Posted in Switch

AC Switch vs DC Switch: What’s the Difference?

The first step on integrating a switch into the network is to get it powered up. And as to power supply, there are AC and DC power for network switch, both of which are used for increasing network uptime. Then what’s the difference between AC power Switch and DC power switch? Which type shall we used for our network? This post will give a detailed introduction for the difference between AC Switch and DC switch, and set out how to make a proper decision over AC Switch vs DC Switch.

AC Switch vs DC Switch: What Are They?

AC powered Ethernet switch often has a fixed AC power supply connector, thus it generally gets powered up through power cables such as IEC power cord, NEMA power cord, etc. PoE switches are typical AC switches. Take FS 24 port PoE switch as example, which is equipped with a single 100-240V AC power supply connector (as shown below). It is easy to power up AC switch. All you need to do is connect it to the power socket with proper power cable. For some advanced network switch, turning on its power switch is also necessary.

AC switch vs DC switch

DC powered Ethernet switch can be configured with an internal or external DC power supply. And the external DC power supply is more popular nowadays, which is also known as redundant power supply. Modern fiber switch often has more than one redundant power supply (e.g the following FS 10GbE switch is equipped with two DC power supply). Except for powering up switch, the DC redundant power supply can also protect other power supply when it fails with shorted outputs.

AC switch vs DC switch

AC Switch vs DC Switch: What’s the Difference?

In the market, there are Ethernet switches that support only AC power supply or DC power supply, and there are also some switches which can be used with both AC and DC power supplies. However, the switch can only support one type of power supply at the same time. That’s to say, if you use DC power supply to power up your switch initially, the switch will detect it and operate with DC power. In this case, AC power supply installed in the switch will be disabled. Even if you try to install AC power supply when the switch is operating with DC power, it will also disable the AC power and generates an alarm. So remember not to mix AC and DC power supplies in a switch.

Conclusion

AC and DC power supplied Ethernet switches are all commonly used nowadays. You can select one or the other according to your own case and needs. FS provides both AC and DC switches. For example, we have AC switches such as 8/24/48 port PoE+ Managed Switches which support up to 600W. High quality DC switches are also available. Customers can also custom the power type of switches.

Originally published at http://www.fiber-optic-transceiver-module.com/ac-switch-vs-dc-switch-whats-the-difference.html

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Posted in Switch

VLAN vs Subnet: What Are Their Differences?

VLAN and Subnet are both developed to deal with segmenting or partitioning a portion of the network. And they also share such similarities as restricting broadcast domains or ensuring security through isolation of different sub-networks. However, there are obvious differences between them on operation, functionality and deeper objectives. This post will focus on VLAN vs Subnet: what’s the difference?

VLAN vs Subnet: What Are They?

Subnet is a small network composed by a group of IP addresses. It is part of a larger network. Any IP address within the same Subnet can communicate with each other without using routing devices. To be clear, we can think Subnet as the department of a company, people in the same department can talk freely without going out of their department. If you want to reach a address outside of your Subnet, you will have to go through a router or modern Gigabit Ethernet switch with router functionality. Since Subnet is related to IP address, it often works at layer 3.

VLAN, also known as virtual LAN, is a group of devices on one or more LANs in regardless of physical location. That’s to say, it allows devices to be grouped together even though they are not connected on the same fiber switch. However, it often requires the network hardware/software to support VLAN functionality, for example, VLAN switch is essential for setting up a VLAN network. In VLAN, configuration of the network can be done via software extensively. Basically, VLANs are used at layer 2 to break up broadcast domains.

VLAN vs Subnet: What’s the Difference?

As mentioned above, VLAN and Subnet are totally different things in a close look. The following chart lists the differences between VLAN and Subnet in details:

Parameter
VLAN
Subnet
Definition
VLAN is a logical LAN that contains broadcasts within itself, and only hosts belonged to that VLAN will see those broadcasts.
Subnet is an IP address range of IP addresses that help hosts communicate over layer 3.
Logical and Physical Network
VLAN allows us to create different logical and physical networks.
Subnet allows us to create logical networks through the same physical network.
Network Member Control
A VLAN is configured at server/router side. The one who controls the router/server decides which computer/port is assigned to which VLAN. For example, if you have a 24 port 10GbE switch, you can assign 12 ports to VLAN 1 and the others to VLAN 2.
A Subnet is determined by the IP you use and the IP can be chosen by the admin of a computer (or device). Therefore it is done on client side – you can not control it.
OSI Layer
VLAN is a layer 2 term where MAC addresses work.
Subnet is a layer 3 term where IP layer works.
Hardware/Software Based
More of software-based terminology.
More of hardware-based terminology.
Security & Control
VLANs perceived to be more secure and provide more robust control for the network.
Subnet has limited control in comparison to VLAN.
Major Benefit
VLAN is extremely flexible, it brings better work performance, less traffic, and more efficiency.
A Subnet will not be affected when other Subnets going down or having technical breakdowns.

VLAN vs Subnet: Which One Do You Like?

VLAN and Subnet both have their advantages and limits. For example, VLAN allows for creation of different logical and physical networks while Subnet only allows for creation of different logical networks. However, if a network sniffer is employed, users from one Subnet can discover the existence of other Subnets, this will not happen to users of different VLANs. So VLAN vs Subnet: which do you prefer?

Originally Published at http://www.fiber-optic-transceiver-module.com/vlan-vs-subnet.html

Posted in Switch

48 Port PoE Switch: Cisco Vs HP Vs FS.COM

To meet the growing requirement of an improved enterprise network management, 48 port PoE switch provides optimized solution for network efficiency, operational cost savings, and ease of management. Cisco always plays a leading role in fiber optical communication while HP switches are renowned for competitive price, quality and service. FS.COM is seen as the rising third-party fiber optics’ vendor. It has gained well reputation for their fiber optical transceiver, fiber jumpers, etc. Today, we would touch the basic introduction of the 48 port PoE switch supplied by these three vendors, analyze the difference, and provide a selection guide.
Cisco 48 Port PoE switch
For Cisco 48 port PoE switch, there are many such switches having been launched, such as SG 500X-48P(170/volume per month), SG2010P(210/volume per month), etc. The Cisco SG2010P 48 port poe switch has 48 RJ-45 connectors for 10BASE-T/100BASE-TX/1000BASE-T with 4 Gigabit combo ports shared between mini-GBIC ports. It is optimized for maximum system availability, with fully redundant stacking, redundant power options, and dual images for resilient firmware upgrades. The enhanced quality of service (QoS) and traffic-management features help ensure clear and reliable voice and video communications. The distinctive features of the Cisco SG2010P 48 port poe switch are showing in the below:
  • IEEE 802.3af PoE delivered over any of the forty-eight 10/100/1000 ports
  • Dual images for resilient firmware upgrades
  • 96 Gbps nonblocking, store-and-forward switching capacity
  • Fully resilient stacking provides optimized growth with simplified management
  • ACLs for granular security and QoS implementation
  • Configuration and monitoring from a standard web browser
HP 48 Port PoE switch
HP also offers many 48 port gigabit poe switch, such as HP J9853A(50/volume per month), HP 2530-48G(1300/volume per month), HP 2530-48G… HP 2530-48G is the hottest one among all the HP 48 port gigabit poe switches. The HP 2530-48G (J9775A) switch 48 RJ-45 auto-sensing 10/100/1000 ports (IEEE 802.3 Type 10BASE-T, IEEE 802.3u Type 100BASE-TX, IEEE 802.3ab Type 1000BASE-T) and four small form-factor pluggable (SFP) slots for fiber connectivity. The HP 2530-48G 48 port gigabit poe switch consists of four fully managed Layer 2 edge switches, delivering cost-effective, reliable, and secure connectivity for business networks.
FS.COM 48 Port PoE switch
Different from Cisco and HP, the total volume of FS.COM 48 poe switch is far less than Cisco and HP. For FS.COM 48 port poe switch, it offers S5800-48F4S, S3800-48T4S, S5850-48T4Q, and etc. S5800-48F4S 48 port poe switch is a availability, high-compatibility and network-scaling applications of data center as a carrier Access switch. It has 48 port 1GbE SFP and 4 port 10GbE SFP+ in a compact 1RU form factor and low latency L2/L3 Ethernet switch. With support for advanced features, including MLAG, SFLOW, SNMP etc, this switch is ideal for traditional or fully virtualized data center.
48 port poe switch fs.com


48 Port PoE switch: Cisco Vs HP Vs FS.COM
In this article, we would mainly give a comparison on 48 port poe switch among the above three vendors in the respective of power budget, switching capacity, and switching layer.
—Power Budget
Power budget attaches great importance to a PoE switch. And that is a vital element that should be considered for every switch buyers. For Cisco SG2010P 48 port poe switch, each port has independent overload and short-circuit protection, along with LED indicators to show power status. Maximum power of 15.4W to an Ethernet port—360W, total available to all ports with regular AC power; 280W, total available with RPS. The power consumption range of HP 2530-48G 48 port gigabit poe switch is between 29.5 W and 59.5 W. The maximum power draw of FS.COM S5800-48F4S 48 poe switch is 75W.
—Switching Capacity
Switch capacity is often a measure of the switch’s fabric bandwidth and the switch’s packets per second forwarding capacity. Sometimes a switch’s capacity (fabric bandwidth and/or PPS) cannot support all its edge ports running at 100% with any frame size. At the access-layer it’s more common with plenty of switch ports but with less switching-capacity (since it’s highly unlikely that all ports are operating at full speed at all times). The switching capacity of Cisco SG2010P is 96 Gbps non-blocking, HP 2530-48G is 104 Gbps, and FS.COM S5800-48F4S is 176 Gbps and its non-blocking bandwidth is 88 Gbps.
—Switch Layer
Network switches are often described as Layer 2 or Layer 3. Small networks can be built using just Layer 2 devices, but most corporate networks will have a mix of Layer 2 and Layer 3 switches. Dumb Layer 2 products are a cheap and easy way of providing connectivity to working groups while more intelligent Layer 3 switches enable departmental networks to be segmented and controlled with no loss of bandwidth. Both Cisco SG2010P and FS.COM S5800-48F4S support layer 2 and layer 3. HP 2530-48G deliver only full Layer 2 capabilities.
Here are the detailed specification of the above mentioned three 48 port PoE switches.
48 port poe switch table


Conclusion
This article mainly introduced three different 48 port PoE switches from Cisco, HP, and FS.COM. Power consumption, switching capacity and switching layer are what the users should consider when choosing a 48 port poe switch. As for selection, you can choose a proper one according to your budget, switching demand and reliable manufacturer. For reliable 48 port gigabit switch poe vendor, FS.COM is a wise choice. Anyway, there is still a promising prospect for 48 port PoE switches.

 

Posted in Switch

Mikrotik Switches Vs Cisco Switches

As a worldwide leader in IT and fiber optical networking, Cisco switches play a leading role in manufacturing network switches and in providing switching solutions for data center and enterprise networks with large and medium-size forms. MikroTik, a Latvian company which was founded in 1996 to develop routers and wireless ISP systems. Their cloud switches are highly favored by many Ethernet users in recent years. And thus, people are entangled with Cisco and Mikrotik switches. This article would give brief introduction to Cisco and Mikrotik switches, and put emphasis on Mikrotik Switches Vs Cisco Switches.

Cisco Switches

According to different usage, Cisco divided their switches into the following categories: LAN Access Switches, LAN Digital Building Switches, LAN Core and Distribution Switches, Data Center Switches, Service Provider Switches, Industrial Ethernet Switches, Virtual Networking and Small Business Switches. And every category has its switching series. The Cisco Catalyst series switch delivers ease of management and configuration for small to medium-sized enterprise wiring closets in a single system, without the need for additional modules. The following list is about the Cisco Catalyst series switch.

Cisco Catalyst series switch

Mikrotik Switches

Comparing to Cisco switches, the total amount of Mikrotik switches is much smaller. According to the official website of Mikrotik, there are only twelve Mikrotik switches. Ethernet smart switches and cloud core router switches are two series switches of Mikrotik switches. The cloud core switch, or cloud router switch, abbreviated as CRS, is a highly configurable switch, powered by RouterOS. They are the new products of Mokrotik switches. For the cloud router switch, there are nine models currently available. Here lists three different cases of the cloud core switch:

  • CRS125-24G-1S-2HnD-IN (integrated wireless, indoor case)
  • CRS125-24G-1S-IN (indoor case)
  • CRS125-24G-1S-RM (rackmount case)
Mikrotik Switches Vs Cisco Switches
—CPU

The CPU on both Cisco and Mikrotik switches is used for management purposes (snmp stats, cli management, etc) and it does not affect the data path. Switching is not done in CPU, neither on Cisco nor on Mikrotik. Switching is done on dedicated ASIC chips specifically designed for this job (thus giving wirespeed). So comparing the CPUs won’t mean much about forwarding performance – which is the metric you should care about.

—Power Consumption

One of big problems with Mikrotik switches is their power. The buyers would prefer to pay another couple hundred dollars to have dual power supplies that are removable. And thus, many Ethernet users cannot use Mikrotik in these cases. Comparing to Mikrotik switches, Cisco switches have less power consumption by their advanced technology.

—Network Monitoring Software Systems

Most network monitoring software systems natively understand, support and auto-detect Cisco devices and support Cisco SNMP OIDs (CPU, temp, load, bandwidth, errors, power supply status, and many other sub-system counters in a Cisco device.

When configuring your existing network monitor system(s), your network monitor system(s) may not even know what a Mikrotik is and probably does not have native built-in MIBs/OIDs used by SNMP to auto-check/monitor a network. Thus, an administrator would probably need to configure the Mikrotik graphic icons and configure all of the SNMP checks for MIBs/OIDs from/to a Mikrotik.

Mikrotik Switches Vs Cisco Switches: How to Select?

Mikrotik routers and switches are great. Most people like them and use them almost everywhere. However, because Mikrotik is still the new kid on the block when it comes to carrier-grade commercial-grade business grade high-throughput products, it may sometimes be a little difficult to find local network technicians or local phone support for Mikrotik products when adding new equipment into your network. So Cisco switch is more solid and people are more satisfied with them.

 

Posted in Switch

25G Switch Vs. 40G Switch: How to Choose?

25G Ethernet and 40G Ethernet are two “transiting” approaches for upgrading network from 10G to 100G. Some analysts believe 25G could be the second highest Ethernet server connectivity technology sold and shipped in the next five years, behind 10G. Meanwhile, a number of comments from industry experts declaring that 40G Ethernet is dead. Is that true? And how to make a right decision? This passage would give a brief introduction on 25G switch and 40G switch and put emphasis on 25G switch Vs. 40G switch.

25G Switch

25G technology is the new standard that offer significant density, cost and power benefits for server to top of rack connections. Its single higher speed 25 Gb/s lanes maximize bandwidth and switch fabric utilization. A single lane per physical port maximizes the number of connected servers or uplinks per switch. Generally, 25G switch is a 48 port switch on the 25G switch market right now. Nowadays, many major brands of switch manufactures have launched their 25G switch, such as Cisco, Juniper, Arista, Mellanox, Dell.

fs-n-series-leaf-spine-switch

40G Switch

Comparing with 25G switch, 40G switch is much familiar to us. A 40G switch generally refers to the data speeds of the ports feeding into the switch. Hence, a 40G switch has 40 Gb/s ports. The overall switching capacity of the 40G switch will be much higher depending on the total number of ports and the power of the switching fabric itself. According to Infonetics Research in early 2015, 40G switch has been popular in the data center market while 100G switch is more popular with service providers. And thus, 40G Ethernet and 40G switch are not so dead like being mentioned in the fast paragraph.

FS S8050-20Q4C 40G switch

25G switch Vs. 40G switch
—Switch Compatibility

Relatively speaking, 25G switch is less common on the market. In terms of 25G switch compatibility, that is depending the switch supplier. Just take Arista 25G switch for an example, the majority of their 25G switches and Network Interface cards offer backward compatibility to 10G, there is the flexibility to manage a gradual migration to higher speed servers and mix and match port speeds. All SFP based 25G ports on Arista switches and 25G NICs from Cavium can be used at 10G speed. The compatibility of 40G switch also depends on the switch brands. But as a new emerging technology, 25G switch has higher compatibility than 40G switch.

—Port and system density

High performance 25GbE chips use single-lane 25G serializer-deserializer (Serdes) technology similar in operation to 10GbE but delivering 2.5 times the performance, thus reducing the power and cost per gigabit significantly. 25G provides higher port and system density than a comparable 40G solution. Both power savings and higher density results in lower cooling requirements and operational expenditure for data center operators.

—Connection Option

Switch-to-server or switch-to-switch (or switch-to-blade switch) are two connection options for 25G switch connection. Right now, network vendors are positioning 25G only for switch-to-server. Until now, no network vendor advertising 25G for switch-to-switch—Cisco doesn’t even offer a 25G fiber transceiver, and HPE has priced theirs higher than 40G and 100G transceivers. In other words, no one is talking about 25G for switch-to-switch links right now. We shall see this in 2018.

—Cabling

25G twinax works best within a single rack with a top-of-rack switch and 1 and 2 meter cables. 25G with 3+ meter cables requires forward error correction (FEC), which adds ~250ns of one-way latency and may introduce vendor interop issues. If you’re adopting 25G, plan to densely pack compute into 10kVA–12kVA racks. 40G DAC cable is more expensive than 25G DAC cable based on the identical cable length.

25G Switch Vs. 40G Switch: How to Choose?

Through the above description and comparison, we are cleared about some pros and cons of 25Gb Ethernet switch and 40Gb Ethernet switch as well as their main differences. As for how to choose the best one, that depends on your demand and usage environment. 25G switch uses less power and produce less heat than 40G, but it is limited at 25G distance. For data center network connectivity, 100G switch is more of a smart choice than 25G switch and 40G switch. In campus and access networks with their long fiber runs and low bandwidth needs, 40G switch is more worthy to buy. So far it seems that 25G switch is not a cost-effective solution.

 

Posted in Switch

Why Stackable Switches Are More Favored?

Up to now, there are three types of switching solutions: standalone, stacked, and chassis. According to researches, stackable network switches have been warmly welcomed by large data center, enterprise network and home networking over the years. Lots of Ethernet users intend to choose a stacked switching solution rather than standalone and chassis switching solutions. So what are the reasons behind this kind of preference? This article would provide a satisfied answer for you.

Stackable switching solution

Simplified management is the paramount advantage for all stacking. Before stacking came along, you had to attach multiple switches together and configure them separately by logging in with a different IP address one by one. As you may know or can imagine, this was a super tedious process. When stacking switches, they all share the same IP address and can be configured as one unit. Instead of looking like multiple separate switches, the solution actually looks like one switch with a larger amount of ports. In the following part, we would further analyze the merits of stackable switching solution.

brocad stackable switches

Benefits of stacking switches

In this text, we would mainly demonstrate the benefits of stacking switches from the aspect of simplicity, scalability, and flexibility.

—Flexibility

For environments where a combination of different port speed and media types are needed, such as a mix of copper gigabit Ethernet and fiber gigabit or 10 gigabit, stackable switches make this possible without needed independent switches or use of a large, perhaps oversized, chassis. We can add ports as we need them by simply purchasing another switch and adding it to the stack.

networking diagram of a stack

We can stack up to nine 3750-X switches and have 432 x 10/100/1000 ports and 18 x 10 Gbps ports. We can do this using only 9RU’s of rack space. A chassis would require over double the rack space to achieve this access port density. This makes these switches very popular as top-of-rack switches in the data center.

—Scalability

For resiliency, devices like servers, downstream switches, or other important devices can be connected via EtherChannel to the stack, with the ports in the EtherChannel spread across multiple switches in the stack. This setup allows for a failure of a switch in the stack with minimal forwarding interruption and any connected hosts still active with only a performance loss.

—Simplicity

A stack of Ethernet switches appears to the operator and the rest of the network as one single switch, making it easier to manage and configure. Newer switch models add stateful failover capability, providing similar behavior as a chassis with dual supervisors in case of a failure or the need to update software on the stack.

Conclusion

This article mainly explained the reasons of people’s preference for stacking switches from three points—simplicity, scalability, and flexibility. When you are looking for a stacking switch, there are some questions you need to consider. How many switches can go into a stack? How far apart can they be stacked? What is the speed of the backplane? What technologies do you need and what can the switch be stacked with? All of these points attach great importance to your stacking switches. And thus, please take a careful consideration before you buy a stacking switch.

 

Posted in Switch

Cisco Catalyst Vs. Small Business Switches

Over the years, Cisco have launched its Catalyst series switches in succession, from Cisco Catalyst 1900 Series Switch to Cisco Catalyst 9500 Series Switch. And they have been widely applied in data center, high-performance computing networks, enterprise core and distribution layers, and service provider applications. Nowadays, small business enterprises account a large share among all the forms of business enterprises. It seems that it is hard to choose network switches between Cisco Catalyst and small business switches. This article would mainly introduce the Cisco Catalyst series switches and small business switches and further analyze their differences.

Introduction to Cisco Catalyst Series Switches

Cisco switches have been highly favored by Ethernet users, for they come in a variety of Ethernet-based platforms, providing everything from simple connectivity to high-end, multilayer intelligent service switching solutions. The Cisco Catalyst series switch delivers ease of management and configuration for small to medium-sized enterprise wiring closets in a single system, without the need for additional modules. These switches also provide high performance switching solutions ideal for public service providers or large private enterprises with a high volume of traffic and mid-sized networks deploying Internet business applications such as IP telephony, e-commerce, or Enterprise Resource Planning (ERP). Cisco Catalyst Switch Series are mainly listed in the following: Until now, Cisco have launched about 25 Cisco Catalyst Series Switches.

Cisco Catalyst 6500 Series Switches

Information About Small Business Switches

Small business switch, also called SMB switch, which is a kind of switch specifically manufactured for small business enterprises. But small businesses can sometimes have a tough time buying networking equipment. The problem is often the cost- that equipment can cost upwards of thousands of dollars, a budget that often isn’t at all feasible for small businesses. Thankfully, however, there are high-performing, stable, and reliable switches for the small business market that come in at under $1000 and are still suitable for small business use. The top five small business switches are Cisco SR2024CT 24 Port Gigabit Switch, Cisco SG 300-28P 28-Port Gigabit Switch, D-Link DGS-1024D 24-Port Gigabit Switch, TP-Link TL-SG1024D 24-Port Gigabit Switch, and Netgear JFS524E-100NAS 100 Megabit Switch.

FS-1-10G-enterprise-switches

Cisco Catalyst Vs. Small Business Switches
—Bandwidth

Switching and forwarding bandwidth are typically higher in the Cisco catalyst series switch. Small business switches are relatively lower in terms of bandwidth. Customers would get better support with the catalyst (smart net) than the small business ( cisco small business )

—Software

The Catalyst series switches’ value is not around performance, but rather around the software and what it brings. Since it is deployed in more diverse and more mission critical environments than any other product in the market, you can pretty much be sure that it is rock solid. It also has a lot more levers and dials to tune around QoS, security, etc.

—Configuration

Small business switches would give basic configuration that would be sufficient for small businesses with less details on controlling the network. On the other hand, the catalyst would provide you with more variety of options and would help you control your network better.

—Costs

Relatively speaking, Cisco small business switches cost less than Cisco Catalyst series switches. One good news the SMB switch will fit the bill at 1/3 the price. Cisco has 4 models of the Small Business Switch line that will meet or beat 176, just shown as the following.

4 Modules of Cisco SMB switches

Conclusion

This article mainly covered the Cisco Catalyst series switches, small business switches and their differences from the aspect of bandwidth, software, configuration and costs. You can choose an appropriate one according to your actual need.

Posted in Switch

Why Do We Use Fiber Optic Switch?

A fiber optic switch is a device of transferring signal and data through fiber optic cables and optical modules. Compared to copper cables, the speed of data transmission is faster and more efficient. Nowadays, the fiber optic switches have been widely applied to our daily life and data center. Some extremely fine glass tubing is used to send signals for phones, computer networks, televisions and other systems. Like with many other great inventions, there are both advantages and disadvantages associated with fiber optic. This article would mainly give an explanation about the reason of using fiber optic switch from the perspective of pros and cons of fiber optic switch.

Advantages

Fiber optic usage can be used in a wide range of applications to enhance service delivery. Phone systems, mechanical systems, lighting, television and computer networking have all benefited from fiber optic developments. The improved system performance is a vital factor in the overall service delivery as well as efficient and improved communications. Congestion and crowded networks are now a thing of the past with the invention of the fiber optic switch. Signals are transmitted as they occur rather than all at once.

Fiber-optic is versatile, it has been penetrated almost every walk of life, the telecommunication industry in particular. Phone systems, mechanical systems, lighting, television and computer networking have all benefited from fiber optic developments. Thanks to the fiber optic switch, the efficiency of the service delivery has been greatly enhanced. With the invention of fiber optic switch, network congestion is no longer a problem. All the signals and data can almost be transmitted and received at the same time. Moreover, the number of transmitting signals are not limited anymore.

fs.com-switch

Fiber optic cable are used for transmitting signals, which could be more clear and stronger than those transmitted via copper cabling. Signals attached great importance to create a more organized system of signal delivery. Through fiber optic installations, crashing or stalling of systems due to signal overload is eliminated.

In addition to signal delivery systems, fiber-optic also has to do with other systems such as electrical noises, radio frequencies, electromagnetic interference or alarm systems. The disruptions caused in the airwaves would not affect signal transmitting. Apart from being more efficient, the fiber switch is also much faster than the previously used copper switch. This has positively lifted the Internet bandwidth. Increased bandwidth and capacity encourages more effective data handling and transfer. Signal security is also much higher with fiber cabling than electric interfaces. This is extremely vital where sensitive and confidential transmissions are involved, such as FBI (Federal Bureau of Investigation), CIA (Central Intelligence Agency), DHS(United States Department of Homeland Security).

Disadvantages

Every new invention has its defects, so does the fiber optic switch. Relatively speaking, the fiber optic is an emerging technology and there is still a long way to go. The expertise and resources required to install fiber cabling have not yet spread out widely. In this way, the fiber cabling really costs a lot. It is a complex project, for it covers a wide range of specialized knowledge, tools and complicate processes.

It seems that fiber optic switch is easy to make network connectivity, but it is not so easy to install it. Installation is both a time and labor-intensive undertaking albeit one that yields improved communications. Prerequisite conditions add to the rigors of installation. Prior to installing of a fiber optic cable and switches, the environment must be checked and found to be free of pollution and dust. Temperatures must not exceed 113 degrees Fahrenheit, and the area must be well-ventilated. It is a delicate process that requires extremely careful handling.

Economic Choices for Fiber Optic Switch

For optical switch, you can take FS.COM for a try. The following is their S3700-24T4S, which is deployed at the access layer of an enterprise network to deliver cost-effective packet switching capability. It provides 24*10/100/1000Base-T Ports and 4 10G SFP+ ports to extend your home or business network at gigabit speeds.

FS enterprise switches

Conclusion

This article mainly talked about the merits and defects of using fiber optic switch. All in all, the advantages outweigh the disadvantages. It has changed our life a lot, and we are benefit from it, especially the datacom industry. Overall, there is a prosperous future ahead for the fiber optic switch, we shall see.

 

Posted in Switch

Layer2 Versus Layer3 Networking Switch

Developed in 1980s, Layer 2 (L2) switches have been widely applied to high-speed data transmission in the enterprise between end stations. Layer 3 (L3) switch works as routing over IP network, which mainly functions as dealing with network traffic. This article would provide general information about layer 2 and layer 3 switches, their differences as well as guidance on making choices between those two switches.

Layer 2 and Layer 3 Networks

Information About OSI Model

If you want to figure out the layer things, you must understand what is the OSI model at first. OSI stands for Open Systems Interconnection, which is a model used to standardise the functions of telecommunication and computing systems around the world. It is a controlled hierarchy where information is passed from one layer to the next creating a blueprint for how information is passed from physical electrical impulses all the way to applications.

Basically, there are totally 7 layers in the OSI model, the “layers” refers to how you configure an IT network. Function of each layer is to provide services to the above layer, so L2 props up L3, shown as the below figure.

osi-model

Layer 2 Switch

As per OSI Model, Layer 2 is Data Link Layer (DLL), which is basically divided into two sub-layers: Logic Link Control (LLC) and Media Access Control (MAC). LLC layer provides services to upper layer, and controls frame synchronization, flow control and error checking. MAC layer performs Layer 2 functions like switching, physical addressing etc. Besides, it controls how a computer on the network gains access to the data and permission to transmit it. Traditional switching operates at layer 2 of the OSI model, where packets are sent to a specific switch port based on destination MAC addresses. There are three distinct functions of layer 2 switching. The following figure shows how layer 2 switching working.

  • Address learning
  • Forward/filter decisions
  • Loop avoidance

layer 2 switching
Layer 3 Switch

With the support of switching and routing technologies, Layer 3 creating logical paths, known as virtual circuits, for transmitting data from node to node. Routing and forwarding are functions of this layer, as well as addressing, internetworking, error handling, congestion control and packet sequencing. Compared to Layer 2 switching, Layer 3 switching is a relatively new term. That has been extended by a numerous vendors to describe their products. Here is an example to illustrate it. one school uses this term to describe fast IP routing via hardware, while another school uses it to describe Multi Protocol Over ATM (MPOA). The following figure shows how layer 3 switching working.

layer 3 switching

Layer 2 Vs. Layer 3 Switching

—Functions

Layer 2 Data Link: Responsible for physical addressing, error correction, and preparing the information for the media.

Layer 3 Network: Responsible for logical addressing and routing IP, ICMP, ARP, RIP, IGRP, and routers.

—Network traffic

Layer 2 networks forward all their traffic, including ARP and DHCP broadcasts. Anything transmitted by one device is forwarded to all devices. This type of broadcast traffic is very fast. When the network gets too large, the broadcast traffic begins to create congestion and decreases network efficiency.

Layer 3 traffic restricts broadcast traffic. Administrators on L3 can segment networks and restrict broadcast traffic to subnetworks, limiting the congestion of broadcast on large networks. This reduce overall traffic levels by allowing administrators to divide networks into smaller parts and restrict broadcasts to only that sub-network.

In a conclusion, there is a limit to the size of a layer 2 network. However, a properly configured layer 3 network with the correct knowledge and hardware can have infinite growth.

—Network routing

Layer 2 switch lacks router hardware, leaving them susceptible to broadcast storm and the additional administrative overhead of IP allocations due to flat subnet across multiple sites. A Layer 3 switch is a high-performance device for network routing. A router works with IP addresses at layer 3 of the model. Layer 3 networks are built to run on on layer 2 networks. But Layer 2 switches only require switching, no routing gear is necessary. Besides, they cost less and offer very low latency.

Which is Better?

This is an open question, and the answer actually depends on what is your need. Both layers of the OSI have their role in the architecture of network performance. An L2 network would be more useful broadcasting information between two computers in the same office, close together. Routing controls happen at Layer 3, and that is what most businesses need.

 

Posted in Modules, Switch

AgilePorts—An Unique Design for Connection on Arista 7150S-64 Switch

In order to meet the requirements of demanding environments such as ultra low latency financial ECNs, HPC clusters and cloud data centers, Arista launched a series of switch—Asita 7150S, including 7150S-24, 7510S-52 and 7510S-64. The Arista 7150S series represents the industry’s leading ultra low latency 1RU 1/10/40GbE layer 2/3/4 wire speed switch family. As one member of the Arista 7150S family, Arista 7150S-64 switch has both SFP+ and QSFP+ ports while the another two haven’t QSFP+ ports. This article would provide the basic information about Arista 7150S-64 switch and its network migration with Agile ports.

An overview on AgilePorts

The most distinctive feature of Arista 7150S switch is the design of AgilePorts on the switch which enables flexible deployment. AgilePorts deliver complete flexibility in connectivity—each SFP+ interface is capable of supporting 100M-10G over a variety of media, including DWDM with distances up to 80 km. The AgilePorts feature also enables groups of adjacent SFP+ ports to be configured for 40Gb operation using 10G transceivers and cables providing maximum port flexibility and a seamless migration from 10Gb to 40Gb.

Information About Arista 7150S-64

The Arista 7150S-64 has 48 SFP+ and 4 QSFP+ ports, you can see the detailed information in the below table. Different from the other two 7150S switches, 7150S-64 has the largest number port and it is the only one has QSFP+ ports. The SFP+ ports can support 1G and 10G operation and also 100Mb support with 100/1000-TX transceivers. On this 7150S-64 switch with QSFP+ ports, you can split the 40G interfaces into 4×10G. The 7150S-64 switch can provide 16×40G interfaces including 4 QSFP+ ports and 12×40G ports (48 SFP+ ports grouped into 12×40G) (see figure1).

Arista 7150S-64 Switch
Description 7150 Switch 48-Port SFP+ 4 QSFP+
Total Ports 64
SFP+ Ports 48
L2/3 Throughput 1.28 Tbps
L2/3 PPS 960 Mpps
Latency 380ns
Typical Power Draw 224 W

Table1: Information about Arista 7150S-64 Switch

7150s-64 switch

Figure1: Rear view on Arista 7150S-64 Switch

Compatible Optical Modules for Arista 7150S-64 Switch

There are many compatible 10GbE SFP+ transceivers for 7150S-64, such as 10GBASE-SR, 10GBASE-LRL, 10GBASE-CR, and so on. You can just plug these SFP+ transceivers into the SFP+ port on the switch. For the QSFP+ ports, there is a wide range of choices as well, including 40GBASE-CR4, 40GBASE-SR4, 40G-PLRL4, 40GBASE-LR4 and etc. The distances can be supported from 100 m over OM3 to 10 km over single-mode fiber on the 7150S-64 switch.

Two Different Connection Solutions

We would mainly compare the common practice of connection with connection with AgilePorts to highlight the key distinction of connection with AgilePorts.

General Connection From 10G to 40G Network

For any network migration, optical transceivers play an essential role. So does the 10G to 40G network migration—you must take 40G QSFP+ transceiver into consideration. If you use the general switches to migrate 10G to 40G network, you can take the following connection solution as a reference. Just as we see in the below picture, an MPO/MTP LGX cassette connects four 10G SFP+ links. And then a Type-B female MPO/MTP trunk cable is used to connect the cassette and 40G QSFP+ Transceiver.

40G-solutions

Figure2: 10G to 40G solution (1)

Connection With AgilePorts on Arista 7150S-64

Like we described before, the Arista 7150S switch’s AgilePosts is designed to address device and cabling life cycles, you can upgrade from 10GbE to 40GbE only with just 10G SFP+ transceivers and cables. It provides maximum port flexibility and a seamless migration. Under this situation, 40G QSFP transceiver is unnecessary. 40G connection is achieved by connecting four 10GBASE-SR SFP+ transceivers with LC duplex fiber patch cables. In this way, time and space are saved through this kind of connection.

40G-solutions-2

Figure3: 10G to 40G solution (2)

Conclusion

The Arista 7150S-64 is a 10/40G Ethernet switch, the distinctive design of AgilePorts on the switch plays a prominent role on the network data rate migration from 10G to 40G.