May 30, 2021 Ethernet Switch
Ethernet switch functions as a central station connecting computers, printers and every other wired device. The switch is also wired to the router and modem to access the internet. The wireless counterpart to Ethernet is Wi-Fi.
An Ethernet switch is one of the three major functions in a wireless router, and although stand-alone Ethernet switches have up to 48 ports, the Ethernet switch in the wireless router typically has only four ports.
Switches can be wired to each other, each one splitting off to other devices. Additional switches become automatic Ethernet boosters, as every transmitted output gets power from the AC outlet switch is plugged into. Regular Ethernet switches transmit data signals only; however, a powered version transmits electrical power to remote devices such as security cameras.
A basic “unmanaged” switch has no user configuration, and there is nothing to do except plug in the cables and turn it on. In contrast, for company networks, a “managed” switch can be configured to perform various tasks such as adjust speeds, combine users in a subgroup, monitor traffic and report activity.
Ethernet Switch is available through Quick Time Engineering Inc.
Wireless Bridge
A wireless bridge is created by linking 2 access points together. One access point adopts the role of being an ‘access point’ and the other the role of bringing a ‘client’ or ‘station’. The client access point connects to the other access point in a very similar way to how a client device such as an iPad or laptop would connect to a normal access point. The difference with a point-to-point wireless bridge is that the connection is an exclusive one between the 2 devices.
Another key difference is that wireless bridges are very directional. In most access points the RF energy is transmitted in a 360degree coverage pattern. This is useful in wireless networking as usually, the client devices are either mobile or there are multiple of them. This means that the access point needs to be able to connect to them wherever they may be about it. With a wireless bridge, however, in most cases both points are fixed so any RF energy not directed towards the other device forming the bridge is effectively wasted.
Wireless bridges are generally required to provide links over long distances. To do this, the devices must focus the RF energy. Typically, a wireless bridge is a Layer 2 Connection between 2 wired ports. If a link is Layer 2 it means that it uses switching rather than a combination of switching and routing for the packets to get to their destination. Both ends of the link will exist within the same Subnet. You should effectively treat most wireless bridges as if they were simply a long Ethernet cable. In fact, it actually doesn't matter what IP addresses you give the radio units at each end of the link, the link will still work, you may however not be able to log into them to manage the link unless they are addressed correctly.
Wireless Bridge is available through Quick Time Engineering Inc.
Ethernet SFP module
SFP module is also known as small form-factor pluggable or mini GBIC (gigabit interface converter), is a compact, hot-pluggable optical transceiver module that is widely used for both telecommunication and data communications applications. Its SFP port accepts both optical modules and copper cables. The SFP transceiver module is not standardized by any official standards body, but rather is specified by a multi-source agreement (MSA). SFP module also supports SONET, Gigabit Ethernet, Fibre Channel and other communication standards.
SFP transceiver module comes in various types based on different classification standards. There are single-mode SFP module and multimode SFP module according to the cable type, which allows users to select the appropriate transceiver according to the required optical range for the network. And the transmission rate of the SFP module is available from 100Mbps up to 4Gbps or more. The working distance of these SFP transceiver modules can be from 500 meters to 100 kilometres. CWDM SFP module and DWDM SFP modules are also available for WDM links. In addition, the copper SFP module allows communications over twisted pair networking cables.
DDM, DOM and RGD are common in SFP transceiver names, which make users confused. In fact, DDM (Digital Diagnostics Monitoring) is a technology that enables users to monitor real-time parameters in SFP modules like input power, output power and temperature. DOM (digital optical monitoring) is similar to DDM, allowing users to monitor the parameters of the SFP transceiver. RGD means the SFP is a “rugged” grade transceiver that is well fit for industrial networking applications such as manufacturing automation, substations and smart transport systems.
There are three main differences between single-mode SFP (SMF SFP) and multimode SFP (MMF SFP). The first one is the fibre cable used with them. Singlemode fibre has a smaller core than multimode fibre, and it allows unlimited bandwidth and lower loss. While multimode fibre can propagate multiple modes of light. The second one is the transmission distance. Singlemode SFP transceiver is often used in long-run links up to 120km, but multimode SFP module is used in short applications. The last one is the cost. Singlemode SFP is more expensive than multimode SFP due to the use of different light-emitting unit.
SFP and SFP+ have the same size and appearance. The main difference between SFP and SFP+ is that SFP is often used for 100Base or 1000Base applications, while SFP+ is used in Gigabit Ethernet applications. And the data rate and transmission distance of them are also different. For example, SFP supports speed up to 4Gbps Fibre Channel transceiver, while the speed of SFP+ transceiver is up to 10.3125Gbps.
In many cases, the SFP+ port accepts SFP optics, but the speed will be down to 1G instead of 10G. However, SFP+ optics cannot be plugged into the SFP port, because SFP+ does not support speed under 1G. In addition, almost all SFP+ ports on Cisco switches can support SFPs, but many SFP+ ports of Brocade switch only support SFP+ optics.
When purchasing a third-party SFP optical transceiver, compatibility is often the most parameter users care about. Before purchasing the SFP module, the compatibility of the SFP module with the devices needs to be checked. Besides, when purchasing any SFP module, always test the optical power and compare the test result with the specification. This helps to detect the second-hand SFP
When comparing with Cisco SFP or other brand SFP modules, third party SFP optical transceivers are more cost-effective. Under normal conditions, price is the only difference. Moreover, as SFP transceiver module is mainly used in data centres or on switches where the temperature may be different in a large range. Too high or too low temperature can affect the optical power and optical sensitivity. Therefore, temperature stability is an important factor to ensure the SFP module work normally. Lastly, when purchasing an SFP module, choose a reliable vendor is important as this can ensure that the SFP modules received are of good quality and the after-sale service of the SFP module is guaranteed.
Ethernet SFP module is available through Quick Time Engineering Inc.
Device Servers
A device server is a specialized network-based hardware device designed to perform a single or specialized set of functions with client access independent of any operating system or proprietary protocol. Device servers allow independence from proprietary protocols and the ability to meet a number of different functions. The RAID controller application discussed above is just one of many applications where device servers can be used to put any device or “machine” on the network.
Device Servers are available through Quick Time Engineering Inc.
Quick Time Engineering Inc is an international company with offices and distribution networks in the USA, Hong Kong, Europe and Malaysia.
In its 20 years of operation since 1998, Quick Time Engineering Inc had emerged from a local engineering company with a single staff that provided solutions in factory automation to become nowadays a company that serves the Oil & Gas industries, EPC contractors, System Integrators and other industrial automation and process control companies worldwide. Customers from over 50 countries worldwide trust us with their need for process control instruments and industrial automation products.
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