Author Archives: Chloe Wang

GLC-LH-SM vs SFP-GE-L: What’s the Difference?

GLC-LH-SM and SFP-GE-L are two Cisco 1000BASE-LX/LH Ethernet transceivers. Due to the similar mode and performance such as supporting distance and working wavelength, users are often confused with Cisco GLC-LH-SM and SFP-GE-L when they are choosing these SFP modules. Then, what’s the difference between Cisco GLC-LH-SM and SFP-GE-L? This post intends to give a simple explanation of GLC-LH-SM vs SFP-GE-L.

GLC-LH-SM vs SFP-GE-L

Specifications of GLC-LH-SM and SFP-GE-L
GLC-LH-SM SFP Module

Cisco GLC-LH-SM is a hot-swapple optical transceiver that supports the maximum data rate of 1Gbps. It’s compatible with the IEEE 802.3z 1000BASE-LX standard, and can operate on standard single-mode fiber optic link spans of up to 10 km and up to 550 m on any multimode fibers.

Modules Interface Wavelength Tx power Receiver Sensitivity DOM Support Temperature Range
Cisco GLC-LH-SM LC duplex 1310nm -9.5 ~ -3dBm < -23dBm No 32℉to 158℉
(0℃ to 70℃)
SFP-GE-L SFP Module

SFP-GE-L transceiver has many similarities with GLC-LH-SM transceiver. It is also a Cisco 1000BASE-LX/LH Ethernet transceiver that designed for Gigabit Ethernet applications. This 1000BASE-LX/LH SFP, compatible with the IEEE 802.3z 1000BASE-LX standard, and can operate on standard single-mode fiber optic link spans of up to 10 km and up to 550 m on any multimode fibers.

Modules Interface Wavelength Tx power Receiver Sensitivity DOM Support Temperature Range
Cisco SFP-GE-L LC duplex 1310nm -9.5 ~ -3dBm < -23dBm No 23℉ to 185℉(-5℃ to 85℃)

Notes: no matter GLC-LH-SM or SFP-GE-L modules, mode conditioning patch cables are required when they are used for 1000BASE-LX/LH applications over FDDI-grade, OM1, and OM2 fiber cables.

GLC-LH-SM vs SFP-GE-L: What’s the Difference?

From the Cisco official notes, Cisco original GLC-LH-SM SFP and SFP-GE-L transceiver have been no longer for sale since March 8, 2013. But this doesn’t affect the market of these two SFP modules. Many users still choose to use them. As mentioned above, GLC-LH-SM and SFP-GE-L are easy to be confused. In fact, it’s not difficult to tell from them.

The first big difference between the two SFP modules is SFP-GE-L SFP supports DOM (digital optical monitoring) while GLC-LH-SM module doesn’t. DOM is an important function available on fiber optic transceiver. It allows users to monitor parameters of modules, such as optical output power, optical input power, temperature, laser bias current, and transceiver supply voltage, in real time, offering users more convenience when using optical modules. Another difference is the operating temperature range. The temperature range of Cisco GLC-LH-SM SFP is 32℉to 158℉(0℃ to 70℃), while the extended operating temperature range of SFP-GE-L module is 23℉ to 185℉ (-5℃ to 85℃).

GLC-LH-SM vs SFP-GE-L: Which One to Select?

From the contents above—GLC-LH-SM vs SFP-GE-L, we can draw a conclusion that GLC-LH-SM and SFP-GE-L nearly can be used as the same one type module sometimes, but their existing differences still differ them from some applications. For example, the WS-SUP32-8GE-3B does not support DOM SFP modules like the SFP-GE-L while supporting GLC-LH-SM SFP. Therefore, buying the suitable one for your devices when choosing from the two modules. As noted above, these two modules are end-of-sale in 2013. However, FS.COM provides these two modules at a cheap price. And other types of compatible optical transceivers are available too. Every optic module in FS.COM is 100% tested to ensure fully compatible. More details, please visit www.fs.com.

Advantages and Disadvantages of OM5 Fiber in Data Center

As the continuously increased bandwidth demand, the types of fiber patch cable are also updating quickly. OM5 fiber cable, also known as WBMMF (wideband multimode fiber), has arrived to meet the growing bandwidth requirements. However, there are different opinions on whether the adoption of OM5 fiber will benefit today’s data center. This post will focus on the advantages and disadvantage that OM5 brings for data centers.

om5 patch cable

Trends in Data Center Deployment

With the cloud computing and web services continuing to drive bandwidth need, data rates grow from 10G, 40G to 100G and beyond in many data center networks. According to the Cisco global cloud index, nearly 99 percent of global traffic will pass through data centers by 2020. That means higher bandwidth, faster services and greater access are required for data center deployments. Therefore, advanced technologies including fiber patch cable and optical transceivers will be needed for performance-improving in data centers.

Will OM5 Fiber Benefit Data Center?

OM5 fiber is a new generation of multimode fiber. It was just standardized in several months ago. Different from OM1, OM2, OM3 and OM4, OM5 fiber is designed to work over a wide range of wavelengths between 850 nm and 950 nm. And it supports SWDM (shortwave wavelength division multiplexing) technology which can reduce fiber counts in optical transmission. Here are the advantages and disadvantages of OM5 fiber cable in data center.

om5 fiber cable

Advantages

Firstly, it cannot deny that the emergence of OM5 is to meet the high bandwidth challenges. At this point, OM5 will definitely benefit data centers in some degree. The main advantages are in the following part.

Compatibility—OM5 cable has the same fiber size of OM4 and OM3, which means OM5 is fully compatible with OM3 and OM4 fiber. In other words, OM5 cabling supports all legacy applications in existing data center infrastructures. If a service provider wants to use OM5 for high speed data center, big changes will not be needed for existing cabling.

Distance—multimode patch cord is often the first choice for short reach connections. As we know, OM4 patch cord can support link length up to 100m with 100G-SWDM4 transceivers. While OM5 can extend the reach to 150m with the same types of fiber optic transceivers, providing another better choice for data center optimization.

Cost—when it comes to data center building, the cost is an important parameter to consider. OM5 cable is beneficial for data center deployments. Compared to single mode fiber cable (SMF), multimode fiber cable (MMF) is more cost-effective, because in most data centers, short reach connection are common. Besides, OM5 provides optimal support of emerging SWDM applications which reduce the amount of fibers needed for high speed transmissions.

Disadvantages

Each coin has two sides. Though OM5 fiber cable can benefit data center building, there are still some problems at present. It’s known to us that OM5 has just been standardized earlier this year. Even though many optical vendors have introduced OM5 fiber patch cables, in the market, the price is a little higher than OM4. And the production of the corresponding optical transceiver like 100G-SWDM4 is still limited. All these restrict the further adoption of OM5 fiber cables.

Summary

It’s getting more costly for fiber optic cabling systems in data centers. As a new MMF type, OM5 offers improved performance over popular OM4 and OM3. With the development of OM5 technology, it will bring more benefits for data centers.

How to Realize 16 Channels Transmission in DWDM Network?

DWDM MUX/DEMUX plays a critical in WDM network building. 16 channels transmission is very common in DWDM networks. How to realize it in a simple way? This article intends to introduce two solutions to achieve 16 channels with different types of components. Which one is more cost-effective and competitive? The comparison between the them also will be explored. Hope it will help you when choosing fiber mux for your DWDM networks.

wdm network

Solutions to Achieve 16 Channels Transmission in DWDM Network

In order to illustrate the solution more clearly, I take two types of DWDM MUX/DEMUX as an example. One is the traditional 16 channels dual fiber DWDM MUX/DEMUX. Another is two FMU 8 channels dual fiber DWDM MUX/DEMUX. The latter has an expansion port.

Solution One: Using Traditional 16 Channels DWDM MUX/DEMUX

The 16 channel DWDM MUX/DEMUX is a passive optical multiplexer designed for metro access applications. It’s built fiber mux and demux in one unit and can multiplex 16 channels on a fiber pair. In addition, this type of fiber mux also can be added some functional ports like expansion port, monitor port and 1310nm port, which make it possible to increase network capacity easily. The following is a simple graph showing the 16 channels transmission with this traditional DWDM MUX/DEMUX.

16 channels dwdm mux demux

Solution Two: Using Two FMU 8 Channels DWDM MUX/DEMUX Modules

The FMU 8 channels DWDM MUX/DEMUX provide 8 bidirectional channels on a dual strand of fiber. Usually they are used together. Unlike the 16 channels DWDM MUX/DEMUX, this FMU 8 channels one has a more compact size, for it only occupies half space in a 1U rack. Put two FMU 8 channels DWDM MUX/DEMUX modules into one 1U two-slot rack mount chassis. two 8 channels DWDM MUX/DEMUX with different wavelengths are connected through the expansion port to realize 16 channels transmission in a DWDM network. Here is a graph showing how to achieve 16 channels DWDM transmission with these two 8m channels fiber muxes. As shown in the figure, two 8 channels DWDM MUX/DEMUX with different wavelengths are connected through the expansion port to realize 16 channels transmission in a DWDM network.

8 channels

16CH DWDM MUX and Two FMU 8CH DWDM MUX: What’s the Difference When Deployed?

From the content above, we can see both solutions can realize the 16 channels transmission in a DWDM network. Then, are there differences between them? Or which is more competitive? Here is a simple analysis of the two solutions.

fiber mux

Firstly, comparing the two graphs above, the FMU 8 channels DWDM MUX/DEMUX are connected together by an expansion port, that’s why it can deliver 16 channels services like the traditional one. Except for connecting 8 channels DWDM MUX/DEMUX, the FMU fiber mux with expansion port also can be combined with other channels fiber mux like 2 channels, 4 channels or other channels, which offer more flexibility for optical network deployment and upgrade. And you can add DWDM into CWDM networks at some specific wavelengths with FS.COM FMU fiber mux.

Secondly, DWDM MUX/DEMUX price is always an important point that many network operators pay attention to. Therefore, when buying a fiber mux, the cost is a critical point to consider. If you search on Google, you will find the lowest price is $1100 in FS.COM. And the cost of using two 8 channels MUX/DEMUX is the same as the deployment of one 16 channels MUX/DEMUX. However, compared with the 16 channels DWDM MUX/DEMUX, the FMU 8 channels fiber mux provides a competitive solution for small networks which needn’t to buy a full-channel fiber mux that supports all 16 channels or more channels.

Conclusion

From the comparison above, the FMU 8 channels DWDM MUX/DEMUX is more flexible and cost-effective when deployed in WDM networks. How to choose is based on the requirements of your networks. FS.COM supplies two different types of these WDM MUX/DEMUX. Here is a simple datasheet of them. If you have more requirements for additional wavelengths, welcome to visit www.fs.com for more detailed information.

Application
ID
Description
16 channels
16 ch. DWDM Mux Demux, C27-C42, , IL <4.6dB, duplex LC/UPC
8 channels
8 ch. Dual Fiber DWDM Mux Demux, C53-C60, with expansion port, IL <4.6dB, LC/UPC