How to Cable a 400G Parallel Data Center?

        There are two transmission schemes for data center optical modules: parallel and WDM (Wavelength Division Multiplexing). For the same data rate, the cost of parallel optical modules is lower than that of WDM optical modules, while the fiber cost is the opposite. Therefore, parallel schemes offer significant advantages for short-haul and medium-to-long-haul transmission. This article uses Hilink's 400G optical modules as examples to explain how 400G parallel optical modules are applied in data centers.

        Parallel fiber solutions are an important way to expand data center capacity today. From multimode parallel solutions between racks to single-mode parallel solutions for medium-to-long distances, the advantages of parallel optical modules lie in their low cost and high reliability. With the continuous upgrade of data rates, many 400G optical modules have been released on the market. Common parallel optical modules include 400G SR8, 400G PSM8, and 400G DR4.

400G parallel optical modules have the following optical ports:

Scenario 1: QSFP-DD to QSFP-DD Local

Solution

• 400G QSFP-DD SR8 connects to a 16/24-fiber MPO/MTP patch cord.

• 400G QSFP-DD PSM8 connects to a 16-fiber MPO/MTP patch cord.

• 400G QSFP-DD DR4 connects to an 8-fiber MPO/MTP patch cord.

Scenario 2: 400G QSFP-DD DR4 Across DC With Trunk

Solution​

• Select a 4×12-fiber MPO/MTP trunk cable for centralized cabling. Use a 4-port MPO/MTP adapter panel to connect the trunk cable to multiple 8-fiber MPO/MTP patch cords.

Scenario 3: 400G QSFP-DD DR4 to QSFP Local

Solution

• The 400G QSFP-DD DR4 uses an 8-fiber MPO/MTP patch cord to connect to an 8-fiber MTP/MPO-to-LC cassette. On the other end, duplex LC patch cords connect to four 100G QSFP28 DR/FR optical modules.

​Scenario 4: 400G QSFP-DD DR4 to QSFP Across DC with Trunk

Solution

• The 400G QSFP-DD DR4 connects to an 8-fiber MPO/MTP patch cord, which then connects to a 4×12-fiber trunk cable via a 4-port MPO/MTP adapter panel. On the other end, the trunk cable connects to four 8-fiber MTP/MPO-to-LC cassettes, which connect via duplex LC patch cords to sixteen 100G QSFP28 DR/FR optical modules.

Scenario 5: 400G QSFP-DD SR8 Across DC With Trunk

Solution

• The 400G QSFP-DD SR8 uses a 16-fiber to 2×8-fiber breakout cable to connect to a 4-port MPO/MTP adapter panel, which then connects to a 4×12-fiber trunk cable.

Scenario 6: 400G QSFP-DD SR8 to SFP Local

Solution

• The 400G QSFP-DD SR8 uses a 16-fiber to 2×8-fiber breakout cable to connect to an 8-fiber MTP/MPO-to-LC cassette. On the other end, duplex LC patch cords connect to SFP optical modules.

Scenario 7: 400G QSFP-DD SR8 to SFP Across DC with Trunk

Solution

• The 400G QSFP-DD SR8 uses a 16-fiber to 2×8-fiber breakout cable to connect to a 4-port adapter panel. On the right side, the 4×12-fiber trunk cable connects via an 8-fiber MTP/MPO-to-LC cassette to SFP optical modules, which are connected using LC duplex patch cords.

Conclusion

        Depending on the specific conditions and requirements of the data center, there are many other possible cabling methods. If you need to deploy your own data center, you can leave us a message, and we will provide you with the requirements and solutions for different optical modules.