Welcome to my blogpost! Last week, we learnt about network and various types of networks. This week we continue exploring in the world of network. We learnt about function of protocol and transmission speed. We even simulated a network system on a website.
Terms
The term data integrity refers to the accuracy and consistency of data which means that data has not been changed and data has not been destroyed deliberately or accidentally during data transmission. Data integrity is necessary when sending data through a network. For example, a user could accidentally try to enter a phone number into a date field. If the system enforces data integrity, it will prevent the user from making these mistakes.
Error checking and error correction can be employed to achieve data integrity. Error checking are used to evaluate your ability to identify errors in sets of data or the correctness of information. For instance, the receivers will send acknowledgement of packets which they receive to acknowledge the senders which help senders do error checking. Error correction is the ability to correct error. When senders receive the acknowledgement and found there are errors, the ability to resend the packets in accurate form to receivers is error correction. Flow control is employed in data communications to manage the flow of data among two different network devices since network infrastructures have limited memory and bandwidth. Transport layer in OSI is responsible for the reliability of a given link through flow control by taking advantage of its protocols and facing situations with an overload of resources. For example, flow control functions when there are thousands of people submit application at the same time and there are always some people could not submit successfully. To be mentioned, throughput is actual transfer rate and it is as fast as the slowest link. Goodput is the transfer rate of usable data. Congestion management in data networking is the reduced quality of service that occurs when a network node or link is carrying more data than it can handle. Typical effects include degraded performance, packet loss or the blocking of new connections. For example, when students submit applications all at the same time, there will be congestion in networking. One of congestion is bottleneck. A bottleneck is a point of congestion in a production system (such as an assembly line or a computer network) that occurs when workloads arrive too quickly for the production process to handle. A deadlock is a situation in which two computer programs sharing the same resource are effectively preventing each other from accessing the resource, resulting in both programs ceasing to function, which can be caused by lost or corrupt signals. The persistence timer is used to resolve the situation. For example, when two computers send message to each other, but both did not send messages, deadlock occurred in this situation.
Source integrity is the identity of sender has been validated. For example, when two computer send information to each other, they should know identities of each other.
TCP/IP and packet switching
TCP/ IP describes all the functions that happen at each layer of protocols within the TCP suite. It can be structured into network access, internet, transport, and application. Packet switching is network communication method that creates and transmits small units of data, through a network, independently of the whole message. First, each original file is divided into packets before transmission and each packet might have various routes to the final destination. Data is split into chunks. Each packet has its own address. If there are many chunks, the order should be noted. packets are sent into the network, from router to router and they can choose different paths. When packets arrive, they are re-ordered. Acknowledgement would be sent to the sender by the recipient to indicate that the message has been received. If there is no confirmation message, sender will transmit the data again.
Network protocols & functions & importance
Protocol is international rules that ensure the transfer of data between systems. A protocol that is standard for a specific type of transfer is called standard protocol. Without predefined rules which is network protocols, communication could not be processed. Thus, network protocols are important in network system and it has various functions. Network protocols should have an identified sender, an identified receiver, a consistent communication method. Receiver and sender should use the same language and same grammar. They need to require the speed and the time of delivery for both receiver and sender. Acknowledgment should be sent. Computer network protocols standardize message format, type of error checking, error detection and correction mechanism, data compression means and algorithms, and recovery and resending of data. It also guarantee data integrity, source integrity, flow control, congestion management, deadlock, error checking, and error correction. Thus, network protocols set rules for basic networking functions which plays a significant role networking system.
Factors influenced data transmission speed
There are various factors that influence data transmission speed. This blog will introduce several factors. The size of bandwidth of the network will influence the data transmission speed. To be mentioned, bandwidth refers to the maximum rate of data transmission. For example, larger bandwidth means faster speed of data transmission. Number of users will influence the speed. More users connected to the network will slow down the speed. For example, data transmission speed must be faster when there are only two users compared with thousands of users. Read speed of storage devices will influence the speed as well. With faster read speed of storage, it will save time for reading storage devices. For example, unlimited reading speed must be faster than 64 bps. The number of connected devices will affect the speed. More devices will have slower speed. For example, a more complex computer system will have slower speed than simpler computer system with less connected devices. The size of the files transferred is also a factor because larger file would spend more time. For example, when people sending 1GB file will use more time than sending 100MB file.
Previous assignments:
A VLAN (virtual LAN) is a subnetwork which can group together collections of devices on separate physical local area networks. As it is mentioned before, a LAN is a group of computers and devices that share a communications line or wireless link to a server within the same geographical area. VLANs are often set up by larger businesses to re-partition devices for better traffic management. In a peer-to-peer (P2P) network, the “peers” are computer systems which are connected to each other via the Internet. Files can be shared directly between systems on the network without the need of a central server. In other words, each computer on a P2P network becomes a file server as well as a client. Storage Area Network (SAN) is a network that provides access to storage. Usually, they have their own storage devices that does not access to wider network. However, SAN acts like a device to the operating system.
LAN vs. VLAN
LAN stands for Local Area Network is a group of network devices which allow the communication between connected devices. On the other hand VLAN stands for Virtual Local Area Network which is used to enhance the performance of LANs (Local Area Networks).The main difference between LAN (Local Area Network) and VLAN (Virtual Local Area Network) is that LAN work on single broadcast domain; on the other hand, VLAN works on multiple broadcast domain. LAN costs more than VLAN. LAN’s latency is higher than VLAN’s which means LAN is slower than VLAN. LAN uses hubs, routers, and switches; while VLAN utilizes bridges and switches. In LAN, packet is advertised to each device. In VLAN, packet is sent to specific broadcast domain. Compared with VLAN, LAN is less efficient. These are the differences between local area network and virtual local area network, which are shown above.
IEEE 802.11 is part of the IEEE 802 set of LAN protocols, and specifies the set of media access control and physical layer protocols for implementing wireless local area network (WLAN) computer communication in various frequencies, including but not limited to 2.4 GHz, 5 GHz, and 60 GHz frequency bands.They are the world’s most widely used wireless computer networking standards, used in most home and office networks to allow laptops, printers, and smartphones to talk to each other and access the Internet without connecting wires.
Internet Simulator Activity
This week we had done a really fun activity during the class. This activity is related with internet simulation. This activity instructs us to simulate how internet functions which helps me to have a better understanding of network and internet. This activity tells me that the sender and receiver should have same encode type (binary, decimal…) and have same bits. Otherwise, they will not get the same message. The speed will influenced by the bandwidth and the speed of reading storages. This activity use real-life examples teach me the knowledge related with network.
This activity also shows how computer get other’s IP address from the router. The user should first ask router1 about the IP address of “hahalorena”. Then, the router1 will send back the IP address back to the user. Then the user can send message to “hahalorena” with the IP address he or she gets from the router1.
This picture shows how users send messages to each other. This activity is really useful and funny!
In conclusion, above are things we have learnt during this week. It can be seen from this blog that the main topic is network protocols, network protocol’s functions, factors influenced data transmission speed, and various terminologies. I am looking forward to next week class!
See you next time !
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