What Is Redundant Link between Switches?

We know that if any chain in the network fails, the operation may break down. Facing this problem, we’ve introduced the stackable switches and together with it is the concept of redundant links. When stacking switches, except the shortest link between switch and the main frame computer, we also prepare other links in case of the break down of the major link. The other links are redundant links between switches.

Introduction of Redundant Link

In order to maintain the stability of the network, composed of multiple switches, some backup connections are usually used to improve the robustness and stability of the network. The backup connection here is also called a backup link or a redundant link. Redundant links in a switches are accomplished through the use of multiple switches or multiple links between switches.

In an enterprise network, a link is redundant if its presence or absence does not affect the nature of the mechanism. That is, even if we remove that link, the mechanism will behave in the same manner.
Redundant link between switches

Pros and Cons of Redundant Link

Pros

The redundancy in networks can improve its reliability. Our intention is that if one device fails, another can automatically take over. By adding a little bit of complexity, we try to reduce the probability that a failure in switch will take the whole network down. Spanning Tree Protocol,the redundancy protocols, can be implemented on any topology or mesh. The Cellular Redundancy provides alternative to running a physical line for redundancy. In addition, with Parallel Redundancy Protocol, we can achieve zero packet loss, “0ms” recovery. And it can be added to any existing network.

Cons

But you cannot have both complexity and reliability at the same time. The more complex something is, the harder it is to maintain, the greater the chance of human error, and the greater the chance of a software bug causing a new failure mode.

The switches between the backup links are often connected to each other to form a loop. The loops can be redundant to a certain extent. The redundant backup of the links can bring robustness, stability and reliability to the network. However, the backup link also causes loops in the network. The loop problem is the most serious problem faced by the backup link. The loop between the switches will cause new network problems: broadcast storm, loops and duplicate frames.

Tips

To make fully use of redundant links, we can minimize the complexity. Select two identical switches as the core switches. If you need gigabit Ethernet switch, for example, you can select two 10 gbe switches that run the same software and have the same connections. We can also introduce the Spanning Tree Protocol (STP) which was developed as a Layer 2 loop-avoidance mechanism for redundant links in a switched network. With STP, there will be only one logical path between all destinations on the network and redundant links that could cause a loop are intentionally blocked.

Conclusion

Redundant links are useful to a great extent. That’s why so many people now choose stackable switches rather than standalone ones to maintain the efficient network operation. Stackable switches are now our star products and focal point. We would like to introduce our high quality fiber switch to every people in need of reliable network performance.

Fibre Channel VS Ethernet Switch: What’s the Difference?

Fibre Channel (FC) is a serial I/O interconnect network technology capable of supporting multiple protocols. It is used primarily for storage area networks (SANs). Ethernet (and TCP/IP) is the most frequently used technology these days for communication between devices. But for storage, the dominant technology in a data center often is Fibre Channel. Fibre channel vs Ethernet switch: what’s the difference? This article makes an analysis from the following aspects: reliability, transmission speed, flexibility and cost.

Fibre Channel VS Ethernet Switch: Reliability

If you are actively engaged in optic communication, you may have noticed that the fibre channel switch is lossless while Ethernet switch is risk of dropping frame. Fibre Channel is often compared to Ethernet in terms of being a lossless protocol. As for fibre channel switch, it works smoothly without dropping a single frame, and frames must be delivered in order. FC switches will send signal when they’re congesting to other devices, so these devices stop sending frames, lest the frames are dropped. This in contrast to Ethernet which will just start dropping frames when congested, relying on upper layers (like TCP) to make sure everything keeps working.

Fibre Channel VS Ethernet Switch: Transmission Speed

The maximum data rate of the fibre channel switch in the very beginning is 1 Gbps. Now it has evolved up to 128 Gbps, with 8, 16, and 32 Gbps versions still available.

The Ethernet switch transmission speed ranges from Fast Ethernet (10/100 Mbps), Gigabit Ethernet (10/100/1000Mbps), 10 Gigabit (10/100/1000/10000 Mbps) to even some 40/100 Gbps speeds. In terms of transmission speed, the Ethernet switch seems to outweigh fibre channel switch. Whereas both are in a high speed evolution.

Fibre Channel VS Ethernet Switch: Cost

Cost is also an element to be considered. In most cases, Ethernet switches are much cheaper than Fibre Channel switches. What’s more, the maintenance is also a factor that should be considered. In large IT systems, if an Ethernet switch breaks down, most admins can deal with it. However, when there is something wrong with the fibre channel switch, you need to turn to manufacturers, instead. Comparing to Ethernet switch, fibre channel switch adopts more complicated design in that it should guarantee the extremely availability of data storage, and is equipped with management function.

 FS switch

Conclusion

Seen from above, there are significant differences between fibre channel switch and Ethernet switch. FC is a network standard to enable hosts (servers) to interconnect with storage devices. It’s completely different from Ethernet. A storage network switch is not the same as an Ethernet network switch. Initially, the only transmission medium of FC was fiber, but these days twisted pair copper wire is also available. That’s the opposite of Ethernet, which originally ran only on copper wires and then on fiber. FS.COM provides a variety of Ethernet switches  and fiber switches which are mostly upgraded and optimized by our research and development staff, ranging from 10gbe switch to gigabit ethernet switchFor more information, you can search “Fiberstore” on website or YouTube.

2 * 8 Port Gigabit Switch or 1 * 16 Port Gigabit Switch

In computer networking, an Ethernet switch is a LAN interconnection device that serves as a bridge between multiple equipment and a Local Area Network (LAN). Ethernet switches are categorized into two main types – modular and fixed configuration. Fixed configuration switches have a fixed number of ports and are not expandable. You can select the switches based on number of ports. The larger the network, the greater number of ports you’ll need. Fixed configuration switches are generally available in 5, 8, 10, 16, 24, 28, 48, and 52-port configurations. Some people may question that is it a good idea to purchase two 8-port switches other than one 16-port switch since the price of two 8-port switches is much lower than that of one 16-port switch? 2 * 8 Port Gigabit Switch VS 1 * 16 Port Gigabit Switch—a good question worthy of discussing.

2 * 8 Port Gigabit Switch VS 1 * 16 Port Gigabit Switch

This question is very common and can be subjective according to the urgency of uptime, financial budget, network management and space involved. If most variables are not a problem, then, the answer is YES. Taking two switches from different vendors as an example, there is a wide gap between their price.

S1130-8T2F Managed PoE+ Switch

FS.COM S1130-8T2F managed PoE+ switch comes with 8x 10/100/1000Base-T RJ45 Ethernet ports. It can supply power to network equipment such as weather-proof IP cameras with windshield wiper and heater, high-performance AP and IP telephone. This managed PoE+ switch is highly flexible, the transmission distance of the SFP fiber port can be up to 120km, and with high resistance to electromagnetic interference. It also features superior performance in stability, environmental adaptability and the price of it is $159.

S1130-8T2F Managed PoE+ Switch

Intellinet 16-Port Gigabit Ethernet PoE+ Web-Managed Switch

Intellinet 16-Port gigabit Ethernet PoE+ web-managed switch with 2 SFP ports is sold at $501. Equipped with sixteen Gigabit Ethernet ports, all of which support 802.3at/af Power over Ethernet (PoE/PoE+), this switch can power wireless LAN access points and bridges, VoIP (Voice over Internet Protocol) telephones, IP surveillance cameras.

Apart from price, there are other elements need to be considered. If the entire network depends on a single switch and, unfortunately the unit undergoes a catastrophic failure, the whole network would break down. However, if one of the 2 switches fails, only half the network is down but still able to limp along until there is a replacement. The only shortcoming is that you will lose two ports by connecting them, which means that you will have a 14-port switch if you buy two 8 ports.

If you need to expand in the future, it’ll be nicer to work with a 16-port switch instead of a couple 8’s. In smaller setups and homes, you can hardly notice the difference between the two, because you seldom have lots of transfers all at the same time and all destined for ports on the opposite switch. While in larger data centers, it can make a difference as you are constricting data flow by forcing 7 ports through one port to get to the other switch.

Conclusion

Gigabit Ethernet transmitting at approximately one gigabit per second, as well as fiber optic cable are all products created in line with people’s desire for faster broadband. Most people turn to gigabit switches as they are easy to use, provide plug and play installations and can save the power consumption. After analyzing the issue—2 * 8 Port Gigabit Switch VS 1 * 16 Port Gigabit Switch, I sincerely hope it can help you make a right choice.

Powering PoE Switch From A PoE Switch: Is It Possible?

PoE (Power Over Ethernet) technology supports power and data transmission over the same Ethernet cable, which makes the cabling easier and greatly saves the space. Characterized by this advantage, PoE switch gains the popularity among many users. In practical application, we may meet some emergency, such as power failure. At this time, is powering PoE switch from a PoE switch possible? This article will discuss this topic.

Working Principe of PoE Switch

Before we come to the answer of powering PoE switch from a PoE switch, let’s learn about working principle of PoE switch. A whole PoE system consists of Powering Sourcing Equipment (PSE) and Power Device (PD). PoE switch is a type of PSE device. The PSE device not only powers Ethernet client devices, but also manage the entire Power over Ethernet process. While the PD device is PSE load which receives power, or we can call it PoE system client. The working principle pf PoE switch can be divided into five steps. For applications of PoE switch, you can read this article: Using PoE Switch for Different IP Camera Systems

Detection: PoE switch outputs very small voltage on the port, until it detects that the PD equipment connected to the cable end supports the IEEE802.3af standard.

PD Classification: After detecting the PD, PoE switch may classify PD equipment, and assess the power loss of PD equipment.

Begin to Supply Power: In a configurable time (usually less than 15μs) start-up period, PoE switch begin to power PD equipment with low voltage, until it provides 48V DC power supply.

Power Supply: PoE switch provide stable and reliable 48V DC power for PD equipment to meet the power consumption which is less than 15.4W.

Power Off: If the PD equipment is disconnected from the network, the PoE switch will stop powering the PD equipment quickly, generally within 300-400ms, and repeat to detect whether the end of the cable is connected to the PD equipment.

Powering PoE Device From A PoE Switch

PoE switch is self-adaptive. When the PSE has the power supply requirement, the PD will output the voltage to the PSE. This means the switch can be powered by PoE while simultaneously providing power by PoE to other devices such as IP phones or wireless access points. This provides great flexibility because it means that the switch can be deployed without the constraints of an AC power outlet. As for powering PoE switch from a PoE switch, Universal PoE (UPOE) technology will be required and the following part will talk about UPOE. The following figure shows the evolution of PoE technology.

Evolution of PoE Standard

Powering PoE Switch From A PoE Switch with UPOE Technology

UPOE technology is a new innovation from Cisco Systems which happens to the industry’s first 60-watt Power over Ethernet technology. It can offer twice the power per port of the switch—providing both power and network access to a greater range of devices through a single standard Ethernet cable. This can surely help to lower the total cost of IT operations. By using UPOE technology, powering PoE switch from a PoE switch is possible. Here is an example to help you have a better understanding of this.

Most major networking vendors provide PoE Passthru, but they all require using higher powered sources. It physically would be impossible otherwise. If X is the power provided to the switch and Y is the power the switch uses, then Z is the power available for PoE devices. Then X – Y = Z. If you want Z to meet the PoE specification, then X has to be at least: Z + Y which means your input power needs to be UPOE.

Conclusion

As the enterprise workspace evolves with more and more end devices for communication, collaboration, security, and productivity, the need of PoE is also evolving to support newer end devices with increased power requirements. Regarded as upgrade of PoE, UPOE technology doubles the power delivered per port over PoE+ to 60 Watts which can extend resilient network power to a broad range of devices. What’s more, it realizes powering PoE switch from a PoE switch.

Introduction to 48 Port Gigabit SFP Switch

As we all know, data center cabling system consists of multiple devices, such as fiber optic transceiver, fiber optic patch cable, fiber patch panel, cable manager, and so on. As the central nerve of the whole cabling system, gigabit switch has been a topic of discussion. To satisfy different sizes of networking deployment, there are various types of Ethernet switches. This article will introduce a kind of 48 port gigabit SFP switch.

Overview of 48 Port Gigabit SFP Switch

FS.COM S5800-48F4S switch is a 48 port gigabit switch with 10gb uplink. It has 48×1GbE SFP ports and 4×10GbE SFP+ ports in a compact 1RU form factor. The switching capacity of this 48 port switch is 176 Gbps and its non-blocking bandwidth is 88 Gbps. And this gigabit switch can provide 130.95 Mpps. Meanwhile, FS.COM S5800-48F4S switch has 2 (1+1 redundancy) hot-swap power supplies and 4 (N+1 redundancy) hot-swappable fans. It is also a low latency L2/L3 Ethernet switch with 2.3us latency. The price of this 48 port gigabit switch with 10gb uplink is US$ 1,699.00. Here is a figure for you which shows front and back panel overview of FS.COM S5800-48F4S 48 port gigabit SFP switch.

front and back panel overview of 48 port gigabit SFP switch

Highlights of 48 Port Gigabit SFP Switch

The S5800-48F4S 48 port gigabit SFP switch with 10GE SFP+ uplinks comes with the complete system software with comprehensive protocols and applications to facilitate the rapid service deployment and management for both traditional L2/L3/MPLS networks. With support for advanced features, including MLAG, SFLOW, SNMP etc, this switch is ideal for traditional or fully virtualized data center. The S5800-48F4S hardware also provides high-availability features, including pluggable redundant fans and using high quality electronic components, which ensures low power consumption.

Applications of 48 Port Gigabit SFP Switch

Designed with 48×1GbE SFP ports and 4×10GbE SFP+ ports, FS.COM S5800-48F4S 48 port gigabit SFP switch can accomplish N×1G to N×1G (N≤48) connection or N×10G to N×10G (N≤4) connection. For example, in 5G to 5G connection, on one side, five 1G SFP transceivers are plugged into SFP ports on S5800-48F4S switch; on the other side, another five 1G SFP transceiver modules are plugged into SFP ports on switch, too. Then, these five SFP optical transceivers are connected by five fiber optic cables. It should be noted that the transceivers and fiber patch cables used in the link are of the same type.

Supported Accessories for 48 Port Gigabit SFP Switch

In the above part, we mention that the S5800-48F4S 48 port gigabit SFP switch can be used with SFP transceiver, SFP+ module and fiber optic cable. This part will go on introducing some support accessories for this 48 port gigabit SFP switch.

Fiber Optic Transceiver
ID Type Wavelength Transmission Distance Interface DOM Support
29838 1000BASE-SX SFP 850 nm 550 m over OM2 MMF LC duplex, MMF Yes
20057 1000BASE-T SFP 100 m over Cat5 RJ45 No
29849 1000BASE-LX/LH SFP 1310 nm 10 km LC duplex, MMF/SMF Yes
11591 10GBASE-LR SFP+ 1310 nm 10 km LC duplex, SMF Yes
11589 10GBASE-SR SFP+ 850 nm 300 m over OM3 MMF LC duplex, MMF Yes
Cable
ID Cable Length Connector Type Fiber Count Polish Type Jacket Material
21278 2 m SFP+ to SFP+ Passive Copper Cable (DAC) PVC (OFNR)
35194 3 m SFP+ to SFP+ Passive Copper Cable (DAC) PVC (OFNR)
40191 1 m LC to LC OS2 Duplex UPC to UPC PVC
40192 2 m LC to LC OS2 Duplex UPC to UPC PVC
41730 1 m LC to LC OM3 Duplex UPC to UPC PVC
40180 1 m LC to LC OM4 Duplex UPC to UPC PVC
CWDM MUX DEMUX
ID Wavelength Channel Spacing Channel Bandwidth Line Type Client Port Special Port
33489 18 channels 1270-1610nm 20 nm ±6.5nm Dual fiber Duplex LC/UPC Monitor Port
43099 8 Channels 1470-1610nm 20 nm ±6.5nm Dual fiber Duplex LC/UPC Expansion Port

Conclusion

As the size of data center becomes larger and larger, cable density increases, too. To simplify the cabling, many data center managers prefer network switch with high density ports. The above 48 port gigabit SFP switch with 10GE SFP+ uplinks is a suitable choice for high density cabling.