FAQs You May Ask When Using 1000BASE-LX/LH SFP

There are many types of fiber optic transceiver used in fiber optic transmission. 1000BASE-LX/LH SFP, one of the commonly used optical transceiver, is now widely used in optical network systems. Here are some common questions we might have when using Cisco 1000BASE-LX/LH SFP (GLC-LH-SM or GLC-LH-SMD) transceivers. And from the answers, we might have a deeper understanding of using these fiber optics.
Q1: Can 1000BASE-LX compatible with 100BASE-LX?
A1: 1000BASE-LX and 100BASE-FX are very different standards. 1000BASE-LX SFP (GLC-LH-SMD) and 100BASE-LX SFP (GLC-FE-100LX) are 2 module types, one for GE and one for FE slots. The GLC-LH-SMD will not operate at 100Mbps. You will need to use a 100Mb module to connect to another device at 100Mb. Check optical transceiver compatibility with your equipment by reviewing the Cisco Fast Ethernet SFP module compatibility document and choose the one it says is compatible.
Q2: What is the difference between LH and LX modules?
A2: Long Haul (LH) denotes longer distances while Long Wavelength (LX) denotes less energy which is obviously shorter distance. Before it was standardized 1000BASE-LX10 was essentially already in widespread use by many vendors as a proprietary extension called either 1000BASE-LX/LH or 1000BASE-LH.
Q3: Does 1000BASE-LX SFP work with 1000BASE-LH SFP? What does it infer if a module says like "Cisco 1000BASE-LX/LH SFP"?
A3: Yes, the 1000BASE-LX will work with the 1000BASE-LH. For instance, Cisco 1000BASE-LX/LH SFP is either made for single mode (long distance) / multimode (short distance). But this module can be used for both Single-mode and Multimode. The Cisco 1000BASE-LX/LH SFP, compatible with the IEEE 802.3z 1000BASE-LX standard, operates on standard single-mode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers. When used over legacy multimode fiber type, the transmitter should be coupled through a mode conditioning patch cable.
Q4: What about Mode Conditioning Patch cords (MCP)?
A4: When selecting an optical transceiver, watch the transceiver’s user documentation for when a MCP should be used (see previous link for MCP information). They are sometimes required when your network’s installed optical cable is OM1 or OM2 rated multimode fiber (MMF). In short, the MCP is an optical jumper that transitions the transmit fiber from a single mode fiber (SMF) to a multimode fiber.
Q5: GLC-LH-SM SFP to 1000BASELX GBIC won't link over MMF?
A5: Cisco compatibility document says: "Some customers might be tempted to connect 1000BASE-LX/LH devices over short reaches of MMF jumper cables without MCP cables. There is a risk associated to this type of nonstandard deployment, especially when the jumper cable is an FDDI-grade or OM1 type. In such case the power coupled directly into a 62.5-micron fiber could be as high as a few dBm (typically 5 to 6 dBm), and if the jumper cable is short, the adjacent receiver will be saturated, causing high bit error rate, and eventually irreversibly damaged. We recommend the use of MCP, but if the customer remains reluctant to the deployment of MCP, a 5-dB attenuator for 1300nm should be used and plugged at the transmitter of the optical module on each side of the link."
Q6: Does GLC-LH-SMD working with GLC-LH-SM?
A6: Yes. Both the GLC-LH-SM and GLC-LH-SMD transceivers support the IEEE 802.3 1000BASE-LX/LH standard and so are compatible with each other. The difference between the two is that the GLC-LH-SMD transceiver has additional support for Digital Optical Monitoring capability.
Q7: How much bandwidth can my single mode fiber (SMF) support?
A7: Single mode fiber has an extremely large bandwidth capacity. The following diagram shows how bandwidth can be scaled on SMF. Scaling bandwidth on fiber is not inexpensive. Depending upon the network, it may be more cost effective to install additional fibers instead of adding WDM technology.
Click through to browse GLC-LH-SMD price
Reference: www.sfp-transceiver-modules.com
Warm Tips: Fiberstore offers amount of in-stock 1000BASE-LX/LH SFP which are compatible for Cisco, Juniper, Dell, Finisar, Brocade, or Netgear (AGM732F) in 10/20 Km options.

Do Not Miss Fiberstore's 40-Channel DWDM Mux/Demux

DWDM (Dense Wavelength Division Multiplexing), an ideal optical multiplexing technology for long-haul data transporting, can put multiple channels of information using individual wavelength on the same fiber and increase the transmission capacity of optical networks considerably. Currently, DWDM technology is being widely applied in telecommunication networks and becomes the choice of many telecommunication operators.
Since the start of DWDM, various equipment and technologies have been used to enhance the high performance of every part in DWDM network. DWDM Multiplexer and demultiplexer are the main equipment that take charge of the data sources' multiplexing and demultiplexing. In the past years, DWDM multiplexers and demultiplexers have been upgraded rapidly to overcome the insertion loss and to meet the demands of the increasing requests for faster telecommunication, and they are always being combined in one rack by today's vendors also known as DWDM Mux/Demux.
Fiberstore as a serious manufacture of optical communication published a 40-channel Duplex DWDM Athermal AWG Mux/Demux with competitive features which are described as following:

• Low Insertion Loss: Insertion loss is an inevitable problem in optical networks. Combining LC/UPCconnectors of high quality and AWG technology, this duplex Mux/Demux reduces the insertion loss to a minimum of 3dB and increases the transmission capacity effectively.
• Athermal AWG Technology: With athermal design this mux/demux device is temperature-intensive and allows multiplexing and demultiplexing of DWDM signals over a wide operating temperature range with long-term stability, reliability and large transmission capacity.
• Large Channel Number & Excellent Channel Isolation: This DWDM Mux/Demux is designed for use within the C-band release of DWDM system which uses 40 channels at 100GHz spacing containing the channels from C21 (wavelength: 1560.606 nm) to C60 (wavelength: 1529.553 nm). Also 1.6nm (200 GHz) are available on request. Excellent channel isolation that eases the fiber handling is also provided.
• Space saving: With a standard 19 inch rack mount housing size, this DWDM Mux/Demux saves space effectively.
• High quality and Inexpensive: The products of Fiberstore has been appreciated by customers for its reliable quality. Comparing with other manufactures, Fiberstore offers the lowest price for such a high quality 40-channel DWDM Mux/Demux.

For detailed specifications of this 40-channel Duplex DWDM Mux/Demux with Monitor Port, please visit Fiberstore's online shop. Fiberstore currently has 10 of this DWDM Mux/Demux in stock and can deliver on the same day of ordering. Fiberstore also provides custom package to meet customers' requirements.
Click through to get more information about WDM fiber optic multiplexer.

1.25G SFP Transceiver Alternative Solution

Introduction

SFP (Small Form Pluggable) optical module is a compact transceiver used for both telecommunications and data communication applications. It can interface a network device motherboard (for a switch, router, media converter or similar device) to a Fiber Channel or Gigabit Ethernet (GbE) optical fiber cable at the other end. Due to its small size, it has replaced the formerly ubiquitous Gigabit Interface Converter (GBIC) gradually. And now it becomes the most used fiber optic transceiver module in the fiber communication industry.

SFP Module Series

SFP transceivers are available in a wide range of data rates and fiber coverages, which allows users to choose the most suitable transceiver for each link. Most used SFP transceivers are the 1.25 Gbps transceiver modules which are of different transmitter and receiver types such as 1000BASE-T, 1000BASE-SX, 1000BASE-LX/LH, etc. Here depict such kinds of transceivers.

1000BASE-SX SFP Transceiver

1000BASE-SX SFP transceiver is a cost effective 850nm module supporting dual data-rate of 1.25Gbps/1.0625Gbps. It is compatible with the IEEE 802.3z 1000BASE-SX standard and operates multimode fibers link up to 550 m. The fiber optic transceiver consists of three sections: a VCSEL laser transmitter, a PIN photodiode integrated with a trans-impedance preamplifier (TIA) and MCU control unit. It is usually applied for Fiber Channel links, Gigabit Ethernet links, Fast Ethernet links, etc.

1000BASE-LX/LH SFP Transceiver

1000BASE-LX/LH SFP transceiver is a high performance 1310nm transceiver for single-mode fibers. It is compatible with the IEEE 802.3z 1000BASE-LX standard and also supports dual data-rate of 1.25 Gbps/1.0625 Gbps with a transmission distance of 10 /15 /20 km. It has three part numbers: SFP-1G31-10-xx, SFP-1G31-15-xx and SFP-1G31-20-xx. The transceiver consists of three sections: a FP laser transmitter, a PIN photodiode integrated with a trans-impedance preamplifier (TIA) and MCU control unit. It is commonly applied for Gigabit Ethernet links, Fiber Channel Switch Infrastructure and other optical transmission systems.

10/100/1000BASE-T SFP Transceiver

10/100/1000BASE-T SFP Transceiver is compatible with the Gigabit Ethernet standard as specified in IEEE STD 802.3. It supports data rates of 10/100/1000 Mbps, fully satisfying 10/100/10001000BASE-T applications such as LAN 10/100/1000Base-T Fiber Channel links, Gigabit Ethernet over Cat 5 Cable, Switch to Switch Interface, Router/Server interface, etc.

Fiberstore Solutions

Fiberstore is a professional manufacturer and supplier for transceiver solutions. We offer such modules which are 100% compatible with large inventories. All those modules are delivered on the day for your convenience. In addition, we are committed to high-quality products and long-term customer confidence with providing return and warranty services. The detailed ordering information is as followed. If interested in our products, you can visit www.fiberstore.com or contact us over sales@fiberstore.com.

Module #	Data Rate	Transmission Distance	Connector Type	Price	Inventory
1000BASE-SX SFP Transceiver	≤ 1.25 Gbps	550 m	LC	US$ 8.00	2000
1000BASE-LX/LH SFP 1310 nm Transceiver	≤ 1.25 Gbps	10/15/20 km	LC	US$ 10.00	5500
10/100/1000BASE-T SFP Transceiver	10/100/1000 Mbps	100 m	RJ45	US$ 18.00	1000

Originally published at: www.fiber-optic-equipment.com

Great Compatible Cisco 10G SFP+ Modules

The enhanced small form-factor pluggable (SFP+) is an enhanced version of the SFP that supports data rates up to 16 Gbit/s. Since SFP+ is mostly used for 10G, we usually call it 10G SFP. It is a popular industry format supported by many network component vendors. In terms of the SFP+ transceivers, there are various major brands, such as Cisco, HP, Juniper etc. In the current market, the Cisco's SFP+ transceivers are very popular with the customers, especially the Cisco SFP-10G-SR and SFP-10G-LR. However, these original transceiver modules are really expensive. To save cost, we usually use 3rd-party transceiver modules instead of the original brand. In this text, two kinds of compatible SFP+ modules that can severally replace the Cisco SFP-10G-SR and SFP-10G-LR will be introduced. These two kinds of compatible modules are all from the Fiberstore, the leading manufacturer and supplier of optical transceiver modules in China.

SFP+ is the Most Popular 10G Transceiver Module

Since there are many different 10GbE physical layer standards, many interfaces consist of a standard socket into which different PHY modules may be plugged. On the market, the common 10G transceiver modules are XENPAK, XPAK, X2, XFP and SFP+. XENPAK was the first MSA for 10GbE and had the largest form factor. X2 and XPAK were later competing standards with smaller form factors. XFP came after X2 and XPAK and it is also smaller. The newest module standard is SFP+. In comparison to earlier XENPAK or XFP modules, SFP+ modules leave more circuitry to be implemented on the host board instead of inside the module. Now SFP+ has become the most popular socket on 10GbE systems.

Common 10GbE Standards for SFP+

10 Gigabit Ethernet is a group of computer networking technologies for transmitting Ethernet frames at a rate of 10 gigabits per second. It was first defined by the IEEE 802.3ae-2002 standard. Some common 10GbE standards for SFP+ are shown in the table below:

Cisco compatible SFP+	Cable Type	Wavelength	Max Range
10GBASE-SR SFP	MMF	850nm	OM3:300m/OM4:400m
10GBASE-LR SFP	SMF	1310nm	10km
10GBASE-LRM SFP	MMF	1310nm	220m
10GBASE-ER SFP	SMF	1550nm	40km
10GBASE-ZR SFP	SMF	1550nm	80km

Two Kinds of Compatible Cisco SFP+ Transceivers from Fiberstore

For 3rd-party transceiver modules are much cheaper than the original brand (Cisco. HP, etc), they are become more and more popular in the market. As a result, suppliers to offer these effective modules are also become more than before. But in my opinion, the Fiberstore does the best among them. They provide all kinds of compatible transceivers, especially the SFP-10G85-3M-CO and SFP-10G31-10-CO, which can entirely replace the Cisco SFP-10G-SR and SFP-10G-LR.

• SFP-10G85-3M-CO

  The SFP-10G85-3M-CO series multi-mode transceiver is a SFP+ module for duplex optical data communications such as 10GBASE-SR and 10GBASE-SW. This transceiver offers the same function with Cisco 10G SR SFP and is fully compatible with Cisco devices. It is a hot-swappable input/output device, which means no need to power down if installing or replacing. Its transmission distance can up to 300m with duplex LC multi-mode Fiber cable.

• SFP-10G31-10-CO

  The SFP-10G31-10-CO single mode transceiver is a small form factor pluggable module for serial optical data communications such as IEEE 802.3ae 10GBASE-LR/LW. This 10GBASE-LR SFP module offers the same function with Cisco SFP-10G-LR and is fully compatible with Cisco devices. This module is designed for single mode fiber and operates at a nominal wavelength of 1310 nm. Its transmission distance can up to 10km with duplex LC single-mode fiber.

All these products offered by Fiberstore are tested in-house prior to shipping to ensure that they will arrive in perfect physical and working condition. Fiberstore can guarantee these 10G SFP+ transceivers to work in your system and all of their 10G SFP+ transceivers come with a lifetime advance replacement warranty. Now they have many SFP-10G85-3M-CO and SFP-10G31-10-CO transceiver modules in stock. Therefore, Same-Day Delivery is available. If you want to know more about their products or services, please feel free to contact them at sales@fiberstore.com.

What You Need to Know When Using 10G over CWDM

Both Passive CWDM and DWDM have been viable solutions in the telecommunications industry, but now, 10G Ethernet is appearing to be the most preferred solution over CWDM, everyone is migrating to the use of 10G Ethernet. This encourages many engineers to figure out how they ought to adjust their new designs to support the transition from 10G to CWDM. If you're one of these designers who's attempting to navigate the transition, the following is what you need to know.
Bandwidth Exts are Easier
In past years, designers who want to increase or improve their bandwidth could achieve this easily over a single or duplex mode fiber. During this period, the 1G Ethernet and CWDM solutions were sufficient, and the only limiting element was the power budget of the optical transceiver or the attenuation of your fiber. That it was possible to transmit up to 200 kilometers and utilize just a 1G Ethernet when designers preferred cheap CWDM.
Now, many people are considering the 10G Ethernet solutions, and that's why it's necessary to understand how everything will differ when using 10G over CWDM. When intending to migrate to 10G, you need to know the fiber type. For the dispersion and attenuation calculation, every designer need to know the recommended parameters from ITU-T and understanding the vendor and product kind of the fiber could also help. Remember that the physical fiber will work better than the standards claim most of the time.
Chromatic dispersion is referred to as the time variance of a single pulse of a signal. To summarize, chromatic dispersion is "the spreading of a light pulse per unit source spectrum width in an optical fibre due to the various group velocities of the different wavelengths composing the source spectrum" or in layman's terms, "the signal is stretched on the fiber transmission path due the dispersion characteristics of the transporting fiber."
Chromatic dispersion always exists, but the higher the link speed is, the greater important it becomes. For instance, a wavelength of 1310nm have a 0 ps/nm chromatic dispersion and 5, 25 dB fiber attenuation. In comparison, a wavelength of 1610 nm have a 330 ps/nm chromatic dispersion and a 3,45 dB fiber attenuation.
CWDM Over DWDM 10G is Cost-Effective
Designers should bear it in mind that CWDM implementation is more cost effective than passive DWDM infrastructure. These solutions will be more expensive because DWDM lasers cost more. DWDM lasers are essentially DFB lasers which are cooled, however, they are recommended as they contain the longevity that are required in these solutions. If you would like transmit a signal over a large distance, you should think about large metro ring topologies.
Though 10GBASE DWDM is more expensive, it's become the first choice because users have started to consider the costs after dividing it over the quantity of customers served. Some customers are more cost-conscious and have lower bandwidth capacity requirements; so, the cheap CWDM infrastructure will make more sense.
Remember that the new 10GBASE DWDM services is usually added over the same fiber. This will enhance the support of the initial CWDM infrastructure capacity by 4 times. This is irresistible to many designers.
Select A Reputable Brand
Selecting a reputable brand for your CWDM Solution is necessary to achieve the best results. When you select a reputable brand, which means that multiple customers have had a favorable experience with this brand, this means that you’re likely to have success with the brand also. Compatible CWDM SFP, CWDM optical multiplexer and add drop CWDM all of these device you can but these form Fiberstore.Inc, which offer warranties and other benefits, also have an option for longer service and support.

How to Use DOM in Cisco System

Do you know that there is a fiber tester inside your optical transceiver? This "fiber tester" we call it DOM, which is short for Digital Optical Monitoring. DOM is a feature which enables the monitoring of some interesting status values on the interface with the most useful values being the optical receive and transmit powers. You can configure your Cisco (or other brand) device to monitor optical transceivers in the system, either globally or by specified port(s). When this feature is enabled, the system will monitor the temperature and signal power levels for the optical transceivers in the specified port(s). CONSOLE messages and SYSLOG messages are sent when optical operating conditions fall below or rise above the optical transceiver manufacturer’s recommended thresholds. By being able to monitor transmit and receive power levels of optical interfaces you are able to characterize the fiber loss and isolate any unidirectional connectivity issues. So, how to use DOM for your optical transceiver in Cisco system is our main topic today.

What Parameters are Monitored by DOM?

DOM allows to monitor some parameters so that network administrators can then check and ensure that the module is functioning correctly. These real-time operating parameters include:

• Optical Tx power
• Optcal Rx power
• Laser bias current
• Temparature
• Transceiver supply voltage

How to Use DOM

Restrictions

There are some restrictions of using DOM in Cisco system including:

• Ensure that your optical transceiver supports DOM. For Cisco original optical transceivers, you need the transceiver module compatibility information for configuring transceiver monitoring.
• In case of combo ports with SFP and RJ45 provision, when SFP is inserted in slot or port and media type is not configured to SFP, DOM is functional only if global transceiver monitoring is enabled.
• CISCO-ENTITY-SENSOR-MIB traps are sent only once after the threshold violation. However, SYSLOG traps are sent according to the monitoring interval.

Procedure

	Command or Action	Purpose
Step 1	enableExample: Router> enable	Enables the privileged EXEC mode.• Enter your password if prompted.
Step 2	configure terminalExample: Router# configure terminal	Enters the global configuration mode.
Step 3	transceiver type allExample: Router(config)# transceiver type all	Enters the transceiver type configuration mode.
Step 4	monitoringExample: Router(config-xcvr-type)# monitoring	Enables monitoring of all optical transceivers.
Step 5	monitoring intervalExample: Router(config-xcvr-type)# monitoring interval 500	(Optional) Specifies the time interval for monitoring optical transceivers. Valid range is 300 to 3600 seconds, and the default value is 600 seconds.

In conclusion, there are three main command that can be used to turn on/off DOM for all transceivers type in the system:

• Router(config)#transceiver type all
• Router(config-xcvr-type)#monitoring
• Router(config-xcvr-type)#end

Once enabled, DOM can be accessed via CLI using "show interface transceiver command", shown as the following picture:

DOM is incredibly handy when troubleshooting fiber issues. A low value in the Rx Power column indicates that you have a bad fiber, or more commonly, a dirty fiber optic patch cable somewhere.

Of all the five values, two mostly used and relevant values are TX and RX power, and temperature is also used sometimes. The operating range of these three values is unique across all modules and is available in the data sheet. Additionally, there is an extension available for this command, which is also very helpful and is used to check threshold values of the above parameters like temperature, Tx and Rx. The command is "show interface gig x/y transceiver detail".

How about Non-Cisco Transceiver with DOM

Though DOM is a very helpful functionality of optical transceiver, not all transceivers support DOM in Cisco's optical transceiver products family. For example, the common SFPs, such as the GLC-LX or GLC-SX units that are used by most network engineers on a day to day basis are not with DOM feature.

Why not add this helpful and convenient feature to all transceivers? Actually, Cisco have their own attitude. They think that DOM functionality is worth an extra $300 a pop, putting the cost of a DOM-enabled single mode SFP close to $800. However, DOM functionality is not a novel thing now. Surprisingly, there are some third-party optical transceiver include the DOM functionality but with a low cost. Fiberstore, for instance, as the professional optical transceiver manufacturer and supplier, they can offer Cisco compatible SFP transceivers with DDM or DOM functionality with a low cost. For example, GLC-LX-SM-RGD offered by Fiberstore just at $18.00, GLC-SX-MMD and GLC-LH-SMD at $10.00. But if we want to use non-Cisco transceivers, we need a little different approach to get started with DOM of non-Cisco transceivers. To enable support for non-Cisco SFPs, command "Router(config)#service unsupported-transceiver" is necessary.

Originally published at www.fiber-optic-transceiver-module.com.