Difference Between WLAN and WWAN

1. WWAN covers a much larger area than WLAN 2. WWAN uses telecom networks while WLAN does not 3. WWAN is inherently secure while WLAN may not be 4. WLAN is much faster than WWAN 5. WLAN has DLNA while WWAN does not

LAN vs WAN

LAN WAN

Data transmission Error:

Experiences fewer data transmission errors Experiences more data transmission errors as compared to LAN

Data transfer rates:

LANs have a high data transfer rate WANs have a lower data transfer rate as compared to LANs

LAN WAN

Technology: Tend to use certain connectivity technologies, primarily Ethernet and Token Ring

WANs tend to use technology like MPLS, ATM, Frame Relay and X.25 for connectivity over the longer distances

Connection: one LAN can be connected to other LANs over any distance via telephone lines and radio waves

Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites

speed: high speed(1000mbps) less speed(150mbps)

Maintenance costs:

Because it covers a relatively small geographical area, LAN is easier to maintain at relatively low costs.

Maintaining WAN is difficult because of its wider geographical coverage and higher maintenance costs.

Fault Tolerance:

LANs tend to have less problems associated with them, as there are a smaller amount of systems to deal with.

WANs tend to be less fault tolerant. as it consists of a large amount of systems there is a lower amount of fault tolerance.

Example: Network in an organization can be a LAN Internet is the best example of a WAN

Geographical spread:

Have a small geographical range and do not need any leased telecommunication lines

Have a large geographical range generally spreading across boundaries and need leased telecommunication lines

Set-up costs: If there is a need to set-up a couple of extra devices on the network, it is not very expensive to do that

In this case since networks in remote areas have to be connected hence the set-up costs are higher. However WANs using public networks can be setup very cheaply, just software (VPN etc)

Ownership: Typically owned, controlled, and managed by a single person or organization

WANs (like the Internet) are not owned by any one organization but rather exist under collective or distributed ownership and management over long distances

Definition: LAN (Local Area Network) is a computer network covering a small geographic area, like a home, office, schools, or group of buildings.

WAN (Wide Area Network) is a computer network that covers a broad area (e.g., any network whose communications links cross metropolitan, regional, or national boundaries over a long distance.

Difference between OSI and TCP/IP reference model OSI

1)It has 7 layers

2)Transport layer gurantees delivery of packets

3)Horizontal approach

4)Seperate presentation layer

5)Seperate session layer

6)Network layer provides both connectionless and connection oriented services

7)It defines the services,interfaces and protocols very clearly and makes a clear distinction between them

8)The protocol are better hidden and can be easily replaced as the technology changes

9)OSI truly is a general model

10)It has a problem of protocol filtering into a model

TCP/IP

1)Has 4 layers

2)Transport layer does not gurantees delivery of packets

3)Vertical approach

4)No session layer, characteristics are provided by transport layer

5)No presentation layer, characteristics are provided by application layer

6)Network layer provides only connection less services

7)It does not clearly distinguishes between service interface and protocols

8)It is not easy to replace the protocols

9)TCP/IP can not be used for any other application

10)The model does not fit any protocol stack.

Difference between Link State and Distance Vector

Distance vector protocols are used in small networks, and it has a limited number of hops, whereas Link state protocol can be used in larger networks, and it has unlimited number of hops.

Distance vector protocol has a high convergence time, but in link state, convergence time is low.

Distance vector protocol periodically advertise updates, but link state advertises only new changes in a network.

Distance vector protocol advertises only the directly connected routers and full routing tables, but link state protocols only advertise the updates, and flood the advertisement.

In distance vector protocol, loop is a problem, and it uses split horizon, route poisoning and hold down as loop preventing techniques, but link state has no loop problems.

Difference Between IPv4 and IPv6

1. An IPv6 address consists of 128 bits, while an IPv4 address consists of only 32.

2. IPv6 has a lot more usable addresses compared to IPv4.

3. IPv6 makes the routers task more simple compared to IPv4.

4. IPv6 is better suited to mobile networks than IPv4.

5. IPv6 addresses are represented in a hexadecimal, colon-separated notation, while IPv4 address use the dot-decimal notation.

6. IPv6 allows for bigger payloads than what is allowed in IPv4.

7. IPv6 is used by less than 1% of the networks, while IPv4 is still in use by the remaining 99%.

Difference between Static IP and Dynamic IP

Static IP is a permanent IP address assigned to a device by an ISP, whereas a dynamic IP is a temporary IP address assigned to a device. Dynamic IP addresses are assigned automatically using the DHCP protocol from a pool of IP addresses, only when a user wants to connect to the internet and it is put back in to the pool when the user disconnects. So, dynamic IP provides a method to use the available IP addresses economically unlike the static addresses, which are permanently assigned. Further, Dynamic IP is less expensive and therefore it is better to be used for typical access of the Internet. But static IPs are better suited for Servers, VOIP applications and gaming.

Difference between IP and TCP

1. TCP is a core operating on a relatively high level; IP operates at a lower level.

2. TCP provides communication services at an intermediate level between an application program and the IP; IP encapsulates all data, and is connectionless.

IP and TCP are two protocols that work together in reliable delivery of data over the networks, especially Internet. While IP defines rules that deliver the data from one host to another, TCP defines rules that make sure delivered data is without any loss or corruption and is delivered in an orderly manner.

The main difference between the two protocols is the layers that they reside in. TCP belongs to Transport Layer and IP belongs to Internet Layer of the Protocol Suit. In addition, while TCP gives priority to the accuracy of the data delivered, IP gives priority to the accuracy of the location of data delivery than accuracy of data.

Furthermore, IP defines a set of logical addresses referred to as IP addresses, which helps in the identification of source and destination hosts that are vital for accurate delivery as well as in maintaining data accuracy, as when corruption or loss of data occurs, the source destination must be known for re-transmission.

Difference Between Hubs, Switches, and Routers 1.Routers are network endpoints while hubs and switches are not. 2.Routers have more advanced capabilities than hubs and switches. 3.Routers can have WiFi while hubs and switches cant. 4.Routers typically contain a switch. 5.A hub does the same job as a switch but is very inefficient.

Major differences between LEO, MEO & GEO satellite systems:

Parameter LEO MEO GEO Satellite Height 500-1500 km 5000-12000 km 35,800 km Orbital Period 10-40 minutes 2-8 hours 24 hours Number of Satellites 40-80 8-20 3 Satellite Life Short Long Long Number of Handoffs High Low Least(none) Gateway Cost Very Expensive Expensive Cheap Propagation Loss Least High Highest

Difference Between URL and IP Address 1.An IP address just specifies the location while a URL specifies location, protocol, and specific resource 2.URL requires a DNS server while an IP address doesnt 3.URLs are unlimited while IP addresses are limited 4.IP addresses and URLs have a one to many relationship.

Difference Between Circuit Switching & Packet Switching

Circuit Switching: 1.) In circuit switching, there are various nodes used in the network through which the signals are passed from one system to another. 2.) In this a number of nodes are available between two devices and hence multiple paths are available to pass a signal. 3.) This concept is mainly used in telephony systems. 4.) This is best used for transmission of audio signals and not suitable for data transmission. 5.) This type of switching is connection oriented and may be connectionless also. 6.) Due to its old version, this technique is less popular and more expensive. Packet Switching: 1.) In packet switching, the data is sent over the network in the form of packets i.e. a large unit of data items wrapped into a single bigger unit. 2.)In these, the packets follows the same path that is defined for them before passing into the network. 3.) It can be used for telephony, DSL services and other data transmission services. 4.) It is best used for sending data over the network and audio and video signals can also be sent over the network in the form of packets. 5.) It is usually a connection less service. 6.) It is a new technology and economic than the circuit switching approach.

Difference Between Subnetting and Supernetting: SUBNET: 1)Subnet is a group of networks having same network id. 2)Subnet increase the number of hosts with same network address, as result it reduces the wastage of addresses. 3)In subnetting bits of hostId will be captured by networdId. 4)It works on host bits, for incresaing or decresing the number of valid host in network. 5) Subnetting is the process of dividing an IP network in to sub divisions called subnets. SUPERNET: 1)Supernet makes all the hosts with in a range of network address belong to a same group. 2)This reduces the entries in the network address table. 3)Supernetting combines the octets of the address. 4)It works on network bits, for increasing or decreasing the number of subnetworks from major networks. 5) Supernetting is the process of combining several IP networks with a common network prefix.

Difference between Unicasting and Multicasting

The main difference between unicasting and multicasting is on how they communicate with receiver. In unicasting, information is transmitted to a single receiver by a single sender and the receiver has a direct relationship with the sender. In multicasting, information is sent to multiple receivers in a single transmission and there is no direct relationship between the senders and receivers. Unicasting is used when a private resource is requested by a client and it is not suitable for transmitting information to lot of clients since it will consume a large bandwidth of the network. On the other hand, multicasting does not make direct connections with the receivers, hence does not consume network bandwidth as unicasting.

Difference between Symmetric Key Encryption and Public Key Encryption

Main difference between symmetric key encryption and public key encryption is the fact that symmetric key encryption use the same (private, secret) key for encryption/decryption, while public key encryption uses both a public and a private key. Both parties should know the key in symmetric key encryption, while there is no such requirement for the public key encryption. Only, either one of the keys is known by the two parties in public key encryption. Because this removes the need to share your private key (as in symmetric key encryption) and the risk of having it compromised, public key encryption can be considered more secure in this regard.

But a major disadvantage of public key encryption is that it is many times slower than symmetric key encryption. So, symmetric key encryption may be better for encrypting large amounts of data. Furthermore, public key encryption algorithms must use a comparatively stronger key than symmetric key encryption to achieve the same strength (for the simple reason that one key is made public in public key cryptography).

Difference between pure aloha and slotted aloha 1) Pure Aloha is a Continuous time system whereas Slotted Aloha is discrete time system.

2) Pure ALOHA doesn't check whether the channel is busy before transmission. Slotted ALOHA send the data at the beginning of timeslot. 3) Pure aloha not divided in to time .Slotted aloha divided in to time

Difference Between CSMA CA and CSMA CD 1.CSMA CD takes effect after a collision while CSMA CA takes effect before a collision. 2.CSMA CA reduces the possibility of a collision while CSMA CD only minimizes the recovery time. 3.CSMA CD is typically used in wired networks while CSMA CA is used in wireless networks.

Difference between CSMA and ALOHA

Main difference between Aloha and CSMA is that Aloha protocol does not try to detect whether the channel is free before transmitting but the CSMA protocol verifies that the channel is free before transmitting data. Thus CSMA protocol avoids clashes before they happen while Aloha protocol detects that a channel is busy only after a clash happens. Due to this, CSMA is more suitable for networks such as Ethernet where multiple sources and destinations use the same channel.

Difference between a Logical Address and a Physical Address

Logical address is the address generated by the CPU (from the perspective of a program that is running) whereas physical address (or the real address) is the address seen by the memory unit and it allows the data bus to access a particular memory cell in the main memory. All the logical addresses need to be mapped in to physical addresses before they can be used by the MMU. Physical and logical addresses are same when using compile time and load time address binding but they differ when using execution time address binding.

Difference between go-back-n ARQ and Selective Repeat ARQ

Go-Back-N ARQ

Retransmission begins with the last unacknowledged frame even if subsequent frames have arrived correctly .duplicate frames are discarded.

Go-back-n ARQ -- Receiver must get Frames in correct order

Selective Repeat ARQ

Only the unacknowledged frame is retransmitted.

It may be (slightly) more efficient than Go-back-n ARQ, but also much more complicated.

Selective repeat ARQ -- correctly-received out-of-order Frames are stored at Receiver until they can be re-assembled into correct order

Difference between Flow Control and Congestion Control

Although, Flow control and congestion control are two network traffic control mechanisms used in computer networks, they have their key differences. Flow control is an end to end mechanism that controls the traffic between a sender and a receiver, when a fast sender is transmitting data to a slow receiver. On the other hand, congestion control is a mechanism that is used by a network to control congestion in the network. Congestion control prevents loss of packets and delay caused due to congestion in the network. Congestion control can be seen as a mechanism that makes sure that an entire network can handle the traffic that is coming to the network. But, flow control refers to mechanisms used to handle the transmission between a particular sender and a receiver.

Difference between Flooding and Broadcasting

Sending a packet to all hosts simultaneously is broadcasting. But flooding does not send packets to all hosts simultaneously. The packets would ultimately reach all nodes in the network due to flooding. Flooding may send the same packet along the same link multiple times, but broadcasting sends a packet along a link at most once. Several copies of the same packet may reach nodes in flooding, while broadcasting does not cause that problem. Unlike flooding, broadcasting is done by specifying a special broadcast address on packets.

Difference between ARP and RARP

ARP maps IP addresses to hardware address, while RARP does the opposite (maps hardware addresses to IP addresses). In other words, input to the ARP is a logical address, while the input for RARP is a physical address. Similarly, the outputs to these two protocols are also reversed. Unlike ARP, RARP is obsolete now and it has been replaced by BOOTP and DHCP protocols.

Difference Between SMTP and IMAP

1.SMTP is used for sending emails while IMAP is used for retrieving emails 2.SMTP is used between servers while IMAP is only used between client and server 3.SMTP is the prevalent protocol for outgoing email while IMAP is only one of two prevalent protocols for email retrieval

Difference Between FTP and Telnet

1. FTP is a protocol used specifically for transferring files to a remote location, while Telnet allows a user to issue commands remotely.

2. FTP can be used with a command line, a dedicated application, and even with most web browsers, while Telnet is restricted to the command line.

3. There are ways to use FTP in a secure environment, while Telnet will always be unsecured.

4. FTP is a well-known and reliable method of uploading files to web servers, while Telnet is now commonly used in diagnosing network services.

Difference Between FTP and HTTP

1. HTTP is used to view websites while FTP is used to access and transfer files. 2. The common HTTP client is the browser while FTP can be accessed via the command line or a graphical client of its own. 3. Most people use HTTP while only a few use FTP, mostly people who maintain websites. 4. Downloading files can either be via HTTP or FTP. 5. FTP is slowly being replaced by other protocols while HTTP will remain for the foreseeable future.

Difference Between Bluetooth and Wireless 1. Wireless LAN is generally used for PC-PC communications while Bluetooth is commonly used for connecting accessories 2. Wireless LAN is meant for longer distances while Bluetooth is intended for short distance use only 3. Wireless LAN is much faster compared to Bluetooth 4. Bluetooth is more widespread compared to wireless LAN 5. Bluetooth is cheaper to implement than wireless LAN