-100G will be able to communicate at 100Gbps even during the transition period. Compatibility was required.The upper left is 200G-FR4-OCP, and the upper right is the Transmit Parameter of 200GBASE-FR4.The former has A to D Deviations (comments) on the right, and the contents are as follows.Items without this footnote are unchanged from 200GBASE-FR4.The maximum light emission power remains unchanged at 10.7dBm (≒3mW) overall and 4.7dBm (≒11.7mW) for each lane, and the extension of the reach is mainly supported by raising the reception sensitivity.On the receiving side, the left side is 200G-FR4-OCP, and the right side is 200GBASE-FR4 Receive Parameter.In fact, when comparing the average receive power, the value of Each Lane is -8.2 to 4.7 dBm (≒ 0.15 to 2.95 mW) to -9.2 to 4.7 dBm (≒ 0.12 to 2.95 mW), and the signal is attenuated accordingly. is assumed.If this is passed as is, the BER will probably deteriorate considerably.To prevent this, 3.4E-6 seems to have been added as the BER floor.Adding FEC to support lower BER makes it impossible to reuse the existing 200GBASE-FR4 PCS.From a purely technical point of view, the PCS itself should be usable, but it seems that FEC will be sandwiched between the PCS and the PMA.In reality, everything from PCS to PMA is completely integrated into a single chip. It seems to have gone in that direction.By the way, another point added with 200G-FR4-OCP is power consumption.This is 100G, that is, 6W when operating as CWDM4-100G, and 6.5W when operating at 200G (that is, 200G-FR4-OCP).Also, the module shape is supposed to use QSFP28 to QSFP56.However, these two have the same module shape and the only difference is whether the signal is 28G NRZ or 56G PAM4 (that is, the electrical signal speed is different).Given that the reach is around 3km, the number of users who want to use it is likely to be smaller than that of CWDM4-OCP-100G, but if demand is still expected in a Facebook-class large-scale data center, there is a market to prepare the product. That's what it means.As for 400G-FR4-OCP, which follows this, as of May 2021, ``400GbE is led by Facebook and Microsoft's DC operators, and the Beyond 400G Study Group insists on standardization of 1.6T at the same time as 800G. ], the specification has not been released yet, and the contents remain unknown.However, as with 200G-FR4-OCP, the base is "400GBASE-FR4" introduced in "400G-FR4 with a maximum 400 Gbps and a reach of 2 km and "400G-LR4-10" with a reach of 10 km. is extended to 3 km, narrowed the operating temperature range to 15 to 65 ° C, and seems to be compatible with 200G-FR4-OCP.What worries me is the module, and it cannot support 400G with QSFP56 as it is.One idea is "QSFP56-DD", which is backwards compatible with QSFP28/QSFP56 and may be adopted.However, I can't say anything about this unless the specification comes out.Freelance technical writer.His expertise spans a wide range of fields, from CPUs, memories, and chipsets to communications, OS, databases, and medical-related fields.Homepage is http://www.yusuke-ohara.com/"CWDM4-OCP-100G" with a reach of 500m begins to be widely distributed as a low-cost 100G Ethernet standardWi-Fi HaLow, a standard for IoT devices with a maximum reach of 80 Mbps and a reach of 1 km at 150 kbps"CWDM4-OCP-100G" with a reach of 500m begins to be widely distributed as a low-cost 100G Ethernet standardAchieving 100 Gbps by consolidating 25 Gbps x 4 into one SMF, "CWDM4 MSA" with a reach of 2 km and "4WDM MSA" with a reach of 10/20/40 km400GbE led by Facebook and Microsoft DC operators, Beyond 400G Study Group insists on standardization of 1.6T at the same time as 800G"400G-FR4" with a maximum of 400 Gbps and a reach of 2 km and "400G-LR4-10" with a reach of 10 kmCopyright ©2018 Impress Corporation.