Things to Know about 40GBASE-SR4 QSFP+ Modules

With the growing demand for high data rates, 40 Gigabit Ethernet (GbE) is now becoming more and more widely adopted. For a 40 GbE network application, precise connectivity is crucial. 40G QSFP (quad small form factor pluggable) portfolio offers customers a wide variety of high-density and low-power 40 Gigabit Ethernet connectivity options. Among them, 40GBASE-SR4 QSFP+ transceiver is a common 40 GbE connectivity option. And here are some things that you need to know about 40GBASE-SR4 QSFP+ transceivers.

Introduction

40GBASE-SR4 is a fiber optic interface for multimode fiber of OM classes 3 and 4 with four parallel OM3 or OM4 fibers in both directions. “S” means short, indicating that it is an interface for short distances. The “R” denotes the type of interface with 64B/66B encoding and the numeral 4 indicates that the transmission is carried out over a ribbon fiber with four multimode fibers in every direction. Each lane has a 10 Gbit/s data rate. 40GBASE-SR4 QSFP+ modules usually use a parallel multimode fiber (MMF) link to achieve 40G. It offers 4 independent transmit and receive channels, each capable of 10G operation for an aggregate data rate of 40G over 100 meters of OM3 MMF or 150 meters of OM4 MMF. It primarily enables high-bandwidth 40G optical links over 12-fiber parallel fiber terminated with MPO/MTP multifiber female connectors.

40GBASE-SR4 QSFP+ module can also be used in a 4x10G mode for interoperability with 10GBASE-SR interfaces up to 100 and 150 meters on OM3 and OM4 fibers, respectively. The worry-free 4x10G mode operation is enabled by the optimization of the transmit and receive optical characteristics to prevent receiver overload or unnecessary triggering of alarm thresholds on the 10GBASE-SR receiver, and at the same time is completely interoperable with all standard 40GBASE-SR4 interfaces. The 4x10G connectivity is achieved using an external 12-fiber parallel to 2-fiber duplex breakout cable, which connects the 40GBASE-SR4 module to four 10GBASE-SR optical interfaces. The picture below shows a Mellanox MC2210411-SR4 compatible 40GBASE-SR4 QSFP+ transceiver.

40GBASE-SR4 QSFP+ Module vs 40GBASE-CSR4 QSFP+ Module

40GBASE-CSR4 QSFP+ module is similar to the 40GBASE-SR4 interface extends supported link lengths to 300m and 400m respectively on laser-optimized OM3 and OM4 multimode fiber cables. Each 10-gigabit lane of this module is compliant to IEEE 10GBASE-SR specifications. This module can be used for native 40G optical links over 12-fiber ribbon cables with MPO/MTP connectors, or in 4x10G mode with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR interfaces. Maximum channel insertion loss allowed is respectively 2.6dB over 300m of OM3 cable or 2.9dB over 400m of OM4 cable.

Conclusion

Fiberstore offers you a wide variety of 40GBASE-SR4 QSFP+ transceivers for your high-density and low-power 40 Gigabit Ethernet connectivity options branded by many famous companies like Cisco, Juniper or HP. And we also provide other compatible 40G QSFP+ transceivers, such as 40GBASE-LR4 QSFP+ transceiver, 40GBASE-ER4 QSFP+ transceiver, 40GBASE-CSR4 QSFP+ transceiver, etc. Every fiber optic transceiver provided by Fiberstore has been tested to ensure its compatibility and interoperability. You can buy from us with confidence.

A Guide to 40 Gigabit Ethernet

The 802.3ba Ethernet standard introduced by the IEEE in June 2010 was in response to the increasing bandwidth demands facing data centers, paving the way for the introduction of 40Gb/s and 100Gb/s Ethernet operations. As you begin to think about the future of your network, understanding all the 40 Gigabit Ethernet (40GbE) and 100 Gigabit Ethernet (100GbE) optical components can be confusing. In this post, a brief overview of the current 40 Gigabit Ethernet to aid in planning for future high-performance Ethernet needs will be given.

What Is 40 Gigabit Ethernet?

40GbE is a standard that enables the transfer of Ethernet frames at speeds of up to 40 gigabits per second (Gbit/s). The 40GbE standard is intended for local server connectivity. One of the most attractive characteristics of 40 Gigabit Ethernet is broad applications and design flexibility. 40 Gigabit Ethernet runs on quad small form factor pluggable (QSFFP) cabling, a high-density fiber connector with 12 strands of fiber. According to the task force, 40GbE fulfills the following requirements and objectives:

• Preserve existing 802.3 frame format, minimum size, and maximum size.
• Support high-bandwidth applications such as video on demand (VoD) and high-performance computing (HPC).
• Support high-speed switching, routing, and application functions in data centers.
• Exhibit a bit error rate (BER) of 10-12 or better.
• Provide support for optical transport network (OTN).
• Provide specifications for operation over single-mode optical fiber, laser optimized multi-mode optical fiber, copper cables, and backplanes.

How Does 40 Gigabit Ethernet Work?

40 Gigabit Ethernet can be deployed using the same cabling systems in use today. Multi-mode will employ parallel optics using MPO interconnects and require additional cable infrastructure depending on the system deployed while single mode fiber will employ serial transmission and use LC or SC connectors. The approach used for the higher speed data rates is based on advanced transceiver technologies engineered to take advantage of the full bandwidth of laser optimized fibers. The 40 Gigabit Ethernet specification calls for a 12-fiber cabling solution, implemented using eight of the twelve fibers in an MPO connector, with each channel featuring four dedicated transmit fibers and four dedicated receive fibers. The middle four fibers remain unused, or dark. Each Tx/Rx pair is operating at 10G.

40 Gigabit Ethernet Cables

Cabling for 40 Gigabit Ethernet can be optical fiber or copper. The supportable channel length depends on the cable and the transceiver type. With regard to connectors, the only significant change outlined in the 802.3ba standard is the use of MPO (Multi-Fiber Push On) type connectors at the multi-mode transceivers to support the multi-fiber parallel optics channels. For data center environments operating at 40Gbps, OM3 and OM4 multi-mode cabling is generally recommended because its reach supports a wider range of deployment configurations compared to copper solutions, and the cost is lower compared to single-mode solutions.

40 Gigabit Ethernet Transceivers

40 Gigabit Ethernet transceivers are being developed along several standard form factors. The C form-factor pluggable (CFP) transceiver features 12 transmit and 12 receive 10Gbps lanes to support up to three 40 Gigabit Ethernet ports. Its larger size is suitable for the needs of single-mode optics and can easily serve multi-mode optics or copper as well. The CXP transceiver form factor also provides 12 lanes in each direction, but is much smaller than the CFP and serves the needs of multi-mode optics and copper. The quad small form-factor pluggable (QSFP) is similar in size to the CXP and provides four transmit and four receive lanes to support 40 Gigabit Ethernet applications for multi-mode fiber and copper. And quad small form-factor pluggable plus (QSFP+) gradually replaces QSFP and is widely used by people as it can provide higher bandwidth. The picture below shows a Cisco WSP-Q40GLR4L compatible QSFP+ transceiver.

Migrating to 40 Gigabit Ethernet will prove very cost-effective for those who do it right. One critical step is to choose appropriate cables and transceivers. Fiberstore is a professional manufacturer and supplier, which offers a large amount of cables and transceivers for your 40GbE applications. For example, HP 805755-B21 compatible QSFP+ transceiver, and Juniper JNP-QSFP-4X10GE-IR compatible QSFP+ transceiver offered by Fiberstore are cost-effective and high-performance transceiver modules fully compatible with major brands.