1. What form-factors are used for 800G transceivers?
There are two main form-factors for 800G transceivers now, the OSFP and the QSFP-DD:
OSFP Form Factor: OSFP is an abbreviation of Octal Small Form-factor Pluggable. This transceiver with Octal (8) electrical lanes, with each lane modulated at 100Gb/s to reach a bandwidth of 800Gb/s. It is slightly larger than the QSFP-DD. With an integrated heat sink, it can greatly improve heat dissipation performance.
QSFP-DD Form Factor: QSFP-DD is short for Quad Small Form-factor Pluggable – Double Density. QSFP-DD is currently the preferred package for 800G optical modules, the QSFP-DD transceivers double the electrical lane density from 4 of QSFP to 8 of QSFP-DD. It can reach 800G if each electrical lane modulated at 100Gb/s.
2. What’s the difference between 800G QSFP-DD and OSFP?
QSFP-DD is smaller and suitable for high-density port layout. In addition, the power consumption of OSFP is slightly higher than that of QSFP-DD. the QSFP-DD form factor is fully backward compatible with QSFP56, QSFP28, and QSFP+, while OSFP is not.
3. Can an OSFP transceiver plugged into a OSFP-DD port and vice versa?
No, the OSFP and QSFP-DD are different form-factors, the size is different, QSFP-DD with the size of 89.4*18.35*8.5mm, and OSFP with the size of 107.8*22.58*13.0mm. QSFP-DD optics should be installed in QSFP-DD fiber port, and OSFP optics should be installed in the OSFP ports.
4. Can an OSFP at one end of an 800G link interoperate with a QSFP-DD at the other?
Yes. The OSFP and QSFP-DD denote the module’s physical form factor. The OSFP and QSFP-DD modules will interoperate with each other if the Ethernet media types are the same.
5. Can an 800G dual-port OSFP transceiver operate with only one port?
Yes, if only one port is used, the transceiver will function at the rate of 400G.
6. Why should using MPO/APC or MTP/APC connectors used for 800G OSFP transceivers with MPO receptacles?
The 100G-PAM4 transceivers are more sensitive to back reflections and use the MPO-12/APC or Angled Polished Connector. The APC connector with an 8-degree polish on the end that causes the back reflections to be diverted into the fiber side cladding and away from the transmitter.
PC and UPC refers to “Physical Contact” or “Ultra Physical Contact” fibers. APC refers to “Angled Physical Contact” fibers. MPO/UPC (flat) cannot be mated together with MPO/APC (angled) connectors.
7. What are the cooling methods for 400G/800G transceivers?
There are two types: Finned-top for enhanced heat dissipation in switches and Flat Top typically used in NlCs due to space limits.
8. What 800G transceivers are available from TARLUZ?
The 800G modules provided by TARLUZ are shown in the table below
| Type | Product | Form Factor | Wavelength | Connector | Reach |
| InfiniBand
|
OSFP-SR8-800G | OSFP Finned Top | 850nm | Dual MTP/MPO-12 APC | 50m@OM4/
30m@OM3 |
| OSFP-DR8-800G | OSFP Finned Top | 1310nm | Dual MTP/MPO-12 APC | 500m | |
| OSFP-2FR4-800G | OSFP Finned Top | 1271nm, 1291nm, 1311nm and 1331nm | Dual LC Duplex UPC | 2km | |
| Ethernet | OSFP-SR8-800G | OSFP Finned Top | 850nm | Dual MTP/MPO-12 APC | 50m@OM4/
30m@OM3 |
| OSFP-DR8-800G | OSFP Finned Top | 1310nm | Dual MTP/MPO-12 APC | 500m | |
| OSFP-2FR4-800G | OSFP Finned Top | 1271nm, 1291nm, 1311nm and 1331nm | Dual LC Duplex UPC | 2km | |
| OSFP800-2LR4-A | OSFP Finned Top | 1271nm, 1291nm, 1311nm and 1331nm | Dual Duplex LC UPC | 10km | |
| QDD-SR8-800G | QSFP-DD | 850nm | MTP/MPO-16 APC | 50m@OM4/
30m@OM3 |
|
| QDD-DR8-800G | QSFP-DD | 1310nm | MTP/MPO-16 APC | 500m | |
| QDD-DR8P-800G | QSFP-DD | 1310nm | MTP/MPO-16 APC | 2km |
