Due to server consolidation, virtualization, and performance improvements, there is a growing need in the data center for 40GbE switch connections. For many data center operators, this upgrade and conversion is more challenging based on two primary factors. Firstly, the potential for a reconfiguration of the physical layer of the network based on reduced reach of the OM3/OM4 multimode optics from SFP+ 10GBASE-SR (300/400 m) to QSFP+ 40GBASE-SR4 (100/150 m). Secondly, the existing fiber optic cabling plant may need to be upgraded based on the additional fiber count needed to support the IEEE-defined 40GBASE-SR4 parallel optics. These two factors bring the 40GBASE-UNIV optical transceiver to market.
The 40GBASE-UNIV QSFP+ is a pluggable optical transceiver with a duplex LC connector that can operate with both single-mode fiber and multimode fiber. Generally, the transmission distance could be up to 150 m over OM3/OM4 and up to 2 km over SMF. It has 4 channels of 10G multiplexed inside the module to transmit and receive an aggregate 40G signal over a single pair (2 strands) of fiber. It is called “Universal” because of its ability to operate with both SMF and MMF without the need for any software/hardware changes to the module or any additional hardware in the network. The 40GBASE-UNIV QSFP+ offers a very cost-effective connectivity solution and unique value proposition for data centers to migrate from 10G to 40G with minimal disruption over existing single-mode and multimode infrastructure.
40G transmission over 2 fibers—Existing 40G transceiver for short reach, such as 40GBASE-SR4, utilizes four independent 10G transmitters and receivers for an aggregate 40G link, requiring a total of 8 fibers per link. It uses an MPO-12 connector and requires a parallel multimode fiber (OM3 or OM4). This is four times more fiber than is required for 10G short reach links (see Figure 1). The 40GBASE-UNIV transceiver also uses four transmitters and four receivers but has built in optical multiplexing and de-multiplexing, which results in a duplex connector and hence operates over the same duplex fiber infrastructure as 10GBASE-SR.
Save cost—Besides the reduced number of fibers per 40G link, the 40GBASE-UNIV transceiver offers significant cost savings in the overall fiber cable infrastructure. Customers retain the existing structured cabling system as is for 10G to 40G migration, but they have to change the patch cables and patch panel infrastructure to use a 40GBASE-SR4 QSFP+.
The Figure 2 shows typical 1-trunk cable infrastructure for QSFP+ SR4, and Figure 3 shows the associated cabling cost with 40G link as in Figure 2.
Figure 4 shows typical 1-trunk cable infrastructure for QSFP+ UNIV, and Figure 5 shows the cabling cost associated with 40G link as in Figure 4.
A saving of over 75% on the cabling equipment alone is realized from the UNIV transceiver. The significant cost savings make the 40GBASE-UNIV transceiver an ideal choice for 40G leaf-spine connections with existing multimode fiber.
Easy migration to 100G with single-mode fiber—As data rates increase from 40G to 100G and beyond to 400G, there is a strong desire for data centers to move to single-mode for cost effectiveness and to future proof the fiber infrastructure. Due to the limitations of multimode transceivers to support existing distances with ever increasing data rates, migrating to 100G and 400G in the future will be simpler with single-mode fiber. However, the major pain point in this transition has traditionally been the optics cost. Single-mode transceivers typically cost up to 4 times more compared to multimode transceivers. The 40GBASE-UNIV transceiver has broken this barrier with the following reasons:
- Cost of the optical transceiver is less than 2 times of multimode transceiver
- Same optics for SMF and MMF
- Investment protection as the same optics can be used when migrating from MMF to SMF
- Compatible with industry standard 40GBASE-LR4 and the LR4-Lite (1km version)
Figure 6 shows typical 1-trunk single-mode fiber cable infrastructure for QSFP+ UNIV, and Figure 7 shows cabling cost associated with a 40G link using all single-mode fiber infrastructure as in Figure 6.
The 40GBASE-UNIV transceiver enables data centers to run at 10G today to seamlessly upgrade to 40G without having to re-design or modify the cable infrastructure. It also offers a transition path for customer planning migrations to single-mode fiber in data centers with a single transceiver that bridges the gap between multimode and single-mode optics. FS.COM provides 40GBASE-UNIV transceivers and the associated optics for 40G and 100G connectivity. All of the optics are tested on the corresponding equipment to ensure the excellent performance with the customers’ devices.