Establishing 40G Links With OM3 and OM4

To meet the needs of Internet users, the business users in particular, who require faster speeds, greater scalability, and higher levels of network performance and reliability, data centers have experienced infrastructure transformation, from 10 Gbps to 40 Gbps and then to 100 Gbps, or even higher, never-ceasing. Actually, during this bandwidth migration, 40G provides an efficient use of hardware and a more logical upgrade path to 100G. And in establishing 40G links, fiber optic cabling, (eg OM3 and OM4) has become an integral part of the overall system design.

Background Information

The Institute of Electrical and Electronics Engineers (IEEE) 802.3ba 40/100G Ethernet Standard was ratified in June 2010 to support the fast-growing demands for bandwidth in data centers. The standard provides specific guidance for 40G/100G transmission with multi-mode fibers (MMFs) and single-mode fibers (SMFs). OM3 and OM4 are the only approved multi-mode fibers included in this standard.

Using OM3 and OM4 for 40G Links

The IEEE 802.3ba only specified OM3 for a maximum reach of 100 m in its original draft. Later, efforts have been made to win the approval to include OM4 in the standard. As a matter of fact, OM4 can achieve the greater reach of 150 m compared with OM3. In 40 GbE transmission which uses MMFs, an optic module interface is used for the simultaneous data transmission and data reception. Like JNP-QSFP-40G-LX4, this Juniper Networks proprietary 40G-LX4 transceiver listed on FS.COM realizes 100 m transmission on OM3, and 150 m transmission on OM4. Besides, JNP-QSFP-40G-LX4 can also run over SMF for 2 km link lengths.

, transmission media :SMF ,MMF

Evaluating OM3 and OM4 Performance

When evaluating the performance of the OM3 and OM4 cabling infrastructure for 40GbE transmissions, three aspects should be taken into consideration: bandwidth, channel connector insertion loss (CIL) and skew.

  • Bandwidth

In the standard, the bandwidth is ensured by meeting the effective modal bandwidth (EMB) specification. The EMB measurement techniques utilized nowadays are effective modal bandwidth calculate (EMBc) which combines the properties of both the source and fiber. The EMBc process predicts source-fiber performance by integrating the fundamental properties of light sources with the MMF’s modal structure which has been measured using a standardized differential modal delay (DMD) measurement. Within 40G links using OM3 and OM4 fibers measured by the EMBc technique, the optical infrastructure shall meet the performance criteria set forth by IEEE for bandwidth.

  • Channel Insertion Loss (CIL)

CIL is a critical performance parameter in current data center cabling deployments. It refers to the total insertion losses that happen when the signal moves along a fiber optic cable. Within a system channel, CIL impacts the ability to operate over the maximum distance at a given data rate. With total connector loss increasing, the maximum distance at that given data rate decreases. The 40/100G standard specifies the OM3 to a 100m distance with a maximum channel loss of 1.9dB, while OM4 is specified to a 150m distance with a maximum channel loss of 1.5dB.

  • Skew

Skew is classified as the difference between the arrival times of simultaneously launched light signals traveling through parallel cable lanes. When evaluating OM3 and OM4 performance for 40applications, selecting one that meets the 0.75ns skew requirement can ensure the performance.

Establishing 40G Links With OM3 and OM4

40G is deployed using eight of the twelve fibers in a MPO connector. Four of these eight fibers are used to transmit while the other four to receive. Each Tx/Rx is operating at 10G. The 40GBASE-SR4 (eg. QFX-QSFP-40G-SR4) interface is as follows: 4 x 10G on four fibers per direction.

40GBASE-SR optical lane: 4 x 10G on four fibers per direction

OM3 and OM4 for 40G connectivity provide a significant value proposition when compared to SMF, as MMF utilizes low cost 850nm transceivers for serial and parallel transmissions. OM3 and OM4 ensure today’s bandwidth needs.


To continue to accommodate the bandwidth needs, OM3 and OM4 are the ideal solution for 40G links in the data center. FS.COM offers broad selections of OM3 and OM4 fibers of high quality, as well as fiber optic transceivers working over OM3 and OM4, such as JNP-QSFP-40G-LX4 and QFX-QSFP-40G-SR4 mentioned above. You can visit FS.COM for more information about OM3 and OM4, MMF.

Introducing Juniper 40G QSFP+ Transceivers

It’s no doubt that 10Gbps speeds for individual streams have been routinely reached under today’s networking environment. And for better network performance, the existing bandwidth has been generated to 40Gbps. Among various network devices designed for 40 Gigabit Ethernet (GbE) links, 40G QSFP+ transceiver are of vital importance in driving the bandwidth to a mounting point. Here this publication puts its focus on the Juniper 40G QSFP+ transceiver, which ensure high density and low latency, as well as small power consumption.

Firstly let’s figure out what is the 40G QSFP+ transceiver.

What Is 40G QSFP+ Transceiver?

The Quad Small Form-factor Pluggable (QSFP) is a compact, hot-pluggable transceiver used for data communications applications. The 40G QSFP+ transceiver is a parallel fiber optical module, using four independent optical transmit and receive channels. It uses a 4 x 10Gb/s link configuration for a 40Gb/s port, offering users high-density 40 Gigabit Ethernet connectivity options for high-performance networks. QSFP+ transceivers can be applied in switches, routers and data center applications. Compared with SFP+ transceivers, QSFP+ transceiver increase the port-density by 3x-4x. Besides, they still enjoy the following features.

Juniper 40G QSFP+ Transceiver Features

Juniper QSFP+ is a Multi-Source Agreement (MSA) for high speed application, such as 40G-BASE, which provide four channels of data in one pluggable interface. Each channel is capable of transferring data at 10Gbps and supports a total of 40Gbps. Juniper 40G QSFP+ transceiver enjoy the following listed key features:

  • QSFP+ MSA, SFF-8436 Compatible;
  • Four Independently Addressable Transmit and Receive Channels;
  • Highly Compact and Electrically Hot-pluggable;
  • Digital Diagnostic Monitoring (DDM) Interface for Better Module Management;
  • Simplified Heat Management With Reduction in Power Consumption;
Two Type of Juniper 40G QSFP+ Transceiver

After discussion on several key features of Juniper 40G QSFP+ transceivers in general, here goes the detailed information about two types of Juniper 40G QSFP+ transceivers: Juniper 40G QSFP+ LX4 transceiver and Juniper 40G QSFP+ LR4 transceiver.

JNP QSFP 40G lx4 Transceiver

The jnp qsfp 40g lx4 transceiver has four 10 Gbps channels, each of which can transmit and receive simultaneously on four wavelengths over a multi-mode fiber (MMF) strand. The result is an aggregated duplex 40 Gbps link over a duplex of two MMF strands. Using duplex LC connectors, QSFP+ LX4 connections can reach 100 meters on OM3 MMF or 150 meters on OM4 MMF. What’s more, this Juniper QSFP+ LX4 transceiver (JNP-QSFP-40G-LX4) addresses the challenges of fiber infrastructure by providing the ability to transmit full-duplex 40Gbps traffic over one duplex MMF cable with LC connectors. In other words, the Juniper QSFP+ LX4 transceiver, a short-reach optical transceiver that delivers 40Gbps over duplex OM3 or OM4 MMF, allows 40Gbps connectivity to connect directly to the 10Gbps fiber and fiber trunk.

Juniper 40G QSFP+ LR4 Transceiver

For Juniper 40G QSFP+ LR4 transceiver, JNP-QSFP-40G-LR4 enables high speed 4 x 10G operations. It’s designed for use in 40 Gigabit Ethernet links over single mode fiber (SMF) with Duplex LC connectors. Compliant with the QSFP+ MSA and IEEE 802.3ba, JNP-QSFP-40G-LR4 is RoHS-6 compliant with built-in DDM interface. Fiberstore compatible Juniper JNP-QSFP-40G-LR4 is intended to support up to 10km over a standard pair of G.652 SMF.

Juniper 40G QSFP+ Transceivers Applications

The Juniper 40G QSFP+ transceivers are well suited for Infiniband, 40GBASE-SR4, 40GBASE-LR4 applications, suitable for short reaches among switches, routers and data center devices. Combined with right fanout cables, these modules can interface up to four SFP+ transceivers.


Juniper 40G QSFP+ transceiver boast of high-density features and provide users with 40Gbps connectivity for better network performances. Fiberstore supplies various Juniper 40G QSFP+ transceiver which are quality and performance assured, such as JNP-QSFP-40G-LX4 and JNP-QSFP-40G-LR4 mentioned above. Please feel free to contact us for more information about Fiberstore 40G QSFP+ transceiver compatible with Juniper.