QSFP-40G-UNIV vs QSFP-40G-SWDM4, How to Choose?

Nowadays, the demand for high bandwidth is continuously increasing, significantly expanding data center footprints. This makes the migration from 10G to 40G more necessary than ever before. In this context, many enterprises are either in the process of upgrading or planning to upgrade their data center network infrastructure. Both the QSFP-40G-UNIV and QSFP-40G-SWDM4 modules utilize short-wavelength division multiplexing (SWDM) technology to enable the migration from 10G to 40G. To better meet users' needs, this article will compare these two modules, aiming to provide an economically efficient optical module solution for 10G to 40G migration applications.

QSFP 40G UNIV Transceiver for SWDM Application

The QSFP 40G UNIV is a pluggable optical module equipped with Duplex-LC connectors, which can be used with both single-mode and multimode fiber patch cords. Therefore, it is also known as a 40G SMF&MMF optical module or a 40G QSFP universal optical module. When using single-mode fiber, the QSFP 40G UNIV can support a 40G connection with a transmission distance of up to 2km. When using multimode fiber OM3/OM4, the transmission distance can reach 150m. Additionally, the QSFP 40G UNIV is designed with four 10G channels, allowing four separate 10G signals to be transmitted and received through a single Duplex-LC fiber optic patch cord, thereby achieving a total 40G connection.

With the help of SWDM technology, the QSFP 40G UNIV module multiplexes four wavelengths: 1270nm, 1290nm, 1310nm, and 1330nm, and transmits four 10G signals through a single Duplex-LC fiber patch cords. When the aggregated 40G signal reaches the receiving end, it is demultiplexed back into four separate 10G signals. Therefore, it is possible to transmit the aggregated 40G signal through a single Duplex-LC fiber optic patch cord. In short, the 40G universal transceiver is an excellent choice for 40G migration as it can be used with LC duplex single-mode or multimode fibers.

QSFP 40G SWDM4 Transceiver for SWDM Application

The QSFP 40G SWDM4 module is designed to work in conjunction with Duplex-LC fiber patch cords to achieve short-range 40G fiber links. It operates on the same principle as the QSFP 40G UNIV, utilizing SWDM technology, but with improved transmission performance. Unlike the QSFP 40G UNIV, which is compatible with both single-mode and multimode fibers, the QSFP 40G SWDM4 is specifically designed for use with multimode fibers. It can transmit multiplexed 40G signals over wideband OM5 fibers with a length of up to 500m. It can also operate in multimode fibers OM3 and OM4, with transmission distances of 300m and 400m, respectively.

Similar to the QSFP 40G UNIV optical module, the QSFP 40G SWDM4 module employs four different wavelengths: 850nm, 880nm, 910nm, and 940nm. To transmit the total 40G signal, these four wavelengths are multiplexed to carry four separate 10G signals, which are then transmitted through Duplex-LC multimode fiber patch cords and demultiplexed at the receiving end.

QSFP-40G-UNIV vs QSFP-40G-SWDM4, Which One is Better?

As mentioned above, both QSFP 40G UNIV and QSFP 40G SWDM4 transceivers allow network operators to increase network capacity without the need for new fiber cabling. In terms of fiber type, the QSFP 40G UNIV module is compatible with both single-mode and multimode fibers, while the QSFP 40G SWDM4 module is primarily designed for multimode fibers such as OM3, OM4, or OM5.

In terms of transmission distance, when used with OM5, the QSFP 40G SWDM4 optical module supports longer 40G fiber links compared to the QSFP 40G UNIV used with OM3/OM4. However, it supports shorter 40G fiber links compared to the QSFP 40G UNIV used with single-mode fiber.

Regarding fiber cabling infrastructure cost, OM5 cabling is approximately 50% more expensive than OM4. Therefore, the choice depends on your network requirements, such as fiber type, fiber link distance, budget, etc. FS provides both QSFP 40G UNIV and QSFP 40G SWDM4 modules to meet your specific needs.