Nt1310 Unit 6

3: Network Layer: The use of network layer is switching and routing technologies. It demonstrates logical path and virtual circuits for transferring data from one node to

Layer 4: Transport - This layer maintains flow control of data and provides for error checking and recovery of data between the devices.

The fifth layer is the session layer this establishes a connection,this layer makes and sets up the connection using co ordinates and could terminate conversations links. the session layer produces services that make authentication after an interruption and not only that but it can reconnect.and as well as the transporting layer it can also have the TCP and the UDP can provide services for all most all applications.An application layer is an abstraction layer that specifies the shared protocols and interface methods used by hosts in a communications network. The application layer abstraction is used in both of the standard models of computer networking; the Internet Protocol Suite (TCP/IP) and the Open Systems Interconnection model (OSI model).Although both models use the same term for their respective highest level layer, the detailed definitions and purposes are different.In TCP/IP, the application layer contains the communications protocols and interface methods used in process-to-process communications

1-2). Now, the importance of protocols when communicating between computers is beyond critical because without the implementation of communication protocols between computers, there is no communication or interaction between computers at all! No communication between company computers and to internet databases would set a company back to the point of extinction.

Task 1: Describe the data communication types used historically and the developments that have led to modern day Local Area Networks (LANs). Detail any emerging technologies and where you think data communications are likely to be in ten year’s time.

When several transmitters set to compete for bandwidth with data speeds used by each transmitter to avoid network overload is necessary. When the router will drop packets arrive and cannot move forward. Also a lot of packages when they drop a lot of packets in a network to reach a stumbling block. Packets that are dropped can move longitudinally alongside the missing packet transmissions used in most cases as a driver again. If an appropriate congestion control is implemented more packages are sent to the network and network capacity while creating network congestion becomes worse, resulting in successful where more data is not delivered the density to be created. [2]

Network congestion is when a node on the network is carrying more data than is recommended. Such as when a queue of packets travelling across the internet, in which the transmitting node is always sending packets to a destination and the receiving nodes can’t remove the packets fast enough. This then decreases the performance which then causes congestion. If the number of packets on the network is within the expected capacity they are delivered with very few packet losses, the only packet losses rejected should be because transmission errors. Congestion affects two main areas of network performance, through-put and delay. To solve congestion problems, congestion control techniques are in use. One of these are called “Open Loop” which is a protocol

Transmission Control Protocol and Internet Protocol are two distinct computer network protocols. A protocol is an agreed-upon set of procedures and rules. When two computers follow the same protocols the same set of rules they can understand each other and exchange data. Transmission Control Protocol and Internet Protocol are so commonly used together, however, that Transmission Control Protocol and Internet Protocol has become standard terminology for referring to this suite of protocols.

2. The data overhead as it adds headers at each layer as the datagram moves down the stack. Thus part of bandwidth is used for the protocol headers instead of message/data.

-Ensures that the arrival of data at the network level is the transmission characteristics and quality of service required by the Level 5 (Session).

The main role of the transport layer is to provide end-to-end service between two or more applications running on various hosts. It segregates the applications and provides a simple interface for application developers. We also know that transport layer also performs flow control, error control and reliable delivery which is required for communicating applications to run with performance. These applications and end users use the transmission control protocol or the user datagram protocol to transmit the data. However, the future applications might require even better functionality. To solve this, the Internet Engineering Task Force (IEFT) has approved stream control transmission protocol.

Layer four of the OSI model consist of the transport layer. In this layer, the protocols in this layer provide a host-to-host communication servers for applications (osi-model.com). Within the layer four transport layer, we have TCP (transmission control protocol) and UDP (user datagram protocol) protocols. TCP is a more reliable protocol in ways of guaranteeing the delivery of the IP traffic. With TCP, you have a three-way handshake in place, meaning that when you send a segment you should receive an acknowledgement that the segment was received. If it was not received, then you could resend. When using UDP, guarantee delivery of packets is not the main concern. The main advantage of UDP is that

Transmission Control Protocol/Internet Protocol is the primary network communication, language since the mid-1990s which is passed down as a communications protocol in a private network. The TCP/IP is a two-layered protocol. The Transmission Control Protocol is the higher layer which administers the collection of messages or files into smaller packets. These packets are transmitted over the Internet. The packets are then amassed and reassembled into the primary message after being received by the TCP layer. The Internet Protocol being the lower layer monitors the address part of each packet, and further gets to the right destination. The TCP/IP establishes an intermediary between two hosts so that they can send messages back and forth for a period.

The ECN mechanism for TCP/IP protocol \cite{floyd1994tcp}\cite{ramakrishnan1998proposal}, TCP-ECN for short, is an end-to-end congestion control scheme deployed on layer 3 and layer 4. TCP-ECN employs Random Early Detection (RED) mechanism to mark the congested packet with \textit{Congestion Experienced} (CE) bit, which is carried in packet's IP header. And the end-host enables ECN-Capable TCP (ECT) bit in the packet header to support the ECN mechanism. Fig. \ref{TCP-ECN} illustrates the working process of TCP-ECN. When the queue length exceeds a fixed threshold, the router will use RED to set the CE bit in the packet header instead of dropping the packet, and

view of the upper layer using it. The upper layer sees itself attached to an access