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How many 4 way switches could you put on a single light fixture?
If you are talking about intermediate switches, the switches that are in the middle of the three way (UK two way) circuit, then you can add as many as your project needs. These type of switches must be in the middle, as if installed on the end, the different position switching will not operate.
How many power inputs does a primary distribution center have?
4
How many power output feeders does a primary distribution center have?
6
What are the importance of transistor?
A transistor is a semiconductor(like many) that amplifies and switches electrical signals(electronic switch) in a circuit, it is used inside a circuit which requires switching without been manually operated.
What is the difference among different types of switching devices in networking?
Switches are data link layer devices that, like bridges, enable multiple physical LAN segments to be interconnected into a single larger network. Similar to bridges, switches forward and flood traffic based on MAC addresses. Any network device will create some latency. Switches can use different forwarding techniques-two of these are store-and-forward switching and cut-through switching. In store-and-forward switching, an entire frame must be received before it is forwarded. This means that the latency through the switch is relative to the frame size-the larger the frame size, the longer the delay through the switch. Cut-through switching allows the switch to begin forwarding the frame when enough of the frame is received to make a forwarding decision. This reduces the latency through the switch. Store-and-forward switching gives the switch the opportunity to evaluate the frame for errors before forwarding it. This capability to not forward frames containing errors is one of the advantages of switches over hubs. Cut-through switching does not offer this advantage, so the switch might forward frames containing errors. Many types of switches exist, including ATM switches, LAN switches, and various types of WAN switches. Asynchronous Transfer Mode (ATM) switches provide high-speed switching and scalable bandwidths in the workgroup, the enterprise network backbone, and the wide area. ATM switches support voice, video, and data applications, and are designed to switch fixed-size information units called cells, which are used in ATM communications. Figure 4-3 illustrates an enterprise network comprised of multiple LANs interconnected across an ATM backbone. Figure 4-3 Multi-LAN Networks Can Use an ATM-Based Backbone When Switching Cells LAN switches are used to interconnect multiple LAN segments. LAN switching provides dedicated, collision-free communication between network devices, with support for multiple simultaneous conversations. LAN switches are designed to switch data frames at high speeds. Figure 4-4 illustrates a simple network in which a LAN switch interconnects a 10-Mbps and a 100-Mbps Ethernet LAN. Figure 4-4 A LAN Switch Can Link 10-Mbps and 100-Mbps Ethernet Segments there is no figures as noted above
Why is fragment-free somewhere between cut-through and store-and-forward in terms of speed and error detection?
Fragment-free switches read more than just the destination MAC address before switching to the out port; that makes them slower than cut-through switches. Because they read more of the frame, however, they catch more errors than cut-through switches. They don't read the entire frame, so fragment-free switches are faster than store-and-forward switches. For this same reason, they don't catch as many errors as store-and-forward switches
How many bushing wells are there for one high voltage input of the Primary Distribution Center?
3
How many ground rod assembilies can be built with the material that comes with the primary distribution center?
2
what about Optical Switching Technologies?
Optical MEMS are miniature devices with optical, electrical, and mechanical functionalities at the same time, fabricated using batch process techniques derived from microelectronic fabrication. Optical MEMS provide intrinsic characteristics for very low crosstalk, wavelength insensitivity, polarization insensitivity, and scalability. Optical MEMS-based switches are distinguished in being based on mirrors, membranes, and planar moving waveguides. The former two are free-space switches; the latter are waveguide switches. Optical switches based MEMS technology are now widely used and are considered a good option for optical switching networks. Opto-optical switches realize switching functions relying on the intensity-dependent nonlinear optic effect (which is ultrafast) in optical waveguides, such as two-photon absorption, lightwave self action and the Kerr effect. They are also called optically controlled switches or all-optical switches. There are two main types: optical fiber-based switches and semiconductor-based switches. Semiconductor based all-optical waveguide switches have many important issues to be considered before practical applications: low operating power, ultrafast operation, high extinction ratio, room temperature operation, and polarization-independent operation. BASIC PERFORMANCE Insertion loss: The insertion loss of optical switching technology is defined as the optical power loss when optical signals pass through the optical switch, consisting of coupling loss, waveguide propagation loss, and excess loss. When designing a network according to optical power budget, optical switches and their cascading impact network performance greatly. Furthermore, insertion loss limits the scalability of optical switches and increases system cost. Switching speed: The switching speed is defined as the time period from the moment the command is given to the switch to change state to the moment the insertion loss of the switched path achieves more than 90 percent of its final value. According to switching applications, the switching time is divided into three levels: multimillisecond order for protection application, nanosecond order for packet switching application, and picosecond order for bit-level optical time-division multiplexing (OTDM) application. Crosstalk: Crosstalk is the ratio of the power leaked to the wrong output and the power correct output, used to measure the signal interference between channels. Low crosstalk and high extinction ratio indicate small signal interference or high signal quality. Typically, the crosstalk value is around 40 or 50 dB. Polarization-dependent loss（PDL）: Polarization sensitivity is used to measure polarization dependence. When it is very high, it harms transmission reliability, and increases monitoring and dynamic compensation requirements. Wavelength dependency. Bit rate and protocol transparency: The ability gives more flexibility in configuring networks. Service providers can switch the whole utilization operation window fiber capacity, or part of it, for more efficient bandwidth and traffic management, and own 1300–1600 nm. Operation bandwidth. Multicast: Multicast can provide powerful connection capability and save many resources. It has become an important parameter for measuring optical switches. Switching device dimension: Switching fabric dimension/switching matrix size reflects the switching capability of an optical switch. The demand for optical switches is based on the of optical switches in the optical network. Small-scale optical switches are ideal for a variety of per-channel applications, such as small channel count programmable optical add-drop multiplexers (OADMs) and protection switches. Large matrix switches are typically deployed at backbone networks where a large number of wavelengths or fibers converge. Scalability: Easy scalability is essential to form larger N × N switches from smaller orders for applications. Nonblocking: Nonblocking means the flexibility to route or reroute any input channel to any unoccupied output channel, if needed. The blocking problem in large-scale or cascaded switches is more obvious than in smaller optical switches. In general, optical switches need to be strict-sense nonblocking, which does not disturb existing connections. Reliability: Given the number of terabits per second the device can switch, reliability is extremely important for optical switching applications. To meet stringent communications standards, switches must meet specified environment requirements for temperature variations, vibration, and humidity. Repeatability: Port-to-port repeatability refers to all paths across the switching fabric being of identical length. Power Consumption: High power consumption increases a system’s cost, and associated heat dissipation increases a system’s ambient temperature.
What switching can follow one of many paths to reach its destination?
Packet Switching
How many type of switching in telephony?
Circuit switching and Packet switching are used in Telephony. Circuit switching is used in voice communication and packet switching is used in transmission of data packets to provide internet connection.
Will layer 3 switches replace routers completely?
Not likely. For a start, they are much more expensive. They may also require special configuration. There are many layer 2 switches unmanaged, working with default settings for basic networks. Not everyone needs Layer 3 operations, therefore it doesn't make sense to buy expensive switches with many possibilities for basic operation. If a simple network even needs layer 3 switching, a router can be used in many cases for this purpose. Unfortunately routers are less powerful than switches, therefore it is not recommended solution. Proper answer is very complex, therefore it really depends on the situation.
