The path to 800G – new Ethernet standards for higher speeds

  

Singlemode and multimode applications for 800G

The growth of the Cloud and, most of all, the further development of hyperscale datacenters are driving transmission standards for even faster Ethernet networks forwards. In particular, applications that make use of AI (Artificial Intelligence) or ML (Machine Learning) as well as the increasing prevalence of home-office work are leading to a growth in bandwidths.

The Ethernet protocol is responding to these growing requirements and will soon support speeds of 800 Gbit/s. What is more, the Ethernet Alliance is already working on the transmission rate which will follow on from 800 Gbit/s, namely 1.6 TBit/s. With this rapid growth in speeds, an Ethernet speed of 3.2 TBit/s by 2025 and 6.4 TBit/s by 2028 is being planned.

  

The transition from 400G to 800G transceivers

Due to the growing bandwidth requirements, the demand for optical 800G transceivers is also increasing and will represent an unavoidable trend in the coming years. Market researchers consider that 400G will hold sway until 2023 and that 800G will come into its own as of 2025. As mentioned above, these high unit volumes will primarily be driven by the hyperscalers. In the opinion of our Product Manager Harald Jungbäck, this development will undoubtedly not take place until the second half of the 2020s for smaller users or even for large enterprise datacenters

  

The two transceiver MSAs Multi Source Agreement) OSFP and QSFP-DD 800 have already proposed specifications for 800G transceivers. In this blog report, we take a look at some of the specifications. You can find more information on all the standards in the video (see below).

  

800G OSFP-Spezifikationen

  

800G OSFP singlemode applications based on 400G technology

The 800GBASE-R standard defines the base layer for 800G networks. The basis for the 800GBASE-R specification is provided by the existing 106.25G lanes, which were defined in 400G Ethernet applications. To achieve greater bandwidths, the number of total lanes in Physical Coding Sublayers (PCS) will be doubled from 4 to 8.

800G-DR4: In this solution, the 800 GBit/s data transfer is performed over four parallel full-duplex 200-Gbit transmission channels (lanes) with PAM4 coding (4x200G=800G). Reach: 1 to 2 km.
Possible connectors: 4 x singlemode MDC Duplex or 4 x singlemode SN Duplex.

Singlemode MDC
Singlemode MDC

MDC 4x (Quad-MDC)

©US Conec Ltd.

Singlemode SN PC 0°
400G-DR4-SN4
Singlemode SN PC 0°

SN 4x (Quad SN)

© SENKO Co. Ltd.

  

800G-FR4: In this solution, the 800 GBit/s data transfer is performed over four parallel full-duplex 200-Gbit transmission channels (lanes) with PAM4 coding (4x200G=800G). Reach: 1 to 2 km.
Connector: Singlemode LC Duplex.

Singlemode LC-Duplex
Singlemode LC-Duplex

LC-Duplex

  

800G-DR8: In this solution, the 800 GBit/s data transfer is performed over eight parallel full-duplex 100-Gbit transmission channels (lanes) with PAM4 coding (8x100G=800G). Reach of the different versions: 1 to 2 km and 1 to 10 km.
Possible connectors: Singlemode MPO/MTP® 16 SM or Dual SM MPO/MTP® 4+4 OCTO, 4 x singlemode MDC Duplex or 4 x singlemode SN Duplex.

Singlemode MPO/MTP®
400G DR4 MTP Octo
Singlemode MPO/MTP®

4 + 4 (OCTO) with an APC 8° oblique cut

Singlemode MDC
Singlemode MDC

MDC 4x (Quad-MDC)

©US Conec Ltd.

Singlemode SN PC 0°
400G-DR4-SN4
Singlemode SN PC 0°

SN 4x (Quad SN)

© SENKO Co. Ltd.

Singlemode MPO/MTP®
Singlemode MPO/MTP®

MPO/MTP® 16 with an APC 8° oblique cut

  

In addition, Google’s 800G-PSM8 specification is also being driven forwards energetically: In this solution, the 800 GBit/s data transfer is performed over eight parallel full-duplex 100-Gbit transmission channels (lanes) with PAM4 coding (8x100G=800G). Reach: up to 100 m.
Connector: Singlemode MPO/MTP® 16
(Source: Google @ OFC 2021, Monday SpE8, “OSA Booth, Tech Talk: Optics to Scale the Datacenter Network”)

Singlemode MPO/MTP®
Singlemode MPO/MTP®

MPO/MTP® 16 with an APC 8° oblique cut

  

800G OSFP multimode applications

800G-SR8: In this solution, the 800 GBit/s data transfer is performed over eight parallel full-duplex 100-Gbit transmission channels (lanes) with PAM4 coding (8x100G=800G). Reach: up to 50m. Possible connectors: Multimode MPO/MTP® 16 APC 8° or Dual MM MPO/MTP® 4+4 OCTO, 4 x multimode OM5 / OM5 MDC Duplex or 4 x SN multimode OM5 / OM5 SN Duplex. Up to a transmission length of 50m, the PreCONNECT® SEDECIM cabling system from Rosenberger OSI fits perfectly for this purpose.

Multimode MPO/MTP®
Multimode MPO/MTP®

4 + 4 (OCTO) with an APC 8° oblique cut

Multimode MDC
Multimode MDC

MDC 4x (Quad-MDC)

©US Conec Ltd.

Multimode SN PC 0°
Multimode SN PC 0°

SN 4x (Quad SN)

© SENKO Co. Ltd.

Multimode MPO/MTP®
Multimode MPO/MTP®

MPO/MTP® 16 with an APC 8° oblique cut

  

Possible connectors

As the overview of the different applications makes clear, a variety of optical fiber connector faces are represented here: LC connectors, MDC connectors, SN connectors and MPO/MTP® connectors in a number of different variants.

The MDC connector (MDC =Miniature Duplex Connector) from US Conec, Ltd. and the SN connector (SN = Senko Nano) from SENKO Co. Ltd. have a very small form factor and belong to the category of VSFF connectors (VSFF = Very Small Form Factor). They therefore confirm the development of optical fiber connectors towards extremely compact, space-saving connector types. The aim is to further increase the port density in datacenters.

In the opinion of our Product Manager Harald Jungbäck, the MDC connector has the potential to replace the LC-Duplex mass-use connector, because it was developed as a Media Dependent Interface (MDI) or Optical Interface for the new OSFP, QSFP-DD and SFP-DD transceivers. Rosenberger OSI has therefore been officially supporting the MDC connector since September 2019, the first cable manufacturer to do so.

  

Cabling solutions for 800G datacenter networks

There are many different ways to prepare a network for 400G and, in the future, 800G applications. A scalable datacenter cabling system that can be adapted quickly and easily to changing requirements permits simple migration. What form does your company’s technology roadmap take? Is your IT infrastructure ready for the growing speed requirements? If you would like to find out more about this topic, please get in touch with our experts.

  

800GBASE-DR8/PSM8 point-to-point cabling

PreCONNECT® SEDECIM patchcord

PreCONNECT® SEDECIM breakout trunk

Part front plates 1/3 MTP®

Connector MTP® 16

  

800GBASE-DR8/PSM8 to 8x50/8x100G SR/SW

Port breakout with MTP® harnesses

PreCONNECT® SEDECIM patchcord

PreCONNECT® SEDECIM breakout trunk

PreCONNECT® SEDECIM MTP®-LCC harness

Connector LCC

Part front plates 1/3 MTP®

Connector MTP® 16

  

Port breakout with MTP® module cassettes

1/3 MTP® module cassettes

Part front plates 1/3 MTP®

PreCONNECT® SEDECIM patchcord

Connector MTP® 16

PreCONNECT® SEDECIM breakout trunk

Connector LCC PPB

PreCONNECT® SEDECIM patchcord LCC-PPB

  

Port breakout avec port breakout unit

1/3 module cassette SMAP-G2 HD
2 x LC8 SM 1 x MTP®16 with pigtail

PreCONNECT® SEDECIM patchcord LCC-PPB

  

Author:
Harald Jungbäck, Product Manager FO cabling systems

Harald Jungbäck draws his fiber optic expertise from his many years of work at Rosenberger OSI. In 1993 he started his career in product and manufacturing process development. Today he is responsible for the consistent expansion of the product range and the technological innovation process in this area.