Network layer is the third layer in the OSI model of computer networking. Packet forwarding including routing through routers and quality of service management are done by the network layer.Nature of the serviceThe transport layer at the host side receives the service provided by the network layer. But the transport layer resides in the hosts while the network layer resides in the subnet.We know the subnet is a collection of routers which consists of only the bottom three layers. Hence, we can say that the service provided by the network layer to the transport layer is more effective, than the ... Read More

Sliding window protocol is a transmission control protocol. To hold the outgoing and incoming packets both the sender and receiver maintains a finite buffer. Every packet sent from the sender side must be acknowledged by the receiver.The sender is maintaining a timer for every packet sent, and any unacknowledged packet in a certain time is resent. The sender will send a complete window of packets before receiving an acknowledgement for the first packet in the window. This leads to a higher transfer rate, as the sender may send multiple packets without waiting for each packet's acknowledgement.The Receiver advertises a window ... Read More

In the Link - State Routing Protocol, the router attempts to construct its own internal map of the network topology. It provides the information about whether the link to reach the router is active or not.Every router will create something called Link state packets.In the first round every node creates link state packets with the help of “Hello packets”.Step 1 − Prepare the link state packet at every router.DSeqTTLC11B7A1CSeqTTLD11B3ASeqTTLB2D1BSeqTTLA2D7C3Step 2 − Every router flood the link state packets to every offer routerAt A −Link state packet B, C, DFrom BA2C3D7From CB3D11From DA1B7C11Now A can construct the entire graph using the ... Read More

Network delay is defined as how much time will take a bit of data to travel from one node to another node.Network delay can be divided into following ways −Transmission delayPropagation delayLet us learn about both of them in detail.Transmission delayIt is the time required to put a packet’s bit (or data bits) on the transmission medium that can be wired or wireless. Transmission delay depends on the length of the packet and bandwidth of the network.Transmission delay can be calculated as follows −Transmission delay = Packet size / bandwidth          packet           ... Read More

Traffic throttling is one of the approaches for congestion control. In the internet and other computer networks, senders trying to adjust the transmission need to send as much traffic as the network can readily deliver. In this setting the network aim is to operate just before the onset of congestion.There are some approaches to throttling traffic that can be used in both datagram and virtual-circuit networks.Each approach has to solve two problems −FirsRouters have to determine when congestion is approaching ideally before it has arrived. Each router can continuously monitor the resources it is using.There are three possibilities, which are ... Read More

The presence of congestion means the load is greater than the resources available over a network to handle. Generally, we will get an idea to reduce the congestion by trying to increase the resources or decrease the load, but it is not that much of a good idea.There are some approaches for congestion control over a network which are usually applied on different time scales to either prevent congestion or react to it once it has occurred.Admission ControlIt is one of techniques that is widely used in virtual-circuit networks to keep congestion at bay. The idea is do not set ... Read More

Traffic awareness is one of the approaches for congestion control over the network. The basic way to avoid congestion is to build a network that is well matched to the traffic that it carries. If more traffic is directed but a low-bandwidth link is available, congestion occurs.The main goal of traffic aware routing is to identify the best routes by considering the load, set the link weight to be a function of fixed link bandwidth and propagation delay and the variable measured load or average queuing delay.Least-weight paths will then favour paths that are more lightly loaded, remaining all are ... Read More

We will match words in the first DataFrame with words in the second DataFrame. For closest matches, we will use threshold. We took the value of threshold as 70 i.e., match occurs when the strings at more than 70% close to each other.Let us first create Dictionaries and convert to pandas dataframe −# dictionaries d1 = {'Car': ["BMW", "Audi", "Lexus", "Mercedes", "Rolls"]} d2 = {'Car': ["BM", "Audi", "Le", "MERCEDES", "Rolls Royce"]} # convert dictionaries to pandas dataframes df1 = pd.DataFrame(d1) df2 = pd.DataFrame(d2)Now, convert dataframe column to list of elements for fuzzy matching −myList1 = df1['Car'].tolist() myList2 = ... Read More

The presence of congestion means the load is greater than the resources available over a network to handle. Generally we will get an idea to reduce the congestion by trying to increase the resources or decrease the load, but it is not that much of a good idea.Approaches to Congestion ControlThere are some approaches for congestion control over a network which are usually applied on different time scales to either prevent congestion or react to it once it has occurred.Let us understand these approaches step wise as mentioned below −Step 1 − The basic way to avoid congestion is to ... Read More

Token bucket algorithm is one of the techniques for congestion control algorithms. When too many packets are present in the network it causes packet delay and loss of packet which degrades the performance of the system. This situation is called congestion.The network layer and transport layer share the responsibility for handling congestions. One of the most effective ways to control congestion is trying to reduce the load that transport layer is placing on the network. To maintain this network and transport layers have to work together.The Token Bucket Algorithm is diagrammatically represented as follows −With too much traffic, performance drops ... Read More