Fiber optic communication

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Very simple tutorial to use visual fault locator. 

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25G Switch Comparison: How to Choose the Suitable One?

Driven by the undeniable growth in demand for bandwidth of private and public cloud data centers, 25G Ethernet over a single lane has become the new trend for sever-to-switch interconnections. And the increasing requirements of higher speeds in data centers have enhanced the adoption of 25G switch, which is the new buzz in recent years. In this post, a simple analysis of 25G switch market and comparison of commonly used 25G switches will be explored.

25G Switch Market Analysis

As we know, before 25G technology advent, the existing options are one lane for 10G, four lanes for 40G, or four lanes at 25Gbps for 100G. The 25G technology meets the specification for existing module form factors like SFP28 and QSFP28, and allows for a breakout connection between 25G and 100G without changing the port on the front of many 100G switches. Besides, driven by the high speed and bandwidth, various switch manufacturers have announced their new 25G switches in recent three years, just to occupy more market shares.

Cisco delivered their Nexus 9300-FX platform switches for 10G/25G/100G switching;

Mellanox launched 25G Ethernet switch SN2410 series for 25G/50G/100G Ethernet networks;

Dell put forward EMC networking S-series 25/40/50/100GbE to help data centers migration;

Broadcom announced its BCM56960 Series 25G switch for cloud-scale networking;

FS.COM introduced N-Series spine/leaf 25G/100G switch for cost-effective data center solutions.

At the same time, 25G optical transceivers, DACs, and AOCs also spring up like mushrooms. According to a study by Dell’oro, Ethernet switch revenue will continue to grow through the end of the decade, with the biggest sales forecast for 25G and 100G ports.

Notes: the source of the research: Crehan research.Inc

From the research we can see, at least in the next three years, 25G/50G/100G bandwidth will continue to grow and occupy half of the total network bandwidth, which in turn enhances the development of 25G switch market. Though challenges still exist for 25G Ethernet, it’s not denied that the trend for ToR 25G switches cannot be blocked.

Comparison Between Commonly Used 25G Switches in the Market

As have mentioned above, 25G switch market is booming due to the growing speed and bandwidth as well as switch vendors promotion. Then how to achieve the optimized network performance with existing 25G Ethernet switches, and control the total investment at the same time? Firstly, let’s have a look at the 25G switches in the market.

All the 25G SFP28 switches listed in the table have the same port configuration: 48 SFP28 ports and 6 QSFP28 uplink ports. And there are ToR/Leaf switches. Usually 25G switch is often used for switch-to-server applications, as for how to realize this, please read the article: How to Use 25G Switch for Switch-to-Server Connection.

For choosing ToR 25G switch, if you have no limited cost budget, Cisco 25G switch maybe a not bad choice, because except for the expensive price, it has high-level performance and configuration as well as its good reputation. All these make Cisco switches are perfect for data centers. Of course, other 25G switch vendors like Dell, Brocade and Mellanox also provide good options for migration from 10G, 25G to 50G and 100G networks.

However, for those who have a tight budget or do not pursue brand, a more wise choices is to select 25G switch like FS.COM N8500-48B6C. This switch supports ONIE installer for 3rd party network operating systems and compatibility with SDN (Software Defined Networks) via OpenFlow 1.3.11. And it also supports the advanced hardware based VXLAN feature to support over 16M virtual networks, making it a suitable option for cost-effective data center solutions.

Summary

25G switch offers a more convenient way to migrate to 100G network. Because it reduces the numbers of cables and switches needed in network designs, which in turn decrease the CAPEX and OPEX. Facing with the fast evolving 25G switch market, are you ready for it?

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Stack Switch: Optimize Your Network Performance to the Maximum

Stacking switch is a common technology used in network design, especially when large numbers of ports are required in data centers or large size networks. Stack switch not only provides high performance, but also maximizes network scalability and simplify network management. That’s why stackable switches are popular among network builders. Then what is stack switch? What’s the common way for switch stacking in the market?

What Is Stack Switch?

Stack switch, also called stackable switch by vendors, allows several switches to stack via specific stackwise port or uplink port. Traditionally the switches stacked together usually is limited to the same series of network switches. Mixed switch stacking is allowed for today’s switches. The number of stacked switches is often determined by switch brand. For example, Cisco 3850 stack switch can have a maximum of eight switches to be stacked, while Dell N4000 series stack switches are up to twelve. When switches are stacked, all members in this stack share the same IP address and can be managed as “one unit” through the CLI (command line interface) or embedded Web interface, which offers great convenience for network administrators without lowering its performance.

Usually stack switches come with fixed configuration like 12, 24, or 48 gigabit Ethernet ports. Compared with modular switches that allow line cards or service modules in and out as needed, stack switches are more cost-effective in enterprise campus networks which offer endpoint connectivity and uplink capabilities for users at a price per port. Therefore, for those who has limited switch port or enterprise networks that lack of physical expandability, stack switch is an excellent choice for network expansion.

How to Achieve Network Switch Stack?

From the first generation of of Cisco 3750 series stack switches, the stackable switch market has become more mature, so does the switch stacking technology. Like Cisco, other network switch vendors like Dell, Brocade and FS.COM also add their own unique features and functionality to their stack switches, which enhance the virtuous circle of switch stacking technology development.

The typical method for switch stacking is to use stacking cable via stackwise port. Take Cisco 3750 series stack switches for example. Stackwise port lies on the rear-panel. Only approved cables can be used to connect the 3750 stack switches with other similar switches. If not, devices easily get damage. In addition, Cisco offers different connection types for this stack: full bandwidth connection and half bandwidth connection, which provide great flexibility for different application requirements.

Another way to achieve switch stack is to use the uplink ports. As has mentioned, many switch vendors upgrade the switch stacking technology to improve their competitiveness. Today’s stack switches can be stacked using several types of Ethernet ports such as 10GBASE-T copper port, 10G SFP+ fiber port and 40G QSFP+ port. Here take FS S3800-24F4S stackable managed switch as an example. As shown in the following picture, in the stack, one fiber cable from a 10G SFP+ port on a stack switch is connected to a SFP+ stacking port on the next switch. This process is repeated until all of the devices are connected. And the first stack switch is also connected with the last one to complete the stacking topology.

Conclusion

Stack switch, no matter uses stack cable or SFP+ stacking/uplink port, provides high bandwidth port density and easy management for network design. But compared with the way of using stack cable, stacking/uplink port is more cost-effective. Besides, using fiber uplink port to stack switch can realize long distance stacking in different areas, which are more popular in today’s network infrastructures.

Sources: http://www.fiber-optic-transceiver-module.com/stack-switch-optimize-your-network-performance.html

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Recommendations for Gigabit Switch with 10G Uplink Port

Gigabit network switches connect Ethernet devices in a network while providing great performance capabilities. In many network structures, gigabit Ethernet switches are often used as access switches that connect devices in a local area network. As the pace of network migration is getting fast, the need for gigabit switch with 10G uplink is growing too. And numbers of network administrators desire to apply 1G switch with 10G uplink in their systems.

Understanding Gigabit Switch with 10G Uplink Port and Its Market

Gigabit switches with multiple port configurations enable the network capacity to expand in consumer or corporate environments. For example, an 8-port gigabit switch can provide fast transmission speed for office users, and an 24-port gigabit switch works effectively for small and mid-sized business networks (SMBs). While 802.11ac has changed the way business support the quantity of devices connecting to each other. For network switches in last three years, 10G uplink added significantly to the cost for the switches with less than 48 ports, which isn’t what the customer want.

Over the years, gigabit switches in the market usually come with gigabit SFP port. When users want to find one 1G switch with 10G uplink port to speed their networks, they find most gigabit switches with 10G uplink port only exist in 48-port gigabit Ethernet switches. However, not every user needs a 48-port gigabit switch for their applications. But they have to pay for the extra ports which they do not use. Considering this, a multitude of vendors like Dell, FS.COM, MikroTik, Netgear and D-link begin to supply gigabit switch with 10G uplink in the market. Now except for the early 48-port gigabit switch, 8-port, 16-port and 24-port gigabit switches with 10G uplink are available in the gigabit switch market for different size applications.

Recommendations for Popular Gigabit Switches with 10G Uplink Port

48-port gigabit switches are the early type of network switches that provide 10G uplink port. And numbers of users are familiar with this switch. Now there is a multitude of 8-port and 24-port gigabit switches with 10G uplink port appear in the switch market, which satisfy users’ demand as well as boom the market. Here are popular 24-port gigabit switches coming with 10G SFP+ uplink port.

From the chart we can see, all the gigabit switches listed above provide 24 port 10/100/1000 Ethernet RJ45 ports. Apart from the MikroTik CRS226-24G-2S+RM 24-port gigabit switch that only has 2 SFP+ ports, the leaf gigabit switches come with 4 10G SFP+ ports for uplink to fully exploit the power of 10G servers and storage supporting high bandwidth applications like data backup and replication, and high-volume transaction processing. And they support extensive Layer 2+ or 3 features, enabling them have the same performance as 48-port gigabit switches.

In addition, with the 10G uplink port, most 1G switches can realize stacking or uplink, which make the entire network more efficient. Lots of users have complained that 10G links are expensive, thus getting cheaper, but still not cheap. However, from the chart, the price of four 24-port gigabit switches with 10G uplink port above is less than $400, which is really cost-effective for today’s Ethernet networks.

Summary

Gigabit switches with 10G uplink port can provide high speed data pipes to servers and storage devices. By taking advantage of the SFP+ fiber optic connectivity, those 8-port or 24-port 1G Ethernet switches offer an ideal solution for remote and branch offices.

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What to Consider When Buying PoE Switch for IP Cameras?

As the growing of business and the increasing awareness of security, IP cameras are widely deployed in areas like schools, public areas and even at home. All these arouse the increasing demand for PoE (power over Ethernet) switches which enabling big benefits for IP surveillance system. However, many users may ask a question: how to choose a PoE switch for my IP cameras? 8-port PoE switch or 24-port gigabit PoE switch? Cisco PoE switch or Netgear PoE switch? This post intends to explore the necessary considerations for buying PoE switch.

Understanding How PoE Switch Works for IP Cameras

As we know, power consumption of different IP cameras is different. The power consumption of PTZ (pan-tilt zoom) cameras is up to 20W, while other IP cameras like indoor/outdoor dome IP cameras may just consume as little as 3 or 4W. In addition, PoE switches transmit both data and power for PoE-enabled devices via a single network/Ethernet cables such as Cat5e, Cat6 and Cat6a. Usually, PoE switch comes with multiple ports to support more than two IP cameras. Take a 8-port PoE switch as an example, it can connect IP cameras, NVR, router, etc. Just like the below picture shows.

Essential Considerations When Buying a PoE Switch

There are various questions about buying a gigabit PoE switch in forums and communities. For example, one user ask in forum: “I have 5 IP cameras in a warehouse, two NVRs in the office, considering the distances, which switch should I choose, is 8-port PoE managed switch enough?” Then if you have the same question, what should you do? Here are some necessary factors to consider.

1.Port Count of PoE Switch

This is a basic factor that should be considered when buy a PoE switch. And it is easy to decide how many ports you need. According to the number of PoE-enabled devices, choosing the switch that has larger PoE ports than your device number, which is for your future-proofing upgrade.

2.PoE Switch Power Budget and IP Camera Power Consumption

The power budget of PoE switch matters a lot. Network designers need to know the power consumption for each switch port. It helps users to know how many IP cameras can be deployed. And this is easy to get. Take FS 8-port gigabit PoE managed switch for example, the power consumption per port is 30W (IEEE 802.3at ). Keep in mind that not all PoE port can reach the max. power consumption at the same time. As has mentioned above, the power consumption of IP camera varies from types to types. Therefore, to ensure the normal work of IP cameras, the power budget of PoE switches is important.

3.Unmanaged or Managed PoE Switch

It’s known to all that PoE switches come with managed switch and unmanaged switch. People who have experience in network design will know clearly the benefits of managed PoE switches. They enable network administrators to check the quality of the network copper cables linked to each switch port. And administrators also can use advanced management functions to have a good command of the whole network.

4.What’s the Distance of PoE? How to Select Ethernet Cable for PoE Switch?

Usually the transmission of PoE switch is 100m, and the commonly used cable is Cat5 Ethernet cable. According to the IEEE802.3af PoE standard, the required PoE output power is 15.4W. And the PD can receive 12.95W power after 100m transmission. FS PoE switches are compliant with 802.3af/at, which is definitely meet this demand. In addition, standard Cat5 cable is enough for the PoE connections. Make sure the Ethernet cable you buy is a standard network cable.

Summary

Choosing a suitable PoE switch is not an easy work, this post explores several considerations when buying a PoE switch for home or small business networks. If you still have questions about buying a PoE switch, you can do the same work like the user who confused about whether to buy a 8-port gigabit PoE switch or not. asking for help in forums or community, or just consult your sale rap.

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Review: Popular 24-Port PoE Switch for Different Size Networks

Purpose built for converged networks where video, voice and data are carried over a single network platform, PoE switches with 8 port, 24 port and 48 port represents an ideal solutions for different size networks like home or SMBs (small and mid-size business networks). 24-port gigabit PoE switch is a relatively commonly used network switch, which in turn cause hot discussions in forums and communities. Then what to consider when choosing a 24-port PoE switch? What’s the popular 24-port gigabit PoE switch to select? This post will give an answer.

Considerations to Choose a 24-port PoE Switch

As we know, the basic types of a network switch are managed switch, smart managed switch and unmanaged switch. Usually, managed and smart managed switches are an optimal choice for SMB applications because of its better control of networks.

Power budget—PoE switches are designed to power devices like IP cameras, VoIP phone, AP, etc. The power the 24-port PoE switch provides should meet the requirements. After all, not all the 24 port on gigabit PoE switches can offer power.

Cost—this factor is that many users care about. Buying a satisfying PoE switch with low cost is a pleasant experience. Here I’d like to say, with the same configuration, not all managed switches are expensive than smart managed switches. Therefore, before buying a 24-port PoE managed switch, try to get more suggestions in related forums or communities like Reddit.

Warranty—do not ignore this factor when choosing a gigabit PoE switch. There are many switch vendors supplying 24-port gigabit PoE switches, but not all manufacturers offer the same warranty. And many buyers are complaint with warranty after buying a network switch.

Review: Popular 24-port PoE Switch

Since there are various ethernet switch vendors in market who provide 24-port PoE switches. Here I will list the most often discussed PoE switches with 24 ports.

Cisco SGE2000P 24-Port Gigabit PoE Switch—$390 on Amazon

Cisco SGE2000P 24-port gigabit PoE switch is one of a popular PoE switches in market. It offers 24 high-speed 10/100/1000 Ethernet ports and 4 SFP ports for the network core or to support bandwidth-intensive applications. This switch is a managed switch that can provide ACL (access control lists), DoS (denial-of-service), VLAN and IEEE 802.1X port authentication. It’s not deny that Cisco 24-port gigabit PoE switch has its own charm for users around the world.

D-link DGS-1100-24P 24-Port Smart Managed PoE Switch—$246 on Amazon

If you are tired of the advanced functions of managed PoE switch, this smart managed switch may give a good choice. This 24-port PoE switch is easy to deploy and use. And it offers PoE power budget of 100W which is enough for home use.

FS S1400-24T4F 24-Port Gigabit PoE Switch—$399 on FS.COM

This 24-port gigabit PoE switch comes with 24x 10/100/1000Base-T RJ45 Ethernet ports, 1x console port, 2x combo port, and 2x gigabit SFP slots. Its maximum PoE power is 400W, which is higher than the PoE switch mentioned above. Maybe that’s why its price is a little higher than others. Besides, best fits for SMB or entry-level enterprise solution which demands industrial, surveillance, IP Phone, IP Camera or wireless applications.

Netgear GS728TP-100NAS 24-Port Smart Managed PoE Switch—$359 on Amazon

Similar to the switch mentioned above, this PoE switch also provides 24 gigabit ports and 4 SFP ports. It’s total PoE budget is 192W, higher than D-Link 24-port PoE switch. According to the product page of Netgear, this switch belongs to a new generation of Gigabit PoE/PoE+ Smart Managed Switches which offer powerful L2 and L2+ features, better PoE functions, aiming to provide users a comprehensive network solution.

Summary

This post just gives a simple review for popular 24-port PoE switches, and some factors that need to be considered when buying 24-port gigabit PoE switches. No matter what type of PoE switch you are choosing, make sure its capabilities can meet your basic requirements.

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Switch Stacking vs Trunking: What’s the Difference?

The performance of Ethernet switches is important in network design, for it will affect the whole network system working. Therefore, to achieve high performance, network managers may use different methods to improve performance of network switches, which cause a hot topic: switch stacking vs trunking. In the article, the knowledge of switch stacking and trunking will be explored as well as the comparison between them.

Switch Stacking vs Trunking: Differences in Basic Definition

Switching Stacking

Switch stacking is to connect two or more stackable switches, usually up to nine, through a stack cable and uses Cisco propriety StackWise protocol. Stacked switches can be regarded as one unit, and use the same IP address. The stack master which contains the saved and running configuration files for the switch stack controls the whole stack units and can be replaced if it fails. And stacking connects the backplane of the switches thus having full backplane speed connectivity between the switches.

Figure 1: Stacking of Cisco Stackable Switch

Trunking

Trunking is different from switch stacking. It is a method to handle multiple signals simultaneously. And trunking is often used to form an internetwork including LANs (local area networks), VLANs (virtual LANs) and WANs (wide ares networks). For example, if two switches are divided into four VLANs, and each switch has two VLANs. When communications are needed between the four VLANs, each switch must have a port designated as a trunk port to allow data flows between these VLANs. That’s trunking. Look at the following trunking example of FS 10G switches.

Figure 2: Port Trunking on FS 10G Switches

Switch Stacking vs Trunking: Further Comparison in Parameters

Switching stacking and trunking are two technologies in network management, then what’s the difference between them?

Configuration Requirements

Generally speaking, not all network switches support stacking. Stackable switches must belongs to one vendors when users want to achieve stacking. The original stackable switches are Cisco Catalyst 3750 series. But now more and more vendors like FS are capable of manufacturing stackable switches. The S3800-24T4S 24-port gigabit stackable managed switch and S3800-24F4S 24-port stackble SFP switch are two cost-effective switches for enterprise networks.

However, trunking is different from stacking. Most network switches in market support trunking, which ensure connection between different VLANs. No other special requirements for trunking.

Cost

Usually stackable switches are more expensive than common switches. Because some stackable switches needs additional cable and modules for stacking, which add extra investment for devices. However, there are also switches come with built-in ports for stacking, which can avoid the possible expense of the modules in stacking. FS gigabit stackable managed switches mentioned above are such type of switches, and the price of them is less than $500.

Figure 3: FS S3800 Series Stackable Managed Switches

Performance

When switches are stacked, they becomes one single unit logically. That is to say, the stack unit (up to nine switches) can be taken as “one switch”. There is just a single management interface for users to deal with, which greatly simplify network management, increase port count available and provide high bandwidth at the same time.

Trunking is based on a layer 2 technology. And a 4-byte header is added into each packet as they leave the first switch, and the header will be removed when the packet arrives at the second switch. That’s how trunking work. It eliminates the frequent port configuration when two or more VLANs need communications. In addition, LAG (Link Aggregation Group Protection) is a way to in trunking that protects links from errors.

Conclusion

In fact, switching stacking and trunking are two different concepts, even though both of them can simplify network management. Switch stacking vs trunking, choosing which one depends on users requirements. If high density port and high speed are the first parameter to consider, stacking and stackable switch are a better choice. If not, then trunking can be taken into consideration.

Sources:http://www.fiberopticshare.com/switch-stacking-vs-trunking-whats-difference.html

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Smart Switch vs Managed Switch: What’s the True Difference?

Ethernet switches can be regarded as the “brain” of a network. In today’s market of network switches, there are mainly three types of Ethernet switches: managed switch, smart switch and unmanaged switch. Like the discussion about managed vs unmanaged switch, the topic of “smart switch vs managed switch” is also be discussed heatedly. Then what’s the true difference between smart switch and managed switch? Let’s have a further look.

Smart Switch vs Managed Switch: Differences lies in Definition

What Is a Smart Switch?

A smart switch provides basic managed switch features such as QoS, security, and web management. Usually, smart switches are managed via a web browser, which provides intuitive guidance for users to manage their networks. If there is no advanced applications needed, smart switch is an optimal solution for simple applications like small and mid-sized business networks.

What Is a Managed Switch?

Managed switch, such as FS S3800-24T24S stackable managed switch, is designed to work for large data center and enterprise networks. Generally speaking, managed switch has a serial port which allow recovery from misconfiguration with minimal downtime. And managed switches have more intelligent functions like port mirroring and monitoring management, which enables users to prioritize network traffic and get high degree control of their networks.

Smart Switch vs Managed Switch: What’s the True Difference?

Differences between smart switch and managed switch have got much attention in both technical forums and communities. Why so many guys are confused with smart switch and managed switch? In the market, to propagate their network switch, many vendors use different terms like smart switch, smart managed switch, web-smart switch to define their switches, which cause troubles for users to understand these terms. Here are some obvious differences between smart switch and managed switch.

Cost

If you search online and you will find that most smart switches in market are slightly crippled versions of managed switches with no CLI or telnet functions. And price seems to be the biggest difference, especially among brand switches like Cisco managed switch and HP managed switch. While some third vendors still supply self-developed managed network switches in a low price.

Performance

Working performance is an important factor to consider when users choose between smart switch and managed switch. Because most managed switches can be accessed by command line interface via a RS-232C console port and telnet and/or SSH session, and often a web GUI. While the so-called smart switches often lack console port, and they may not support telnet, SSH, though they have a web GUI. In addition, smart switches usually have limited selection of advanced management, poorer scope of configuration flexibility and little to no security features.

Summary

Smart switch vs managed switch, the differences do exist. Regardless of which type of network switch you choose, the features that best fit your network are what you should consider first. If you have no limit of expenditure and want to have more control over the network, managed switches are the best choice. If not, smart switches or unmanaged switches can be an alternative.

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Best Replace for D-Link DGS-1100-10MP 8-Port PoE Switch

As the ever-increasing of small business, Ethernet switches with PoE (power over Ethernet) technology to realize real-time monitoring and management. 8-port PoE switch is one of the commonly used PoE switches in business networks. Considering different factors, it’s common for users to find a matched cheap PoE network switch to replace the expensive one. In this post, the alternative—FS S1130-8T2F 8-port PoE managed switch—for D-Link DGS-1100-10MP 8-port PoE switch and why it can replace DGS-1100-10MP switch will be talked about in details.

Overview of DGS-1100-10MP and FS S1130-8T2F 8-Port PoE Switch

D-Link DGS-1100-10MP 8-Port PoE Switch

D-Link DGS-1100-10MP smart managed PoE switch offers 8 10/100/1000 ports and 2 gigabit SFP ports, providing an affordable solution for business of all sizes. It’s mainly deployed for Video IP surveillance applications. Different from other 8-port PoE switches like Cisco and HP, D-Link DGS-1100-10MP is much cheaper for users.

FS S1130-8T2F 8-Port PoE Managed Switch

Similar to D-Link DGS-1100-10MP PoE gigabit switch, FS S1130-8T2F 8-port PoE managed switch comes with 8 10/100/1000Base-T RJ45 Ethernet ports, 1 console port, and 2 gigabit SFP slots. With fanless design, this managed PoE switch provides silent and reliable operation and offers high performance for VoIP phones, wireless APs and IP surveillance cameras.

8-Port PoE Switch: DGS-1100-10MP vs FS S1130-8T2F

Why FS S1130-8T2F 8-port PoE managed switch can be used to replace D-Link DGS-1100-10MP? Let’s have a look at the following chart.

Parameter

From the chart above, we can see that FS S1130-8T2F 8-port gigabit PoE switch has the same parameters with D-Link DGS-1100-10MP PoE switch. And in some aspects, FS 8-port managed PoE switch has more advantages. As we know, managed switches often enable network administers have more control of their networks, which is why managed switch becomes popular in small and mid-sized business networks. Besides, FS 8-port gigabit PoE managed switch is fanless design which provides silent operation, offering more pleasant operating experience.

Application

Though the parameters of these two PoE switches are similar, what about their applications? Can FS 8-port PoE managed switch have the same performance with DGS-1100-10MP? The answer is “yes”. As has mentioned above, DGS-1100-10MP PoE switch is designed to IP Surveillance applications. So does the FS S1130-8T2F. Except for web management interface which allows administrators to manage the switch down to the port level in an user-friendly way, FS 8-port PoE managed switch also supports various advanced management like CLI, TELNET and SNMP. The picture below shows its regular applications.

Cost

Cost is an important parameter that many users will consider when buying a 8-port PoE switch. FS S1130-8T2F 8-port gigabit PoE switch is available at $159 online, while the price of DGS-1100-10MP PoE switch is $290 average. In terms of cost, FS S1130-8T2F PoE switch seems to be a better choice.

Conclusion

PoE switches provide an ideal solution for quick and easy PoE IP camera and surveillance deployment with power feeding. In this article, compared with D-Link DGS-1100-10MP 8-port PoE switch, FS S1130-8T2F PoE switch has a comprehensive management function with lower price, which can be a replacement when building IP surveillance networks.

Sources:http://www.fiberopticshare.com/best-replace-d-link-dgs-1100-10mp-8-port-poe-switch.html  

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48 Port PoE Switch Stacking: Do You Really Need It?

When network designers build their networks, there is a common problem that they may meet: whether to stack switches or not. Because, limited by the switch port counts, designers have to get more switches or stack switches to meet network build requirements. In the article, the stack of 48-port PoE switch will be used as examples to explore how to achieve optimized network performance through switch stacking, and when network designers need to stack their network switches.

How to Decide Whether Switch Stacking Is Need?

Switch stacking is to connect two or a group of network switches to form a single stack unit that can be managed in a simple way. In this way, available switch ports are increasing as well as management simplicity. For example, in an small business network (PoE is necessary), if 48 gigabit ports are needed, two 24-port gigabit PoE switches can be stacked to achieve the target. Of course, one 48 port PoE gigabit switch also can be used. However, whether to choose stacking or not depends on what the designer want to accomplish. If cost savings and some sense of isolating network outages are important parameters to consider, stacking is a better choice like the two 24-port PoE switches. If features related to simplicity, scalability and flexibility are more important, then choose the one 48 port PoE switch.

How to Stack 48 Port PoE Switch?

Generally speaking, there are two types of switch stacking—ring topology and chain topology. The main differences are the numbers of stacking cables used in these two topologies. Furthermore, ring type protects networks from a single failure because communications between the switches continue in a direct way. Chain topology is not a recommended stacking type, for it can cause split stack easily, though it requires less number of cables.

Therefore, the following example is to illustrate how to stack three 48 port PoE switches together.

In the picture, all the three 48-port PoE switches are connected via SFP+ port. The connections of SFP+ ports are:

Switch # 1,SFP+ port # 1—Switch # 2, SFP+ port # 2

Switch # 2,SFP+ port # 1—Switch # 3, SFP+ port # 2

Switch # 3,SFP+ port # 1—Switch # 1, SFP+ port # 2

By connecting these switches in this way, a logical progressions from port 1 to port 2 is established. This could prevent a single point failure effectively. At the same time, switches stacking together require more power, which sometimes requires cooling devices.

Do You Really Need Switch Stacking?

As network devices growing, more switches are deployed in networks. There are advantages and disadvantages of stackable switches and standalone switches. In fact, whether to need swtich stacking depend on how your network is going to be planned today and tomorrow. Standalone switches like FS 48 port gigabit PoE switch are beneficial for small business that looks for network efficiency, operational cost savings, and ease of management. While for large enterprise business networks with VoIP traffic and hosting, to simplify management and get more advanced features, stackable switches maybe a better choice.

Summary

In summary, switch stacking allows network administers to manage several switches as “one switch”, ensuring the performance as well as network management simplification. However, as mentioned above, whether to choose stackable switch depend on the network deployment. Cisco 48 port PoE switch usually support stacking, which is good for large enterprises. While other brand switch like FS 48 port PoE switch that doesn’t support stacking is ideal for SMB networks.

Sources: http://www.fiberopticshare.com/48-port-poe-switch-stacking-really-need.html

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Recommendations for Popular 12-Port 10GbE Switches

As the total expenditure decreases of 10GbE network and the increasing data traffic in modern business, the specific demands for 10GbE switches have been put forward. As we know, there are 8-port 10GbE switch, 12-port 10GbE switch, 24-port 10GbE switch and 48-port 10GbE switch in the market. With so many types to choose from, many users have troubles in making a decision. In this tutorial, several kinds of 12-port 10GbE switch will be introduced, aiming to offer a reference for users’ selection of 12-port 10GbE switches.

Overview of Popular 12-Port 10GbE Switches in Market

As we can search on many forums and communities, Cisco 10GbE switches are the hottest topic. However, not every user, especially some SMB (small and mid-sized business) network builders will hesitate to choose Cisco switches due to its high price. Considering this point, here are some 10GbE switches that much cheaper.

D-link DXS-1210-12SC

D-link DXS-1210-12SC is a 12-port 10GbE SFP+ switch that features with extensive management, layer 2 features, QoS and bandwidth control. Designed with 12 SFP+ ports and 2 10GBASE-T/SFP+ combo ports, this smart managed switch supports 10GbE copper and fiber connections for a wide range of network needs.

FS S5800-8TF12S

Similar to D-Link DXS-1210-12SC switch, FS S5800-8TF12S is also a 12-port 10GbE SFP+ switch that offers and 8 ports 1GbE SFP/RJ45 combo and 12 ports 10GbE uplink in a compact 1RU form factor. Offering high performance for traditional or fully virtualized data center and SMb networks, this 10GbE switch also can work with hyper-converged infrastructure. The unique port count of this switch makes the perfect fit for hyper-converged infrastructure, which providing future-proofing assurance for the growth of virtualization, cloud-based services and applications.

Netgear XS712T

Netgear 10GbE switches are popular in SMB networks. The XS712T is a 12-port 10GbE switch that has 12 10G copper ports and 2 SFP+ combo ports for 10GbE fiber links, which is different from FS 12-port 10GbE switch. In addition, this 10GbE smart switch also offers advanced and comprehensive set of layer 2 features for small and medium sized network management.

Mellanox SX1012X

Mellanox SX1012X 12-port 10GbE SFP+ switch is a good switch for ToR solution. It offers 12 1/10GbE ports in a half 1U form factor. This unique design allows side-by-side deployment in racks. In addition, what the users should pay attention to is the 12 1/10GbE ports come with QSFP+ connector, which means if users buy this switch, the corresponding DACs and optical modules have to be bought together.

How to Choose a Suitable 10GbE Switch for Your Network?

Here is a simple chart showing the port of the 12-port 10GbE switches mentioned above.

From the chart, we can conclude that vendors have different definitions for their 12-port 10GbE switches. Therefore, users may have troubles in selecting a suitable network switches. Take these 10GbE switches as examples, the following part intends to talk about some factors that users many confused in purchasing a 10GbE switches.

The first factor is port type. If searching on Google, many questions will be shown about SFP+ port count of a 10GbE switch. For in 10GbE networks, core switches or access switches with SFP+ port are necessary. Take FS S5800-8TF12S 12-port 10GbE SFP+ switch as an example, to meet part of network builders’ need for hyper-converged infrastructure, the 12 SFP+ ports is designed.

The second one is the performance. Some users are fond of Cisco managed switches because of their advanced functions. However, as many network geeks said in forums or communities, most advanced functions will not be used in networking, and it’s no need to pay for some features that will not come in handy.

The last one is the vendor or company. A good and reliable vendor or company can not only provide quality switches, but considerate services which help users solve unnecessary problems and save cost. Popular brands are known to us all like Cisco, Dell and HP. For small business, some vendors who offer cheap but quality products are also popular like FS.COM. Of course, other good vendors and companies are needed to be explored.

Summary

In a word, Ethernet switches are the key part in 10GbE networks. This post recommends some popular 12-port 10GbE switches for users, and some factors about switch selection are also mentioned. Hope it will be helpful for you.

  Sources: http://www.fiberopticshare.com/recommendations-popular-12-port-10gbe-switches.html

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Server Power Cords Applications in Different Cabling Systems

Each power supply has a separate power cord to support its work. Server power cord connecting the servers and PDU (power distribution unit) plays a critical role in this process. Since the power cords standard for connector types and voltage levels varies from country to country. It’s important to choose the most suitable one for network systems. This post intends to give a simple introduction to server power cords and their applications in different systems.

Power Cords Overview

Usually standard power cords or jumper power cords are available for connection to the server. Power cord consists of three necessary parts: plug, cord and receptacle. And there are many different types of power cords used all over the word. The most commonly seen types are the IEC60320 power cord and NEMA power cord. The former one is often used in US. While the latter is usually seen in North America and other countries that use the standards set by the NEMA.

Among these two types of power cords, the most popular one in some vendors like Dell, HP and IBM is the C13 to C14 power cord. And there are many kinds in this two types of power cords. Here is a simple table showing them.

C14-C13

Applications in Different Cabling System

Cabling for Low Density System

It’s relatively easy to install cords for low density systems. Take servers in a tower configuration for an example. It needs to use a country-specific power cord for direct connection to a facility AC feed. However, server availability goals can require providing redundant AC power to the server in the form of a redundant AC bus or a UPS. The following figure shows two servers connected an UPS with a different types of server power cords. Server in picture A uses C13 to C14 power cord, and server in picture B uses NEMA 5-15P to C13 power cord.

Note: Connection to a local AC outlet requires an optional country-specific power cord for each power supply. Just shown in picture A above.

Cabling for Medium Density System

Medium density system is a little complex than low density system. Therefore different types and other accessories are maybe needed to achieve an effective power connection. Just shown in the following picture, power connections are achieved using modular PDH, extension bars and C13 to C14 power cord assemblies.

Note: some servers contain hot-pluggable fans accessible by sliding the chassis out on rails. This means the power cords or jumper cables connecting to the servers must have adequate length and slack to allow chassis movement while staying connected and powered up.

Cabling for High Density System

Compared with the application of power cords in the two systems mentioned above, power cords used in high density systems can be short since cable movement is of little. This following figure shows three kinds of methods to connect enclosures to AC power. The first one shown in the upper area of this figure is that the C13 to C14 power cord is used to connect a single-supply server to a vertical mount PDU, which is suitable for lower-density installations. The second shown in the central area of the figure is to use the C13 x4-to-C20 fixed cord extension bars, a method recommended for extreme-density installations using redundant power supplies. The last one shows the use of a C13 x2-to-C20 Y-cable assembly recommended for connecting a server with dual 1200-watt power supplies directly to a PDU core with C19 outlets.

Note: Considering there are many cables used in high-density systems, color coding power cords are helpful in systems like that.

Conclusion

Power cords serve as an important bridge in the network device power supply system. FS.COM offers several varieties of IEC power cords, NEMA power cords, and jumper cords for server rack equipment in up to 12 colors with many different types and options for your data center power cords, including: IEC C14 to C13, C20 to C19, C14 to C15, etc. Welcome to visit our website www.fs.com for more information.

Sources:http://www.fiber-optical-networking.com/server-power-cords-applications-different-cabling-system.html

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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.

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.

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.

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.

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.

 Sources:http://www.fiber-optic-tutorial.com/16-channels-dwdm-mux-demux-in-dwdm-network.html

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Optical Amplifier Used in CATV Transmission Network

CATV technology has matured steadily over the past several years, and has expanded into diverse applications. However, as the quick expansion in technology and services, it’s important to improve CATV network component performance for higher visual and audio signals transmission. Optical amplifier for CATV application is the key element in such transmission. This post intends to give a clear introduction of optical CATV amplifier and its application in CATV transmission.

Introduction to CATV Amplifier

CATV amplifier is also a type of EDFA (Erbium Doped Fiber Amplifier) amplifier which is the most popular optical amplifier in optical network communications. It is mainly used to amplify damped TV signals (compensation for loss) for improved signal quality before sending them to each subscriber. Moreover, CATV amplifiers not only amplify the signal, but also amplify the noise on the line, and bring some return loss. That’s why a quality CATV amplifier price is a little high, because it can provide better performance for the whole network transmission.

Why CATV Amplifier Is Needed?

As we all know, CATV network is a multi-channel TV system to transmit high quality video and sound signal from a large number of digital or analog broadcast television and radio channel via fiber optic cable or coaxial cable. CATV amplifier often acts as booster optical amplifier in this system to get satisfying transmission effect. The following picture illustrates a basic long haul CATV transmission system using EDFA amplifier.

In most cases, the satellite providers deliver high quality digital video and audio to users’ home depending on the users’ equipment. However, the signal incoming cable feed is connected to more than one equipment with use of optical splitters. And if the incoming signal gets fragmented and rerouted, the overall speed and quality will be worse. Under this condition, an optical amplifier can be used to boost the signal power and help users get better services.

CATV Amplifier in Long-Haul CATV Transmission System

As have mentioned above, a basic long-haul CATV communication link consists of head end, transmitter, receiver, optical amplifier, and sometimes fiber splitter is also needed in this type of transmission network. The head end receives TV signals off the air or from satellite feeds, and supplies them to the transmission system. The optical splitters are often utilized in a poin-to-multipoint configuration. Here are two CATV fiber network cases using CATV booster amplifier.

Case one

This is a point-to-multipoint medium size private CATV network. In the head end, the transmitter receives signals from the RF combiner on the 1310nm or 1550nm wavelength. Then the signals split into several parts and are received by the CATV receiver. Finally, all the signals are amplified by the CATV amplifier and sent to the subscriber.

Case two

In the above application case, the optical amplifier lies behind the CATV receiver, but in this case, it’s a little different.

As we can see from the graph, the CATV amplifier lies in the front of the receiver to boost the transmission distance longer. Except for that, this transmission network also deploys two DWDM Mux/Demux to multiply the eight different wavelengths into one fiber for better transmitting. Please note that this graph just illustrates part of the long-haul CATV system.

Conclusion

CATV amplifiers are used to boost the quality of optical signals and improve the speed and reliability of the services that users get. FS.COM offers various CATV amplifiers with different values and CATV optical transmitter. All of them are high quality. If you are interested, please contact us via [email protected].

Sources:http://www.fiber-optic-components.com/catv-amplifier-used-in-catv-transmission-network.html

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Understanding WDM MUX/DEMUX Ports and Its Application

Wavelength division multiplexing (WDM) is a commonly used technology in optical communications. It combines multiple wavelengths to transmit signals on a single fiber. To realize this process, CWDM and DWDM mux/demux are the essential part. As we all know, there are several different ports on the WDM mux and demux. This article will give a clear explanation to these ports and their applications in WDM network.

Overview of Different Ports on WDM MUX/DEMUX

Line Port

Line port, sometimes also called as common port, is the one of the must-have ports on CWDM and DWDM Mux/Demux. The outside fibers are connected to the Mux/Demux unit through this port, and they are often marked as Tx and Rx. All the WDM channels are multiplexed and demultiplexed over this port.

Channel Port

Like the line port, channel ports are another must-have ports. They transmit and receive signals on specific WDM wavelengths. CWDM Mux/Demux supports up to 18 channels from 1270nm to 1610nm with a channel space of 20nm. While DWDM Mux/Demux uses wavelengths from 1470nm to 1625nm usually with channel space of 0.8nm (100GHz) or 0.4nm (50GHz). Services or circuits can be added in any order to the Mux/Demux unit.

Monitor Port

Monitor port on CWDM and DWDM Mux/Demux offers a way to test the dB level of the signal without service interruption, which enable users the ability to monitor and troubleshoot networks. If the Mux/Demux is a sing-fiber unit, the monitor port also should be a simplex one, and vice verse.

Expansion Port

Expansion port on WDM Mux/Demux is used to add or expand more wavelengths or channels to the network. By using this port, network managers can increase the network capacity easily by connecting the expansion port with the line port of another Mux/Demux supporting different wavelengths. However, not every WDM Mux/Demux has an expansion port.

1310nm and 1550nm Port

1310nm and 1550nm are one of WDM wavelengths. Many optical transceivers, especially the CWDM and DWDM SFP/SFP+ transceiver, support long runs transmission over these two wavelengths. By connecting with the same wavelength optical transceivers, these two ports can be used to add 1310nm or 1550nm wavelengths into existing WDM networks.

Application Cases of Different Ports on WDM MUX/DEMUX

Although there are several different ports on WDM Mux/Demux, not all of them are used at the same time. Here are some examples of these functioning ports in different connections.

Example One: Using 8 Channels CWDM Mux/Demux with Monitor Port

This example is a typical point-to-point network where two switches/routers are connected over CWDM wavelength 1511nm. The CWDM Mux/Demux used has a monitor port and 1310nm port, but the 1310nm does not put into use. In addition, an optical power meter is used to monitor the power on fibers connecting the site A and B.

Example Two: Achieve 500Gbps at Existing Fiber Network with 1310nm Port

In this example, two 40 channels DWDM Mux/Demux with monitor port and 1310nm port are used to achieve total 500Gbps services. How to achieve this? First, plug a 1310nm 40G or 100G fiber optical transceiver into the terminal equipment, then use the patch cable to connect it to the existing DWDM network via the 1310nm port on the DWDM Mux/Demux. Since the 1310nm port is combined into a 40 channels DWDM Mux, then this set-up allows the transport of up to 40x10Gbps plus 100Gbpx over one fiber pair, which is total 500Gbps. If use 1550nm port, then the transceiver should be available on the wavelength of 1550nm.

Example Three: Stack Two CWDM MUX/DEMUX Using Expansion Port

The connection in this example is similar to the last one. The difference is that this connection is achieved with expansion port not 1310nm port. On the left side in the cases, a 8 channels CWDM Mux/Demux and a 4 channels CWDM Mux/Demux are stacked via the expansion port on the latter Mux/Demux. And the two 4 channels CWDM Mux/Demux are combined with the line port. If there is a need, more Mux/Demux modules can be added to increase the wavelengths and expand network capacity.

Summary

Different ports on the CWDM and DWDM Mux/Demux have different functions. Knowing more their function is helpful in WDM network deployment. FS.COM supplies various types of CWDM and DWDM Mux/Demux for your preference. And customer services are also available. If you have any needs, welcome to visit our website www.fs.com.

Sources:http://www.fiber-optic-components.com/understanding-wdm-muxdemux-ports-application.html

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Application Cases of 10G CWDM Network

CWDM network, as an easy-to-deploy and cost-effective solution, has been applied in many areas. Although CWDM network is not as perfect as DWDM networks in data capacity, it still can satisfy a wide range of applications in optical applications. And CWDM is a passive network, allowing any protocol to be transported over the link, as long as it is at the specific wavelength. This article is going to describe several application cases of 10G CWDM networks in different areas.

Benefits of 10G CWDM Network

Although 40G and 100G networks are developing rapidly, many of them still need to grow on the basis of 10G networks. And due to the high cost of 40G and 100G, 10G networks are still the most common networks to be deployed. Here are the main benefits of 10G CWDM networks.

CWDM Mux/Demux is a passive component and requires no extra power, offering a cost-effective choice for network designers.

Increased network connections and easy to evolve from 10G to 40G and 100G networks. For example, 10G CWDM network can combine DWDM wavelengths using the 1550nm channel on CWDM Mux/Demux. And if an operator want to upgrade its 10G network to 40G or 100G, there are various fiber components in market that can help him realize this conversion.

Lower cost. 10G hardware has become cheaper, which make 10G CWDM network more economical. For example, buying one pcs 8 channels CWDM Mux/Demux which is the most often used in CWDM networks needs less than 330 dollars in some stores. And 10G CWDM optical transceivers are also very cheap now.

10G CWDM Network Infrastructure

As has mentioned above, 10G CWDM network has been widely deployed in different areas. Here are the common CWDM network infrastructures.

Point-to-point 10G CWDM Network

A point-to-point CWDM network is the simplest network structure of CWDM networks, but it is the basis of other complex network infrastructures. By adding other components like CWDM OADM, the point-to-point CWDM network is easy to be changed into more complicated networks. The following figure shows a point-to-point CWDM network using 8 channels CWDM Mux/Demux.

10G CWDM Ring Network

CWDM ring links are suitable for interconnecting geographically dispersed LANs and storage area networks. Business can benefit from CWDM by using multiple Gigabit Ethernet. As shown in the below picture, the four buildings are connected by several 8 channels CWDM Mux/Demuxes.

Application Cases of 10G CWDM Network

Applications in Service Providers

CWDM uses different wavelengths to carry different signals over a single optical fiber, which offers many benefits to service providers that need to better utilize the existing fiber infrastructure. In this application, two Cisco switches are connected together through four 8 channels CWDM Mux/Demuxes. Signals are multiplexed and then transmitted through two strands fiber cables.

10G CWDM Application in Campus Network

As the scale expansion of many campus, the need for adding bandwidth of new applications is increasing too. And the new campus, school teaching and student life Internet require a lot of bandwidth resources, so building a new network is undoubtedly needs a large investment. Then how to make a full use of existing fibers is a problem needed to be resolved.

In this case, four 8 channels CWDM Mux/Demux with expansion port are used to double the capacity on the existing fiber without the need for installing or leasing additional fibers, which reduce cost and labor.

Summary

As the development of WDM technology and market, the deployment of CWDM network will be more lower. FS.COM provides affordable CWDM network components at a low price. Following is a list of our products.

Product ID    Description

42945        8 channels 1290-1430nm dual fiber CWDM Mux Demux 

43099        8 channels 1470-1610nm dual fiber CWDM Mux Demux with expansion port 

19367        Cisco Compatible 10G CWDM SFP+ 1470nm 80km DOM Transceiver 

31290        Cisco Compatible 10G CWDM SFP+ 1290nm 40km DOM Transceiver 

Sources: http://www.fiber-optic-components.com/application-cases-10g-cwdm-network.html

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How to Calculate Power Budget and Link Distance in CWDM Network

By multiplexing separated wavelengths from multiple ports onto a single fiber in the network, coarse wavelength division multiplexing (CWDM) network increases fiber capacity at a low cost. And all the CWDM components are passive and do not need power, which requires lower investment than DWDM networks and make it popular. This article intends to explore how to calculate the power budget and link distance in CWDM network, offering more conveniences for your CWDM network deployment.

Understand Optical Power Budget in CWDM system

One important factor of network design, including various optical networks like DWDM and PON, is the optical power budget. Optical power budget is the amount of light available to make a fiber optic connection. The difference between the output power of the transmitter and the input power requirements of the receiver is referred to as the power budget. The power budget with various losses in an optical fiber, as shown in the picture below, is obtained by first determining the optical power emitted by the source, usually expressed in dBm, and subtracting the power (expressed in same units, e.g., dBm) required by the detector to achieve the design quality of performance (Receiver Sensitivity). Here is a common equation that can be used to calculate the power budget in a decided length fiber link.

Link Power Budget = Min Transmit Power - Min Receiver Sensitivity

Calculate Power Budget in CWDM Network

When designing a CWDM network, power budget is often used to determine the maximum distance that a link can support. The transmission power budget is the difference between the optical transmitter output power and the receiver sensitivity. In order to explain the calculation process clearly, all the equations will be given an example for illustrating.

Power Budget = Tx Power - Rx Sensitivity.

Example one. A -2 dBm optical transmitter and a -25 dBm receiver provide a total transmission power budget of 23 dB.

Power Budget = Tx Power - Rx Sensitivity = -2 dBm - (-25 dBm) = 23 dB

As we all know, in a CWDM system, CWDM Mux/Demux, CWDM OADM and other components are common. And each one of them will introduce loss once added into the CWDM system. For example, when using a CWDM OADM in CWDM network, the point where a channel is dropped, added, or passed will cause a loss of signal strength. Therefore, when calculating power budget for a CWDM link, all losses must be added together. As shown in the following equation.

Power Budget = Tx Power - Rx Sensitivity - Losses

Example two. Here is a link A shown as below. There are four CWDM Mux/Demuxes and two CWDM SFP transceivers in this link. The Mux/Demux #1 and Mux/Demux #4 are 8-channel CWDM Mux/Demux. The left two is 4-channel CWDM Mux/Demux. Link A is the distance from CWDM SFP #1 and CWDM SFP#4. Each CWDM Mux/Demux has a low insertion loss. For instance, the insertion loss of the 8-channel CWDM Mux/Demux is less than 3.1dB (including connectors and adapters).

Here is the calculating process.

Power Budget = Tx Power - Rx Sensitivity - Losses

Tx Power = 2 dBm

Rx Sensitivity = -23 dBm

Losses = (8-channel Mux/Demux #1 loss) + (4-channel Mux/Demux #2 loss) + (4-channel Mux/Demux #3 loss) + (8-channel Mux/Demux #4 loss)

= 2.5 dB + 2.0 dB + 2.0 dB + 2.5 dB = 9.0 dB

Power Budget = Tx Power - Rx Sensitivity - Losses = 2 dBm - (-23 dBm) - 9.0 dB = 16 dB

Calculate Maximum Link Distance in CWDM Network

After determining the power budget for a fiber link, we can use the value to calculate the maximum distance that the link can support. The calculation equation is shown as below.

Power Budget = Buffer Distance/Fiber Attenuation

Usually, a buffer of 2 dB is subtracted from the power budget to account for other factors that may affect the loss of transmission power. These factors include fiber aging, temperature, poor splice, etc. Fiber attenuation is the loss of signal strength as it travels through the fiber. The attenuation varies with the wavelength. Typical values are 0.2 to 0.35 dB/km.

Then we will calculate the maximum supported distance of link A in example two. Here we take the worst value for the fiber attenuation. The distance is:

Distance = (18 dB-2 dB)/0.35dB/km = 40km

The maximum supported distance of link A is 40km.

Summary

Knowing how to calculate the power budget and transmission distance can help engineers estimate the CWDM network deployment cost, and also can avoid some unnecessary problems in network design. This post gives a clear illustration to calculate them. Hope it would help you. In addition, FS.COM is a professional manufacturer and supplier of optical components. If you have any need, welcome to visit our website www.fs.com.

Sources:http://www.fiber-optic-components.com/calculate-power-budget-link-distance-cwdm-network.html