How to Choose Fiber Optic Cable for 10G SFP+ Optical Transceiver?

How to choose fiber optic cables for 10G SFP+ transceivers? It seems like a dumb question for most of the fiber optic technicians. However, there are still some people, especially the green-hand network installers, may not know the compatibility between fiber optic cables and optical transceiver modules. Today, I want to make a clear illustration of how to choose the right transmission media (OS2/OM3/OM4/Cat6/Cat6a) for 10G SFP+ optical transceiver modules.

Overview of SFP+ Optical Transceiver Module

Before coming to the main part of this article, let’s first have a brief overview of the SFP+ optical transceiver modules and 10G fiber & copper cables.

• 10GBASE SFP+ optical transceivers

SFP+ optical transceivers, according to the IEEE standards, can be divided into several types, for example, 10GBASE-LRM SFP+, 10GBASE-LR, 10GBASE-ER SFP+, 10GBASE-ZR SFP+, 10GBASE-SR SFP+, 10GBASE-T SFP+. Each SFP+ optical transceiver type has its own specification and usage that are not be listed here. For more, please review the previous articles.

• BiDi SFP+ Modules

Besides the above 10GBASE SFP+ modules, 10GBASE-CWDM SFP+, 10GBASE-DWDM SFP+ and SFP+ BiDi optical transceiver modules are also the most commonly used 10G SFP+ optics. SFP+ BiDi optical transceiver usually uses two different wavelength to achieve 10G transmission over one fiber. The most frequently used wavelength of BiDi optical module is 1310nm/1550nm, 1310nm/1490nm, 1510nm/1590nm.

• CWDM/DWDM SFP+ Modules

The Coarse Wavelength-Division Multiplexing (CWDM) and Dense Wavelength-Division Multiplexing (DWDM) SFP+ optics are the convenient and cost-effective solution for the adoption of 10 Gigabit Ethernet in campus, data-center, and metropolitan-area access networks. This 10G fiber optic transceiver type can support up to eight channels of 10GbE over single-mode fibers for distance over 80km.

10G Fiber & Copper Patch Cables

Fiber optic cables can be categorized into two types: single-mode and multimode fiber optic cables. They have different core size and fiber optic transmission equipment, which makes them suitable in different applications. Single-mode fiber patch cables, or OS1/OS2 (OS1 is now not popular on the market) are normally used for long-distance transmission with laser diode based equipment.

Multimode fiber cables, or OM1/OM2/OM3/OM4, have a relatively large light carrying core, usually utilized for short-distance transmission with LED based equipment. OM1, with a core size of 62.5um, supports 1GB network within 300m. OM2 (50um) can support up to 10GB, with a distance of 600m. OM3 and OM4 are the laser-optimized multimode fibers, which can be used in 10GB network with a link length of 300m, 550m respectively. These types of optical cables can be also used on 40G/100G network utilizing a MTP/MPO connector.

Cat6/Cat6a cables are the Copper Ethernet Network cables used for 10G network. Compared with Cat5e (1 Gigabits of data) and Cat5 cables (10/100 Mbps), Cat6 is the Ethernet cable that can handle up to 10Gbps with the distance limited to 164ft. Cat6a is the advanced version of Cat6 cables that further reduce crosstalk, which makes it can support the full 328 feet of Ethernet cable.

Choosing Fiber Optic Cables for 10G SFP+ Optical Transceivers

As noted before, single-mode patch cables can be used for 10G 10GBASE-LRM SFP+, 10GBASE-LR SFP+, 10GBASE-ER SFP+, 10GBASE-ZR SFP+, 10GBASE-CWDM SFP+, 10GBASE-DWDM SFP+ and SFP+ BiDi modules.

	Cable Type	Connector	Max Distance
10GBASE-LRM SFP+	9/125 SMF	LC Duplex	200m
10GBASE-LR SFP+	9/125 SMF	LC Duplex	10km
10GBASE-ER SFP+	9/125 SMF	LC Duplex	40km
10GBASE-ZR SFP+	9/125 SMF	LC Duplex	80km
CWDM SFP+	9/125 SMF	LC Duplex	80km
DWDM SFP+	9/125 SMF	LC Duplex	80km
SFP+ BiDi	9/125 SMF	LC/SC Simplex	80km

Multimode fibers, especially the OM3 and OM4 cables, are supported for 10GBASE-SR SFP+ transceiver modules. The following chart displays the part No. of customized OM3 and OM4 cables.

Customized Part ID	Connector	Fiber Mode	Polish Types	Jacket	Stock Length
17235	LC Duplex	50/125 OM4	UPC	PVC	1m-30m (3ft-98ft)
17235	LC Duplex	50/125 OM4	UPC	LSZH	1m-15m (3ft-49ft)
17235	LC Duplex	50/125 OM4	UPC	OFNP	1m-15m (3ft-49ft)
12018	LC Duplex	50/125 OM3	UPC	PVC	1m-30m (3ft-98ft)
12018	LC Duplex	50/125 OM3	UPC	LZSH	1m-30m (3ft-98ft)
12018	LC Duplex	50/125 OM3	UPC	OFNP	1m-15m (3ft-49ft)

Cat6 and Cat6a Patch cables can be only used on the 10GBASE-T SFP+ transceivers.

Keep in mind, the newly available SFP+ copper transceiver modules can only support up to 30m.

Conclusion

This article lists all the existing the 10G fiber & copper patch cables and SFP+ transceiver module types, as well as the guidance about how to select the right patch cables for 10G SFP+ optical transceivers. FS.COM offers a full range of SFP+ optical transceiver modules and patch cables. Please contact us if you need any help.

Original article: 10GBASE-T SFP+ COPPER RJ45 TRANSCEIVER MODULE – INNOVATIVE BUT CONTROVERSIAL

Laser-optimized Multimode Fiber – OM3 and OM4

How do I determine the type of fiber needed for my campus backbone? This is the question routinely asked by network designers. I must say, with many cabling options available in the market, it is a huge project to deploy a Gigabit Ethernet network—10GbE or 40/100GbE. As system engineers should not only decide which fiber type and the cabling infrastructure is perfect for their network, but the fiber counts. This article will briefly analyze the benefits of using laser-optimized 50µm multimode fiber in a Gigabit Ethernet application.

50µm Multimode Fibers Were Introduced 
Before the advent of Gigabit Ethernet, choosing fiber type in a network design was quite easy. Standard 62.5µm multimode fiber (OM1) was used for any application up to 2000 m and network speeds up to 622 Mbps and single-mode fiber was used for anything else. But Gigabit and 10GbE changed these rules. Laser-optimized 50µm multimode fiber (like OM3 and OM4) was developed with increased bandwidth performance for 10GbE, and the fiber performance was included in the ANSI/TIA-568 Standard. Figure 1 provides a vivid impression on 50µm and 62.5µm multimode fiber.

Why Consider 50 µm Over 62.5 µm?
The major difference between 50µm and 62.5µm multimode fiber is the bandwidth. 50µm fiber is specifically designed to produce higher bandwidth values than 62.5µm at 850 nm, which enables the fiber to be used with lower cost 850nm VCSEL transmitters. Standard 50µm fiber has three times the bandwidth of standard 62.5µm fiber in the short wavelength operating window while some of the never laser-based 50µm fiber designs have 10-20 times the bandwidth of standard 62.5µm fiber (see in Figure 2). The most commonly used 50µm fibers on the market for Gigabit Ethernet is OM3 and OM4.

OM3 and OM4 Fibers
OM3 and OM4 fibers are essential components to the success of 10G optical connectivity, which are optimized for laser-based 850nm operation and have a minimum 2000 MHz•km and 4700 MHz•km effective modal bandwidth, respectively. 10G operation is supported on OM3 to 300 m and OM4 to 550 m compared to 100 m with CAT 6A copper cable. The laser-optimized fibers provide a migration path for supporting even higher data rates such as 16G and 32G Fibre Channel and 40/100G Ethernet where CAT 6/6A has no migration beyond 10G. OM3/OM4 laser-optimized 50µm multimode fiber for 10G optical connectivity in data center enables better transmission distance and performance when comparing with OM1 and OM2 fibers. For example, GP-10GSFP-1S is compatible Dell Force10 10GBASE-SR SFP+ transceiver. It required an OM3 cable to realize the link length of 300m.

As increased bandwidth requirements are called out in new installations, which have dictated a need to transition from cost-effective multimode systems to more costly single-mode systems to solve the problem of limited transmission distance in the existing infrastructure. However, compared with the expensive single-mode cabling, OM4 effectively provides an additional layer of performance that supports these applications at longer distances, thereby limiting the number of installations that truly require OS2 single-mode fiber. OM4 can even provide a minimum reach of 125m over multimode fiber within the 40 and 100GbE standards. For example, FTL410QE2C (compatible Finisar 40GBASE-SR4 QSFP+) covers a distance of 150m over OM4 cable.

Conclusion
When determining fiber types for a network application, a couple of key points should be drawn to help make the best decision. First, use the standards of each technology, do some analysis, understand the physical topology and the logical topology, then examine where you can save money. Last but not least, for distances less than 550 m, a laser-optimized multimode fiber may yield a price savings compared to a single-mode solution. Fiberstore provides a full range of multimode fibers including OM1, OM2, OM3 and OM4 multimode fibers. We offer these cables at a minimum price but with high quality. If you have any requirement of our products, please contact us directly.

How to Select the Basic Materials of the LAN

Installing or designing network may pose a challenge as there are multiple optical solutions that meet the same specification or requirement. But by understanding the basic optical components and the specific performance requirements, you will be able to generate a cost-efficient bill of materials for your project. Thus before picking any products for your infrastructure, you must read this article.

Fiber Type
There are two basic fiber types: single-mode and multi-mode. Multi-mode fiber is graded by OM (optical multi-mode), the higher the OM grade, the better bandwidth performance you can expect. And it comes in both 50μm and 62.5μm core sizes with 50 μm multi-mode available in both standard (OM2) as well as a laser-optimized version (OM3/OM4). Single-mode are graded by OS (optical single-mode) and can run at OS1 and OS2, as described in TIA-568 C.3. Keep the consistency within your network is critical for long-term performance, therefore you shouldn’t mix new fiber type or performance with your old plant.

In addition, the cost of the components should be considered. The transceiver associated with single-mode fiber are more expensive than those for multi-mode. For example, the price of JG661A (compatible HP 40GBASE-LR4/OTU-3 QSFP+ transceiver) is much higher than JG325B (compatible HP 40GBASE-SR4 QSFP+ transceiver). The decision must be made to balance the performance and the cost. Single-mode system will provide for future expansion, yet multi-mode fiber is only for today and the near future. To sum up, single-mode fiber operate better at long reach while multi-mode fiber is ideal for short reach, choosing single-mode or multi-mode depends on your networks needs.

Termination Method
Deciding on a termination methods is typical affected by many factors. If your biggest concern is time, no epoxy/no polish connectors are probably your best choice. The fiber end faces are factory polished and easily installed with a tool kit. This types of termination method allows you to perform terminations quickly, but the cost is usually higher than that of epoxy and polish connector.

If your biggest concern is cost. epoxy and polish connectors might be a good fit because of their low initial price. This type of termination need considerable time to learn how to properly hand-polish connectors that meet specification, and it requires a large workspace to lay out the polishing papers, polishing pucks, epoxy, etc. If your work environment or network condition is not allowed, it is advisable not to select this method.

Fusion Splicer or Optical Connector
Keep in mind that whether to choose fusion splicing or a connector for your network will always need an experienced installer under adequate training. Fusion splicer, as we all know, is very expensive. If your company do not own one, it can be a large investment to make and you need to order the correct splice tray for your hardware and heart-shrinks to keep your splices intact. But if you already have a fusion splicer, fusion-spliced pigtails might be the right choice for you that can provide high quality results and easy to use in areas. The following picture shows a Fujikura FSM-80S Core Alignment Fusion Splicer.

Specifications, density, electronics interfaces and existing plant often drive connector choices. LC connector is favored for its maximum density and room-saving. It is also available in duplex from, which allows you to manage polarity by simply reversing the connector via a duplex clip. SC connectors feature an easy push/pull locking mechanism and are available in simplex and duplex forms. ST compatible connectors have a spring-loaded bayonet locking system that helps them stay in place but are only available in simplex versions.

Hardware
To determine the type of hardware you need, take into consideration the space that will be utilized for the network. If you are installing inside of a closet or other cramped quarters and need low density, wall mountable hardware is the best selection as it does not take up a lot of room. If racks are already in place, or if there is enough room to install them, rack-mount hardware is the best selection because it is sturdy and easy to access.

Additional Information
Designing a network may be a big project as you should take a lot of things into consideration. To make sure the high performance of you network, please think about all the aspects that I have written in this text. What’s more, there are three basic categories for cable: indoor, outdoor and indoor/outdoor. The types of cables you have to choose for your infrastructure depend on where the cables will be run. Fiberstore supplies a whole variety of optical equipment including fiber optical cables, optical transceivers, fusion splicer and optical connectors. Come to us to help your data transmission initiatives for future proof.