How Much Do You Know about Ethernet Switches?

Today, all plants are virtually networked via Ethernet. High requirements are placed on the network infrastructure and network components. Ethernet switches are the integral piece of IT infrastructure, capable of receiving, processing and transmitting data between two devices connected by a physical layer. Due to the increasing application of big data analytics and cloud-based services in various end-user segments, data centers are envisaged to fuel the adoption of Ethernet switches. The augmented global demand for data centers is the key driver for the growth of Ethernet switches market. To satisfy the large and ever-increasing market for Ethernet switches, there are many varieties of switches offered different purposes. This article will help you get a deep understanding of the different types of Ethernet switches.

What is an Ethernet Switch?

A Ethernet switch is a tool for connections between the systems and equipment to forward data selectively to one or more connected devices on the same network. These connections are generally created through the use of structured cabling that links both the station side and the device that you are trying to share data with, such as a server or another computer. In this way, Ethernet switches can control the flow of traffic passing through a network, maximizing the network’s efficiency and security. More advanced Ethernet switches, called managed switches, are also capable of providing additional functions, such as network load balancing, address translation or data encryption and decryption.

FS Ethernet switches

How Dose an Ethernet Switch Work?

Ethernet switches link Ethernet devices together by relaying Ethernet frames between the devices connected to the switches. By moving Ethernet frames between the switch ports, a switch links the traffic carried by the individual network connections into a larger Ethernet network. Ethernet switches perform their linking function by bridging Ethernet frames between Ethernet segments. To do this, they copy Ethernet frames from one switch port to another, based on the Media Access Control (MAC) addresses in the Ethernet frames. Ethernet bridging was initially defined in the 802.1D IEEE Standard for Local and Metropolitan Area Networks: Media Access Control (MAC) Bridges. The standardization of bridging operations in switches makes it possible to buy switches from different vendors that will work together when combined in a network design. That’s the result of lots of hard work on the part of the standards engineers to define a set of standards that vendors could agree upon and implement in their switch designs.

diagram of Ethernet switches connections

Different Types of Ethernet Switches

Ethernet switches are broadly categorized into two main categories – modular switches and fixed switches. Modular switches allow you to add expansion modules into the switches as needed, thereby delivering the best flexibility to address changing networks. Fixed switches are switches with a fixed number of ports and are typically not expandable. This category can be broken down even further into unmanaged, lightly managed, and fully managed.

Unmanaged Switch

An unmanaged switch is mostly used in home networks and small companies or businesses, as it is the most cost effective for deployment scenarios that require only basic layer 2 switching and connectivity. The unmanaged switch is not configurable and have all of their programming built in. It is ready to work straight out of the box. And it is the easiest and simplest installation, because of its small cable connections. An unmanaged switch is perfect in this situation since it requires the least amount of investment with regards to both expense and time.

Smart Switch / Lightly Managed Switch

A smart switch is the middle ground between the unmanaged and fully managed switches. These smart switches offer limited customization, but do possess the granular control abilities that a fully managed switch has. In addition, smart switches offer certain levels of management, quality-of-service (QoS), security, but they are lighter in capabilities and less scalable than the managed switches. Smart switches tend to have a management interface that is more simplified than what managed switches offer. They also offer the capability to set up options like Quality of Service (QoS) and VLANs, which can be helpful if your organization has VoIP phones, or if you want to segment your network into work groups. Therefore, smart switches are the cost-effective alternative to managed switches. They are still valid choices for the regular consumer, as they are generally easy to use and you can glean a bit more information off of them on how your network is configured compared to unmanaged switches.

Fully Managed Switch / Enterprise Managed Switch

Managed Layer 2 Switch: A modern managed switch provides all the functionality of an unmanaged switch. In addition, it can control and configure the behavior of the device. This typically introduces the ability to support virtual LANs (VLANs), which is why almost all organizations deploy managed switches versus their cheaper alternatives.

Managed Layer 3 Switch (Multilayer Switch): This type of switch provides a mix of functionality between that of a managed Layer 2 switch and a router. The amount of router function overlap is highly dependent on the switch model. At the highest level, a multilayer switch provides better performance for LAN routing than almost any standard router on the market, because these switches are designed to offload a lot of this functionality to hardware.

data-center-network-architecture

Managed switches are designed to deliver the most comprehensive set of features to provide the best application experience, the highest levels of security, the most precise control and management of the network, and offer the greatest scalability in the fixed configuration category of switches. As a result, they are usually deployed as aggregation/access switches in very large networks or as core switches in relatively smaller networks. Managed switches should support both L2 switching and L3 IP routing, though you’ll find some with only L2 switching support.

Conclusion

The Ethernet switch plays an integral role in most modern Ethernet local area networks (LANs). Mid-to-large sized LANs contain a number of linked managed switches. Small office/home office (SOHO) applications typically use a single unmanaged switch. This article has introduced the different types of switches. Depending on the number of devices you have and the number of people using the network, you have to choose the right kind of switch that fits your space. FS.COM has provided a comprehensive set of Ethernet switches. If you have any requirements, welcome to visit our website for more detailed information.

Which 10G SFP+ Optics Are Compatible with Intel X520 Adapter?

The escalating deployments of servers with multi-core processors and demanding applications are driving the need for 10 Gbps connections. Intel X520 10 GbE Adapter is the most flexible and scalable Ethernet adapters for today’s demanding data center environments. At the same time, 10G SFP+ optics play the most important role for its 10G connectivity. But seriously, do you know which 10G SFP+ optics are compatible with the Intel Ethernet converged network adapter X520 series? This blog will give you solutions.

Intel X520 Adapter

Intel X520 adapter is powered by reliable and proven 10G Ethernet technology, which offers high performance for high-IO intensive applications and showcase the next generation in 10 GbE networking features for the enterprise network and data center. It is designed for multi-core processors, which supports for technologies such as multiple queues, receive-side scaling, multiple MSI-X vectors and Low Latency Interrupts. It addresses the demanding needs of the next-generation data center by running mission-critical applications in virtualized and unified storage environments. In a multicore platform, the Intel X520 adapter supports Intel I/O Virtualization Technology (IOVT), which helps accelerate data across the platform, therefore improving application response times. For virtualized environments, it offers advanced features with VMDq (Virtual Machine Device Queues) that lower processor utilization and increase I/O performance.

Intel X520 Dual Port 10GbE SFP+ Adapter

Figure 1. Intel X520 Dual Port 10GbE SFP+ Adapter

The Intel X520 adapter provides SFP+ based connectivity options (fiber or DAC cabling). Intel X520 adapters are provided with 7 models: X520-QDA1, X520-DA2, X520-SR1, X520-SR2, X520-DA1OCP, X520-DA2OCP and X520-LR1. X520-SR1 is shipped with 1 SR SFP+ Optic,  X520-SR2 has dual-port and is shipped with 2 SR SFP+ Optics, X520-LR1 has single-port and is shipped with 1 LR SFP+ Optic, and X520-DA2 has dual-port and does not ship with any optics or cables, which is the most suitable one for 10G SFP+ Optics and the most popular one on the market. The following table lists the detailed information of Intel X520 adapter series in Table 1.

Intel X520 Adapter Product Code Connector and Cable Cable Type Ports
X520-QDA1 QSFP+ direct attach copper (4x10GbE mode) QSFP+ direct attached twinaxial cabling up to 10m Single port
X520-SR1 Fiber optic MMF up to 300 m Single port
X520-SR2 Fiber optic MMF up to 300 m Dual port
X520-DA2 SFP+ direct attach copper SFP+ direct attached twinaxial cabling up to 10 m Dual port
X520- LR1 Fiber optic SMF up to 10 km Single port
X520-DA1OCP SFP+ direct attach copper SFP+ direct attached twinaxial cabling up to 10 m Single port
X520-DA2OCP Copper SFP+ direct attached twinaxial cabling up to 10 m Dual port

Table 1: Intel X520 Series Adapters

10G SFP+ Optics for Intel X520 Adapter

A 10 Gigabit Ethernet network is essential for businesses that demand high bandwidth for virtualization and fast backup and restore for an ever-growing amount of data. To ensure maximum flexibility, Intel X520 adapters supports the ability to mix any combination of the SFP+ optical modules, direct attach copper cables or 1000BASE-T SFP modules. Besides, 10G SFP+ Optics are available in both short range (SR) 850 nm and long range (LR) 1310 nm options. This enables customers to create the configuration that meets the needs of their data center environment.

10G SFP+ Optical Modules

Intel Ethernet SFP+ SR optics and Intel Ethernet SFP+ LR optics are the only 10 Gbps optical modules supported. Other brands of SFP+ modules are not allowed and can’t be used with the X520 adapters. The following table lists the supported 10Gb Ethernet SFP+ optical transceivers for Intel X520 adapters in Table 2. (Note: Other brands of SFP+ optical modules will not work with the Intel Ethernet Server Adapter X520 Series.)

10G SFP+ Optical Modules
Name Intel Product Code (MFG PART#) FS P/N Type
Intel 10G SFP+ SR Optical module E10GSFPSR SFP-10GSR-85 Dual Rate 10GBASE-SR/1000BASE-SX
Intel 10G SFP+ LR Optical module E10GSFPLR SFP-10GLR-31 Dual Rate 10GBASE-LR/1000BASE-LX

Table 2: 10G SFP+ Optical Transceivers for Intel X520 Adapters

1000BASE-T SFP Modules

Some 1000BASE-LX and 1000BASE-SX modules can work with Intel Ethernet Converged Network Adapter X520 series. These modules referred to only highlight specifications and compatibility with Intel Ethernet server adapter X520 series. The table lists tested modules in Table 3. Other similar modules may work but have not been tested (many similar modules can be purchased in FS.COM). Remind you to use your own discretion and diligence to purchase modules with suggested specifications from any third party.

1000BASE-T SFP Modules
Name Intel Product Code (MFG PART#) FS P/N Type
Avago Gigabit Ethernet Module ABCU-5710RZ SFP-GB-GE-T 1000BASE-SX
Intel Gigabit Ethernet Module TXN22120 SFP1G-LX-31 1000BASE-LX

Table 3: 1000BASE-T SFP Modules for Intel X520 Adapters

10G SFP+ Direct Attach Copper Cables (10G SFP+Cu)

A direct attach twinaxial cable is a 2-pair shielded copper cabling terminated with SFP+ electrical modules. Intel X520 Adapters require that any SFP+ passive or active limiting direct attach copper cable should comply with the SFF-8431 v4.1 and SFF-8472 v10.4 specifications. SFF-8472 Identifier must have value 03h (You can verify the value with the cable manufacturer). Maximum cable length for passive cables is 7 meters. Support for active cables requires Intel Network Connections software version 15.3 or later. The following table lists the fully compatible 10Gb DAC cables for Intel Ethernet server adapter X520 series in Table 4.

10G SFP+ DAC Cables
Name Product Code (MFG PART#) FS P/N Type
Intel Ethernet SFP+ Twinaxial Cable, 1 meter XDACBL1M SFP-10G-DAC 10G SFP+ Passive Direct Attach Copper Twinax Cable
Intel Ethernet SFP+ Twinaxial Cable, 3 meter XDACBL3M SFP-10G-DAC 10G SFP+ Passive Direct Attach Copper Twinax Cable
Intel Ethernet SFP+ Twinaxial Cable, 5 meter XDACBL5M SFP-10G-DAC 10G SFP+ Passive Direct Attach Copper Twinax Cable

Table 4: 10G DAC cables for Intel X520 Adapters

QSFP+ Breakout Cables

The new QSFP+ single-port X520-QDA1 can connect the server to the latest 40GbE switches with a single cable operating in 4x10GbE mode. This adapter can also utilize existing 10GbE SFP+ switches using the QSFP+ to 4xSFP+ breakout cable. The QSFP+ adapter supports direct attach copper cables and Intel Ethernet QSFP+ SR optical transceivers. Intel Ethernet QSFP+ breakout cables have one QSFP+ connector on one end and break out into four SFP+ connectors on the other end for direct attachment to SFP+ cages. The following table lists the Intel Ethernet QSFP+ breakout cables for Intel adapter X520-QDA1 in Table 5.

Intel Ethernet QSFP+ Breakout Cables for Intel Adapter X520-QDA1
Name Product Code (MFG PART#) FS P/N
Intel Ethernet QSFP+ breakout cable, 1 meter QSFP-4SFP10G-CU1M QSFP-4SFP10G-DAC
Intel Ethernet QSFP+ breakout cable, 3 meter QSFP-4SFP10G-CU3M QSFP-4SFP10G-DAC
Intel Ethernet QSFP+ breakout cable, 5 meter QSFP-4SFP10G-CU5M QSFP-4SFP10G-DAC

Table 5: QSFP+ Breakout Cables for Intel Adapter X520-QDA1

Summary

From what we have discussed, 10G SFP+optics are determined to the data transmission of Intel X520 adapters. SFP+ SR Optics, SFP+ LR optics, 1000BASE-T SFP modules, 10G SFP+ direct attach copper cables and QSFP+ breakout cables are available stock in FS.COM. All SFP+ cables are 100% tested to ensure the compatible and quality. Welcome to visit www.fs.com.

Understanding PoE & PoE Switch

Enterprises are quickly evolving with new network devices to improve communication and security. Power over Ethernet (PoE), a way to deliver electrical power over LAN cables to network devices, has been widely deployed to provide power to various endpoints in the enterprise environments. If you want to upgrade you network to PoE, one way is to deploy a PoE switch. This paper will provide an overview of the PoE technology and PoE switches.

What Is a PoE in Networking?

Power over Ethernet, also known as PoE, is a networking feature defined by the IEEE 802.3af and 802.3at standards. POE is able to combine the two connections into one Ethernet cable so that single network cable will transmit both data and 25W of electricity. By this way, it can minimize the number of wires when installing the network, which realize the lower cost, less downtime, easier maintenance, and greater installation flexibility in networking.

POE-working-principle

Why Use PoE?

Because PoE is allowed to use one cable for both power and data transmission, PoE can save money on purchasing and running cable for networking equipment. It can brings many advantages to the network as follows.

  • Time and cost savings

Network cables do not require a qualified electrician to install them, and can be located anywhere, so PoE eliminates the time and cost of hiring professional electrical installers.

  • Flexibility

Network administrators can deploy devices (eg: IP cameras and wireless access points) at wherever they are needed most, and redeploy easily if required.

  • Safety

Because PoE utilizes a relatively low voltage, it presents low risks of electrical hazards.

  • Scalability

PoE makes it simple to add new equipment to a network.

What is a PoE Switch Used for?

A POE switch is a network switch that has a built-in PoE injection. It can connect other network devices as normal, and the switch will detect whether they are PoE-compatible and enable power automatically. PoE switches are available to suit all applications, ranging from low-cost unmanaged edge switches with a few ports, to complex multi-port rack-mounted units with sophisticated management. They can run PoE up to 100 meters from the switch or hub to the NIC, regardless of where the power is injected. The limitation is not the power, it’s the Ethernet cabling standards that limit the total length of cabling to 100 meters.

POE Switch

Which FS Switches Are PoE-capable?

FS.COM provides fully managed PoE switches, which are available with 8, 24 or 48 PoE Gigabit Ethernet ports of auto-sensing IEEE 802.3af/at. The PoE Switches are ideal for small business networks that need to inexpensively use PoE to deploy wireless access points and IP-based network surveillance cameras. They deliver robust performance and intelligent switching for growing networks, so PoE switches will be a best choice to install and manage your devices. The model details of FS’s PoE switches are listed below.

fs-poe-switches

How to Ensure Successful PoE Deployments?
1.Provide Sufficient Power to the Remote Powered Device

According to the IEEE 802.3af standard, the powered remote device can draw up to 12.95 watts of power. Considering the loss of the cable length, the power sourcing equipment (PSE) must have the ability to provide 15.4 watts of power to each port. For example, a 24-port Ethernet switch needs approximately 370 watts of power to supply the necessary power to each port. The PoE switches should have in excess of 370 watts available in view of the size of the power supply used in each device. It depends on how much power their switching functions require.

2.Connect the Power Source to Uninterruptible and Redundant Power

Connect the critical power-sourcing devices to an uninterruptible power supply, and use devices with dual redundant power supplies to ensure that your critical devices never lose power.

3.Deploy Only IEEE 802.3af-compliant Devices

Carefully read the technical documentation and contact the technical-support number to determine compatibility. Failure to do so will leave you frustrated and will cost you time and money.

4.Pay Attention to Cabling-performance Specifications

Pay close attention to the manufacturer’s specifications and look for Cat5e and Cat6a compliance. Also, you should remember per TIA standards, only four connectors can exist between the switch or hub and the network interface card (NIC). A midspan device should be counted and treated as one of these connection points.

5.Use the Most Cost-effective PoE Method for Your Network

The business motivation behind deploying IP-based technologies like WiFi and VoIP is to decrease networking costs. A significant benefit of PoE is that it runs on your existing infrastructure.

Conclusion

PoE is a recently-developed technology, and it simplifies the enterprise deployment with lower operating expense, higher availability, and faster deployment. FS has provided PoE switches in a variety of specifications, which may make your trip as comfortable as possible. For more information, please welcome to www.fs.com.

Are You Ready to Install White Box Switches in Your Network?

With the development of Cloud services and networking, FS has introduced a series of high performance 40G/100G white box switches. The goal is to provide Web scale organizations and service providers more control and flexibility in their data center networks. So what are white box switches? White box switches refers to the ability to use ‘generic,’ off-the-shelf switching (or white box switching) and routing hardware, in the forwarding plane of a software-defined network (SDN). Moreover, white box switches rely on an operating system (OS), which may come already installed or can be purchased from a software vendor and loaded separately, and then integrate with the deploying organization’s Layer 2/Layer 3 topology and support a set of basic networking features. On the whole, OS is an integral part of white box switches, and the rise of SDN has brought white box switches into the public eye. Next, let’s take a closer look at white box switches.

FS 40G100G White Box Switches

OS Defines White Box Switches

White box switches are useless without software, because every switch needs an operating system. The OS needs to seamlessly integrate with existing L2/L3 topology and support a basic set of features. A common operating system for white box switches is Linux-based, because many open and free Linux tools are available, which can help administrators customize the switches to their needs. Typically, a white box switch may come pre-loaded with minimal software or it may be sold as a bare metal device. The advantage of the white box switches is that switches can be customized to meet an organization’s specific business and networking needs.

FS Network OS

However, how to put the OS on the white box switches? Some vendors sell a complete solution with the OS that is already installed on the white box, while others set up distributors to provide the bare metal devices that the OS is directly brought from the software vendor. Both of these two approaches are feasible, depending on the scale of the deployment and the desire for the network.

SDN & White Box Switches

Beyond the operating system, white box switches are more valuable if they interact with SDN controllers. And the widespread implementation of SDN has boosted the use of white box switches. SDN is an approach to design, build and manage networks, which can separate the network’s control and forwarding planes. In result, the network control will become directly programmable and the underlying infrastructure will be abstracted for applications and network services. The goal of SDN is to enable cloud and network engineers and administrators to respond quickly to changing business requirements via a centralized control console. At the same time, the switches in SDN environment rely on software-based network function virtualization (NFV), which offers great convenience for the users of white box switches. Because white box switch allows its customers to choose the best suitable operating system for themselves. And in the future, most white box switches will function in an SDN environment in which the SDN controller is making forwarding and control-plane decisions from a centralized point for all switches in the network.

sdn

The Growing Market for White Box Switches

In general, the data center Ethernet switch market has seen tremendous growth and investment over the past years. The Layer 2-3 Ethernet switch market is expected to exceed $25 billion in 2019, according to Dell’Oro Group. What’s more, some high-end users are tired of vendor lock-in switches, and they might be ready to try a white box switch to get what they want. White box switches can customize the system to limit unneeded processes and concentrate the processing power of the switch on the important features, so it leads to a customized switch platform that provides perfect performance for a narrow range of uses. Customers with highly unique support needs will also benefit from white box switches. Through the separation of software and hardware, customers can obtain different support levels for hardware and software.

FS 40G/100G White Box Switches Solutions

FS 40G/100G white box switches are based on IPinfusion’s ZebOS with integration of Layer 2 to Layer 4 packet processing engine, traffic management and fabric interface. The aim is to achieve flexibility, scalability, efficiency and cost effectiveness in data center networks. Furthermore, the operating systems of these switches are developed on the basis of Linux and similar to Arista EOS. Last but not least, all the 40G/100G white box switches in FS support SDN function which can make networks more affordable and easier to manage.

fs-40g-100g-white-box-switches

All in all, the S9000 series white box switches support current and future data center requirements, which is ideally suited for data center environments in either Leaf or Spine deployments. They provide superior low latency and power efficiency in a clean PHYless design, while offering high reliability features such as redundant and hot swappable power supplies and fans in forward and reverse airflow configurations. And they provide QSFP+ ports, which enable flexible choices of port speed providing unparalleled flexibility and the ability to seamlessly transition data centers to the next generation of Ethernet performance.

Summary

White box switches can be deployed either in the data center or in the access network. Hyperscale data centers can deploy white box switches to reduce capital expenditures and leverage open SDN tools to improve time to deployment and automation. If you want to deploy white box switches with lower cost and great flexibility, welcome to contact us via www.fs.com.

A Brief Introduction to Cisco Single-Mode SFP Modules

Introduction

Small form-factor pluggable (SFP) module is a hot-pluggable interface transceiver which links switches and routers to network. These small, modular optical interface transceivers offer a convenient and cost effective solution for the adoption of Gigabit Ethernet and Fibre Channel in data center. Cisco’s industry-standard SFPs can be used and interchanged on a wide variety of Cisco products and can be intermixed in combinations of IEEE 802.3z compliant 1000BaseSX, 1000BaseLX/LH, or 1000BaseZX interfaces on a port-by-port basis. Cisco SFP modules are commonly available in several different types: 1000BASE-T, 1000BASE-SX, 1000BASE-LX/LH, 1000BASE-EX, 1000BASE-ZX, and 1000BASE-BX-D/U. This post will give an introduction to Cisco single-mode SFP modules.

Cisco 1G single-mode SFP

Cisco 1G Single-Mode SFP Modules

Cisco 1G single-mode SFP modules consist of 1000BASE-LX/LH, 1000BASE-EX, 1000BASE-ZX, 1000BASE-BX-U, 1000BASE-BX-D, GLC-BX40-D-I, GLC-BX40-DA-I, GLC-BX40-U-I, GLC-BX80-D-I, and GLC-BX80-U-I. The 1000BASE-LX/LH SFP is compatible with the IEEE 802.3z 1000BASE-LX standard, functions on single-mode fiber-optic link and its transmission range can cover 550 m to 10 km on any multimode fibers. 1000BASE-EX SFP functions on standard single-mode fiber-optic link with spanning up to 40 km in length. 1000BASE-ZX SFP functions on standard single-mode fiber-optic link and its transmission range reaches approximately 70 km in length.

The 1000BASE-BX-D and 1000BASE-BX-U SFPs which are compatible with the IEEE 802.3ah 1000BASE-BX10-D and 1000BASE-BX10-U standards function on a single strand of standard SMF (Single-Mode Fiber) and its operating transmission range covers up to 10 km. The Cisco GLC-BX40-D-I, GLC-BX40-DA-I, and GLC-BX40-U-I SFPs also operate on a single strand of standard SMF and its transmission range can reach 40 km. A GLC-BX80-D-I and GLC-BX80-U-I device function on a single strand of standard SMF with an operating transmission range up to 80 km.

Another difference between these SFP modules is the transmission direction: 1000BASE-LX/LH, 1000BASE-EX and 1000BASE-ZX’ transmission is duplex while 1000BASE-BX-U, 1000BASE-BX-D, GLC-BX40-D-I, GLC-BX40-DA-I, GLC-BX40-U-I, GLC-BX80-D-I, and GLC-BX80-U-I’s transmission is simplex. One thing they have in common is that all these Cisco single-mode SFP modules adopt LC interfaces and Cisco SFP 1G transceivers can transmit optical signals through simplex or duplex LC patch cable.

Transmission of a Single Strand of SMF

Features and Benefits

Cisco single-mode SFP modules feature a variety of different types of modules supporting different transmission ranges and direction, and they are also compatible with products of other categories. The hot-swappable input/output device directly plugs into an Ethernet SFP port of a Cisco switch, which maximizes uptime and simplifies serviceability when installing or replacing. The robust design enhances capability and the small factor features great density per chassis. Its flexibility of media and interface choice on a port-by-port basis bring you convenience. “Pay as you Populate” model lowers initial costs. It can support digital optical monitoring (DOM) capability for strong diagnostic capabilities. Cisco quality identification (ID) feature enables a Cisco platform to identify whether the module is certified and tested by Cisco and it can be interoperable with other IEEE-compliant 1000BASE interfaces where applicable.

Conclusion

This post briefly introduces Cisco single-mode SFP modules, covering its definition, types of these SFPs and introduction of each type, and features and benefits of Cisco single-mode SFP modules. Now there are a number of modules for you to choose, but be sure to find the right one based just on your needs and at the same time take a few factors into consideration.

Switches Used in LAN Network

LAN refers to local area network, which is a network of computers that are in the same general physical location, usually within a building or a campus, share a common communications line or wireless link to a server. Typically, LAN can achieve file management, application software sharing, printer sharing, workgroup scheduling, e-mail and fax communication services and so on. A local area network may serve several hundred users in a larger office, which comprises cables, switches, routers and other components that let users connect to internal servers, websites and other LANs via wide area networks.

LAN network

Figure 1. LAN Frame

How Does LAN Work?

When two or more network devices have data to send at the same time, the data packets from one user may collide with another, because multiple devices cannot talk on the network simultaneously. For this reason, there should be some methods for the data to access the cable without disturbing another at a time.

Access methods define a set of rules governing how computers access the network – put data onto the network cable and take data from the cable at the same time.This is done in two main methods:

Carrier-Sense Multiple Access with Collision Detection (CSMA/CD)
  • All computers listen for traffic on the LAN.
  • If no traffic, computer that wishes to transmit may transmit data.
  • If a collision occurs, computers must wait a random amount of time.(The busier a network becomes, the more collisions occur)
  • The computer with the smallest random number send again first. (In most cases, a collision will not occur again between the two computers.)
Token Passing
  • All computers need the token which is passed around the network.
  • If a computer has data to send, it must wait until it has the token and then sends its data.
  • When the data transmission is completed, the token is released.
  • It helps to calculate the maximum time when a computer has the chance to send data.
Switches used in LAN Network

Switches that provide a separate connection for each computer in the internal network are called LAN switches. Essentially, a LAN switch creates a series of instant networks that contain only the two devices communicating with each other at that particular moment. LAN switches are designed to switch data frames at high speed. LAN switches are the “cornerstone” of building a network platform,which require less configuration, smaller space, fewer cabling, cheaper prices, and higher and more reliable performance.

Switching technologies are crucial to network design that is a form of packet switching used in LAN. LAN switching uses different kinds of network switches. A standard switch is known as a layer 2 switch and is commonly found in nearly any LAN. Layer 3 or layer 4 switches require advanced technology and are more expensive, and thus are usually only found in larger LANs or in special network environments. Here are two main LAN access switches:

S3800-24F4S

S3800-24F4S mode contains one console port that connects to computer for Command Line Interface (CLI) management, four 1GE combo ports, in which RJ45 and SFP ports with same figure are a couple of shared ports, 20 100/1000BASE SFP ports and 4 10GE SFP+ ports.

lan switches

S3800-24T4S

As for S3800-24T4S mode, it offers one console port, 24 100/1000BASE-T ports and 4 10GE SFP+ ports.

lan switches 1

S3800-24F4S and S3800-24T4S high performance Metro Ethernet switches are designed to meet the demand of cost-effective Gigabit access or aggregation for enterprise networks and operators customers, which adopt high performance and low power processor to provide full speed forwarding and line-dormant capacity. Besides, they support multiple configuration modes to make it easy for network management and maintenance and offer flexible port combination form to facilitate user operations so that you can directly connect to a high-performance storage server or deploy a long-distance uplink to another switch.

Outstanding Features of These Switches:
  • Enterprise-Class Features: support advanced Layer 2+ switching and max transfer rate of single port can reach 10GE compared to Layer
  • High-Capacity Uplinks: every port can be used as the uplink port. SFP+ ports support uplinks of up to 10GE. For high-capacity uplinks, the SFP+ ports can reach 40GE via WEB or order.
  • Switching Capacity: offer 128Gbps switching capacity to simultaneously process traffic on all ports at line rate without any packet loss.
  • Line-Dormant Support: the ports will switch to power saving mode when date traffic is relatively small.
Summary

The network switch plays an integral role in most modern Ethernet LAN, because the LAN switches greatly improve the rate of data transmission and the user experience. In addition, LAN access switches are the fundamental solutions to help you save time and focus on more strategic initiatives, which provide high-speed connectivity, application, and communication systems that efficiently and securely manage bandwidth-intensive data transmission.

Time-to-Link Test for 1000BASE-T and 10GBASE-T

Background

This post is composed on the basis of the physical layer (PHY) behavior assessment of 1000BASE-T and 10GBASE-T. In order to understand the test results and the meaning of this discussion, some terminologies have to be introduced first.

The Meaning of Time-to-Link

Time-to-link (TTL) is a system performance standard that characterizes and measures the PHY behavior through autonegotiation (AN) and 1G/10GBASE-T startup sequences (correspond to training). It is one of the two primary performance measures (the other is bit error rate) used to characterize BASE-T PHY link rate interoperability.

For Ethernet over twisted pair, autonegotiation is defined in clause 28 of IEEE 802.3. It is a procedure by which two connected devices choose common transmission parameters. In this process, the link partner firstly share their capabilities, such as speed, duplex mode, and flow control, and then choose the highest performance transmission mode they both support.

Since servers networking drivers must meet the third party certifications, the TTL standard used to measure link interoperability becomes rather important. Otherwise, long TTLs (>6s) can lead to device certification failures.

How to Measure the Link Interoperability?

There are several representative link interoperability metrics associated with TTL. Their meanings are explained as follows:

TTL: time to achieve link after link initiate event.

Link attempts number: number of attempts made to resolve Master/Slave status for each link. Within a link, one link partner is designated as the master timing source for transmitted signals in both directions. One partner is Master and one partner is Slave.

Link drops number: number of link drops observed after link is established.

Clock recovery: Some digital data streams, especially high-speed serial data streams, such as Ethernet, are sent without an accompanying clock signal. The receiver generates a clock from an approximate frequency reference, and then phase-aligns the clock to the transitions in the data stream with a phase-locked loop (PLL). This is one method of performing a process commonly known as clock and data recovery (CDR). Here it is also called Master/Slave resolution.

TTL distribution: percentage of links by link time.

Speed downshift/downgrade: resolved speed if other than 10Gbps.

Presentation and Analysis of the Results

Totally 1550 link tests are performed, and the results are:

  • 1,050 out of 1,550 tests, or 67% of the total number of link tests, achieved a link state in 7s or less (green slice).
  • 499 out of 1,550 tests, or 32% of the total number of link tests, achieved a link state somewhere between 7s and 15s (blue slice).
  • 1 out of 1,550 tests, or < 1 % (actually 0.15%) of the total number of link tests, achieved a link state longer than 15s (exactly 16.4s; yellow splice, actually it should be smaller than presented in the pie chart).

TTL % of total trials pie chart

Source: http://www.ieee802.org

Characterizing TTL behavior

Cumulative percentage (%) TTL is the distribution of measured link times as a percentage of total measured link time. Total link time recorded for all 1,550 tests is 10,837,835ms or about 3h 0min 38sec. The measured link time and cumulative percentage of each result is recorded in following table and chart:

Cumulative percentage TTL

Source: http://www.ieee802.org

TTL behavior

Source: http://www.ieee802.org

TTL Distribution and Master/Salve Resolution by Channel Length

In this part, the example of 10GBASE-T TTL measured from 2m to 115m channels (9790 links) will be given. The average TTL across 2m to 100m is 7.5s; the average time in autonegotiation is 5s; the average time in training is 2.6s. The following two charts illustrate the TTL distribution and clock recovery results by channel lengths from 2m to 115m.

TTL distribution by channel length

Source: http://www.ieee802.org

clock recovery distribution by channel length

Source: http://www.ieee802.org

According to the charts, we can see that there is an apparent loop timing trend towards Master preference with increasing channel length. And very long TTLs (>15s) at >100m channels are associated with downshits to 1Gb link speed.

AN & Training Times for 1000BASE-T and 10GBASE-T

Measured autonegotiation and training times from 1550 1Gb links for 10GBASE-T device to 1000BASE-T link partner, and 10GBASE-T device to 10GBASE-T link partner are respectively:

AN & traning times and TLL

Conclusion

From the test results on 1000BASE-T and 10GBASE-T, user TTL experience of 1000BASE-T installed over Cat5e cable or better is between 3s and 4s, and 10GBASE-T installed over Cat6a or better is about 7s, or longer in some cases. And the measured autonegotiation times for 1000BASE-T and 10GBASE-T are comparable. And for future 2.5/5GBASE-T, it is highly desirable that their autonegotiation and startup times can be improved, and that total TTL be minimized, so as to be more aligned with end-users’ expectations and requirements.

Appendix: AN & Training Times for 1000BASE-T and 10GBASE-T

1G AN time ditribution

1G traning time ditribution

10G AN time ditribution

10G traning time ditribution

Source: http://www.ieee802.org

Comparison Between Single Mode Transceiver and Multimode Transceiver

Fiber optic transceiver is a commonly used device which can send or receive data in optical links. As the growing demand for higher speed and bandwidth, more high-speed optical transceivers like 40G QSFP+, 100G CFP and QSFP28 springs up in the market. And we cannot divide them according to data rate, but also the transmission mode—single mode transceiver and mulitmode transceiver. Then what’s the difference between them? Let’s uncover it.

Overview of Single Mode Transceiver and Multimode Transceiver

It’s known to us that fiber optic cables can be classified into single mode and multimode according to its transmission mode. It’s same to fiber optic transceiver. Single mode fiber is a type of transceiver that allows one mode to propagate. It uses single mode fiber cable to receive and transmit data, which make it suitable for longer transmission. While multimode fiber optic transceiver support multiple mode transmission, and works with multimode fiber cable which has a larger core than single mode fiber cable. It’s transmission distance is less than that of single mode fiber transceiver because of dispersion.

single mode fiber transceiver vs multimode fiber transceiver

Single Mode Transceiver Vs. Multimode Transceiver: What’s the Differences?

Since there are so many types of optical transceivers in the market, choosing which types and cabling systems to install isn’t an easy thing. Therefore, knowing the differences between them is important. Here are the differences between single mode transceiver and multimode transceiver.

Laser sources: multimode optical transceiver often uses VCSEL which offers lower manufacturing package cost when compared with edge-emitting lasers. While single mode fiber has a core diameter of 9µm, which has less tolerance to fiber core misalignment as compared to multimode fiber. Therefore, it has higher requirement and cost for lasers.

Power consumption: multimode transceivers consume less power than a single mode transceivers, which is an important consideration especially when assessing the cost of powering and cooling a data center.

Distance: the reach distance of the two types transceiver is different. The multimode optical transceivers generally have a reach of approximately 550 meters, while the single mode transceivers can get you through 10 km, 40 km, 80 km and even farther.

Speed: in telecom applications where the fiber cost is high due to long-distance data transmission, single mode transceivers can support higher speed rates with fast response time, advanced modulation formats and wavelength division multiplexing (WDM) technology.

Cost: in terms of cost, single mode transceiver are nearly two or three times higher in price when compared to multimode transceiver. Because single mode fiber cables cost more to make and are more “fragile” in nature, which makes them more expensive than multimode fiber cables.

Summary

This post gives a simple comparison between single mode transceiver and multimode transceiver. Both of them have their own advantages in data center applications. Whether you choose the single mode or multimode transceiver, it’s important to note that different optical transceivers aren’t interchangeable due to the differences in fiber core size and wavelengths. FS.COM, as a professional optical products supplier, offers various fiber optic transceiver to meet customers’ diverse needs. If you have any need, please visit www.fs.com for more detailed information.

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.

catv amplifier 1

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.

catv amplifier 2

Case two

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

catv amplifier 3

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 sales@fs.com.

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.

40ch dwdm mux demux

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.

dwdm mux demux

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

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

dwdm mux 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

cwdm mux with 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.