Introduction
The past few decades have witnessed a dramatic increase in the number of internet users. This upward trend has been accompanied by an almost parallel increase in the process of streaming, which is a data transferring technique which enables users to process data continuously without interruptions in the form of an uninterrupted stream of information. Streaming has gained popularity mostly due to the fact that a normal internet connection is not fast and efficient enough to allow its users to download large multimedia files rapidly. Streaming is a process which helps in overcoming this shortcoming by allowing the user to browse through and display the entire data before complete file transmission.
The description of how Telnet and FTP work. What is common between these protocols?
Telnet is one of the numerous network protocols used over the Internet globally. To use Telnet, the special procedure should be provided. First of all, a special program should be installed on the personal computer. This program by means of special processes connects the computer’s server with the server on the network. After all installations are completed, the user receives the access to the net server. The procedure of the access is provided through the Telnet as if it is run directly, without any intermediate programs. Telnet as a connector is rather useful as it allows to increase the functions of the user (that is to provide simultaneous connection with the different servers) and to control the situation in the net and with the aim to protect the user from different “open connection”. This step allows informing the program about the user’s intention to provide the connection.
In order to create a connection, the Telnet address can be written in two different ways, (1) fcc.edu.au – the domain name format or (2) 111.168.1.1 the Internet Protocol (IP) address format. Once a connection is successfully established, a new window appears, which displays the commands that the user’s computer is sent to the remote computer. Moreover, the user is also required to enter the following details in order, to log in: User ID and Password insert.
FTP is defined as a file transfer protocol which allows the exchange and manipulation of files over any TCP- based computer network. It is a common mode for the exchange of files independent of the operating systems involved. The procedure to use FTP is similar to that of using Telnet in the meaning that to use FTP, the ‘FTP client’ should be downloaded on the computer. Once the download is complete and the software is installed, the users can establish a connection with the host server and then carry out file transfer. In order to open an FTP session, the user is required to provide the following details: The name of the host with which a connection is required (User name and Password).
Once a session is established, the user is demanded to select the folder to which file transfer is required and subsequently select a mode for file download. Thus, the downloading procedure begins and the user is informed, the downloading is complete. The mentioned accounts of Telnet and FTP highlight the procedure of the use of both the protocols and the common aspects between them. However, there are some of unpleasant situations which may occur in the web services.
The World Wide Web is frequently cited as an example. In order to use Telnet, the initial step is to download the software which is termed as ‘client’. To access Telnet, a user can either double click on the Telnet icon, which is the commonest way, or can type the command in the address bar of the web browser: telnet://domain. name.
There are some cases when the user has to run a telnet session by session by means of using the additional command. The user is required to call the command
the important similarities between these protocols and their salient features are summarized as follows:
- Both FTP and Telnet are network protocols used over the internet,
- Both require the download of the ‘client’ software,
- Both require the User ID and password for log in.
But, Telnet used commonly to remotely control web servers and FTP uses the internet’s TCP/IP protocols to enable data transfer
In general, Telnet protocol enables a user to establish a connection between his/her pc and a remote one and log on to that pc, while FTP can also be used to request specific files from remote computers but in this case it is impossible to log in on that computer.
The description of how Ethereal can be used to study traffic and what can be achieved with Ethereal
The term Ethereal refers to a network analyzer, which mainly serves with the purpose of capturing and decoding sets of information from a network. The main opportunities of Ethereal are the following: to analyze the network packages, to capture these packages, to discover the list of information. The main consumers of Ethereal are the administrators as they are helped in the diagnosis and decision problems. However, it also has the potential hazard of being misused by intruders to obtain unauthorized information.
Ethereal can be used to serve a multitude of purposes including the following:
- It is used to capture and analyze network packets
- It helps in troubleshooting network issues
- It provides a log of the network traffic for forensic analysis
- It enables the detection of network intrusion
However, it can be potentially abused by attackers, enabling them to achieve the following tasks:
- Gaining and misusing usernames and passwords
- Having illegal access to sensitive or proprietary information
- Network mapping.
The description of how a network sniffer can be used to identify streams and information in a packet, such as a password
Network sniffer refers to a type of computer software or software that has been designed in order to intercept and maintain a log of the traffic that passes through a certain part of a network or the entire network. A sniffer serves the purpose of capturing individual packets of information, decoding them and analyzing their contents as per appropriate specifications, as the data proceeds to pass through the network.
The above mentioned properties of the network sniffer enable it to easily detected network problems. A network sniffer is an effective tool for network analysis containing a well integrated set of functions which have been designed in a way which enables this software to efficiently deal with network problems.
A network sniffer can perform the following tasks:
- Create a list all of the network packets which are working at a particular time on a multi network card,
- Support capturing packets based on the applications,
- Enable the users to observe all traffic of any application of their interest.
Most commonly, network sniffers are used to analyze network traffic in order to promptly identify any problems arising in the network. Any computer which has a network sniffer is directed by the sniffer to pay attention to any traffic headed towards other computers by alerting its NIC to do so. This is achieved by placing the NIC in a state known as promiscuous mode, a status requiring administrative or root privileges. Any NIC that is in such a mode has access to all the data transmitted on its segment. Once in a promiscuous mode, the program starts functioning and begins the process of screening all the information which enters the PC via the network card.
The sniffer has the ability to penetrate through the layers of encapsulation and decode all the information stored within. Whether it is source computer or destination computer, targeted port number or payload, the sniffer has access to every single piece of information that is being exchange between the two computers, a property which is endowed to it by mean of strict formatting.
The description of how a PBX can be simulated in the lab
A private branch exchange (PBX) is the special communications channel which serves only for this very company, office or business. PBX is opposed to the general used common telephone company operators which serve public. PBX performs various different purposes, possessing the knowledge of which would enable one to stimulate its functions in the lab.
The general tasks of the PBX are as follows,
- to connect two users (i.e. it maps a dialed number to a physical phone and makes sure that the phone);
- to provide the necessary time of connection (i.e. voice signals are channeled to and fro between the users);
- to disconnect the users at the end of the communication;
- to provide the information with the accounting purposes.
Once a basic functioning of PBX is known, it can be easily stimulated in a lab by following a manual which would direct a user about the process of installation of the cables and achieving the desired settings.
What are the protocols available for VoIP?
The opportunity to make voice calls by means of the Internet connection is named as VoIP. The signals of the user are converted into a digital system during the usage of VoIP service and than transmitted to the Internet. The advantage of the VoIP service is that any type of connection may be used, such as personal computer, special adapter or even a public telephone system. The possibility to use VoIP through the wireless mode makes the opportunity to use it distantly, for example in the street, café or airport.
VoIP can utilize various different protocols, some of which have been described below:
- Real-Time Protocol (RTP): This is a kind of protocol which enables users to transmit audio and video packets between communicating computers.
- Secure RTP: This kind of protocol has the additional advantage of implementing authentication and integrity of the audio and video packets which are being handled between communicating equipments which is offered by a regular RTP.
- Session Initiation Protocol (SIP): the interconnection between two computers is provided by through media flow as the “intelligent endpoint protocols”. He more
There are some advantages and disadvantages by using VoIP.
The two main advantages are as follows: (1) the VoIP services are the best among the similar services providing. In comparison with the traditional telephone company which can only send and receive voice and written messages, the VoIP has much more opportunities and services to provide in order to please the customers and (2) the VoIP saves the finances of the user as its communications are cheaper and there is no need in public phone line as VoIP provides all the services which are traditional line does but with the additional services and broader opportunities.
In spite of the fact that there are so many advantages and that the system seems ideal, there are still some disadvantages which should be mentioned, that are (1) certain VoIP services require electricity to function properly and in some situation the cut of electricity may prevent the usage of VoIP as the required service and in this caser the necessity to use traditional telephone lines appears. This fact make impossible to provide the connection only to VoIP and the traditional telephone line is also required. (2) 911 is the universal service in the case of emergency, but the problem with VoIP is that not all of them connect directly to the emergency service when the number is dialed. Such disadvantage may be very disappointment if not to say dramatic in the case of incidents. (3) The absence of the directory assistance or white page listings may create some inconveniences to the user of the service and make him to provide some additional expenses to sort it out.
Conclusion
The past few decades have witnessed a dramatic increase in the number of Internet users and an almost parallel increase in the process of streaming. This upward trend has been accompanied by an almost parallel increase in the process of streaming, which is a data transferring technique which enables users to process data continuously without interruptions in the form of an uninterrupted stream of information. Streaming has gained popularity mostly due to the fact that a normal internet connection is fast and efficient enough to allow its users to download large multimedia files rapidly.
Telnet is used in the World Wide Web as the network protocol. Telnet helps the user to connect to other servers in the Internet as if the computer is already connected to them. The File Transmission Protocol allows connecting two different computers by means of the protocol. The FTP is mainly used to exchange the files between different computers with the help of the Internet. Telnet and FTP have a similar procedure of the use and share several common aspects between them.
Ethereal is a network analyzer, which mainly serves the purpose of capturing and decoding sets of information from a network. The main aim of the Ethereal is to traffic the formatted and converted data by means of the Internet in such a way that this data may be understood by the receiver.
Private branch exchange is the type of connection which is provided to the limited members. Such kind of communication is very convenient for the inside connection of different companies.
All named communications have its advantages as the advanced technologies are usually better than the old ones, but they still have disadvantages what means that the inventions should be provided with additional work and development.