The current state of-the-art for data center intraconnect, up to 2km, is 100G but that is not enough. The largest data center operators, the ICPs, want 400G. At OFC 2018, the industry stepped up with a multitude of announcements and demonstrations, covering the breadth of the 400G ecosystems. The optical components and semiconductor community offered modules, discrete lasers, and communications semiconductors. To date, Ovum has tracked the following:
AOI 400G QSFP-DD DR4 and FR4, PAM4 DML and EML
Broadcom Tomahawk 3: 56Gbps PAM4 SerDes, 400G gearbox
Inphi 400G PAM4 DSP for QSFP-DD and OSFP, TIA and driver
Finisar 400G QSFP-DD AOC VCSEL based
Lumentum 400G modules: QSFP-DD FR4, DR4 and OSFP FR4, 100G PAM4 EML
Macom EML driver for 53GBaud PAM4, PAM4 VCSEL driver and TIA
MaxLinear 400G PAM4 DSP with integrated laser driver
NeoPhotonics 53 GBaud EML with integrated driver, PIN PD, TIA
Oclaro 400Gbps QSFP56-DD FR4, 53GBaud TOSA and ROSA, gearbox IC, PAM4 EML, DFB-MZ PIC
Source Photonics QSFP-DD 400GBASE-LR8
Sumitomo QSFP-DD 400G-FR4
The 400G market is in its infancy. Substantial commercial revenues are in some way in the latter half of 2019. There will be different consumptions models: Some ICPs may buy discretes and task contract manufacturers to assemble, while others will be complete modules. The industry will work feverishly to reduce cost leveraging photonic integration and optimized manufacturing processes. The ICPs may throw further curve balls, recalling the cost-optimized 100G CWD4 OCP with relaxed specifications for cost efficiency. 400G will be a highly competitive contest. May the lowest cost per bit providers win.
At OFC 2018, Microsemi has introduced OTN3.0. OTN1.0 supported the 10G lineside era, while OTN2.0 stepped up to 100G. Meanwhile, OTN3.0 needs to support a much more complex era of variable lineside speeds from 100G to 600G. In addition, the client side has evolved to 10GE, 25GE, 100GE, 200GE, 400GE, FlexE, and FlexO. And network operators would also like a power consumption reduction.
Microsemi's OTN3.0, DIGI-G5, is a 1.2Tbps chip, supporting the client-side options noted above, and connects to optical transceivers and coherent DSPs via 56G PAM4 SerDes. The DIGI-G5 supports core OTN switching and network-edge applications. Wirespeed OTN encryption is included.
OTN began with a small set of CSP proponents. As lineside speeds rose and SONET/SDH faded, OTN gained further favor as the switching and aggregation mechanism of choice. With greater flexibility on the line and client sides, OTN is the essential client-to-line mapping mechanism. The OTN application space has broadened, so much so, that dare ICPs consider OTN?