by Dinesh Thakur Category: Communication Networks

VLANs have the primary role to enable easier configuration and management of large corporate networks built around many bridges. There are several implementation strategies for these virtual networks.

 
by Dinesh Thakur Category: Communication Networks

A switch, which resembles a hub, is known as switching hub. But there is stark difference between hub and switching hub or a switch. Hub acts as a LAN concentrator, and repeater. It consists of a single box with multiple ports. Each port is connected with a separate computer. A signal transmitted by a computer travels to all ports like a bus topology.



 
by Dinesh Thakur Category: Communication Networks

The gateways are used to connect two networks that do not communicate with the same network protocol, so it is necessary to translate these protocols between both networks. These are predecessors of router nowadays and are technology-wise more expensive and highly functional. They in general consist of software which resides in a host computer, such as mid-range or mainframe. For example, a gateway can use as a connection point between an IBM AS400 microcomputer and a LAN-based PC.



 
by Dinesh Thakur Category: Communication Networks

Routers are used to connect both similar and dissimilar LANs. Router operates on the network layer of OSI model using the physical layer, data link layer and network layer to provide connectivity, addressing and switching. These are highly intelligent devices. In case of TCP/IP network, Internet Protocol (IP) is used as addresses for network; this is the router which interprets the IP address and delivers the packet reliably.

 
by Dinesh Thakur Category: Communication Networks

Bridges are connection devices between networks that operate in the data link layer of the OSI model. It means that bridges have more functionality (in terms of connection) than Layer 1 devices, such as repeaters and hubs. Bridges are used to segment networks that have grown to a point where data traffic through the physical environment of the network slows down the global transfer of information.



 
by Dinesh Thakur Category: Communication Networks

The repeaters take the signal they receive from the network devices and regenerate it to keep it intact during its transmission through the physical environment. Since all components of the physical environment of a network (copper, fiber optic cables and wireless media) have to control the attenuation that limits the possible distance between the different nodes of the network, repeaters are an excellent way to extend the net physically.

 
by Dinesh Thakur Category: Communication Networks

The 100VG-AnyLAN is a new high-speed network technology, currently being defined by IEEE as IEEE 802.12 standard that provides a data rate of 100Mbps on 4-pair unshielded twisted-pair (UTP) cable. Future implementations also support 2-pair UTP, 2-pair shielded twisted-pair (STP), and fiber-optic cabling. The 100VG-AnyLAN technology supports all of the network design rules and topologies of 10 Base T Ethernet and token ring networks. These features allow organizations to upgrade their existing network and cable infrastructures to higher transmission speeds.

 
by Dinesh Thakur Category: Communication Networks

Fast Ethernet is based on twisted pair and fiber-optic media systems, and provide high-speed network channels for use in the backbone systems. Fast Ethernet standard uses a particular protocol called auto-negotiation protocol that allows multi-speed Ethernet interfaces to be built. This section deals with 100BaseT.
To speed up the original Ethernet system to 100 Mbps, keeping the original CSMA/CD medium access control mechanism as it is. This approach is called 100Base-T Fast Ethernet. 100BaseT is the IEEE specification for the 100Mbps Ethernet implementation over Unshielded Twisted-Pair (UTP) and Shielded Twisted-Pair (STP) cabling.



 
by Dinesh Thakur Category: Communication Networks

Wireless LANs offer the obvious advantage of avoidance of cabling costs, which can be especially important in a dynamic environment where there is frequent reconfiguration of the workplace. Additionally, wireless LANs provides LAN capabilities in temporary quarters where costly cabling would have to be abandoned. Each workstation is fitted with a low power radio antenna.

 
by Dinesh Thakur Category: Communication Networks

Due its outstanding performance characteristics, fiber-optic cable is also used in LAN s. FDD I (Fiber Distributed Data Interface) is the current LAN standard (IEEE and ANSI) for such a network. FDDI can be extended to the desktop, either directly or through the use of twisted pair in a CDDI application.

 
by Dinesh Thakur Category: Communication Networks

The maximum allowable length of a segment for the 10Base5 is 500 meters. Up to 100 nodes can be connected to a segment. That is up to 100 transceivers can be connected. Repeaters are used to connect terminals that are separated from one another beyond the distance specified above, or to connect more than a limited number of nodes. Each repeater has two ports so that it receives signals through one of these ports and sends them through the other port after amplification. An example of the 10Base5 LAN, Up to 1024 nodes can be connected to a LAN expanded by using repeaters.

 
by Dinesh Thakur Category: Communication Networks

CDDI is also known as TPDDI (Twisted-pair Distributed Data Interface). CDDI employs Cat 5 UTP as an inexpensive means of connecting workstations and peripherals to FDDI fiber optic backbone LANs. A transmission rates up to 100 Mbps may be achieved in this scheme.

 
by Dinesh Thakur Category: Communication Networks

What is Hub: Another name of Hub is Ethernet Hub, Repeater Hub, Active Hub and Network Hub. Basically, it is a similar to switch but are not as "smart", 

Hub Definition and Meaning

hub in computer network is used for connecting multiple computers or segments of a LAN. Normally, it is used for Peer to Peer small Home Network. LAN Hub receive data packets (frames) through one port and broadcasts them through all other ports, so that all other computers or other network devices can see all packets.



 
by Dinesh Thakur Category: Communication Networks

A pair of wires twisted together form a twisted pair. They have more noise immunity than the two-wire open lines. Each wire is insulated and has thickness in the order of 0.016 inches to 0.015 inches.

 
by Dinesh Thakur Category: Communication Networks

The Figure shows the BNC connector and T-connector. The BNC connector and T-connector, these are simple connectors that cannot exchange data. An NIC and T-connector must be directly connected.

 
by Dinesh Thakur Category: Communication Networks

This is also known as 10Base2, uses coaxial of thinner gauge of 5 mm in diameter and bus topology as in the case of 10Base5 so that multiple computers can be connected to a single transmission line. Primarily it was used in office environments. The thinner cable is less costly to acquire and deploy, although its performance is less in terms of transmission distance. Because of its cost it is sometimes called as cheapnet. 10Base2 signifies in the same manner as 10Bases5 except 2 is signified here as 200 meters maximum segment length (actually 185 meters).

 
by Dinesh Thakur Category: Communication Networks

The transceiver exchanges data signals handled by the NIC and electric signals sent over a transmission line. A I5-pin D-SUB connector is used to connect transceivers and transceiver cables. Multiport transceiver supports more than one NIC.

 
by Dinesh Thakur Category: Communication Networks

This uses traditional thick baseband coaxial cable in bus topology to connect multiple computers as shown. This single transmission line is called a segment. A coaxial cable 10 mm in diameter, known as a thick coaxial cable is used as a transmission line. A terminator is connected at each end of the cable. Note that proper data communication cannot be assured even if one of these terminators is missing or not properly connected.

 
by Dinesh Thakur Category: Communication Networks

Definition: Media access control (MAC) and logical link control (LLC) are the sublayers of the data link layer (Layer 2) in OSI Reference Model. 'MAC' is also refer to as MAC layer. It use MAC protocols to provides unique addressing identification and channel access control mechanism for network nodes to communicate with other nodes across a shared channel.



 
by Dinesh Thakur Category: Communication Networks

Broadband A communications medium that can carry a wide range of signal frequencies, typically from audio up to video frequencies. In telecommunications the significance of a broadband system is that it can carry television and videoconferencing data as well as voice calls. A broadband medium can be made to carry many signals at once by apportioning its total bandwidth into many independent channels, each of which carries only a specific range of frequencies. In contrast, a BASEBAND can carry only a single channel. ATM, ADSL and Cable TV are all broadband media, while standard ISDN barely qualifies.

 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.