Smooth Migration to 40/100GbE with OM3 and OM4

The continued requirement for expansion and scalability in the data center drives the migration to 40/100GbE. In the process of upgrading to higher-bandwidth data center, cable deployment plays an important part. The fiber optic cable used in data center should provide reliable performance not only for current but also for future applications. OM3 and OM4 were available as the future-proof cabling for 40/100 Gigabit Ethernet network. Today, we are going to introduce these two types of cable in details.

Multimode Fiber Cable - OM3 and OM4

As we all know, multimode fiber is often categorized into four types—OM1, OM2, OM3 and OM4. OM3 and OM4 are laser-optimized, high-bandwidth 50 micron multimode fiber cables, which are designed to enhance the system cost benefits enabled by 850nm vertical cavity surface emitting lasers (VCSELs) for existing 1G and 10G applications as well as future 40G and 100G applications. The following image shows OM3 and OM4.

Advantages of OM3 and OM4

As increasing bandwidth requirements are called out in new installations, particularly 40 and 100GbE standards, transmission distances over fiber optic cables contained in existing infrastructure may become increasingly limited. And these higher bandwidth system requirements have dictated a need to transition from cost-effective multimode systems to more costly single-mode systems. Until OM3 and OM4 was formally specified, many next-generation 40/100GbE applications would have had to make the leap to single-mode system solutions. OM3 and OM4 provides many advantages that helps the smooth migration to 40/100GbE.

High Bandwidth: Bandwidth is the first reason why OM3 and OM4 are preferable. OM3 and OM4 are optimized for 850nm transmission and have a minimum 2000 MHz•km and 4700 MHz•km effective modal bandwidth(EMB) respectively, while OM1 and OM2 with maximum 500 MHz•km as we can seen in the following table. It is obvious that with OM3 and OM4, the optical infrastructure deployed in the data center will meet the performance criteria set forth by IEEE for bandwidth.

Long Transmission Distance: The transmission distance of fiber optic cables will influence the data center cabling. Compared to traditional multimode fiber, OM3 and OM4 can support longer transmission distance. Generally, OM3 can run 40/100Gbps at 100 meters and OM4 can support the link length up to 150 meters at the data rate of 40/100Gbps.

Low Insertion Loss: Insertion loss has always been an important factor that technically should consider during the data center cabling. The lower the insertion loss, the better the performance. According to the 40/100G standard, OM3 is specified to a 100m distance with a maximum channel loss of 1.9dB, and OM4 is specified to a 150m distance with a maximum channel loss of 1.5 dB, including a total connector loss budget of 1.0 dB as we can seen from the table below.

Cost Saving: Budget is always the most vital factor that should be taken into consideration when setting up data center. As we have mentioned above, when upgrading to higher bandwidth network previously, many IT managers will choose costly single-mode fiber to achieve connections, but with the appearance of and OM4, the cost used in the migration to 40/100GbE will greatly reduce.

With OM3, Why We Still Need OM4?

Actually, OM3 has the similar performance as OM4 from the four aspects that we have discussed above, but with OM3, why we still need OM4?

It is important to note that OM4 is not necessarily designed to be a replacement for OM3. For most systems, OM3 is sufficient to cover the bandwidth needs at the distances of the current installation base. Most system requirements can still be reliably and cost-effectively achieved with OM3. The primary benefit that OM4 provides is additional reach at extended bandwidth at an overall cost still less than that of an OS2 single-mode system. In other words, OM4 provides a solution that allows more installations to avoid the significantly higher costs of single-mode systems. Additionally, OM4 provides an opportunity to future-proof cabling infrastructure. OM4 is completely backward-compatible with existing OM3 systems. The additional bandwidth and lower attenuation of OM4 offer additional insertion loss margin. As a result, users of OM4 gain additional safety margin to help compensate for less-than-ideal cabling installations as well as provide margin for degradation due to moves, adds, and changes over the life of the installation.

Summary

As the ever-increasing need for higher-speed transmission, upgrading to 40/100GbE is underway. OM3 and OM4, as future-proof cabling, play an important role in the smooth migration to higher bandwidth networks. FS.COM provides a range of OM3 and OM4 in different types according to your requirements, and we devote to offer the most affordable fiber optic cable price for customers. Want to know more information, kindly visit FS.COM.

Loose-Tube VS. Tight-Buffered Fiber Optic Cable

It is known that fiber optic cable has been the preferred medium for the data center backbone due to channel capacity and scalability, total immunity to electromagnetic interference (EMI) and radio frequency interference (RFI), elimination of the crosstalk inherent in copper cabling (like twinax cable), smaller diameter, and ease of installation, particularly when using pre-terminated modular trunk cables. Selecting the right type of fiber optic cable boils down to the applications and the installation. This post will introduce and compare two fiber optic cable types based on different cable constructions—loose-tube and tight-buffered fiber optic cable.

Loose-Tube Fiber Optic Cable Overview

In loose-tube construction, the fiber is laid helically into semi-rigid tubes, allowing the cable to stretch without stretching the fiber itself, which can protect the fiber from tension during laying and due to temperature changes. Loose-tube fiber may be “dry block” or gel-filled. Dry block offers less protection to the fiber than gel-filled, but costs considerably less. Loose-tube fiber cable comes in various fiber counts that typically range from 6 to 144, with some manufacturers offering higher counts up to 216 fibers. Except a 6-fiber cable, the fibers are grouped into sets of 12 for maximum density.

Structure of Loose-Tube Cable

The following image shows the main components used to construct a Loose-tube cable.

• Multiple 250um coated bare fibers in loose tube.
• One or more loose tubes holding 250um bare fibers. Loose tube stranded around the central strength member.
• Moisture blocking gel in each loose tube for water blocking and protection of 250um fibers.
• Central strength member in the center of the cable and is stranded around by loose tubes.
• Aramid Yarn as strength member.
• Ripcord for easy removal of outer jacket.
• Outer jacket(PVC is most common for outdoor cables because of its moisture resistant, abrasion resistant and stable over wide temperature range characteristics).

Advantages of Loose-Tube Cable

• Extreme Temperature Resistant: Loose-tube cable establishes a strain-free environment for the optical fiber by mitigating the influence of external effects, which makes it perform well at extreme temperatures. Besides, this characteristic also enhances the performance of the loose-tube cable design under a variety of mechanical forces, such as tensile, flexure, twisting, crush, etc.
• Water-blocking Characteristic: As we all know, the core fiber of loose-tube cable is surrounded with a dry water-swellable tape and yarns, or with a gel, which can effectively stop the entry and migration of water.
• UV Protection: The outer jacket of loose-tube cable consists of carbon black, which can provide maximum ultraviolet protection, making the cable able to withstand direct exposure to ultraviolet sunlight in aerial installations.

Tight-Buffered Fiber Optic Cable Overview

Instead of a loose tube, the fiber may be embedded in a heavy polymer jacket, commonly called “tight buffer” construction. Tight-buffered cables are offered for a variety of applications, but the two most common are “breakout” and “distribution”. Tight-buffered cable comes in fiber counts ranging from 2 to 144 fibers, with larger fiber counts featuring fiber subunits of 6 or 12 fibers within the cable. For example, a 144-fiber cable usually has twelve 12-fiber subunits while a 36-fiber cable could have six 6-fiber subunits or three 12-fiber subunits.

Structure of Tight-Buffered Cable

The following image shows the structure of tight-buffered cable.

• Multiple 900um tight-buffered fibers stranded around the central strength member.
• Central strength member in the center of the cable.
• Aramid Yarn(trade name Kevlar) wrapped around the fibers for physical protection and cable pulling.
• Ripcord for easy removal of outer jacket.
• Outer jacket or sheath(usually PVC).

Advantages of Tight-Buffered Cable

• Easy to Install: Tight-buffered cables are easier to install, because there is no messy gel to clean up and they don’t require a fan-out kit for splicing or termination. You can crimp connections directly to each fiber.
• Higher Survivability Standard: Based on military technology for survival under mechanical and environmental stresses.
• Flexibility: No stiff strength member is needed, making the cable more flexible. The cable is also “tight bound” allowing it to be pulled around multiple bends or hung vertically without causing “fiber axial migration”.

Which One to Choose—Loose-Tube or Tight-Buffered?

After we have introduced these two types of fiber optic cables, people may wonder which one is the best for their project. Actually, these two cable types are deployed in different applications.

Loose-tube cable is specifically designed for harsh environments. It has a water-resistant gel that surrounds the fibers, which helps the fibers from moisture, making the cable ideal for harsh, high-humidity environments where water or condensation can be a problem. The gel-filled tubes can also expand and contract with temperature changes. Loose-tube cable has a higher tensile strength than tight-buffered cable. But it is not the best choice when cable needs to be routed around multiple bends, which is often true in indoor applications. Excess cable strain can force fibers to emerge from the gel.

Tight-buffered cable is optimized for indoor applications. Because it’s sturdier than loose-tube cable, it is more available for moderate-length LAN/WAN connections or long indoor runs, and even direct burial. Tight-buffered cable is also recommended for underwater applications.

Summary

Choose the right cable types for your applications can effectively improve network performance and ensure the life span of the whole project. FS.COM offers a wide range of loose-tube and tight-buffered cables in different fiber counts and with single-mode fiber or multimode fiber. For more detailed information, please visit FS.COM.

Brief Introduction to Ubiquiti EdgeSwitch and UniFi Switch

By using just one switch, you can power a number of different devices using PoE. Ubiquiti Network, as one of the most famous American technology companies, who focuses on manufacturing wireless data communication products for enterprise and wireless broadband providers, have offered a range of different switch types and models. Generally, Ubiquiti EdgeSwitch and UniFi switch are two commonly used switch types. Although these two switch types have introduced to the market for several years and have gained great popularity, there are still many people who do not know them clearly. Today’s post will introduce these two types of Ubiquiti switch in the following text.

Ubiquiti EdgeSwitch Overview

Ubiquiti EdgeSwitch delivers forwarding capacity that simultaneously processes traffic on all ports at line rate without any packet loss. It is a fully managed, PoE+ Gigabit switch, delivering robust performance and intelligent switching for growing networks. The Ubiquiti EdgeSwitch targets the Broadband/ISP/Carrier market, which offers an extensive suite of advanced Layer-2 switching features, and also providers Layer-3 routing capability.

Specific Information About Ubiquiti EdgeSwitch

Switching Performance: The EdgeSwitch can provide total, non-blocking throughput: 8-port model up to 10Gbps, 16-port model up to 18Gbps, 24-port up to 26Gbps, and 48-port up to 70Gbps as shown in the following table.

PoE+ Flexibility: The Edge models are available with 8, 16, 24, 48 PoE Gigabit Ethernet ports of auto-sensing IEEE 802.3af/at or configurable 24V passive PoE to simplify your infrastructure.

Fiber Connectivity: The EdgeSwitch provides fiber connectivity options for your growing networks. The 8, 16, and 24-ports models include two SFP ports, providing up to 1Gbps uplinks. For high-capacity uplinks, the 48-port models include two SFP and two SFP+ ports, providing uplinks of up to 10Gbps. Both of these two connectivity options can be achieve by SFP/SFP+ optical transceivers and fiber patch cables.

UniFi Switch Overview

UniFi switch has many similarities as the Ubiquiti EdgeSwitch. It also delivers the forwarding capacity to simultaneously process traffic on all ports at line rate without any packet loss. The UniFi switch range has four models, offering either 24 or 48 RJ45 Gigabit ports, at either 250 or 750 watts as shown in the following table. For its total, non-blocking throughput, the 24-port model supports up to 26Gbps, while the 48-port model supports up to 70Gbps. Different from the EdgeSwitch, UniFi switch targets the Enterprise/SMB market, which is designed for a wider IT audience, and therefore, tend to be simpler, and easier to use.

Features of UniFi Switch

Power Performance: As we have mentioned above, the UniFi switch simultaneously processes traffic on all ports at line without any packet loss. The 48 RJ45-port type delivers up to 70Gbps of total non-blocking throughput, and the 24 RJ45-port type delivers up to 26Gbps.

Versatile Fiber Connectivity: Like the EdgeSwitch models, these two UniFi switch models both include two SFP ports for uplinks of up to 1Gbps. The 48-port model adds two SFP+ ports for high-capacity uplinks of up to 10Gbps, so you can directly connect to a high-performance storage server or deploy a long-distance uplink to another switch.

Advanced Enterprise Switching: The UniFi switch integrates with the UniFi controller software for centralized management of your UniFi devices. Advanced features include static or 802.1x VLAN tagging, port isolation, storm control, and guest/user control, including 802.1x authentication.

Compatible SFP/SFP+ Modules for Ubiquiti EdgeSwitch and UniFi Switch in FS.COM

As we have mentioned above, both EdgeSwitch and UniFi switch require SFP or SFP+ modules to achieve 1G or 10G connections. FS.COM, as a professional supplier and manufacturer of fiber optic cabling products, provides a series of compatible SFP/SFP+ modules for Edgeswitch and UniFi switch, such as Cisco GLC-SX-MM, Cisco GLC-LH-SM for EdgeSwitch, and Cisco SFP-SX-85 for UniFi switch. All of these optical transceivers has been fully tested with these two Ubiquiti brand switch types. If you have related needs, please visit FS.COM, or contact sales@fs.com.

Why We Choose Fiber Cable over Copper Cable?

When selecting networking cable for your project, fiber cable or copper cable as shown below, which one do you prefer? Actually, both of them have advantages and specific features. Copper cable has already existed in many places and it is economical in network devices connection. However, with the dramatic reduction of optical deployment cost, optical fiber cable has become one of the most popular mediums for both new cabling installation and upgrades, including backbone, horizontal, and even desktop applications. There are several advantages which make fiber cable a more enticing infrastructure solution than its copper counterpart. This passage will present five reasons for the choice in optical fiber cable instead of copper cable.

Bandwidth

Copper cable has very limited bandwidth that is perfect for voice signals transmission, since it is made of copper which will cause high loss at high frequencies. However, optical fiber cable, consisting of glass, provides more bandwidth than copper cable and has standardized performance more than 10Gbps (some special-designed fiber optic cable can support data rate of 40Gbps, or even 100Gbps). More bandwidth means optical cable can carry more information with greater fidelity than copper cable. For example, a cat6a cable can only support the maximum link length of up to 100 m at data rate of 10Gbps, while a multimode fiber optic cable can support the maximum link length of up to 10 km at the same data rate of 10Gbps.

Speed and Distance

Fiber optic cable transmission versus copper cable transmission can be boiled down to the speed of photons versus the speed of electrons. Copper cable uses electric waves to send signals, which makes it only suitable for short distance transmission, since the electric signals will start to break down when applied to higher speed and greater distance applications. However, the fiber optic signal is made of light, which will cause little signal loss during transmission, allowing data to move at higher speeds and greater distances. Therefore, Fiber optic cable does not have the 100-meter distance limitation like copper cable, and its distances can range from 550 meters to 40 km, depending on different cable types (single-mode fiber or multimode fiber), different data rates and different wavelengths. The following image shows different bandwidth and distance of fiber cable and copper cable.

Security

The data transmitted over the fiber are always safe. Eavesdropping on a LAN using copper cables only requires a sensitive antenna to pick up the energy radiated from the cable. Since fiber optic cable doesn’t transmit electricity, it won’t radiate energy and cannot be tapped by an antenna, while the copper cable using electricity is easy to be tapped which will cause the entire system to fail. The optical fiber does not produce EMI, so it cannot catch on fire. Besides, you will not have to worry about replacing fiber cables as frequently as copper cables. Because the fiber core is made of glass, the optical fiber won’t break as easily as copper based cable.

Immunity and Reliability

There are a number of factors that can cause outages when an organization is reliant on copper cable-based network, such as temperature fluctuations, severe weather conditions, and moisture. However, fiber cable is completely immune to these environmental factors that makes it extremely reliable in data transmission. You can use armored fiber cable in some harsh environment, and there is also bend water-proof fiber patch designed for weather exposure conditions. What’s more, fiber cable is also impervious to electrometric interference (EMI) and radio-frequency interference (RFI), crosstalk, impedance problems and so on. You can apply fiber cable next to industrial equipment without worry.

Cost

A few years ago, the overall price of fiber cables was 100% to 200% higher than copper cables. With the maturity of production technology, the cost for fiber cables, components, and hardware has steadily decreased. Fiber cable is certainly more expensive compared to copper cable when you are looking at it on a short term basis, but cheaper in the long term, since fiber cable costs less to maintain and needs less networking hardware compared to its copper counterpart.

Summary

With its wide bandwidth, high speed, long distance, great security and reliability, as well as low cost, fiber cable has already replaced the copper cable in many aspects of networking. As fiber optic connectivity improves, fiber construction will become more convenient. FS.COM provides a wide range of fiber optic cables for different applications. If you have related needs, please kindly visit FS.COM or contact sales@fs.com.

Fiber Optic Transceivers With CWDM Technology

CWDM (coarse wavelength division multiplexing) is the low-cost type of WDM technology, which is often used in metropolitan area network access networks. It is considered to be a flexible and economical solution to expand the existing network capacity without adding additional optical fibers. There are many devices deploying with CWDM technology used in telecommunication applications, like CWDM modules and CWDM Mux/Demux, to provide a cost-effective way for migrating to higher-rate infrastructures. This post will mainly introduce several fiber optic transceivers with CWDM technology.

Overview of CWDM Transceiver and Its Working Principle

CWDM transceiver is a hot-pluggable transceiver that combines with CWDM technology usually used to achieve connectivity between existing network equipment and CWDM Mux/Demux. This type of transceiver module can provide high-capacity bandwidth by carrying up to 16 channels on a single fiber in the spectrum grid from 1270 nm to 1610 nm with a 20 nm channel spacing, when used with CWDM Mux/Demux.

Similar to the working principle of prism, there is a multiplexer and a demultiplexer at the either end of the whole CWDM system. A multiplexer is at the transmitting end to combine several signals together, and a demultiplexer is at the receiving end to split the signals apart. The more detailed information can be see in the following image.

Several CWDM Transceiver Types

Actually, with the increasing need for CWDM technology in different applications, there are many types of fiber optic transceivers with CWDM technology, such as CWDM SFP, CWDM SFP+, CWDM XFP, CWDM X2, and CWDM XENPAK, etc. In the following part I will mainly introduce CWDM SFP, CWDM SFP+ and CWDM XFP.

CWDM SFP: CWDM SFP is hot-pluggable and transceiver component which is compliant with SFP MSA and IEEE 802.3 & ROHS. The transceiver uses a LC single-mode fiber to achieve data rates of 1G, 2G and 4G for the maximum link length of up to 200 km. You can connect the CWDM SFPs to CWDM passive optical system, add/drop multiplexer (OADM) modules or multiplexer and demultiplexer plug-in modules using single-mode fiber optic cables. Here is a Cisco CWDM-SFP-1270.

CWDM SFP+: CWDM SFP+ as shown below is based on the popular SFP form factor, which is an MSA standard build. It is designed for 10G Ethernet applications in data center, campus and metropolitan area access networks where require flexible and cost-effective systems. This type of CWDM module can reach a maximum speed of 11.25Gbps and is commonly used to support up to eight channels of 10G Ethernet over single-mode fiber at the wavelength including 1490 nm, 1510 nm, 1530 nm,1550 nm, 1570 nm, 1590 nm and 1610 nm.

CWDM XFP: CWDM XFP as shown in the image below, compatible with XFP MSA, is designed for single-mode fiber and operates at a nominal wavelength of CWDM technology, from 1270 nm to 1610 nm. CWDM XFP is mainly used for typical routers and switch line card applications.

Advantages of CWDM Transceiver

• Cost-saving—As we have mentioned above, CWDM module combining with CWDM technology can share a single fiber with several optical connections, thus expanding the bandwidth of fiber and allowing multiple applications to run over the same resources, which saves more cost than using other types of optical transceivers. Besides, due to the broader channel spacing in CWDM, cheaper uncooled lasers are used in CWDM modules, giving them another cost advantage.
• Increasing Network Capacity—By transmitting multiple data channels using separate optical wavelengths on the same optical fiber, CWDM modules can greatly increase network capacity. They reduce network equipment inventories, and eliminate the need to maintain extra units or devices with various fiber types for network repairs or upgrades. They can also enable the network to upgrade and to be in use over a longer time without replacing the whole network by providing interchangeable fiber connectors which can easily adapt to and modify any existing network.
• Low Power-consumption—Another advantage of CWDM module is low power-consumption. CWDM lasers without thermoelectric cooler and temperature control function, it is possible to significantly reduce the power consumption. For example a DWDM based module each laser is about 4 W power consumption, while the cooler CWDM module laser consumes only 0.5 W.

Summary

CWDM transceiver provides high speed and physical compactness that today’s networks require while delivering the deployment flexibility and inventory control that network administrators demand. FS.COM offers a wide range of CWDM modules, including the common used three types we have mentioned above, and the types we don’t discussed in detail, like CWDM X2, CWDM XENPAK, and CWDM GBIC. All of these modules are fully compatible with the original brand ones. You can come to FS.com for more detailed information.

Introduction to Three Cisco SFP Module Types

Although the 10 Gigabit Ethernet system has become the dominant deployment in telecommunication market, there are still many 1GbE infrastructures existing in today’s networks. SFP optical transceiver, as a critical component to support 1G data transmission, is also increasingly required in most Gigabit Ethernet networks. Many vendors, like Cisco, one of the most well-known and reliable company in telecommunication industry, have provided various types of SFP transceiver modules to the market. This post aims to introduce three common Cisco SFP module types for you references.

SFP Optical Transceiver Overview

SFP (small form factor pluggable) transceivers are hot-plugable and compact optical transceivers which provide instant fiber or copper connectivity for SONET, Gigabit Ethernet, Fibre Channel, and other communications standards. They are a cost-effective way to connect a single network device to a wide variety of fiber cable distances and types. With the existence of SFP module, network upgrades could be easier, since SFP is interchangeable fiber connectors that can adapt to any existing network. For example, by simply replacing the pluggable optical transceiver, a media converter that was originally used in a multimode network can be re-configured to operate over a CWDM network. SFP optics come in four versions: 1000Base-T, 1000Base-SX, 1000Base-LX, and 1000Base-ZX. The 1000Base-SX will work on multimode fiber for the link length of 550 m, while the 1000Base-LX and 1000Base-ZX work only on single-mode fiber for the maximum distance of 10 km and 80 km respectively, and the 1000Base-T is the RJ-45 version. The following image shows the structure of SFP module.

Three Common Cisco SFP Module Types

GLC-SX-MM SFP: GLC-SX-MM 1000Base-SX SFP is a duplex SFP transceiver used over multimode fiber at the wavelength of 850 nm for optical communications. It is compatible with IEEE 802.3z and could support the data rate of 1Gbps for the reach of 550 meters over 50/125 multimode fiber, and 220 meters over 62.5/125 multimode fiber. But since March 8th, 2013, there is no longer GLC-SX-MM SFP modules on sale in Cisco. It is replaced by the new model SFP transceiver module—GLC-SX-MMD SFP. However, for usage and cost considerations, many users still use the old model SFP, because GLC-SX-MMD is much more expensive, and except the additional DOM function, they work as the same when used in Cisco switch. These old Cisco compatible GLC-SX-MM SFPs can be still purchased in Fiberstore at very lower prices as shown in the following image.

GLC-LX-SM SFP: GLC-LH-SM 1000Base-LX-LH Ethernet transceiver is a LC duplex SFP transceiver used for optical networks. It operates at 1310 wavelength, rated for distances up to 10 km and a maximum bandwidth of 1Gbps. This type of SFP module is compliant with MSA (multisource agreement) and the IEEE 802.3z 1000Base-LX standard, which can both operate over single-mode fiber for the link spans of up to 10 km and up to 550 m on any multimode fibers. The following picture is Cisco GLC-LH-SM-15 Compatible 1000BASE-LXLH SFP in Fiberstore.

GLC-T SFP: GLC-T (as shown below) is a type of copper SFP module used over standard Cat5 unshielded twisted pair copper cabling of link length up to 100 m (328ft). It provides 1Gbps data transfer and offers full-duplex Gigabit Ethernet connectivity to high-end workstations and between wiring closets over existing copper network infrastructure. Cisco GLC-T SFP transceiver module can offer a flexible and simple method to be installed into SFP MSA compliant ports at any time with no interruption of the host equipment operation. It enables for seamless integration of fiber with copper LAN connections wherever SFP interface slots can be found.

Summary

We have mentioned three commonly used Cisco SFP modules in the previous text, and each module is applied in different applications. GLC-SX-MM SFP is used for multimode fiber based equipment, while GLC-LX-SM SFP is more suitable for single-mode fiber based infrastructure and GLC-T SFP is often deployed with copper cable, like Cat5 Ethernet cable. Besides these aspects, you should also take your budget into consideration. As we all know, Cisco brand SFP transceiver is expensive, but with the increasing popularity of third-party modules, we have a good alternative. Fiberstore provides a wide range of Cisco compatible SFP modules at affordable prices. If you have related needs, please visit FS.COM for more information.