The data is usually in bits. Transmission normally takes place through media. One of the model which best describes the transmission of data is the TCP/IP model. It contains four layers. The first one is the network interface layer which is responsible for receiving and placing TCP/IP packets on the network. The second layer is the Internet layer. It performs the routing, packaging and addressing functions of a network. It consists of the IP, ICMP, ARP and IGMP protocols.
The third layer is transport layer. It is responsible for the sending of packets in the network. It mainly consists of the TCP and UDP protocols. TCP is used to provide a one to one reliable connection. UDP is used to provide one to one or one to many unreliable communications. The last layer is known as the application layer. Its main function is to facilitate layer to layer access. It also facilitates the exchange of information. It contains protocols such as SMTP which is used for mail messages and attachments. Also, there is the HTTP protocol which is used in transferring files that make up web pages or websites. (Norstedt.B, 1984) Communication begins at the network interface layer. In the second layer, data encapsulation occurs. Data encapsulation is when data is added to the packet header. The third layer involves setting up of a secure connection then in the last layer the packets are delivered.
Network service is an application that provides communication, manipulation, presentation and data storage and is mostly implemented through a peer to peer or client server architecture. One example is the domain name system (DNS) which is used to translate domain names to IP addresses. Another example is the dynamic host configuration protocol (DHCP) which is used to give network configuration information to network hosts. TCP/IP network services commonly use the port numbers which are assigned by the Internet technical governance. The common port number for web based servers is 80 while for email is 25. TCP and UDP protocols are vastly used. However, it is important to note that UDP is more prone to network congestion hence users of this protocol are advised to be careful. TCP, on the other hand, is largely reliable and is used in transferring files that require complete accuracy. (Norstedt.B, 1984)
Security is very paramount when it comes to networks. Organizations always invest heavily in security so as to ensure no data loss of any kind happens. There are many techniques used by various organizations. One of them is access control. It is important to know the devices and users that are accessing the network. Use of antivirus and antimalware is also very common. Malicious software and viruses can destroy everything that is linked by the network. Firewalls are also very effective in ensuring security is achieved. Intrusion prevention system cover the whole network. They are designed to block attacks. (Li.M, Lou.W., and Ren, K, 2010, 17) It is important to note that wireless networks are not very safe as compared to wired networks.
A server is a computer program that provides assistance to the other computer programs. A server is essential in linking up various computer programs so that they can perform the task that has been requested of them. Examples of servers are; File server- stores network users` data files. Communication server- handles many common communication functions for the network, such as e-mail, fax, remote access, firewall or internet services. Application server-shares network-enabled versions of common application software and eliminates the need for software to be installed on each workstation. Database server- manages common databases for the network, handling all data storage, database management and requests for data. Domain server- authenticates and authorizes computers and users to access resources within the logical domain. (Li.M, Lou.W., and Ren, K, 2010, 17)
There are two types of the server architecture. One is called the event based and the other one is called the thread based. The thread based approach looks at every incoming connection with its thread. It isolates requests and hides concurrency. The event-based model depends on asynchronous I/O operations and high-performance event notifiers. There is an event queue followed by an event log then event collectors and finally the reply queue.
Managing access to resources (physical and logical)
Managing access to resources is very challenging especially in large organizations. Data can easily fall into the wrong hands. Use of cable locks is one way of making sure that data does not fall into the wrong hands. Authentication requirements is also a very safe method; it ensures that only the required people access the data. Backups should be created by organizations to ensure that in the case of hacking not all data is lost.
User and group management
Different user groups in the organization possess different characteristics. Each user has his role hence the level of clearance to access specific information varies. Use of authentication and tokens helps determine the people who access information and those who can’t. This is very useful during audits since activity logs can be salvaged easily and they will tell who accessed the information and at what time. Data encryption is also very useful when it comes to guarding data.
Network attacks and firewall protections
Network attacks have become very common. Organizations use firewalls and anti-virus software to protect themselves from these attacks. It is important to note that the design of an organization data system should be assessed so that loopholes are found. Regular checking of the storage disks is also crucial so that action can be taken early enough.
Monitoring and optimizing server performance
Server performance can be measured with how fast it is processing information and providing feedback. Various background programs hinder the performance of servers. Servers should be used for a single purpose to ensure the performance levels are high. Servers can be optimized to ensure they provide the services they are required to.