ISDN stands for Integrated Services Digital Network. It is used to bridge the Central Office's local loop and the premise connection (home). ISDN uses the existing wiring so that no new cabling is required. It is a digital service that restores the analog plain old telephone set.An Integrated Digital Network (ISDN) is a network in which digital switching connections are used to transmit digital signals. Integrated Services refers to ISDNs ability to deliver two simultaneous connections, in any merging of data, voice, video and fax, over an individual line. Multiple devices can be connected to the line and sent as ... Read More

ARC NET stands for Attached Resources Computing Network. It is the central LAN topology in which coaxial cables are used. It is very similar to a thin net (thin Ethernet) in appearance, but the cable used in it is 93 ohm RG-62 A/U cable which is not interchangeable with the thin net cable.ARC NET is a topology that uses a token passing method. It is an old token-based topology that is rarely used nowadays. ARC NET was developed before the token ring networks, and initially, it used the bus topology to connect the workstations.The network operates at 2.5 Mbps and ... Read More

RF can travel through air or space but require specific transmitting and receiving mechanisms. It has frequencies between 10 kHz to 14 kHz. In VLF (very low frequency), LF (Low Frequency), and MF (Medium Frequency) bands, radio waves follow ground waves.AM radio broadcasting uses the MF band. Radio waves in these bands pass through the building quickly. HF (High Frequency) and VHF (Very High Frequency) tend to be absorbed by the earth, but these waves travel through the Ionosphere. These waves are refracted by it and sent back to earth. The military communicates in HF and VHF bands.AdvantagesIt is easy ... Read More

VSAT represents a Very Small Aperture Terminal. It is a two-way satellite ground terminal with a dish wire that is lower than 3 meters. It is generally used to transmit narrowband data (point of sale transactions such as credit card, polling) or broadband information (for the provision of satellite internet access to remote areas, VOIP or video). It is also used for mobile communications.Features of VSATBand L has a Bandwidth of 15 MHz where Downlink frequency is 1.5 GHz, and Uplink frequency is 1.6 GHz. For Band S, Bandwidth is 70 MHz where Downlink is 1.9 GHz, and Uplink is ... Read More

There are various types of ETHERNET Cables which are as follows −10Base 5The first standard defined in IEEE 802.3 is 10 Base 5. It is a Thick Ethernet or Thicknet. It is a bus topology LAN with baseband signaling. The data speed is 10 Mbps, and the maximum allowed segment length is 500 meters. The bus's total length should not exceed 2500 meters, i.e., with a segment of 500 meters, each resulting in only five segments to be used. Each station should be separated from its neighbours by 2.5 meters, i.e., only 200 stations are permitted in maximum in each ... Read More

Ethernet is a LAN architecture developed by XEROX and extended by DEC, IC and Xerox. It is specified by IEEE 802.3, and it defines two categories.These categories are as follows−BasebandBroadbandBaseband uses digital signals, while broadband uses analog signals. Baseband is further divided into five standard names as follows −10 Base 510 Base 210 Base T1 Base 5100 Base TThe first numbers used in all standards, i.e., 10, 1, 100, indicate the data rate in Mbps, while the last numbers 2, 5, and letter T indicate the maximum cable length or type of cable. Only one specification is defined for broadband, ... Read More

There are various network security threats and attacks which are explained below−Natural DisastersEarthquakes, floods, lightning, and fire can cause several damages to computer systems. It could include other threats such as riots, wars, and terrorist attacks could be included here. Although they are human-caused threats, they are classified as disastrous.Deleting and altering dataMalicious attackers who delete or alter data usually do this to prove a point or take revenge for something that has occurred to them. Inside attackers frequently do this to spite the organisation because they are disgruntled about something. Outside attackers might need to prove that they can ... Read More

The objective of the network is to send data among its users located locally or remotely. Hence, it is possible that undesired users can hack the web and prove harmful to the network or the user's health.The network administrator should follow a few essential points to provide the network with adequate security other than network-specific security, such as e-commerce. These are given below:Networks are designed to share data. Therefore, it should configure the network to identify shareable data and non-shareable data.The network must also clear with whom can share the shareable data.With the increase of network security, the cost for ... Read More

SMTP represents Simple Mail Transfer Protocol. SMTP is a set of interaction guidelines that allow the software to transmit electronic mail over the internet, referred to as Simple Mail Transfer Protocol.The main objective of SMTP is used to set up communication rules between servers. The servers have a way of recognizing themselves and announcing what kind of communication they are trying to perform. They also have a way of handling errors such as incorrect email address. For example, if the recipient address is wrong, then receiving a server reply with an error message of some kind.Working of SMTPSMTP is an ... Read More

TFTP operation is very simple. The client sends a read or write request at the server's UDP port 69. The server accepts the request by sharing data messages in case of the read request and sending acknowledgement in the write request. In either case, the server chooses a UDP port for further dialogue and sends its first response to the client through the selected UDP port.Each data message has a fixed size of the data block (512 octets) and is individually acknowledged. The last data block containing EOF (End of File) or a data block containing less than 512 octets ... Read More