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Network Devices
Computer network devices are used
to communicate with each other and the most commonly
used devices are routers, hubs, switches, LAN cards,
modems, CSU/DSU, access points and broadband routers.
While installing and configuring the devices certain
types of errors can be occurred and if not handled
properly they can be very problematic. |
In this section, you will learn how to
install, configure and troubleshoot the different devices
in different types of networks such as LAN, MAN, WAN and
wireless network.
After reading the articles from this section
you will be able to install, troubleshoot and configure
your devices properly. Network infrastructure consists of
these devices and a small to big computer network can be
established by using the hubs, switches and routers. Learn
how to configure and troubleshoot the common problems with
the communication devices.
Network Devices
The hardware that is used to connect two or more device that operates on different layers of OSI model is called Network Devices. Networking devices can be separated in two groups networking devices and internetworking devices. Amplifiers, repeater, hub, bridge (simple bridge, learning bridge, multiport bridge), switch are included in networking devices while router and gateways are internetworking device.
Amplifiers
Amplifier is physical layer device which take weak signal and send it after making it strong. Amplifiers re used to boost up analog signals which are used in many electronic devices like radios, telephone and television.
Repeater
Repeater a physical layer electronic device that receives a low level or weak signal and resends it at high level so that signal can cover up long space devoid of degradation. Repeater does not work like an amplifier but it regenerates the signal. Repeater connects LAN segments without having any filtering ability repeater forwards every frame.
Hubs
Hub is a network device that is used to make small network via common connection on network. A hub generally connects segments of LAN by having multiple ports in it. When a port receives any packet it makes it copy and send it to other ports so that all segments can see all packet of LAN. Without having filtering ability hub forwards every frame.
Bridge has three types
- Simple Bridge
- Learning Bridge
- Multiport Bridge
Bridges
Bridges are used to connect to similar LANs having same protocols. Bridges operate at data link layer and physical layer of the OSI model. Bridges make easy host-to-host communication by linking multiple LAN segments. Bridge includes limited number of ports normally 16 ports and bride has ability to examine one frame at a time. Bridge use table in filtering matters. Physical or Mac address in frame can not be changed by bridge.
Switches
Switches are used in star topology in place of hub within a LAN to connect two individual computers. As compared to hub switch provide dedicated bandwidth by supporting multiple ports. Switches perform filtering process like bridges. Switch hold number of ports even new modular switches number of ports can be increased easily. Switch has ability to examine number of frames at a time.
Internetworking Devices
Routers
Router an intelligent internetworking device functions at physical layer, data link layer and network layer. Router’s function is much more than repeater and bridge.
Router is quite different from a switch as switch is used to connect devices to make a LAN while router transmits data packets to their targets crossways internetwork however all the different networks must have a common protocol for communication. In case of different protocol router can not forward data packet. Router works as a link between or more networks to send data packets. The process of forwarding data packet across an internetwork is called routing.
Gateways
Gateway is internetworking device that is used to connect incompatible and vast networks and operates at all seven layers of OSI model. A gateway can forward a data packet across different network however they have different protocols and have ability to translate between different frame formats. In some cases some header changes are required. The task of gateway is not that easy as it has to keep a check of data rates, frames size, frame formats, acknowledgement scheme etc.
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